SSNA1 stabilizes dynamic microtubules and detects microtubule damage

Sjögren's Syndrome Nuclear Autoantigen 1 (SSNA1/NA14) is a microtubule-associated protein with important functions in cilia, dividing cells and developing neurons. However, the direct effects of SSNA1 on microtubules are not known. We employed in vitro reconstitution with purified proteins and TIRF microscopy to investigate the activity of human SSNA1 on dynamic microtubule ends and lattices. Our results show that SSNA1 modulates all parameters of microtubule dynamic instability - slowing down the rates of growth, shrinkage and catastrophe, and promoting rescue. We find that SSNA1 forms stretches along growing microtubule ends and binds cooperatively to the microtubule lattice. Furthermore, SSNA1 is enriched on microtubule damage sites, occurring both naturally, as well as induced by the microtubule severing enzyme spastin. Finally, SSNA1 binding protects microtubules against spastin's severing activity. Taken together, our results demonstrate that SSNA1 is both a potent microtubule stabilizing protein and a novel sensor of microtubule damage; activities that likely underlie SSNA1's functions on microtubule structures in cells.

Some data on the biology of stone cockscomb Alectrias alectrolophus (Stichaeidae) from the Tauysk Bay of the Sea of Okhotsk

On the basis of the materials collected in the period of 2010–2018 the features of biology: the size-age structure, linear growth pattern and body mass growth of the stone cockscomb Alectrias alectrolophus from the Tauysk Bay, the Sea of Okhotsk, have been studied. In the intertidal zone, in the period from May to September, individuals of this species the body length 31.2–133.4 mm and body weight 0.1–12.8 g at the age of up to 6+ years are found in large quantities. The size and age characteristics, rates of growth of females and males are quite similar, but in general, females are slightly larger than males.

The end of the internet rush

The concept of natural growth in competition is being exploited to produce forecasts for the use of Internetworldwide. Population trends and Internet-user trends indicate that the percentage of the population using theInternet is slowing down everywhere despite large discrepancies: 68% in the US, 45% in Europe, and 8% in therest of the world. Whereas new growth phases with slow rates of growth should be expected from the third world,the boom years of Internet explosion are over. Significant growth in the use of Internet in the rest of the world mustawait for a couple of decades.

Canadian Trends and Projections in Prescription Drug Purchases: 2001–2023

Limited data are available to understand costs and trends over time in the Canadian pharmaceutical market across all sectors. To fill this gap, a retrospective time series analysis of annual prescription drug purchases in Canada between 2001 and 2020 was conducted using data from the IQVIA Canadian Drugstore and Hospital Purchases Audit. Spending has grown over the past 2 decades at a steady pace, with annual average growth of 5.3% and 7.1% in the retail and hospital sectors, respectively. Total prescription purchases in 2020 were approximately $32.7 billion, 4.3% higher than in 2019 (3.8% growth in retail, 6.9% in hospital). New approvals of specialty and oncology drugs and generic formulations of the top 25 drugs may influence drug purchases in 2021 to 2023. Overall drug purchases in Canada are projected to continue growing. The forecast for the outpatient sector is continued moderate levels of growth in drug spending (3% to 4%), with higher rates of growth (7% to 8%) in the hospital setting. Action should be taken to curb sustained growth in pharmaceutical spending in Canada. Otherwise, these costs may be shifted to other budgets, private industry, and/or patients.

Environmental and Life-history Factors Influencing Juvenile Demography of a Temperate Reef Fish

<p>Realistic population models and effective conservation strategies require a thorough understanding of the processes that drive variation in individual growth and survival, particularly within life stages that are subject to high mortality. For fragmented marine populations it is also important to consider how processes driving variation performance may vary through space and time. In this study I assess the interaction of two primary factors driving juvenile demography: benthic habitat composition and larval history traits, in a temperate reef fish, Forsterygion lapillum (the common triplefin). It is well understood that juveniles of many marine organisms are closely associated with structured nearshore habitats as they provide resources (refuge and food sources) that are critical for juvenile growth and/or survival. Nursery habitats are often assessed using measures of fitness of juveniles inhabiting them (e.g. rates of growth). However individual fitness measures may not only be indicative of conditions experienced in the benthic phase, but also an individual's prior history. Recent evidence suggests that variation in larval traits at settlement (e.g., size and age at settlement, larval growth rate) can impact on subsequent ecological performance (e.g., feeding ability and/or predator avoidance) and therefore influence subsequent fitness (i.e. rates of growth and/or probabilities of survival). I used otolith microstructure to assess separate and joint effects of habitat composition and larval traits on the growth of young F. lapillum. Both macroalgal composition of habitat patches and larval traits affected juvenile growth rates, and results suggested that habitat composition may have the potential to mediate fitness-related advantages that may accrue to certain individuals as a result of paternal effects and/or larval dispersal history. Quantifying spatio-temporal variability in the post-settlement fitness of Individuals with that differ in larval traits is essential for effective spatial management of marine populations. I further explore the joint effects of macroalgal composition and larval traits, within the context of additional spatial and temporal environmental variation. Results provide direct evidence that habitat can mediate the strength of carryover effects, but that the impact of habitat was variable between local populations and settlement events through time. In chapter 4 of my thesis, I focus on how small-scale variation in macroalgal composition within a nursery habitat (while controlling for individual variation) can affect the strength of density dependent growth and survival rates of F. lapillum. Density-dependent survival is evident during the first 30 days after settlement, and the strength of density dependence varied as a function of macroalgal composition. Resulting variation in estimates of nursery value (i.e., the number of late-stage juveniles produced per area unit of habitat) highlight the importance of incorporating local scale variation in juvenile demography into assessments of nursery habitat. Lastly, I assess a potential strategy of fishes to persist in a wide range of benthic environments. The ability to adjust traits (i.e., phenotypic plasticity) may allow organisms that encounter a range of unpredictable environmental conditions to maximise fitness within a single generation. In chapter 5 I explore patterns of variation in morphology of juvenile F. lapillum from two different subpopulations and from different macroalgal habitats. I evaluate possible evidence for constraints on morphological variation arising from variation in growth rate prior to and following settlement. Results suggest that for organisms with complex life cycles, variation in growth rates experienced during dispersal may constrain plasticity in later stages.</p>

Environmental and Life-history Factors Influencing Juvenile Demography of a Temperate Reef Fish

<p>Realistic population models and effective conservation strategies require a thorough understanding of the processes that drive variation in individual growth and survival, particularly within life stages that are subject to high mortality. For fragmented marine populations it is also important to consider how processes driving variation performance may vary through space and time. In this study I assess the interaction of two primary factors driving juvenile demography: benthic habitat composition and larval history traits, in a temperate reef fish, Forsterygion lapillum (the common triplefin). It is well understood that juveniles of many marine organisms are closely associated with structured nearshore habitats as they provide resources (refuge and food sources) that are critical for juvenile growth and/or survival. Nursery habitats are often assessed using measures of fitness of juveniles inhabiting them (e.g. rates of growth). However individual fitness measures may not only be indicative of conditions experienced in the benthic phase, but also an individual's prior history. Recent evidence suggests that variation in larval traits at settlement (e.g., size and age at settlement, larval growth rate) can impact on subsequent ecological performance (e.g., feeding ability and/or predator avoidance) and therefore influence subsequent fitness (i.e. rates of growth and/or probabilities of survival). I used otolith microstructure to assess separate and joint effects of habitat composition and larval traits on the growth of young F. lapillum. Both macroalgal composition of habitat patches and larval traits affected juvenile growth rates, and results suggested that habitat composition may have the potential to mediate fitness-related advantages that may accrue to certain individuals as a result of paternal effects and/or larval dispersal history. Quantifying spatio-temporal variability in the post-settlement fitness of Individuals with that differ in larval traits is essential for effective spatial management of marine populations. I further explore the joint effects of macroalgal composition and larval traits, within the context of additional spatial and temporal environmental variation. Results provide direct evidence that habitat can mediate the strength of carryover effects, but that the impact of habitat was variable between local populations and settlement events through time. In chapter 4 of my thesis, I focus on how small-scale variation in macroalgal composition within a nursery habitat (while controlling for individual variation) can affect the strength of density dependent growth and survival rates of F. lapillum. Density-dependent survival is evident during the first 30 days after settlement, and the strength of density dependence varied as a function of macroalgal composition. Resulting variation in estimates of nursery value (i.e., the number of late-stage juveniles produced per area unit of habitat) highlight the importance of incorporating local scale variation in juvenile demography into assessments of nursery habitat. Lastly, I assess a potential strategy of fishes to persist in a wide range of benthic environments. The ability to adjust traits (i.e., phenotypic plasticity) may allow organisms that encounter a range of unpredictable environmental conditions to maximise fitness within a single generation. In chapter 5 I explore patterns of variation in morphology of juvenile F. lapillum from two different subpopulations and from different macroalgal habitats. I evaluate possible evidence for constraints on morphological variation arising from variation in growth rate prior to and following settlement. Results suggest that for organisms with complex life cycles, variation in growth rates experienced during dispersal may constrain plasticity in later stages.</p>

Epidemiological Dynamics of SARS-CoV-2 VOC Gamma in Rio de Janeiro, Brazil

The emergence and widespread circulation of SARS-CoV-2 variants of concern (VOC) or interest (VOI) imposes an enhanced threat to global public health. In Brazil, one of the countries most severely impacted throughout the pandemic, a complex dynamics involving variants co-circulation and turnover events has been recorded with the emergence and spread of VOC Gamma in Manaus in late 2020. In this context, we present a genomic epidemiology investigation based on samples collected between December 2020 and May 2021 in the second major Brazilian metropolis, Rio de Janeiro. By sequencing 244 novel genomes through all epidemiological weeks in this period, we were able to document the introduction and rapid dissemination of VOC Gamma in the city, driving the rise of the third local epidemic wave. Molecular clock analysis indicates this variant has circulated locally since the first weeks of 2021 and only seven weeks were necessary for it to achieve a frequency above 70%, consistent with rates of growth observed in Manaus and other states. Moreover, a Bayesian phylogeographic reconstruction indicates VOC Gamma spread throughout Brazil between December 2020 and January 2021, and that it was introduced in Rio de Janeiro through at least 13 events coming from nearly all regions of the country. Comparative analysis of RT-qPCR cycle threshold (Ct) values provides further evidence that VOC Gamma induces higher viral loads (N1 target; mean reduction of Ct: 2.7, 95% CI = ±0.7). This analysis corroborates the previously proposed mechanistic basis for this variant enhanced transmissibility and distinguished epidemiological behavior. Our results document the evolution of VOC Gamma and provide independent assessment of scenarios previously studied in Manaus, therefore contributing to the better understanding of the epidemiological dynamics currently being surveyed in other Brazilian regions.

Examining the impact of daily exposure to body-positive and fitspiration Instagram content on young women’s mood and body image: An intensive longitudinal study

The aim of the present study is to investigate the effect of daily exposure to body-positive and fitspiration Instagram posts on young women’s mood, body satisfaction, and appearance comparison tendency. One hundred and twenty-two young Italian women (Mage = 22.29 ± 2.26 years) were randomly assigned to three different conditions of daily exposure on Instagram (i.e., body-positive, fitspiration and neutral content) and followed with an experience sampling method over a period of 28 consecutive days. Comparisons between groups were performed via multilevel regression modelled as a linear growth model. Results showed that daily exposure to body-positive images was associated with the highest rates of growth of positive mood and body satisfaction. Daily exposure to fitspiration images was associated with the highest rates of growth of negative mood and appearance comparison. In conclusion, the body-positive movement may be considered in interventions aimed at improving young women’s body image. Fitspiration content on Instagram should be deemed inappropriate.

Role of the kdpDE Regulatory Operon of Mycobacterium tuberculosis in Modulating Bacterial Growth in vitro

Bacteria use K+-uptake transporters differentially for adaptation in varying growth conditions. In Mycobacterium tuberculosis, two K+-uptake systems, the Trk comprising the CeoB and CeoC proteins and the Kdp consisting of the two-component system (TCS), KdpDE and KdpFABC, have been characterized, but their selective utilization during bacterial growth has not been completely explored. In the current study, the roles of the M. tuberculosis KdpDE regulatory system alone and in association with the Trk transporters in bacterial growth were investigated by evaluating the growth of M. tuberculosis KdpDE-deletion and KdpDE/Trk (KT)-double knockout mutant strains in planktonic culture under standard growth conditions. The KT-double knockout mutant strain was first constructed using homologous recombination procedures and was evaluated together with the KdpDE-deletion mutant and the wild-type (WT) strains with respect to their rates of growth, K+-uptake efficiencies, and K+-transporter gene expression during planktonic growth. During growth at optimal K+ concentrations and pH levels, selective deletion of the TCS KdpDE (KdpDE-deletion mutant) led to attenuation of bacterial growth and an increase in bacterial K+-uptake efficiency, as well as dysregulated expression of the kdpFABC and trk genes. Deletion of both the KdpDE and the Trk systems (KT-double knockout) also led to severely attenuated bacterial growth, as well as an increase in bacterial K+-uptake efficiency. These results demonstrate that the KdpDE regulatory system plays a key role during bacterial growth by regulating K+ uptake via modulation of the expression and activities of both the KdpFABC and Trk systems and is important for bacterial growth possibly by preventing cytoplasmic K+ overload.