The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Mechanomyographic amplitude and frequency responses during dynamic muscle actions: a comprehensive review

The purpose of this review is to examine the literature that has investigated mechanomyographic (MMG) amplitude and frequency responses during dynamic muscle actions. To date, the majority of MMG research has focused on isometric muscle actions. Recent studies, however, have examined the MMG time and/or frequency domain responses during various types of dynamic activities, including dynamic constant external resistance (DCER) and isokinetic muscle actions, as well as cycle ergometry. Despite the potential influences of factors such as changes in muscle length and the thickness of the tissue between the muscle and the MMG sensor, there is convincing evidence that during dynamic muscle actions, the MMG signal provides valid information regarding muscle function. This argument is supported by consistencies in the MMG literature, such as the close relationship between MMG amplitude and power output and a linear increase in MMG amplitude with concentric torque production. There are still many issues, however, that have yet to be resolved, and the literature base for MMG during both dynamic and isometric muscle actions is far from complete. Thus, it is important to investigate the unique applications of MMG amplitude and frequency responses with different experimental designs/methodologies to continually reassess the uses/limitations of MMG

Raman studies of tribological model systems

The purpose of this study was to explore tribological model systems. Specifically, the types of molecular forces a chemical bond will undergo while under tribological stress. While tribology has been a growing field of interest, many of the studies have focused on the mechanical conditions while few have considered the chemical wear and tear. Tribological forces are generally mechanical in nature, but molecules undergoing these mechanical force changes are known to change their respective vibrational frequencies or break apart and form derivatives. In this study directly, molecular bonds of different types have been investigated by Raman spectroscopy under different types of shear stress. The different types of shear stress included compression, stretching, and elongation. While suggestions are given about the next step in the formation of molecular derivatives, the main thrust of the study has been to focus and explain the molecular bond changes as a function of tribological shear stress

Advances in the Use of DNA Barcodes to Build a Community Phylogeny for Tropical Trees in a Puerto Rican Forest Dynamics Plot

Background Species number, functional traits, and phylogenetic history all contribute to characterizing the biological diversity in plant communities. The phylogenetic component of diversity has been particularly difficult to quantify in species-rich tropical tree assemblages. The compilation of previously published (and often incomplete) data on evolutionary relationships of species into a composite phylogeny of the taxa in a forest, through such programs as Phylomatic, has proven useful in building community phylogenies although often of limited resolution. Recently, DNA barcodes have been used to construct a robust community phylogeny for nearly 300 tree species in a forest dynamics plot in Panama using a supermatrix method. In that study sequence data from three barcode loci were used to generate a well-resolved species-level phylogeny

Influência do processo de familiarização para avaliação da força muscular em testes de 1-RM Influencia del proceso de familiarizacion para evaluación de la fuerza muscular en tests de 1-RM Influence of familiarization process on muscular strength assessment in 1-RM tests

Embora testes de uma repetição máxima (1-RM) sejam freqüentemente utilizados para a avaliação da força muscular, acredita-se que os resultados obtidos possam ser afetados pela falta de familiarização prévia, até mesmo em sujeitos com experiência em exercícios com pesos. Assim, o objetivo deste estudo foi investigar o impacto do processo de familiarização para avaliação da força muscular em testes de 1-RM. Para tanto, 21 homens (24,5 &plusmn; 3,8 anos), aparentemente saudáveis, com experiência prévia de pelo menos seis meses em treinamento com pesos, foram submetidos a testes repetitivos de 1-RM nos exercícios supino em banco horizontal, agachamento e rosca direta de bíceps. Os testes foram executados em quatro sessões, intervaladas a cada 48-72 horas. Um número máximo de três tentativas, com intervalo de três a cinco minutos para recuperação, foi utilizado em cada exercício, nas quatro sessões de testagem. ANOVA para medidas repetidas, seguida pelo teste post hoc de Tukey, quando p < 0,05, foi utilizada para o tratamento dos dados. Aumentos significantes na força muscular (p < 0,01) foram encontrados nos três exercícios analisados entre a primeira e a quarta sessão de familiarização (2,4% no supino em banco horizontal, 3,4% no agachamento e 5,4% na rosca direta de bíceps). Todavia, nenhuma diferença estatisticamente significante foi encontrada entre a segunda e a quarta sessão de familiarização na rosca direta de bíceps (p > 0,05), bem como entre a terceira e a quarta sessão no supino em banco horizontal e no agachamento (p > 0,05). Os resultados indicam que a falta de familiarização prévia com testes de 1-RM pode comprometer a avaliação da força muscular. Portanto, sugere-se, para avaliação mais acurada da força muscular mediante testes de 1-RM, a execução de duas a três sessões de familiarização em homens adultos com experiência em exercícios com pesos.<br>Embora la utilización de tests de una repetición máxima (1-RM) es frecuente para la evaluación de la fuerza muscular, se acredita que los resultados obtenidos puedan ser afectados por la falta de familiarización previa, hasta mismo en sujetos con experiencia en ejercicios con pesos. Asi, el objetivo de este estudio fué investigar el impacto del proceso de familiarización para evaluación de la fuerza muscular en tests de 1-RM. Por lo tanto, 21 hombres (24,5 &plusmn; 3,8 años), aparentemente saludables con experiencia previa de por lo menos seis meses de entrenamiento con pesos, fueron sometidos a tests reptitivos de 1-RM en los ejercicios supino en banco horizontal, agachamiento y rosca directa de bíceps. Los tests fueran ejecutados en cuatro sesiones, intervaladas en cada 48-72 horas. Un número máximo de tres tentativas, con intérvalo de tres a cinco minutos para recuperación, fué utilizado en cada ejercicio, en las cuatro sessiones de testeo. ANOVA se utilizó para medidas repetidas, seguida por el test post hoc de Tukey, cuando p < 0,05, fué utilizada para el tratamiento de los datos. Aumentos significantes en la fuerza muscular (p < 0,01) fueron encontrados los tres ejercicios analizados entre la primera y la cuarta sesión de familiarización (2,4% en supino en banco horizontal, 3,4% en agachamiento y 5,4% en la rosca directa del bíceps). Todavía, ninguna diferencia estadísticamente significativamente fuera encontrada entre la segunda y la cuarta sesión de familiarización en la rosca directa de bíceps (p > 0,05), bien con entre la tercera y la cuarta sesión en el supino en el banco horizontal y en el agachamiento (p > 0,05). Los resultados indican que la falta de familiarización previa con tests de 1-RM puede comprometer la evaluación de la fuerza muscular. Por lo tanto, se sugiere para la evaluación mas acurada de la fuerza muscular mediante tests de 1-RM la ejecución de dos a tres sesiones de familiarización en los hombres adultos con experiencia en ejercicios con pesos.<br>Although the use of maximum repetition tests (1-RM) is frequent for assessment of the muscular strength, one believes that the results obtained may be affected by the lack of previous familiarization, even in skilled subjects in exercises with weights. Thus, the objective of this study was to investigate the impact of the familiarization process on the muscular strength assessment in 1-RM tests. To do so, 21 men (24.5 &plusmn; 3.8 years of age), apparently healthy and with previous experience of at least six months on weight training, were submitted to repetitive tests of 1-RM in bench press, squat, and arm curl exercises. The tests were performed in four sessions with intervals every 48-72 hours. A maximum number of three attempts with 3-5 minutes interval for recovery was used in each exercise in the four testing sessions. The analysis of variance ANOVA for repeated measures followed by the post hoc Tukey test when p < 0.05 were used for the data treatment. Significant increases on the muscular strength (p < 0.01) were found in the three exercises analyzed between the first and the fourth familiarization session (2.4% in bench press, 3.4% in squat, and 5.4% in the arm curl). However, no statistically significant difference was found between the second and fourth familiarization sessions in the arm curl (p > 0.05) as well as between the third and fourth sessions in the bench press and squat (p > 0.05). The results indicate that the lack of previous familiarization with 1-RM tests may impair the muscular strength evaluation. Therefore, the performance of two to three familiarization sessions in adult men with previous experience with weightlifting is suggested for a more accurate muscular strength assessment by means of the 1-RM tests