Mimicry of Short Linear Motifs by Bacterial Pathogens: A Drugging Opportunity.

Bacterial pathogens have developed complex strategies to successfully survive and proliferate within their hosts. Throughout the infection cycle, direct interaction with host cells occurs. Many bacteria have been found to secrete proteins, such as effectors and toxins, directly into the host cell with the potential to interfere with cell regulatory processes, either enzymatically or through protein-protein interactions (PPIs). Short linear motifs (SLiMs) are abundant peptide modules in cell signaling proteins. Here, we cover the reported examples of eukaryotic-like SLiM mimicry being used by pathogenic bacteria to hijack host cell machinery and discuss how drugs targeting SLiM-regulated cell signaling networks are being evaluated for interference with bacterial infections. This emerging anti-infective opportunity may become an essential contributor to antibiotic replacement strategies.

HIV Risk Behaviors and the Use of Geosocial Networking Dating Apps among Men Who have Sex with Men and Transgender Women in Lima, Peru: a Cross-Sectional Study.

Geosocial networking dating apps (GSN apps) are an increasingly widespread technology used by populations throughout the world to facilitate sexual encounters. Studies from a variety of settings suggest a possible association between GSN app use and HIV risk behaviors, including among sexual and gender minority populations such as men who have sex with men (MSM) and transgender women (TW). However, it remains unclear to what extent GSN apps play a causal role. We explored the relationship between GSN app use and sexual risk behaviors among MSM and TW in Lima, Peru by analyzing data from a multi-site cross-sectional survey assessing both general and partner-specific sexual behaviors. We performed bivariate analysis to estimate the association of GSN app use with different individual and partner-specific factors, then fit multivariable regression models adjusting for age and education. Among 741 total participants (698 MSM, 43 TW), 64% met at least one sex partner in the prior three months using a GSN app. GSN app users were significantly more likely to report engaging in HIV risk behaviors in general, including condomless receptive anal sex, group sex, transactional sex, and sex under the influence of alcohol or drugs. Having condomless anal sex with a given partner was not associated with meeting that partner via GSN app. These findings highlight GSN app users as a particularly vulnerable subpopulation among MSM and TW in Lima. GSN apps could provide a useful vehicle for targeted HIV prevention efforts for priority populations in Peru.

RESUMEN: Las aplicaciones de citas de redes geosociales (aplicaciones GSN) son una tecnología con creciente alcance en todo el mundo usadas para facilitar encuentros sexuales. Diferentes estudios sugieren una posible relación entre uso de aplicaciones GSN y comportamientos de riesgo para VIH entre hombres que tienen sexo con hombres (HSH) y mujeres transgénero (MT). No es claro hasta qué punto aplicaciones GSN tendrían un papel causal directo. Exploramos la relación entre uso de aplicaciones GSN y comportamientos sexuales de riesgo entre HSH y MT en Lima, Perú, analizando datos de una encuesta transversal que evaluó comportamientos sexuales en general y en parejas específicas. Realizamos análisis bivariable para estimar la asociación del uso de aplicaciones GSN con diferentes factores individuales y específicos de la pareja. También aplicamos modelos de regresión multivariables ajustados por edad y educación. Entre 741 participantes totales (698 HSH, 43 MT), 64% conoció al menos a una pareja sexual en los últimos tres meses mediante una aplicación GSN. Los usuarios de aplicaciones GSN fueron significativamente más propensos a reportar comportamientos de riesgo de VIH en general, incluyendo sexo anal receptivo sin condón, y sexo grupal, transaccional y bajo influencia de alcohol o drogas. Tener sexo anal sin condón con una pareja determinada no se asoció con conocer a esa pareja mediante aplicación GSN. Estos hallazgos muestran a usuarios de aplicaciones GSN como una subpoblación particularmente vulnerable entre HSH y MT en Lima. Aplicaciones GSN podrían ser útiles para iniciativas de prevención del VIH en poblaciones prioritarias en Perú.

The Eukaryotic Linear Motif resource: 2022 release.

Almost twenty years after its initial release, the Eukaryotic Linear Motif (ELM) resource remains an invaluable source of information for the study of motif-mediated protein-protein interactions. ELM provides a comprehensive, regularly updated and well-organised repository of manually curated, experimentally validated short linear motifs (SLiMs). An increasing number of SLiM-mediated interactions are discovered each year and keeping the resource up-to-date continues to be a great challenge. In the current update, 30 novel motif classes have been added and five existing classes have undergone major revisions. The update includes 411 new motif instances mostly focused on cell-cycle regulation, control of the actin cytoskeleton, membrane remodelling and vesicle trafficking pathways, liquid-liquid phase separation and integrin signalling. Many of the newly annotated motif-mediated interactions are targets of pathogenic motif mimicry by viral, bacterial or eukaryotic pathogens, providing invaluable insights into the molecular mechanisms underlying infectious diseases. The current ELM release includes 317 motif classes incorporating 3934 individual motif instances manually curated from 3867 scientific publications. ELM is available at: http://elm.eu.org.

Comprehensive comparative analysis of the periodontal pathogen Porphyromonas gingivalis: exploring the pan-genome, the reconstruction of the gene regulatory network and genome-scale metabolic network.

Porphyromonas gingivalis is a nonmotile, obligate anaerobic, Gram-negative bacterium known for its association with periodontal disease and its involvement in systemic diseases such as atherosclerosis, cardiovascular disease, colon cancer, and Alzheimer's disease. This bacterium produces several virulence factors, including capsules, fimbriae, lipopolysaccharides, proteolytic enzymes, and hemagglutinins. A comparative genomic analysis revealed the open pangenome of P. gingivalis and identified complete type IV secretion systems in strain KCOM2805 and almost complete type VI secretion systems in strains KCOM2798 and ATCC49417, which is a new discovery as previous studies did not find the proteins involved in secretion systems IV and VI. Conservation of some virulence factors between different strains was observed, regardless of their genetic diversity and origin. In addition, we performed for the first time a reconstruction analysis of the gene regulatory network, identifying transcription factors and proteins involved in the regulatory mechanisms of bacterial pathogenesis. In particular, QseB regulates the expression of hemagglutinin and arginine deaminase, while Rex may suppress the release of gingipain through interactions with PorV and the formatum/nitrate transporter. Our study highlights the central role of conserved virulence factors and regulatory pathways, particularly QseB and Rex, in P. gingivalis and provides insights into potential therapeutic targets.

Maxillary sinus angiolymphoid hyperplasia with eosinophilia associated to orbital and cutaneous lesion.

INTRODUCTION: We describe the first case of ALHE in the orbit with extension to the maxillary sinus and the importance of a multidisciplinary approach to achieve removal of the lesion. CASE STUDY: A 72-year-old man presented with epiphora of the left eye and several episodes of recurrent acute dacryocystitis. Magnetic resonance imaging revealed a solid homogeneous mass located in the inferomedial region of the left orbit. In addition, it was associated with destruction of the adjacent ethmoidal wall and upper wall of the left maxillary sinus. Incisional biopsy of the orbital mass was compatible with ALHE. RESULTS: It was decided to perform surgery using an orbital floor approach, left medial wall via subconjunctival and caruncular approach together with an endoscopic nasal approach (ESS), achieving complete removal of the orbital mass and cleaning of the maxillary sinus. After one year of treatment, no tumor recurrence was evident through endoscopy and imaging tests and the patient is asymptomatic. CONCLUSIONS: ALHE is a very rare benign vascular tumor that presents subcutaneous nodules in the head and neck region. We do not know of any case of ALHE in the paranasal sinuses described in the literature, either in isolation or together with orbital or cutaneous ALHE. In conclusion, ALHE disease should be considered as a diagnosis when faced with an orbital mass with extension to the paranasal sinuses, and a complete excision through a combined endonasal and orbital approach prevents recurrence in most cases.

Correlates of condomless anal intercourse with different types of sexual partners among men who have sex with men and transgender women in Lima, Peru.

CLINICAL TRIAL REGISTRATION: The Sabes study was registered in March 2013 with the National Institutes of Health at ClinicalTrials.gov (identifier: NCT01815580).

Genetic insights into the microevolutionary dynamics and early introductions of human monkeypox virus in Mexico.

The recent global outbreak of mpox, caused by monkeypox virus (MPV) emerged in Europe in 2022 and rapidly spread to over 40 countries. The Americas are currently facing the highest impact, reporting over 50,000 cases by early 2023. In this study, we analyzed 880 MPV isolates worldwide to gain insights into the evolutionary patterns and initial introduction events of the virus in Mexico. We found that MPV entered Mexico on multiple occasions, from the United Kingdom, Portugal, and Canada, and subsequently spread locally in different regions of Mexico. Additionally, we show that MPV has an open pangenome, highlighting the role of gene turnover in shaping its genomic diversity, rather than single-nucleotide polymorphisms (SNPs), which do not contribute significantly to genome diversity. Although the genome contains multiple SNPs in coding regions, these remain under purifying selection, suggesting their evolutionary conservation. One notable exception is amino acid position 63 of the protein encoded by the Cop-A4L gene, which is intricately related to viral maturity, which we found to be under strong positive selection. Ancestral state reconstruction indicated that the ancestral state at position 63 corresponds to the amino acid valine, which is present only in isolates of clade I. However, the isolates from the current outbreak contained threonine at position 63. Our findings contribute new information about the evolution of monkeypox virus.

Evidence of natural selection and dominance of SARS-CoV-2 variant Lambda (C.37) over variants of concern in Cusco, Peru.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineage C.37 (Lambda) has spread rapidly in Peru and other Latin American countries. However, most studies in Peru have focused on Lima, the capital city, without knowing the dynamics of the spread of the variant in other departments. Cusco, Peru, is one of the most popular departments in the country for tourists, so the introduction of new variants of SARS-CoV-2 might occur despite closure of the borders. Therefore, in this work, we analyzed the variants circulating in Cusco. The aim of this work was to better understand the distribution of SARS-CoV-2 lineages circulating in Cusco and to characterize the genomes of these strains. To this end, 46 SARS-CoV-2 genomes from vaccinated and unvaccinated patients were sequenced in the first half of 2021. The genomes were analyzed using phylogenetic and natural selection methods. Phylogenetic trees from Cusco showed dominance of the Lambda lineage over the variants of concern (VOCs), and there was no clustering of variants by district. Natural selection analysis revealed mutations, mainly in the spike protein, at positions 75, 246, 247, 707, 769, and 1020. In addition, we found that unvaccinated patients accumulated more new mutations than did vaccinated patients, and these included the F101Y mutation in ORF7a, E419A in NSP3, a deletion in S (21,618-22,501), and a deletion in ORF3a (25,437-26,122).

Genomic characterization of two bacteriophages (vB_EcoS-phiEc3 and vB_EcoS-phiEc4) belonging to the genus Kagunavirus with lytic activity against uropathogenic Escherichia coli.

In this study, the genomes of two lytic bacteriophages, vB_EcoS-phiEc3 and vB_EcoS-phiEc4, were sequenced and characterized using bioinformatics approaches. Whole-genome analysis showed that both phages belonged to the Kagunavirus genus, Guernseyvirinae subfamily and Siphoviridae family. Moreover, their genomes had 45, 288 bp and 44,540 bp, and G + C content of 48.42% and 50.04%, respectively. The genome of vB_EcoS-phiEc3 harbored 80 protein coding sequences (CDSs), whereas vB_EcoS-phiEc4 harbored 75 CDSs. Among them, 50 CDSs in vB_EcoS-phiEc3 and 44 CDSs in vB_EcoS-phiEc4 were considered as functional genes. Their lytic activity against multidrug-resistant uropathogenic Escherichia coli (UPEC) strains, as well as the absence of antibiotic resistance genes, lysogenic and virulence genes, enable vB_EcoS-phiEc3 and vB_EcoS-phiEc4 as a safe therapy option against UPEC infections.

Community-based accompaniment for adolescents transitioning to adult HIV care in urban Peru: a pilot study.

We piloted a community-based intervention to improve outcomes among adolescents living with HIV who were transitioning to adult-oriented care in Lima, Peru. We assessed feasibility and potential effectiveness, including within-person changes in self-reported adherence, psychosocial metrics (NIH Toolbox), and transition readiness ("Am I on TRAC" questionnaire, "Got Transition" checklist). From October 2019 to January 2020, we enrolled 30 adolescents (15-21 years). The nine-month intervention consisted of logistical, adherence and social support delivered by entry-level health workers and group sessions to improve health-related knowledge and skills and social support. In transition readiness, we observed within-person improvements relative to baseline. We also observed strong evidence of improvements in adherence, social support, self-efficacy, and stress, which were generally sustained three months post-intervention. All participants remained in treatment after 12 months. The intervention was feasible and potentially effective for bridging the transition to adult HIV care. A large-scale evaluation, including biological endpoints, is warranted.

RESUMEN: Piloteamos una intervención comunitaria para mejorar los resultados de adolescentes viviendo con el VIH que se encontraban en transición a la atención de VIH orientada a adultos en Lima, Perú. Evaluamos la viabilidad y la eficacia potencial, incluidos los cambios personales en la adherencia auto-reportada, criterios psicosociales (NIH Toolbox), y preparación para la transición (cuestionario "Estoy en el TRAC", lista de verificación "Got Transition"). Desde octubre de 2019 hasta enero de 2020, enrolamos a 30 adolescentes (15 a 21 años). La intervención de nueve meses consistió en apoyo logístico, de adherencia y social brindado por técnicos de enfermería y sesiones grupales para mejorar tanto el conocimiento y las habilidades relacionados con la salud, como el apoyo social. En cuanto a la preparación para la transición, observamos mejoras comparada con el basal. También observamos una fuerte evidencia de mejoras en la adherencia, apoyo social, autoeficacia y estrés, que se mantuvieron, generalmente, tres meses después del fin de la intervención. Todos los participantes seguían en tratamiento después de 12 meses. La intervención fue factible y potencialmente efectiva para tender un puente en la transición a la atención del VIH para adultos. Esto amerita una evaluación a mayor escala y que incluya criterios clínicos.

Exploring HIV risk behavior and sexual/gender identities among transgender women and their sexual partners in Peru using respondent-driven sampling.

HIV prevalence is high among transgender women, but little is known about cisgender men who have sex with transgender women (MSTW). The objective of this study was to investigate characteristics and behavior of MSTW compared to transgender women and men who have sex with men (MSM) using a modified respondent-driven sampling design. Seed participants completed a survey and invited up to three sex partners. Forward recruitment continued in waves through the referral of sex partners. Cross-sectional data were assessed using mixed effects models. From February to July 2018, 479 participants in Lima, Peru enrolled (n = 199 transgender women, n = 196 MSTW, and n = 45 MSM). MSTW behavior and identity differed significantly from that of transgender women and MSM. MSTW primarily identified as bisexual (69%) or heterosexual (15%) and only 6% reported male partners. Insertive condomless anal intercourse was reported by 61% of MSTW; 46% did not know their HIV serostatus. Compared to MSTW without male partners, those with recent male partners were more likely to sell sex (OR 15.7, 95% CI 4.1-60.5), and report condomless receptive anal intercourse (OR 89.0, 95% CI 19.1-414.8). This evidence suggests that MSTW are a distinct population from MSM, and highlights the critical need to include MSTW in HIV research and interventions.

High levels of mild to moderate depression among men who have sex with men and transgender women in Lima, Peru: implications for integrated depression and HIV care.

ABSTRACTDepression disproportionally affects people at risk of acquiring or living with HIV and is associated with worse health outcomes; however, depression care is not routinely integrated with HIV prevention and treatment services. Selection of the best depression intervention(s) for integration depends both on the prevalence and severity of depression among potential users. To inform depression care integration in a community-based setting in Lima, Peru, we retrospectively analyzed routinely collected depression screening data from men who have sex with men and transgender women seeking HIV prevention and care services (N = 185). Depression was screened for using the Patient Health Questionnaire-9. Prevalence of any depression (PHQ-9 ≥ 5) was 42% and was significantly associated with the last sexual partner being "casual" (p = 0.01). Most (81%) depressive symptoms were mild to moderate (≥5 PHQ-9 ≤ 14). Integrating depression care with HIV prevention and treatment services in Peru should begin by implementing interventions targeting mild to moderate depression.

Linkage to care after HIV diagnosis among men who have sex with men and transgender women in Lima, Peru.

In Lima, Perú, HIV prevalence is estimated to be 15% among men who have sex with men (MSM) and 30% among transgender women (TW). We investigated timely linkage of MSM and TW to HIV care, as linkage to antiretroviral therapy (ART) is critical to protect the health of those living with HIV and to prevent onward transmission. We investigated linkage within 90 days of HIV diagnosis by matching data from two studies conducted in Lima between 2013 and 2015 to national ART program records. We used generalized linear modeling to assess predictors of timely linkage and late presentation to care. Of 487 newly-diagnosed MSM and TW, only 44% presented for care at an HIV clinic within 90 days. Timely linkage was less common among TW (aPR 0.7, 95% CI 0.5-1.0), those younger than 24 (aPR 0.8, 95% CI 0.6-1.0), and those reporting a history of sex work (aPR 0.7, 95% CI 0.6-0.9). Proximity to an ART program clinic was not associated with linkage; most participants linked to clinics offering "LGBTQ-friendly" care. The pattern of clinics selected by participants suggests the importance of concerns about confidentiality and stigma in decision-making about where to link to care.

ELM-the eukaryotic linear motif resource in 2020.

The eukaryotic linear motif (ELM) resource is a repository of manually curated experimentally validated short linear motifs (SLiMs). Since the initial release almost 20 years ago, ELM has become an indispensable resource for the molecular biology community for investigating functional regions in many proteins. In this update, we have added 21 novel motif classes, made major revisions to 12 motif classes and added >400 new instances mostly focused on DNA damage, the cytoskeleton, SH2-binding phosphotyrosine motifs and motif mimicry by pathogenic bacterial effector proteins. The current release of the ELM database contains 289 motif classes and 3523 individual protein motif instances manually curated from 3467 scientific publications. ELM is available at: http://elm.eu.org.

Phage Therapy for Crops: Concepts, Experimental and Bioinformatics Approaches to Direct Its Application.

Phage therapy consists of applying bacteriophages, whose natural function is to kill specific bacteria. Bacteriophages are safe, evolve together with their host, and are environmentally friendly. At present, the indiscriminate use of antibiotics and salt minerals (Zn2+ or Cu2+) has caused the emergence of resistant strains that infect crops, causing difficulties and loss of food production. Phage therapy is an alternative that has shown positive results and can improve the treatments available for agriculture. However, the success of phage therapy depends on finding effective bacteriophages. This review focused on describing the potential, up to now, of applying phage therapy as an alternative treatment against bacterial diseases, with sustainable improvement in food production. We described the current isolation techniques, characterization, detection, and selection of lytic phages, highlighting the importance of complementary studies using genome analysis of the phage and its host. Finally, among these studies, we concentrated on the most relevant bacteriophages used for biocontrol of Pseudomonas spp., Xanthomonas spp., Pectobacterium spp., Ralstonia spp., Burkholderia spp., Dickeya spp., Clavibacter michiganensis, and Agrobacterium tumefaciens as agents that cause damage to crops, and affect food production around the world.

Optimized Route for the Fabrication of MnAlC Permanent Magnets by Arc Melting.

The rare-earth-free MnAlC alloy is currently considered a very promising candidate for permanent magnet applications due to its high anisotropy field and relatively high saturation magnetization and Curie temperature, besides being a low-cost material. In this work, we presented a simple fabrication route that allows for obtaining a magnetically enhanced bulk τ-MnAlC magnet. In the fabrication process, an electric arc-melting method was carried out to melt ingots of MnAlC alloys. A two-step solution treatment at 1200 °C and 1100 °C allowed us to synthesize a pure room-temperature ε-MnAlC ingot that completely transformed into τ-MnAlC alloy, free of secondary phases, after an annealing treatment at 550 °C for 30 min. The Rietveld refinements and magnetization measurements demonstrated that the quenched process produces a phase-segregated ε-MnAlC alloy that is formed by two types of ε-phases due to local fluctuation of the Mn. Room-temperature hysteresis loops showed that our improved τ-MnAlC alloy exhibited a remanent magnetization of 42 Am2/kg, a coercive field of 0.2 T and a maximum energy product, (BH)max, of 6.07 kJ/m3, which is higher than those reported in previous works using a similar preparation route. Experimental evidence demonstrated that the synthesis of a pure room-temperature ε-MnAlC played an important role in the suppression of undesirable phases that deteriorate the permanent magnet properties of the τ-MnAlC. Finally, magnetic images recorded by Lorentz microscopy allowed us to observe the microstructure and magnetic domain walls of the optimized τ-MnAlC. The presence of magnetic contrasts in all the observed grains allowed us to confirm the high-quality ferromagnetic behavior of the system.

TransPrEP: Results from the Pilot Study of a Social Network-Based Intervention to Support PrEP Adherence Among Transgender Women in Lima, Peru.

We conducted a pilot randomized controlled trial of a social network-based intervention to promote PrEP adherence among transgender women (TW) in Lima, Peru. We enrolled 89 TW from six social networks and cluster-randomized them 1:1 to standard of care (n = 44) or the TransPrEP intervention (n = 45). Core workshops discussed strategies to support PrEP adherence and defined group adherence objectives. Maintenance workshops discussed participants' experiences taking PrEP and collective adherence goals. At 3-month follow-up, we evaluated 40 participants and obtained 29 hair samples for tenofovir level measurements. Though no significant differences were observed, 36.4% (4/11) of participants of TransPrEP participants and 10.0% (1/10) of control participants had tenofovir levels > 0.023 ng/mg, consistent with ≥ 4 doses per week. 81.8% (9/11) of intervention and 40.0% (4/10) of control participants had any detectable tenofovir in their hair. Pilot assessment of our network-based intervention suggested a trend towards improved PrEP adherence, measured objectively, for TW in Peru.

RESUMEN: Realizamos un estudio piloto controlado y aleatorizado de una intervención basada en redes sociales para promover la adherencia al PrEP en mujeres transgénero (MT) de Lima, Perú. Enrolamos a 89 MT de 6 redes sociales y las aleatorizamos por grupos a razón 1:1 al estándar de atención como control (n = 44) o a la intervención TransPrEP (n = 45). En los talleres centrales se discutieron estrategias para respaldar la adherencia al PrEP y se definieron los objetivos de adherencia del grupo. En los talleres de mantenimiento se discutieron las experiencias de los participantes al tomar PrEP y los objetivos de adherencia colectiva. A los 3 meses de seguimiento, evaluamos a 40 participantes y obtuvimos 29 muestras de cabello para medir el nivel de tenofovir. Aunque no se observaron diferencias significativas, el 36.4% (4/11) de los participantes de TransPrEP y el 10.0% (1/10) de los participantes del grupo control tenían niveles de tenofovir> 0.023 ng/mg, congruente con 4 o más dosis por semana. El 81.8% (9/11) del grupo de intervención y el 40.0% (4/10) de los participantes de control tenían tenofovir detectable en el cabello. La evaluación piloto de nuestra intervención basada en redes sugiere una tendencia hacia una mejor adherencia al PrEP, medida objetivamente, para las MT en Perú.

Self-Identity, Beliefs, and Behavior Among Men Who Have Sex with Transgender Women: Implications for HIV Research and Interventions.

While transgender women have been identified as a global priority population for HIV prevention and treatment, little is known about the cisgender male partners of transgender women, including their sexual behavior and HIV prevalence. Previous research has suggested that these male partners have varied identities and sexual behavior, which make identifying and engaging them in research difficult. This paper describes interviews conducted with fifteen cisgender men who reported recent sexual activity with transgender women in Lima, Peru. The purpose of this research was to explore how these men reported their identities and sexual behavior, to better understand how they would interact with HIV outreach, research, and care. The major themes were sexual orientation and identity; view of transgender partners; social ties to transgender women and other men with transgender women partners; disclosure of relationships; HIV knowledge and risk perception; and attitudes toward interventions. We found that language used to assess sexual orientation was problematic in this population, due to lack of consistency between orientation and reported behavior, and unfamiliarity with terms used to describe sexual orientation. In addition, stigma, lack of knowledge of HIV prevention methods, and fear of disclosure of sexual behavior were identified as barriers that could impact engagement in HIV research, prevention, and care. However, participants reported social relationships with both transgender women and other men who have transgender partners, presenting possible avenues for recruitment into HIV research and healthcare services.

Use of Individual Relative Thresholds to Assess Acceleration in Young Soccer Players According to Initial Speed.

ABSTRACT: Martínez-Cabrera, FI, Núñez-Sánchez, FJ, Losada, J, Otero-Esquina, C, Sánchez, H, and De Hoyo, M. Use of individual relative thresholds to assess acceleration in young soccer players according to initial speed. J Strength Cond Res 35(4): 1110-1118, 2021-The aims of the current study were (a) to analyze the characteristics of acceleration efforts using individual relative thresholds according to the initial speed during official matches in elite young soccer players according to player position and (b) to compare the differences between absolute and relative thresholds in assessing high-intensity acceleration. Player acceleration profiles were assessed using an individual relative threshold based on their acceleration capacity at different initial speeds (standing, 6, 10.8, and 15 km·h-1), and the number of accelerations (>75% of the maximal acceleration) performed during soccer matches was divided into 3 categories attending to the initial speed. (S1 = 0-7 km·h-1; S2 = 7.1-14 km·h-1; and S3 = ≥14.1 km·h-1). Within-group analyses showed that the number of accelerations performed in each category was higher when the effort started from a static or walking position than at moderate- or high-intensity running (S1 > S2 > S3; very likely to almost certain). Between-group analyses revealed substantial differences between some playing positions according to initial speed. In S1 and S3, central defenders had the lowest number of accelerations (likely to almost certain), whereas midfielders had the greatest number of high-intensity accelerations in S1 and S2. There were also substantial differences between the other playing positions (possibly to almost certain). Regarding relative and absolute thresholds (>3 m·s-2), the results showed that absolute threshold overestimated the number of high-intensity accelerations compared with the individual relative threshold in S1 and underestimated the results in S2 and S3 (almost certain). The use of an individual relative threshold to measure acceleration demands allows to distinguish between the numbers of accelerations in function of the initial speed and playing positions. In addition, the absolute acceleration threshold could overestimate or underestimate the acceleration demands in young soccer players as a function of the initial speed. Then, the absolute acceleration thresholds should be taken with caution in the assessment of acceleration activities.

Predicting Loading Intensity Measuring Velocity in Barbell Hip Thrust Exercise.

ABSTRACT: de Hoyo, M, Núñez, FJ, Sañudo, B, Gonzalo-Skok, O, Muñoz-López, A, Romero-Boza, S, Otero-Esquina, C, Sánchez, H, and Nimphius, S. Predicting loading intensity measuring velocity in barbell hip thrust exercise. J Strength Cond Res 35(8): 2075-2081, 2021-The barbell hip thrust is an increasingly used exercise to target the hip extensors. Direct and indirect measurement of 1 repetition maximum (1RM) to determine the relative load of each exercise is time-consuming; therefore, practitioners may be more in favor of monitoring velocity and determining relative load through velocity-based prediction models for an exercise. This study aimed to assess the relationship between mean velocity (MV) and mean propulsive velocity (MPV) at different relative training loads (%1RM) in the barbell hip thrust exercise. One hundred two male sport science students performed an incremental 1RM testing protocol for the barbell hip thrust exercise, and a linear position transducer measured MV and MPV of the barbell. The 1RM was reached at 0.25 ± 0.03 m·s-1, and the regression model generated to estimate a relative load showed an acceptable standard error of estimate (7.01 ± 1.05% 1RM and 7.36 ± 1.05% 1RM for MV and MPV, respectively) with a very large explained variance (R2 = 0.94). These results may have important practical applications for the prescription and monitoring of the accessory exercise of the hip thrust for monitoring training load and predicting 1RM without undertaking a RM test.