Four weeks of augmented eccentric loading using a novel leg press device improved leg strength in well-trained athletes and professional sprint track cyclists

This study assessed the efficacy of strength training using augmented eccentric loading to provoke increases in leg strength in well-trained athletes, and sprint track cyclists, using a novel leg press device. Twelve well-trained athletes were randomly allocated traditional resistance training (TRAD, n = 6), or resistance training using augmented eccentric loading (AEL, n = 6). A further 5 full-time, professional sprint track cyclists from a senior national squad programme also trained with augmented eccentric loading (AEL-ATH) alongside their usual sport-specific training. Participants completed four weeks of twice-weekly resistance training using the leg press exercise. In TRAD the lowering phase of the lift was set relative to concentric strength. In AEL and AEL-ATH the lowering phase was individualised to eccentric strength. Concentric, eccentric, isometric and coupled eccentric-concentric leg press strength, and back squat 1 repetition maximum (1RM), were assessed pre- and post-training. The AEL and AEL-ATH groups performed the eccentric phase with an average 26 ± 4% greater load across the programme. All groups experienced increases in concentric (5%, 7% and 3% for TRAD, AEL & AEL-ATH respectively), eccentric (7%, 11% and 6% for TRAD, AEL & AEL-ATH respectively), and squat 1RM (all p < 0.05), where the AEL-ATH group experienced relatively greater increases (13% vs. 5% in TRAD and AEL, p < 0.01). The TRAD and AEL groups also increased isometric strength (p < 0.05). A four-week period of augmented eccentric loading increased leg strength in well-trained athletes and track cyclists. The eccentric leg press stimulus was well-tolerated, supporting the inclusion of such training in the preparation programmes of athletes

The Aid Effectiveness Literature: The Sad Results of 40 Years of Research

The aid effectiveness literature (AEL) consists of empirical macro studies of the effects of development aid. By the end of 2004, it had reached 97 econometric studies of three families, which have been analyzed in one study for each family using meta-analysis. The AEL is an ideal subject for meta-analysis as it uses only a few formally similar models which try to catch precisely the same effects. Also, it is an area with strong beliefs – often generated by altruism – and interests. In this survey of the AEL, we shows that when the whole of the literature is examined, a clear pattern emerges in the results: after 40 years of development aid, the evidence indicates that aid has not been effective. We show that the distribution of results is significantly asymmetrical in a way that reflects the reluctance of the research community to publish negative results. The Dutch Disease effect of aid has been ignored but is a plausible explanation for aid ineffectiveness

TELMISARTAN AND AZELNIDIPINE QUANTIFICATION EMPLOYING HPLC STRATAGEM; STABILITY INVESTIGATION ON TELMISARTAN AND AZELNIDIPINE

Objective: The focus of our research was to create a fairly sensitive HPLC stratagem for determining telmisartan (TLM) and azelnidipine (AEL) in bulk and tablet types. Methods: Analysis of TLM and AEL was performed on a “C18 Kromasil stationary column (5 µm, 250 mm × 4.6 mm)”. The mobile phase was made of 0.1M NaH2PO4 solution (pH 3.5) and methanol at a comparative volume ratio of 50% each. The analysis of TLM and AEL was isocratic, with the flow velocity adjusted at 1.0 ml/min and indeed, the TLM and AEL analysis was done at 256 nm using a PDA device sensor. TLM and AEL were stressed with acid, peroxide, dry heat, alkali, and sunlight-induced settings. Results: The retention/elution periods for the TLM and AEL were observed at 2.225 min and 3.178 min, respectively. The HPLC stratagem developed have a straight-line relation with relative concentrations in the ranges of 20-60 µg/ml for TLM and 4-12 µg/ml for AEL. The LOQ’s for TLM and AEL were 0.2516 μg/ml and 0.0871 μg/ml, respectively. The validation investigational findings done for TLM and AEL with the established sensitive HPLC stratagem were passed out in conformity with the ICH standards. Conclusion: The established sensitive HPLC stratagem was shown as competent for the quality check of bulk samples of TLM and AEL throughout batch release as well as in the course of TLM and AEL stability investigations

Effect of Augmented Eccentric Training in Older Adults

The purpose of this study was to investigate the effect of a six-week augmented eccentric load program on rate of force development (RFD), center of pressure (COP) excursion and performance in the five-time-sit-to-stand (STS-5) in older adults. Eighteen moderately active older adults, (≥ 60 years) participated in this study. Subjects were separated into two groups; one group added augmented eccentric training in addition to resistance training (AEL) and a resistance training only group (RT). The AEL group participated in a six-week AEL training program that consisted of six lower extremity body exercises. Eccentric phases of each exercise movement were augmented beginning with no weight and increasing by five percent weekly up to 20 percent body weight. AEL group improved the time to complete the clinical STS-5 fall risk assessment test by -2.21 ± 1.50 s, p = 0.03. AEL demonstrated a significant increase in the RFD moving from 785 ± 176 N·s-1 to 1041 ± 187 N·s-1 (p = 0.02) during chair rising. AEL showed significant improvements in M-L and (A-P) excursion from right foot during quiet standing, 0.075 ± 0.07 m to 0.003 ± 0.01 m and 0.157 ± 0.11 to 0.005 ± 0.01. AEL improved M-L excursion in right foot and A-P excursion of left foot compared to baseline, 0.457 ± 0.20 m to 0.012 ± 0.00 m, p =0.002 and 0.465 ± 0.15 m to 0.013 ± 0.01 m, p = 0.0001. Therefore, AEL training may be a beneficial exercise prescription for older adults

Braking and Propulsion Phase Characteristics of Traditional and Accentuated Eccentric Loaded Back Squats

The purpose of this study was to examine the differences in braking and propulsion force-time characteristics and barbell velocity between traditional (TRAD) and accentuated eccentric loaded (AEL) back squats using various load combinations. Sixteen resistance-trained men participated in four separate testing sessions which included a one repetition maximum (1RM) back squat during the first session and three squat testing sessions. During the squat testing sessions, participants either performed sets of three repetitions of TRAD back squats each with 50, 60, 70, and 80% 1RM or performed the same loads with the addition of weight releasers that increased the total eccentric weight of the first repetition of each set to either 100 (AEL-MAX) or 110% 1RM (AEL-SUPRA). Braking and propulsion mean force, duration, and impulse as well as mean and peak barbell velocity were compared between each condition and load. Significantly greater braking impulses were produced during the AEL-MAX and AEL-SUPRA conditions compared to TRAD (p \u3c 0.03) with small-moderate effect sizes favoring AEL-SUPRA. No other significant differences existed among conditions for other braking, propulsion, or barbell velocity variables. AEL-MAX and AEL-SUPRA back squats may provide a greater braking stimulus compared to TRAD squats; however, the propulsion phase of the movement does not appear to be impacted. From a loading standpoint, larger and smaller load spreads may favor rapid and maximal force production characteristics, respectively. Further research on this topic is needed as a large portion of the braking stimulus experienced during AEL back squats may be influenced by relative strength

Amplified EPOR/JAK2 Genes Define a Unique Subtype of Acute Erythroid Leukemia

ゲノム解析から急性赤白血病の変異プロファイルと治療標的を解明 --特定の遺伝子変異群の組み合わせと、特徴となる遺伝子の増幅が鍵--. 京都大学プレスリリース. 2022-08-05.Acute erythroid leukemia (AEL) is a unique subtype of acute myeloid leukemia characterized by prominent erythroid proliferation whose molecular basis is poorly understood. To elucidate the underlying mechanism of erythroid proliferation, we analyzed 121 AEL using whole-genome/exome and/or targeted-capture sequencing, together with transcriptome analysis of 21 AEL samples. Combining publicly available sequencing data, we found a high frequency of gains/amplifications involving EPOR/JAK2 in TP53-mutated cases, particularly those having >80% erythroblasts designated as pure erythroid leukemia (10/13). These cases were frequently accompanied by gains/amplifications of ERG/ETS2 and associated with a very poor prognosis, even compared with other TP53-mutated AEL. In addition to activation of the STAT5 pathway, a common feature across all AEL cases, these AEL cases exhibited enhanced cell proliferation and heme metabolism and often showed high sensitivity to ruxolitinib in vitro and in xenograft models, highlighting a potential role of JAK2 inhibition in therapeutics of AEL

PERMASALAHAN MENGGUNAKAN BAHASA INGGRIS PADA TEKNISI DI PT. AFRICAN EXPOSIVE LIMITED INDONESIA

Penelitian ini dilakukan dikarenakan beberapa permasalahan komunikasi yang sering terjadi diantara para teknisi di PT. AEL, lapangan penelitian ini adalah di PT. AEL Balikpapan dengan subjek penelitian ini adalah teknisi yang menangani perbaikan perbaikan mesin produksi yang dimiliki oleh perusahaan rekanan PT. AEL, dari penelitian ini didapatkan beberapa hal yang dilakukan oleh perusahaan dalam meminimalisir permasalahan komunikasi yang terjadi, yang dilakukan oleh perusahaan diantaranya adalah dengan berusaha untuk meningkatkan kepercayaan diri para teknisi mereka untuk bisa terus melakukan komunikasi dengan konsumen dengan menggunakan bahasa Inggris. Penelitian ini menggunakan metode kualitatif deskriptif dengan pengumpulan data menggunakan observasi, literature review dan interview.Kata kunci : Teknisi, Komunikasi,Mesin, ProduksiTHE PROBLEMS OF USING ENGLISH FOR TECHNICIANS AT PT. AFRICAN EXPOSIVE LIMITED INDONESIAThis research was conducted due to several communication problems that often occur among technicians at PT. AEL, this research field is at PT. AEL Balikpapan with the subject of this research is a technician who handles repairs to repair production machines owned by a partner company PT. AEL, from this research, found several things that were done by the company in minimizing the communication problems that occurred, which was done by the company, including trying to increase the confidence of their technicians to be able to continue to communicate with consumers using English. This study uses descriptive qualitative methods with data collection using observation, literature review and interviews.Key word: Technician, Communication, Machine, Productio

Post-activation Performance Enhancement after a Bout of Accentuated Eccentric Loading in Collegiate Male Volleyball Players

The purpose of this study was to investigate the benefit of post-activation performance enhancement (PAPE) after accentuated eccentric loading (AEL) compared to traditional resistance loading (TR). Sixteen male volleyball athletes were divided in AEL and TR group. AEL group performed 3 sets of 4 repetitions (eccentric: 105% of concentric 1RM, concentric: 80% of concentric 1RM) of half squat, and TR group performed 3 sets of 5 repetitions (eccentric & concentric: 85% of 1RM). Countermovement jump (CMJ), spike jump (SPJ), isometric mid-thigh pull (IMTP), and muscle soreness test were administered before (Pre) exercise, and 10 min (10-min), 24 h (24-h), and 48 h (48-h) after exercise. A two-way repeated measures analysis of variance was used to analyze the data. Peak force and rate of development (RFD) of IMTP in AEL group were significantly greater (p 0.05) groups x time. AEL seemed capable to maintain force production in IMTP, but not in CMJ and SPJ. It is recommended the use of accentuated eccentric loading protocols to overcome the fatigue

Acute neuromuscular, kinetic, and kinematic responses to accentuated eccentric load resistance exercise

Neurological and morphological adaptations are responsible for the increases in strength that occur following the completion of resistance exercise training interventions. There are a number of benefits that can occur as a result of completing resistance exercise training interventions, these include: (i) reduced risk of developing metabolic health issues; (ii) decreased risk and incidence of falling; (iii) improved cardiovascular health; (iv) elevated mobility; (v) enhanced athletic performance; and (vi) injury prevention. Traditional resistance exercise (constant load resistance exercise (CL)) involves equally loaded eccentric and concentric phases, performed in an alternating manner. However, eccentric muscle actions have unique physiological characteristics, namely greater force production capacity and lower energy requirements, compared to concentric actions. These characteristics have led to the exploration of eccentric-focused resistance exercise for the purposes of injury prevention, rehabilitation, and enhancement of functional capacity. Accentuated eccentric load resistance exercise (AEL) is one form of eccentric-focused resistance exercise. This type of resistance exercise involves a heavier absolute external eccentric phase load than during the subsequent concentric portion of a repetition. Existing training study interventions comparing AEL to CL have demonstrated enhancements in concentric, eccentric, and isometric strength with AEL. However, no differences in strength adaptations have been reported in other AEL vs. CL training studies. Only 7 d intensified AEL training interventions have measured neuromuscular variables, providing evidence that enhanced neuromuscular adaptations may occur when AEL is compared to CL. Therefore, a lack of information is currently available regarding how AEL may differentially affect neuromuscular control when compared to CL. Furthermore, the equivocal findings regarding the efficacy of AEL make it difficult for exercise professionals to decide if they should employ AEL with their athletes or patients and during which training phase this type of resistance exercise could be implemented. Therefore, the aims of this thesis were: (i) to examine differences in acute neuromuscular, kinetic, and kinematic responses between AEL and CL during both lower-body single-joint resistance exercise and multiple-joint free weight resistance exercise; (ii) to assess acute force production and contractile characteristics following AEL and CL conditions; (iii) to investigate the influence of eccentric phase velocity (and time under tension) on acute force production and contractile characteristics following AEL and CL conditions; and (iv) to compare common drive and motor unit firing rate responses after single- and multiple-joint AEL and CL. Before investigating neuromuscular, kinetic, and kinematic responses to AEL it was deemed necessary to evaluate normalisation methods for a multiple-joint free weight resistance exercise that would permit the implementation of AEL. Therefore, the aim of the first study of the thesis was to evaluate voluntary maximal (dynamometer- and isometric squat-based) isometric and submaximal dynamic (60%, 70%, and 80% of three repetition maximum) electromyography (EMG) normalisation methods for the back squat resistance exercise. The absolute reliability (limits of agreement and coefficient of variation), relative reliability (intraclass correlation coefficient), and sensitivity of each method was assessed. Strength-trained males completed four testing sessions on separate days, the final three test days were used to evaluate the different normalisation methods. Overall, dynamic normalisation methods demonstrated better absolute reliability and sensitivity for reporting vastus lateralis and biceps femoris EMG compared to maximal isometric methods. Following the methodological study conducted in Chapter 2, the next study began to address the main aims of the thesis. The purpose of the third chapter of the thesis was to compare acute neuromuscular, kinetic, and kinematic responses between single-joint AEL and CL knee extension efforts that included two different eccentric phase velocities. Ten males who were completing recreational resistance exercise attended four experimental test day sessions where knee extension repetitions (AEL or CL) were performed at two different eccentric phase velocities (2 or 4 s). Elevated vastus lateralis eccentric neuromuscular activation was observed in both AEL conditions (p= 0.004, f= 5.73). No differences between conditions were detected for concentric neuromuscular or concentric kinematic variables during knee extension efforts. Similarly, no differences in after-intervention rate of torque development or contractile charactersitics were observed between conditions. To extend the findings of the third chapter of the thesis and provide mechanistic information regarding how AEL may differentially effect acute neuromuscular variables that have been reported to be undergo chronic adaptations, additional measures that were taken before and after the intervention described in the previous chapter were analysed. Therefore, the purpose of the fourth chapter of the thesis was to compare motor unit firing rate and common drive responses following single-joint AEL and CL knee extension efforts during a submaximal isometric knee extension trapezoid force trace effort. In addition, motor unit firing rate reliability during the before-intervention trapezoid force trace efforts was assessed. No differences in the maximum number of detected motor units were observed between conditions. A condition-time-point interaction effect (p= 0.025, f= 3.65) for firing rate in later-recruited motor units occurred, with a decrease in firing rate observed in after-intervention measures in the AEL condition that was completed with a shorter duration eccentric phase. However, no differences in common drive were detected from before- to after-intervention measures in any of the conditions. The time period toward the end of the plateau phase of before-intervention trapezoid force trace efforts displayed the greatest absolute and relative reliability and was therefore used for motor unit firing rate and common drive analysis. The purpose of the fifth chapter was to compare acute neuromuscular and kinetic responses between multiple-joint AEL and CL back squats. Strength-trained males completed two experimental test day sessions where back squat repetitions (AEL or CL) were performed. Neuromuscular and kinetic responses were measured during each condition. No differences in concentric neuromuscular or concentric kinetic variables during back squat repetitions were detected between conditions. Elevated eccentric phase neuromuscular activation was observed during the AEL compared to the CL condition in two to three of the four sets performed for the following lower-body muscles: (i) vastus lateralis (p< 0.001, f= 15.58); (ii) vastus medialis (p< 0.001, f= 10.77); (iii) biceps femoris (p= 0.003, f= 6.10); and (iv) gluteus maximus (p= 0.001, f= 7.98). There were no clear differences in terms of the neuromuscular activation contributions between muscles within AEL or CL conditions during eccentric or concentric muscle actions. Following the investigation of acute motor unit firing rate and common drive responses to lower limb single-joint AEL and CL in the fourth chapter of the thesis, the question arose as to whether or not similar responses would occur in a more complex model, such as a multiple-joint resistance exercise. Multiple-joint resistance exercise poses different neuromuscular activation, coordination, and stabilisation demands. Therefore, the purpose of the sixth chapter of the thesis was to compare acute motor unit firing rate and common drive responses following multiple-joint lower-body free weight AEL and CL. In addition, motor unit firing rate reliability during the before-intervention trapezoid force trace efforts, performed on a custom-built dynamometer, was assessed. No differences in motor unit firing rate or the number of motor units detected were observed between conditions. Condition-time-point interaction effects were observed for maximum peak cross-correlation coefficients (p= 0.028, f= 8.24), with a decrease from before to after intervention measures in the CL condition. However, differences in mean peak cross-correaltion coefficients and cross-correlation histogram distributions were not detected between conditions. As in Chapter 4 the time period toward the end of the plateau phase of before-intervention trapezoid force trace efforts displayed the greatest absolute reliability and was therefore used for motor unit firing rate and common drive analysis. Whereas, relative reliability was shown to be “poor” across all time phases. The results of the studies that comprise this thesis contribute new knowledge to the AEL research literature. In particular, the way that motor unit recruitment strategy responses were investigated following interventions provided new information regarding the acute neuromuscular effects of AEL and a new potential approach to investigating the hypothesised similarities between motor learning and resistance exercise. Previously, only transcranial magnetic stimulation had been used for this purpose. However, the contrasting motor unit firing rate and common drive response results of Chapter 4 and 6 of the thesis indicate further research is required to ascertain how acute measures quantified through the decomposition of surface EMG (such as motor unit firing rate and common drive) are related to chronic neuromuscualr adaptations following resistance exercise. The findings presented in the thesis also add to the existing body of AEL research literature by providing practitioners with novel data regarding the acute neuromuscular, kinetic, and kinematic responses during AEL. The results presented in Chapter 3 and 5 of the thesis suggest that AEL resistance exercise implemented in both single- and multiple-joint resistance exercise models presents no negative acute variable responses. Neither of the AEL models investigated acutely reduced concentric kinetic outputs, decreased neuromuscular contributions or activation from key agonist muscles during concentric or eccentric phases, or caused after-intervention lower-body force production or contractile characteristics to decline more than following CL. In addition, both AEL models involved greater eccentric phase knee extensor muscle contributions compared to CL. Therefore, given these findings exercise professionals who prescribe training interventions may want to consider the use of AEL depending on the characteristics and training goals of the individuals they work with. Despite these encouraging acute neuromuscular, kinetic, and kinematic responses to AEL further research is clearly required to confirm the efficacy of AEL on a longitudinal basis. Specifically, the efficacy of AEL for the concurrent enhancement of both chronic concentric and eccentric knee and hip extensor strength, eliciting chronic neuromuscular adaptations in these muscles, and preventing injury in a range of populations remains unclear

Neural Activity Affects Distribution of Glutamate Receptors during Neuromuscular Junction Formation inDrosophilaEmbryos

AbstractChanges in the distribution and density of transmitter receptors in the postsynaptic cell are required steps for functional synapse formation. We raised antibodies againstDrosophilaglutamate receptors (DGluR-II) and visualized the distribution of receptors during neuromuscular junction formation in embryos. In wild-type embryos, embryonic development is complete within 22 hr after egg lying (AEL) and neuromuscular junction (NMJ) formation begins at 13 hr AEL. At the time of initial synapse formation, DGluR-IIs appeared as clusters closely associated with some muscle nuclei. Subsequently, these nonjunctional clusters dispersed while DGluR-IIs accumulated at the junctional region. In a paralytic temperature-sensitive mutant,parats1,neural activity decreases drastically at restrictive temperatures. When neural activity was blocked throughout synaptogenesis by rearing embryos at a restrictive temperature prior to the beginning of synaptogenesis, 12 hr AEL, the dispersal of extrajunctional clusters was significantly suppressed and no accumulation of receptors at the junction was observed at 22 hr AEL. However, when neural activity was blocked later, by rearing embryos at a restrictive temperature from 13 hr AEL, DGluR-IIs did not accumulate at the NMJ, although extrajunctional clusters dispersed normally. These findings suggest that the neural activity differentially regulates dissipation of receptor clusters in the nonjunctional region and accumulation of receptors at the junctional region