Efficacy of alendronic acid solution in removal calcium hydroxide from root canals.

Background: Intracanal medication is considered an alternative after instrumentation in the case of pulp necrosis. However, the elimination of this medication plays an important role in the obturation process, which is why various chelating solutions have currently been studied for this purpose. Therefore, this study aimed to analyze the irrigant based on alendronic acid (AA), which contains in its chemical structure functional groups capable of forming complexes with Ca2+ ions. Material and Methods: 90 single-rooted teeth were crowned and standardized to a length of 13 mm. They were instrumented with a progressive K file (Dentsply Maillefer) from #15 to #30. Ca(OH)2 was placed as intracanal medication for 7 days. The roots were randomly divided into the following 4 experimental groups (n=13) according to the irrigant used: 2.25% NaClO, calcium suspension, 0.22% AA, and 10% citric acid; as well as negative (n=5; saline solution) and positive controls (n=5, 17% EDTA). The roots were divided longitudinally and the % of permeable dentinal tubules (% PDT) was determined by thirds (cervical, middle and apical), by analyzing the micrographs obtained by scanning electron microscope (SEM) and the imageJ program. The quantification of the remaining Ca2+ was determined using the Arsenazo III technique. Results: The Kruskal Wallis test was used for the % of permeable dentinal tubules where a significant difference was determined for the different thirds (p<0.005). In the apical third, citric acid and AA irrigants presented a median of 17.71 and 17.51 % PDT respectively. In relation to the quantification of the remaining total calcium, the lowest value was found with AA with a concentration of 4.83 mmol/L. Conclusions: The 0.22% AA solution has the same capacity to remove Ca(OH)2 from the root canal walls as 17% EDTA and 10% citric acid. Key words:Alendronic acid, calcium hydroxide, citric acid, EDTA, irrigant solution,root canal.

Neurofibromatosis Type 1-Retinal Alterations Detectable with Optical Coherence Tomography Angiography.

Neurofibromatosis type 1 (NF 1) is a multisystemic genetic disorder involving aberrant proliferation of multiple tissues of a neural crest origin. It represents a tumor predisposition syndrome characterized by a wide range of clinical manifestations, such as benign tumors, which primarily affect the skin and the nervous system. The most frequent clinical signs of NF 1 include café-au-lait spots all over the surface of the skin and axillary freckling; however, these signs can be accompanied by more severe manifestations such as the growth of both benign and malignant nervous system tumors and skeletal dysplasia, as well as a wide range of ocular manifestations. We report the rare case of retinal microvascular alterations and choroidal nodules in a 15 year old male patient with NF 1, detectable on optical coherence tomography angiography (OCTA). The hyperreflective choroidal nodules modified the profile of the choroidal vasculature. The retinal microvascular alterations in the form of clustered capillaries were detected in the superficial capillary plexus located nasally to the macular region. Retinal vascular abnormalities undetectable on fundus photography or fundoscopy can be present in patients with NF 1. Indirect ophthalmoscopy of our study patient was unremarkable. However, retinal vascular abnormalities were seen on OCTA scans in the superficial capillary plexus and choroidal nodules were detected on raster OCT scans. OCTA represents a useful imaging technique for detecting retinal microvascular abnormalities, which can be considered additional distinctive signs of NF 1.

Fecal microbiota and concentrations of long-chain fatty acids, sterols, and unconjugated bile acids in cats with chronic enteropathy.

Feline chronic enteropathies (FCE) are common causes of chronic gastrointestinal signs in cats and include different diseases such as food-responsive enteropathy (FRE), inflammatory bowel diseases (IBD), and low-grade intestinal T-cell lymphoma (LGITL). Although changes in intestinal microbiota and fecal metabolites have been reported in dogs and humans with chronic enteropathy, research in cats has been limited. Therefore, this study aimed to evaluate the fecal microbiota and lipid-related fecal metabolites in cats with FCE to a clinically healthy comparison group (CG). A total of 34 cats with FCE (13 FRE, 15 IBD, and 6 LGITL) and 27 cats in the CG were enrolled in this study. The fecal microbiota was evaluated by the qPCR-based feline Dysbiosis Index (DI). The feline DI in cats with CE (median: 1.3, range: -2.4 to 3.8) was significantly higher (p < 0.0001) compared to CG (median: - 2.3, Range: -4.3 to 2.3), with no difference found among the FCE subgroups. The fecal abundances of Faecalibacterium (p < 0.0001), Bacteroides (p < 0.0001), Fusobacterium (p = 0.0398), Bifidobacterium (p = 0.0004), and total bacteria (p = 0.0337) significantly decreased in cats with FCE. Twenty-seven targeted metabolites were measured by gas chromatography-mass spectrometry, including long-chain fatty acids (LCFAs), sterols, and bile acids (BAs). Fecal concentrations of 5 of 12 LCFAs were significantly increased in cats with FCE compared to CG. Fecal concentrations of zoosterol (p = 0.0109), such as cholesterol (p < 0.001) were also significantly increased in cats with FCE, but those of phytosterols were significantly decreased in this group. No differences in fecal BAs were found between the groups. Although no differences were found between the four groups, the fecal metabolomic pattern of cats with FRE was more similar to that of the CG than to those with IBD or LGITL. This could be explained by the mild changes associated with FRE compared to IBD and LGITL. The study showed changes in intestinal microbiota and alteration of fecal metabolites in FCE cats compared to the CG. Changes in fecal lipids metabolites suggest a dysmetabolism of lipids, including LCFAs, sterols, and unconjugated BAs in cats with CE.

Exome Sequencing has a high diagnostic rate in sporadic congenital hypopituitarism and reveals novel candidate genes.

CONTEXT: The pituitary gland is key for childhood growth, puberty, and metabolism. Pituitary dysfunction is associated with a spectrum of phenotypes, from mild to severe. Congenital Hypopituitarism (CH) is the most commonly reported pediatric endocrine dysfunction with an incidence of 1:4000, yet low rates of genetic diagnosis have been reported. OBJECTIVE: We aimed to unveil the genetic etiology of CH in a large cohort of patients from Argentina. METHODS: We performed whole exome sequencing of 137 unrelated cases of CH, the largest cohort examined with this method to date. RESULTS: Of the 137 cases, 19.1% and 16% carried pathogenic or likely pathogenic variants in known and new genes, respectively, while 28.2% carried variants of uncertain significance. This high yield was achieved through the integration of broad gene panels (genes described in animal models and/or other disorders), an unbiased candidate gene screen with a new bioinformatics pipeline (including genes high loss of function intolerance), and analysis of copy number variants. Three novel findings emerged. First, the most prevalent affected gene encodes the cell adhesion factor ROBO1. Affected children had a spectrum of phenotypes, consistent with a role beyond pituitary stalk interruption syndrome. Second, we found that CHD7 mutations also produce a phenotypic spectrum, not always associated with full CHARGE syndrome. Third, we add new evidence of pathogenicity in the genes PIBF1 and TBC1D32, and report 13 novel candidate genes associated with CH (e.g. PTPN6, ARID5B). CONCLUSION: Overall, these results provide an unprecedented insight into the diverse genetic etiology of hypopituitarism.

Teaching Literacy to Filipino Deaf Students in Multilingual Classrooms Amid a Pandemic.

This article describes the current landscape of teaching literacy to Filipino Deaf students in a multilingual, multi-cultural classroom amid the pandemic. The article highlights the uniqueness of Filipino Deaf students as multilingual learners in a multi-cultural classroom and the lack of literature and research on Deaf multilingualism both locally and globally. Moreover, the article focuses on the role of Deaf teachers in teaching Filipino Deaf students, especially in their literacy development. The steps being done to ensure that the curriculum is inclusive of Deaf learners who use Filipino Sign Language (FSL), teacher preparation and materials development, and the challenges in the shift to distance learning amid the COVID-19 pandemic are also discussed. Future directions and recommendations include review of curriculum and adaptation, enhancement of teacher preparation, promotion of collaborative teaching and research efforts, and the production of more appropriate and accessible instructional materials for Deaf students.

Propiedades psicométricas de las versiones larga y corta del cuestionario de agresión AQ en una muestra de presos españoles / Psychometric properties of the long and short forms of the AQ aggression questionnaire in a sample of Spanish inmates

Objetivos: El cuestionario de agresión (AQ) de Buss-Perry (Buss-Perry Aggression Questionnaire; Buss y Perry, 1992) es una medida utilizada en la población en general. Existe un debate sobre la interpretación de las puntuaciones y la utilidad de una versión más breve (AQ-SV [short version]). El objetivo de este estudio es analizar y comparar las propiedades psicométricas de la versión larga (AQ-LV [long version]) y la breve y comprobar la fiabilidad de la versión breve en una muestra de varones encarcelados. Material y método: La muestra estaba formada por 236 varones encarcelados (edad media de 40,4 años) del Centro Penitenciario Ocaña I (Toledo), que se ofrecieron a participar en el estudio. La muestra se seleccionó mediante la técnica de muestreo aleatorio por niveles, basada en el número de reclusos internos. También se incluyó una lista aleatoria de posibles sustitutos en caso de negativa a ser entrevistados, interrumpiéndose la sustitución en caso de dos negaciones consecutivas. Este estudio es un diseño descriptivo transversal. Resultados: La versión breve de la escala demostró un mejor ajuste que la versión larga, como indican los valores mayores del índice de ajuste comparativo (CFI, comparative fit index) y los menores del cuadrado medio residual ponderado (WRMR, weighted root mean square residual). El número de penas de prisión se asoció positivamente con la agresión física, la agresión verbal, la ira y la hostilidad. Los coeficientes fueron ligeramente superiores para la versión breve que para la versión larga. Discusión: La versión breve del cuestionario AQ es un instrumento válido y de utilidad para medir la agresividad en contextos penitenciarios en relación con la versión larga, y se correlaciona con subescalas de agresión con más fuerza que la versión larga.(AU)

Objectives: The Buss-Perry Aggression Questionnaire (AQ; Buss & Perry, 1992) is a broad measurement tool used with the general public in Spain. There is some debate regarding the interpretation of AQ scores and the usefulness of a shorter version. The aim is to study and compare the psychometric properties of the long and short version of the AQ and check the reliability of the short version in a sample of male prisoners. Material and method: The sample was composed of 236 incarcerated males (mean age of 40.4 years of age) from Ocaña 1 prison center who volunteered to participate in the study. The sample was selected by using the tiered random sampling technique based on the internal inmate number. A random list of possible substitutes was also included in the event of refusal to be interviewed, with replacement being discontinued in the event of two consecutive refusals. This study is a descriptive cross-sectional design. Results: The short version of the scale demonstrated better adjustment than the long version, as indicated by the larger CFI and smaller WRMR values. The number of prison sentences was positively associated with physical aggression, verbal aggression, anger, and hostility. The coefficients were slightly higher for the short version of the scale than the long one. Discussion: The short version of the AQ is a valid instrument for measuring aggressiveness in prison contexts in relation to the long version, and correlates with subscales of aggression more strongly than the long one.(AU)

Holistic food safety evaluation of herbs: methods for the determination of organic and inorganic trace contaminants in Moringa stenopetala as a case study.

Moringa stenopetala is considered a superfood due to the many bioactive compounds that it provides to the diet. However, like all edible plants, it is mandatory to guarantee food safety. Thus it is necessary to develop analytical methods that can rapidly and accurately determine hazardous pollutants, to evaluate compliance with food regulations. In this regard, two multi-component procedures were developed trying to cover some of the main organic and inorganic potential contaminants. A microwave-assisted digestion followed by electrothermal atomic absorption spectrometry was used for arsenic, cadmium, and lead determination, while a modification of the QuEChERS protocol followed by gas chromatography-tandem mass spectrometry was employed for the determination of 55 pesticides from different families. Both analytical methods were thoroughly validated according to international guidelines. The analyzed samples obtained from the Uruguayan market showed compliance with both, national and international, food regulations. The holistic approach employed in this research is not commonly presented in the literature, thus constituting a novel way to face food safety.

Minimal Mechanisms of Microtubule Length Regulation in Living Cells.

The microtubule cytoskeleton is responsible for sustained, long-range intracellular transport of mRNAs, proteins, and organelles in neurons. Neuronal microtubules must be stable enough to ensure reliable transport, but they also undergo dynamic instability, as their plus and minus ends continuously switch between growth and shrinking. This process allows for continuous rebuilding of the cytoskeleton and for flexibility in injury settings. Motivated by in vivo experimental data on microtubule behavior in Drosophila neurons, we propose a mathematical model of dendritic microtubule dynamics, with a focus on understanding microtubule length, velocity, and state-duration distributions. We find that limitations on microtubule growth phases are needed for realistic dynamics, but the type of limiting mechanism leads to qualitatively different responses to plausible experimental perturbations. We therefore propose and investigate two minimally-complex length-limiting factors: limitation due to resource (tubulin) constraints and limitation due to catastrophe of large-length microtubules. We combine simulations of a detailed stochastic model with steady-state analysis of a mean-field ordinary differential equations model to map out qualitatively distinct parameter regimes. This provides a basis for predicting changes in microtubule dynamics, tubulin allocation, and the turnover rate of tubulin within microtubules in different experimental environments.

Storylines of family medicine VII: family medicine across the lifespan.

Storylines of Family Medicine is a 12-part series of thematically linked mini-essays with accompanying illustrations that explore the many dimensions of family medicine as interpreted by individual family physicians and medical educators in the USA and elsewhere around the world. In 'VII: family medicine across the lifespan', authors address the following themes: 'Family medicine maternity care', 'Seeing children as patients brings joy to work', 'Family medicine and the care of adolescents', 'Reproductive healthcare across the lifespan', 'Men's health', 'Care of older adults', and 'Being with dying'. May readers appreciate the range of family medicine in these essays.

Parameter Identifiability in PDE Models of Fluorescence Recovery After Photobleaching.

Identifying unique parameters for mathematical models describing biological data can be challenging and often impossible. Parameter identifiability for partial differential equations models in cell biology is especially difficult given that many established in vivo measurements of protein dynamics average out the spatial dimensions. Here, we are motivated by recent experiments on the binding dynamics of the RNA-binding protein PTBP3 in RNP granules of frog oocytes based on fluorescence recovery after photobleaching (FRAP) measurements. FRAP is a widely-used experimental technique for probing protein dynamics in living cells, and is often modeled using simple reaction-diffusion models of the protein dynamics. We show that current methods of structural and practical parameter identifiability provide limited insights into identifiability of kinetic parameters for these PDE models and spatially-averaged FRAP data. We thus propose a pipeline for assessing parameter identifiability and for learning parameter combinations based on re-parametrization and profile likelihoods analysis. We show that this method is able to recover parameter combinations for synthetic FRAP datasets and investigate its application to real experimental data.

The Effects of Chia Defatted Flour as a Nutritional Supplement in C57BL/6 Mice Fed a Low-Quality Diet.

Today, consumption of diets rich in saturated fat and fructose, associated with a variety of metabolic deregulations, has increased. The aim of this study was to evaluate the effect of dietary supplementation with a residue of defatted chia seed on a diet with low nutritional quality. To do this, C57BL/6 male mice were fed with the Control (C), Low-Nutritional-Quality (LNQ), or supplemented-with-chia-defatted-flour (LNQ+C) diets. After 12 weeks, the glucose and lactate levels were determined in the serum, liver, and kidney, along with reactive oxygen species (ROS) levels, antioxidant enzyme activity, reduced glutathione (GSH), and protein oxidation (AOPP). The LNQ diet increased the glucose and lactate levels (+25% and +50% approx. in the liver, with respect to the control group) and generated oxidative stress by modifying the levels of ROS and the activity of antioxidant enzymes, causing oxidative damage to proteins (+12% in the liver, with respect to the control). Chia supplementation helped to restore the glucose to control levels and modulate the endogenous antioxidant system, resulting in a decrease in protein oxidation products with no differences compared to the control group. In conclusion, supplementation with chia showed beneficial effects on the general health of mice, even when fed a low-nutritional-quality diet.

Direct in-situ insights into the asymmetric surface reconstruction of rutile TiO2 (110).

The reconstruction of rutile TiO2 (110) holds significant importance as it profoundly influences the surface chemistry and catalytic properties of this widely used material in various applications, from photocatalysis to solar energy conversion. Here, we directly observe the asymmetric surface reconstruction of rutile TiO2 (110)-(1×2) with atomic-resolution using in situ spherical aberration-corrected scanning transmission electron microscopy. Density functional theory calculations were employed to complement the experimental observations. Our findings highlight the pivotal role played by repulsive electrostatic interaction among the small polarons -formed by excess electrons following the removal of neutral oxygen atoms- and the subsequent surface relaxations induced by these polarons. The emergence and disappearance of these asymmetric structures can be controlled by adjusting the oxygen partial pressure. This research provides a deeper understanding, prediction, and manipulation of the surface reconstructions of rutile TiO2 (110), holding implications for a diverse range of applications and technological advancements involving rutile-based materials.

Mental Health Professionals' Perception of Respect for Human Rights and Organizational Well-Being in Three Countries of South America.

The respect for human rights in mental health care services significantly contributes to organizational well-being and is evolving into an actual benchmark of quality standards. This study assesses the perception of the respect for human rights for users and staff, as well as organizational and job satisfaction among mental health professionals in three South American countries, through the well-being at work and respect for human rights (WWRR) questionnaire and assesses whether there are significant differences. Seven mental health facilities in Argentina, Colombia, and Peru were involved in this observational study. The sample comprised 310 mental health professionals. The three countries exhibited differences in WWRR, particularly in the staff's satisfaction with resources for care (η2 = 0.166) and staff's satisfaction with organizational aspects (η2 = 0.113). Colombia had the lowest scores in these factors but the highest in the perception of the respect for human rights for users and staff, although this difference did not reach a statistical significance. Despite the progress made in recent years towards coercion-free medical standards and an increased focus on mental health polices in Latin American countries, there is a need to enhance the quality standards of mental health services, recognizing the value that the respect for human rights holds for the organizational well-being of both mental health users and professionals.

Multiple names for multi-scope analytical methods, more than a semantic issue.

The use of multiple names for multi-scope analytical methods is often confusing. More precise classification to better accommodate the scope of analytical validation and application is needed.

Antioxidant activity of chia flour as a food supplement in a cellular model: Repercussions of processing and in vitro digestion.

Food processing and digestion can alter bioactive compound composition of food, affecting their potential biological activity. In this study, we evaluated the direct and protective antioxidant effects of polyphenols extracted from defatted chia flour (DCF) (salviaflaside, rosmarinic and fertaric acid as major compounds), sweet cookies supplemented with DCF (CFC) (same major compounds), and their digested fractions (rosmarinic acid, salviaflaside, fertaric and salvianolic E/B/L acid as major compounds) in HepG2 cells in basal and in oxidative stress conditions. DCF showed protective antioxidant effects by decreasing reactive oxygen species (ROS) and protein oxidation products (POP) while increasing reduced glutathione (GSH). Additionally, CFC revealed similar protective effects and even showed enhanced modulation of the antioxidant system due to the activation of antioxidant enzymes. However, the digested fractions only decreased ROS, indicating continued antioxidant effects. This study underscores the importance of evaluating manufacturing and digestion effects to confirm a food's antioxidant properties.

Survival of patients with chronic acid sphingomyelinase deficiency (ASMD) in the United States: A retrospective chart review study.

Background: Acid sphingomyelinase deficiency (ASMD), historically known as Niemann-Pick disease type A, A/B, and B, is a rare lysosomal storage pathology with multisystemic clinical manifestations. The aims of this study were to estimate the survival probability in patients in the United States with chronic ASMD (ASMD types B and A/B), and to describe the disease characteristics of these patients. Methods: This observational retrospective study included medical chart records of patients with chronic ASMD with retrievable data abstracted by 69 participating physicians from 25 medical centers in the United States. Included patients had a date of ASMD diagnosis or first presentation to a physician for ASMD symptoms (whichever occurred first) between January 01, 1990, and February 28, 2021. Medical chart records were excluded if patients were diagnosed with ASMD type A. Eligible medical chart records were abstracted to collect demographic, medical and developmental history, and mortality data. Survival outcomes were analyzed using Kaplan-Meier survival analyses from birth until death. Results: The overall study population (N = 110) included 69 patients with ASMD type B, nine with type A/B, and 32 with ASMD "non-type A" (ASMD subtype was unknown, but patients were confirmed as not having ASMD type A). The majority of patients were male with a median age at diagnosis of 3.8 years. Thirty-eight patients died during the study observation period, at a median age of 6.8 years. The median (95% confidence interval) survival age from birth was 21.3 (10.2; 60.4) years. At diagnosis or first presentation, 42.7% patients had ≥1 ASMD-related complication; splenic (30.0%) and hepatobiliary (20.9%) being the most common, and 40.9% required ≥1 medical visit due to complications. Conclusion: Patients with chronic ASMD in the United States have poor survival and significant burden of illness.

Long-term symptoms after SARS-CoV-2 infection in a cohort of hospital employees: duration and predictive factors.

PURPOSE: To evaluate the frequency, duration and patterns of long-term coronavirus disease 2019 (COVID-19) symptoms and to analyse risk factors for long-lasting COVID-19 sequelae among a cohort of hospital employees (HEs). METHODS: We conducted a survey regarding persistent COVID-19 related symptoms with all HEs from three medical centres in Cologne, Germany, who were tested SARS-CoV-2 PCR positive from March 2020 until May 2021. Duration of symptoms and possible risk factors for protracted COVID-19 course were analysed. RESULTS: Of 221 included HEs, a number of 104 HEs (47.1%) reported at least one persisting symptom for more than 90 days after initial SARS-CoV-2 detection. Each one cycle higher initial Ct value significantly increased the chances of overcoming symptoms (odds ratio [OR] 1.05; 95% confidence interval (95%CI) 1.01-1.09; p = 0.019). The occurrence of breathlessness within the first ten days (OR 7.89; 95%CI 1.87-41.43; p = 0.008), an initial Ct value under 30 (OR 3.36; 95%CI 1.22-9.94; p = 0.022) as well as the occurrence of anosmia or ageusia within the first ten days (OR 3.01; 95%CI 1.10-8.84; p = 0.037) showed a statistically significant association with increased odds of illness duration over 90 days. CONCLUSION: About half of the HEs suffered from long lasting symptoms over 90 days after almost entirely mild acute COVID-19. Predictive factors could possibly be used for early treatment to prevent development of long-term symptoms after COVID-19 in future.

Different perceptual worlds: Parent and youth perspectives on parenting outcome trajectories from a Latino family-based program.

Discrepancies between parent and youth perceptions of their relationship are a common aspect of generational acculturation gaps influencing immigrant families. Programs designed to strengthen parenting practices among immigrant Latino families commonly address immigration stresses, including differences between parent and youth perceptions, but little is known about discrepancies in their appraisals of program effects on parenting behavior. A randomized trial was conducted examining effects on parent behavior of a program for immigrant families with youth aged 10-14, developed through community-based participatory research principles. Families (346 parents and youth) were recruited by organizations serving Latino families in a Midwestern metropolitan area and randomly assigned to the eight-session psychoeducation and skill-building program or a waitlist control. Parents and youth completed self-report measures at pre-intervention, post-intervention (4 months), and a 6-month follow-up regarding parents' expression of acceptance, efforts to solicit information about the child's experiences, and consistency of discipline, key foci of the program. Based on social cognition theory, the study focused on possible differences in parents' and youths' perceptions of change in parenting behavior. Parents in the treatment group reported pre-post improved acceptance, consistent discipline, and solicitation, whereas youth reported improvement only in parental solicitation, a pattern maintained at follow-up. In the control group, the only change was youth-reported reduction in parental acceptance. Parents' perceptions of improvement are encouraging, but overall lack of improvements from the youth perspective poses a potential problem for impact on parent-child relations. Interventions may need to target both parent and youth cognitions about behavior changes directly.

Minimal Mechanisms of Microtubule Length Regulation in Living Cells.

The microtubule cytoskeleton is responsible for sustained, long-range intracellular transport of mRNAs, proteins, and organelles in neurons. Neuronal microtubules must be stable enough to ensure reliable transport, but they also undergo dynamic instability, as their plus and minus ends continuously switch between growth and shrinking. This process allows for continuous rebuilding of the cytoskeleton and for flexibility in injury settings. Motivated by in vivo experimental data on microtubule behavior in Drosophila neurons, we propose a mathematical model of dendritic microtubule dynamics, with a focus on understanding microtubule length, velocity, and state-duration distributions. We find that limitations on microtubule growth phases are needed for realistic dynamics, but the type of limiting mechanism leads to qualitatively different responses to plausible experimental perturbations. We therefore propose and investigate two minimally-complex length-limiting factors: limitation due to resource (tubulin) constraints and limitation due to catastrophe of large-length microtubules. We combine simulations of a detailed stochastic model with steady-state analysis of a mean-field ordinary differential equations model to map out qualitatively distinct parameter regimes. This provides a basis for predicting changes in microtubule dynamics, tubulin allocation, and the turnover rate of tubulin within microtubules in different experimental environments.