Determination Of Growth Rate Research Articles

Two decades of body length measurements of larval and juvenile fish populations in English rivers

Long-term datasets provide context and understanding of complex ecological processes, including temporal variations in species diversity and ecosystem dynamics. This dataset is comprised of body length measurements (mm) of more than 380,000 larval or juvenile fish of 30 species from five English river catchments collected almost monthly over two decades. Such information can be used to determine growth rates, future recruitment success, population structure and compliance with monitoring protocols and conservation objectives. The dataset provides a baseline for analysing the impacts of anthropogenic disturbances such as climate change, pollution and habitat degradation, and, given that many fish populations are size structured with a positive relationship between fish body length and various biological attributes such as swimming ability, survival and fecundity, it will be invaluable for investigating natural and human- induced disturbances.

Growth and Survival Outcomes for Immature Gopher Tortoises in Contrasting Habitats: A Test of Drone-Based Habitat Assessment.

Juvenile growth rate is a critical demographic parameter, as it shortens the time to maturity and often dictates how long individuals remain vulnerable to predation. However, developing a mechanistic understanding of the factors determining growth rates can be difficult for wild populations. The gopher tortoise (Gopherus polyphemus) is an ecosystem engineer threatened by habitat loss and deficient management of pinelands in the southeastern United States. We investigated the factors governing immature gopher tortoise growth and explored the use of drone-based imagery for habitat assessment by comparing predictive models based on ground-based plant surveys versus drone-derived data. From 2021 to 2022, we tracked and measured immature tortoises in native sandhill and human-modified, ruderal habitat in south-central Florida. Using quarterly, high-resolution drone imagery, we quantified plant cover types and vegetation indices at each occupied burrow and measured the frequency of occurrence of forage species by hand. Annual growth rates of immature tortoises in ruderal habitat were higher than those in sandhill and were the highest published for this species. Models based on drone-derived data were able to explain similar proportions of variation in growth as ground-collected measures of forage, especially during the late dry season when both types of models were most predictive. Habitat differences in forage nitrogen content were also more pronounced during this season, when dominant ground cover in ruderal habitat (bahiagrass) had much higher nitrogen content than dominant ground cover in sandhill (wiregrass). Despite concerns about potential growth-survival trade-offs, tortoises in ruderal habitat did not exhibit lower apparent survival. Our findings indicate that habitat dominated by nutritious non-native grass can provide a valuable supplement to native sandhill through the mechanism of increased growth rates due to higher forage quality. Finally, our study demonstrates that drone technology may facilitate management by providing less labor-intensive ways to assess habitat quality for this and other imperiled herbivores.

Optimising height-growth predicts trait responses to water availability and other environmental drivers.

Future changes in climate, together with rising atmospheric , may reorganise the functional composition of ecosystems. Without long-term historical data, predicting how traits will respond to environmental conditions-in particular, water availability-remains a challenge. While eco-evolutionary optimality theory (EEO) can provide insight into how plants adapt to their environment, EEO approaches to date have been formulated on the assumption that plants maximise carbon gain, which omits the important role of tissue construction and size in determining growth rates and fitness. Here, we show how an expanded optimisation framework, focussed on individual growth rate, enables us to explain shifts in four key traits: leaf mass per area, sapwood area to leaf area ratio (Huber value), wood density and sapwood-specific conductivity in response to soil moisture, atmospheric aridity, and light availability. In particular, we predict that as conditions become increasingly dry, height-growth optimising traits shift from resource-acquisitive strategies to resource-conservative strategies, consistent with empirical responses across current environmental gradients of rainfall. These findings can explain both the shift in traits and turnover of species along existing environmental gradients and changing future conditionsand highlight the importance of both carbon assimilation and tissue construction in shaping the functional composition of vegetation across climates.

Discovery of Molecular Intermediates and Nonclassical Nanoparticle Formation Mechanisms by Liquid Phase Electron Microscopy and Reaction Throughput Analysis

Formation kinetics of metal nanoparticles are generally described via mass transport and thermodynamics‐based models, such as diffusion‐limited growth and classical nucleation theory (CNT). However, metal monomers are commonly assumed as precursors, leaving the identity of molecular intermediates and their contribution to nanoparticle formation unclear. Herein, liquid phase transmission electron microscopy (LPTEM) and reaction kinetic modeling are utilized to establish the nucleation and growth mechanisms and discover molecular intermediates during silver nanoparticle formation. Quantitative LPTEM measurements show that their nucleation rate decreases while growth rate is nearly invariant with electron dose rate. Reaction kinetic simulations show that Ag4 and Ag− follow a statistically similar dose rate dependence as the experimentally determined growth rate. We show that experimental growth rates are consistent with diffusion‐limited growth via the attachment of these species to nanoparticles. The dose rate dependence of nucleation rate is inconsistent with CNT. A reaction‐limited nucleation mechanism is proposed and it is demonstrated that experimental nucleation kinetics are consistent with Ag42+ aggregation rates at millisecond time scales. Reaction throughput analysis of the kinetic simulations uncovered formation and decay pathways mediating intermediate concentrations. We demonstrate the power of quantitative LPTEM combined with kinetic modeling for establishing nanoparticle formation mechanisms and principal intermediates.

Tracking microstructural evolution and hardening in Al–Zn–Mg–Cu alloys aged artificially via electrical conductivity measurements

Precipitation hardening, a crucial mechanism for strengthening aluminum alloys, involves stages like Guinier–Preston (GP) zone formation, precipitation, peak aging, and precipitate coarsening. This study focuses on the aluminum 7050 alloy, proposing a method to gauge artificial aging through electrical conductivity measurement. The evolving microstructure and time to peak hardness during aging are vital for creating high-strength alloys. The electrical conductivity variation over time is utilized to analyze the diffusion process governing the clustering and growth of specific phases (η′, η, and S) during artificial aging. The paper demonstrates the impact of GP zones, precipitate formation, and grain growth on electrical conductivity, correlating these factors with hardness, microstructure, and tensile strength to determine the hardening stage. Differential electrical conductivity plots, highlighting aging stages, assist in identifying the hardening phase. Tensile strength and hardness plots differentiate the precipitation phases. The Johnson–Mehl–Avrami–Kolmogorov equation models particle growth kinetics, determining growth rates for AA 7050 alloy. The overall activation energy for precipitate growth is 40.77 kJ/mol, with a growth constant ( m) of ∼4, indicating S phase nucleation during η′ and η growth.

Evaluation of the effect of clonazepam and its metabolites on the life cycle of Megaselia scalaris (Loew) (Diptera: Phoridae)

Fly colonization patterns and development are crucial in estimating the post-mortem interval (PMI) of decomposing corpses. Understanding the potential effects of xenobiotics on species development in cadaveric entomofauna is essential for accurate PMI estimation, given their presence in decomposing bodies. Benzodiazepines, commonly prescribed for their anxiolytic, hypnotic, and muscle relaxant effects, are of forensic interest due to their potential for abuse, dependence, intoxication, and overdose-related deaths. This study aimed to explore the effect of clonazepam and its metabolites on Megaselia scalaris, a species commonly used to estimate PMI, the alteration of which could impact the accuracy of said estimation. The S9 biotransformation fraction, an in vitro model consisting of an array of metabolic enzymes, was used to generate phase I and II metabolites for evaluating their effect on M. scalaris development, representing an innovative approach to this type of study. Megaselia scalaris larvae were reared in synthetic growth media under controlled conditions. The study compared different groups: control, clonazepam, and clonazepam with S9 fraction. Larvae were measured daily to determine growth rate, and clonazepam concentrations were analyzed using HPLC-DAD. Results showed that larvae grown in media containing clonazepam or clonazepam with S9 fraction developed faster than control larvae, reaching their pupal stage earlier. Growth rates were also altered in treated groups. In conclusion, the presence of clonazepam and its metabolites accelerated the life cycle of M. scalaris, potentially impacting the accuracy of PMI estimation. These findings underscore the importance of considering xenobiotics in forensic entomological studies for precise post-mortem interval determination.

Higher Education Landscape in India: Government Expenditure and Its Implications on Growth and Access

India’s higher education system grapples with myriad challenges perpetuated by scarcity of resources. This study seeks to analyse the quantitative growth of India’s higher education since independence, particularly focusing on the post-reform period. The research employs regression models, including the semi-log, Gompertz and multiple linear models, to determine growth rates and forecast variables up to 2035. The study reveals a significant expansion of higher education during the examined period, though it falls short of meeting the increasing demands. To achieve the goal of a 50 per cent Gross Enrollment Ratio (GER) by 2035, the Government of India must take steps to boost its expenditure on higher education. The analysis powerfully underscores that despite the extensive proliferation of higher education in India, its efficacy might be limited without concurrent implementation of robust policies directed towards amplifying government expenditure within the sector.

Lipids productivity of cyanobacterium Anabaena vaginicola in an internally illuminated photobioreactor using LED bar lights

Concerns over environmental issues exists and desire to decrease of their extent, have directed efforts toward green energy production. Growth behavior of Anabaena vaginicola was determined in a photobioreator which illuminated internally (IIPBR) using LED bar light. Excessive heat generated in the IIPBR was taken care of by applying a novel air-cooled system. Further note in experimentation was to find favorable cultivation conditions in the IIPBR for A. vaginicola growth and its lipids production capacity. The following results are expressed: 80 µmol photons m−2 s−1 as light intensity, 0.5 g/l as NaNO3, and 120 ml/min as CO2 amount being expressed in terms of aeration rate. The findings were interpreted in terms of a two-component system where the genes encoded to the relevant proteins are present in cyanobacteria and their expressiveness depends on environmental stress. By determining growth rate constant as 0.11 d−1, the productivity in terms of biomass formation was calculated as 202.6 mg L−1 d−1. While rate of lipids production by the test cyanobacterium is 15.65 mg L−1 d−1. Based on total energy used for IIPBR performance, biomass productivity per unit power input equals to 0.74 g W−1 d−1 and this is in favorable position compared with other photobioreactors.

An Effective and Affordable Internet of Things (IoT) Scale System to Measure Crop Water Use

Scales are widely used in many agricultural applications, ranging from weighing crops at harvest to determine crop yields to regularly weighing animals to determine growth rate. In agricultural research applications, there is a long history of measuring crop water use (evapotranspiration [ET]) using a particular type of scale called weighing lysimeters. Typically, weighing lysimeters require very accurate data logging systems that tend to be expensive. Recent developments in open-source technologies, such as micro-controllers and Internet of Things (IoT) platforms, have created opportunities for developing effective and affordable ways to monitor crop water use and transmit the data to the Internet in near real-time. Therefore, this study aimed to create an affordable Internet of Things (IoT) scale system to measure crop ET. A scale system to monitor crop ET was developed using an Arduino-compatible microcontroller with cell phone communication, electronic load cells, an Inter-Integrated Circuit (I2C) multiplexer, and analog-to-digital converters (ADCs). The system was powered by a LiPo battery, charged by a small (6 W) solar panel. The IoT scale system was programmed to collect data from the load cells at regular time intervals and send the data to the ThingSpeak IoT platform. The system performed successfully during indoor and outdoor experiments conducted in 2023 at the Clemson University Edisto Research and Education Center, Blackville, SC. Calibrations relating the measured output of the scale load cells to changes in mass resulted in excellent linear relationships during the indoor (r2 = 1.0) and outdoor experiments (r2 = 0.9994). The results of the outdoor experiments showed that the IoT scale system could accurately measure changes in lysimeter mass during several months (Feb to Jun) without failure in data collection or transmission. The changes in lysimeter mass measured during that period reflected the same trend as concurrent soil moisture data measured at a nearby weather station. The changes in lysimeter mass measured with the IoT scale system during the outdoor experiment were accurate enough to derive daily and hourly crop ET and even detect what appeared to be dew formation during the morning hours. The IoT scale system can be built using open-source, off-the-shelf electronic components which can be purchased online and easily replaced or substituted. The system can also be developed at a fraction of the cost of data logging, communication, and visualization systems typically used for lysimeter and scale applications.

Determining growth rates of heterotrophic bacteria from 16S rRNA gene sequence-based analyses of dilution experiments

Vital rates, including growth responses to environmental variability, are poorly characterized for the diverse taxa of heterotrophic bacteria (HBact) in marine ecosystems. Here, we evaluated the potential for combining molecular analyses with dilution experiments to assess taxon-specific growth (cell division) and net growth rates of HBact in natural waters. Two-treatment dilution experiments were conducted with in situ incubations under 3 environmental conditions in the California Current Ecosystem, at offshore and inshore sites during a warm upwelling-suppressed year (2014) and for normal inshore upwelling, representing a 33-fold primary production range. Relative sequence reads from 16S rRNA metabarcoding were normalized to total HBact counts from flow cytometry for community abundance and rate calculations. Composition varied from dominance of Alphaproteobacteria (56%) in oligotrophic offshore (SAR11) and mesotrophic inshore waters (SAR11 and Rhodobacteria) to Bacteriodes/Flavobacteria dominance (64%) and mixed sub-taxon importance (Polaribacter, Rhodobacteria, Formosa) during upwelling. Net growth rates in bottles, validated by comparison to ambient community net growth following a satellite-tracked drifter, varied from near steady state for offshore and inshore conditions to dynamic community changes during upwelling. Mean growth rates doubled (0.33 to 0.62 d-1) over the productivity range, and taxon estimates varied from -0.17 d-1 (Formosa, offshore) to 1.53 d-1 (SAR11, upwelling). Increasing growth of Flavobacteria and Rhodobacteria paralleled their abundance and dominance increases with productivity. SAR11 growth remained higher than average with increasing production, despite declining abundances. We highlight possible PCR or 16S rRNA gene copy biases of growth rate estimates as research needs for further applications of this approach.

Research progress on the method and index evaluating strong seedlings of winter wheat during overwintering stage.

The extreme weather disasters before winter caused by global climate change seriously affect the formation of strong seedlings of wheat. Cultivating strong seedlings is the premise of realizing high yield, high efficiency, and high quality of wheat. The cultivation of strong wheat seedlings is closely related to seed quality, straw returning quality, land preparation quality, sowing quality, water and fertilizer operation and meteorological factors. Seed quality and tillage measures are the primary factors affecting the cultivation of strong wheat seedlings, which determine the quality of wheat seedling emergence. Secondly, meteorological factors determine growth rate and photosynthetic production of wheat seedlings. Mounting studies have addressed the cultivation of strong seedlings and the evaluation of seedling conditions of wheat. This research focused on comparing and summarizing the evaluation methods and indices of strong seedlings of winter wheat, the historical changes of evaluation standards and the main technical measures for cultivating strong seedlings, and proposed the cultivation and evaluation methods of strong seedlings of winter wheat in the future. We aimed to further improve the evaluation method of winter wheat strong seedlings, advance the classification management, precise guidance and fine service of winter wheat seedlings, and realize strong seedlings through scientific and technological ways.

A study of incidence of fibroid uterus, symptomatology, and therapeutic outcome of different procedures in patients with fibroid uterus

Abstract Background: Fibroids are benign, monoclonal tumors of smooth muscle cells of myometrium. Due to wide spectrum of clinical symptoms, they represent tremendous public health burden on women and economic costs to society. Strategies are needed to prevent its formation to limit growth and to treat nonsurgically. Objective: The objective of the study was to study the incidence of fibroid uterus, symptomatology, and therapeutic outcome of different procedures in fibroid uterus. Materials and Methods: Hospital-based prospective study was carried out among 14,250 patients. Among them, 3277 patients had fibroid uterus and 100 cases were included. Diagnosis was made by clinical examination and confirmed by radiological evaluation. Asymptomatic patients were monitored at every 6 months with pelvic examination and pelvic ultrasonography to determine growth rate of fibroid and symptoms. Medical therapy with gonadotropin-releasing hormone agonist was given as an adjunct to surgical treatment where temporary postponement of surgery was required. Myomectomy, laparoscopic myomectomy, hysteroscopic myoma resection, uterine artery embolization and hysterectomy were performed as per individual patient indication. Postoperatively, all patients were followed for 1 year, and outcome of various procedures in relieving symptoms and fertility was recorded. Results: The incidence of fibroid uterus was 23%. The incidence of fibroid was more in 31–35 years, in nulliparous women. The incidence of symptoms was 52%; most common was menorrhagia (44.2%). Dysmenorrhea was the most common cause of pain (37.5%). Proportion of patients got relieved of symptoms was the highest with hysterectomy (92%). Highest conception rate was after laparotomy/myomectomy in 58.3%. Conclusion: Dysmenorrhea was the most common cause of pain. Hysterectomy was best for relief of symptoms. Laparotomy/myomectomy was best for those who want to conceive.

Modelling the Effect of mercury on the Growth Rate of an SDS-degrading Pseudomonas sp. strain Maninjau1

The SDS-degrading bacterium Pseudomonas sp. strain Maninjau1 experienced significant inhibition by mercury. Observations of bacterial growth at varying mercury concentrations revealed a sigmoidal pattern, with lag periods extending from 7 to 12 hours. Increasing mercury concentrations progressively impeded growth, with a concentration of 1.0 mg/L nearly halting bacterial activity. To analyze these effects, the modified Gompertz model was employed to determine growth rates across different mercury concentrations. These rates were then subjected to several models, including the modified Han-Levenspiel, Wang, Liu, Shukor, modified Andrews, and Amor models. Among these, the Amor model failed to appropriately fit the growth curves. Statistical analysis indicated that the Shukor model performed the best, evidenced by the lowest values for Root Mean Square Error (RMSE) and Akaike’s Information Criterion corrected (AICc), the highest adjusted correlation coefficient (adR2), and values of Accuracy Factor (AF) and Bias Factor (BF) closest to unity. The parameters obtained from the Shukor model, which are mmax (h-1) and Sm (mg L-1) and n which represent maximum growth rate, critical heavy metal ion concentration and empirical constant values were 0.187, 1.126 and 2.406, respectively. The Shukor model allows for the prediction of the critical heavy metals concentration which can completely inhibited bacterial growth. This robust modeling approach underscores the Shukor model's suitability for predicting the impact of mercury on the growth dynamics of Pseudomonas sp. strain Maninjau1 under toxic stress conditions.

Droplet-based methodology for investigating bacterial population dynamics in response to phage exposure

An alarming rise in antimicrobial resistance worldwide has spurred efforts into the search for alternatives to antibiotic treatments. The use of bacteriophages, bacterial viruses harmless to humans, represents a promising approach with potential to treat bacterial infections (phage therapy). Recent advances in microscopy-based single-cell techniques have allowed researchers to develop new quantitative methodologies for assessing the interactions between bacteria and phages, especially the ability of phages to eradicate bacterial pathogen populations and to modulate growth of both commensal and pathogen populations. Here we combine droplet microfluidics with fluorescence time-lapse microscopy to characterize the growth and lysis dynamics of the bacterium Escherichia coli confined in droplets when challenged with phage. We investigated phages that promote lysis of infected E. coli cells, specifically, a phage species with DNA genome, T7 (Escherichia virus T7) and two phage species with RNA genomes, MS2 (Emesvirus zinderi) and Qβ (Qubevirus durum). Our microfluidic trapping device generated and immobilized picoliter-sized droplets, enabling stable imaging of bacterial growth and lysis in a temperature-controlled setup. Temporal information on bacterial population size was recorded for up to 25 h, allowing us to determine growth rates of bacterial populations and helping us uncover the extent and speed of phage infection. In the long-term, the development of novel microfluidic single-cell and population-level approaches will expedite research towards fundamental understanding of the genetic and molecular basis of rapid phage-induced lysis and eco-evolutionary aspects of bacteria-phage dynamics, and ultimately help identify key factors influencing the success of phage therapy.

Rapid growth rate responses of terrestrial bacteria to field warming on the Antarctic Peninsula

Ice-free terrestrial environments of the western Antarctic Peninsula are expanding and subject to colonization by new microorganisms and plants, which control biogeochemical cycling. Measuring growth rates of microbial populations and ecosystem carbon flux is critical for understanding how terrestrial ecosystems in Antarctica will respond to future warming. We implemented a field warming experiment in early (bare soil; +2 °C) and late (peat moss-dominated; +1.2 °C) successional glacier forefield sites on the western Antarctica Peninsula. We used quantitative stable isotope probing with H218O using intact cores in situ to determine growth rate responses of bacterial taxa to short-term (1 month) warming. Warming increased the growth rates of bacterial communities at both sites, even doubling the number of taxa exhibiting significant growth at the early site. Growth responses varied among taxa. Despite that warming induced a similar response for bacterial relative growth rates overall, the warming effect on ecosystem carbon fluxes was stronger at the early successional site—likely driven by increased activity of autotrophs which switched the ecosystem from a carbon source to a carbon sink. At the late-successional site, warming caused a significant increase in growth rate of many Alphaproteobacteria, but a weaker and opposite gross ecosystem productivity response that decreased the carbon sink—indicating that the carbon flux rates were driven more strongly by the plant communities. Such changes to bacterial growth and ecosystem carbon cycling suggest that the terrestrial Antarctic Peninsula can respond fast to increases in temperature, which can have repercussions for long-term elemental cycling and carbon storage.

Genome content predicts the carbon catabolic preferences of heterotrophic bacteria.

Heterotrophic bacteria-bacteria that utilize organic carbon sources-are taxonomically and functionally diverse across environments. It is challenging to map metabolic interactions and niches within microbial communities due to the large number of metabolites that could serve as potential carbon and energy sources for heterotrophs. Whether their metabolic niches can be understood using general principles, such as a small number of simplified metabolic categories, is unclear. Here we perform high-throughput metabolic profiling of 186 marine heterotrophic bacterial strains cultured in media containing one of 135 carbon substrates to determine growth rates, lag times and yields. We show that, despite high variability at all levels of taxonomy, the catabolic niches of heterotrophic bacteria can be understood in terms of their preference for either glycolytic (sugars) or gluconeogenic (amino and organic acids) carbon sources. This preference is encoded by the total number of genes found in pathways that feed into the two modes of carbon utilization and can be predicted using a simple linear model based on gene counts. This allows for coarse-grained descriptions of microbial communities in terms of prevalent modes of carbon catabolism. The sugar-acid preference is also associated with genomic GC content and thus with the carbon-nitrogen requirements of their encoded proteome. Our work reveals how the evolution of bacterial genomes is structured by fundamental constraints rooted in metabolism.

Determining growth rates from bright-field images of budding cells through identifying overlaps.

Much of biochemical regulation ultimately controls growth rate, particularly in microbes. Although time-lapse microscopy visualises cells, determining their growth rates is challenging, particularly for those that divide asymmetrically, like Saccharomyces cerevisiae, because cells often overlap in images. Here we present the Birth Annotator for Budding Yeast (BABY), an algorithm to determine single-cell growth rates from label-free images. Using a convolutional neural network, BABY resolves overlaps through separating cells by size and assigns buds to mothers by identifying bud necks. BABY uses machine learning to track cells and determine lineages and estimates growth rates as the rates of change of volumes. Using BABY and a microfluidic device, we show that bud growth is likely first sizer- then timer-controlled, that the nuclear concentration of Sfp1, a regulator of ribosome biogenesis, varies before the growth rate does, and that growth rate can be used for real-time control. By estimating single-cell growth rates and so fitness, BABY should generate much biological insight.

TOP5: Heart Transplant versus LVADs: Is destination therapy the new goal?

Background: With improving survival of patients following acute coronary syndromes and chronic heart failure, more patients are reaching the end stage of illness requiring heart transplantation (HT) as a finalgoal therapy. Mechanical circulatory support (MCS) devices like the left ventricular assist device (LVAD) play a major role as destination therapy or bridging therapy for this patient demographic. The improvement of modern LVADs paired with the increase of life expectancy, and the underwhelming engagement of HT donation in the US, ponders on the suggestibility of redirecting efforts for destination or bridging therapy for a growing population. This study assesses the tendencies of LVAD use in comparison to those of HT performance, and analyses the direct correlation with one another as predictive values for future directives in the AHF population. Methods: National data from the Organ Procurement & Transplantation Network (OPTN) was retrieved for the use of LVADs, the performance of primary HT and re-do HT over the last 30 years. Upon data retrieval, descriptive statistics were identified for 6 different groups (ages 18-34, 35-49, 50-64, above 65 years, and the collective adult cohort) including annual growth rate, and comparison within the group means. A regression analysis was performed to determine the variable relationship between LVAD placement and performance of HT. Results: Since 1992, a total of 75098 HT, and 21041 LVAD placements have been performed in the US. There is a significant difference in the number of HT and LVAD placements performed (LVAD vs PT: p=0.0001; LVAD vs re-do HT: p=0.0001). However, upon regression analysis, 64% of LVAD placement determines the subsequent bridging to HT, and the annual growth rate of LVAD placement has a positive significant correlation with the relatively sustained number of HT performed yearly (Coefficient of 0.87; Confidence interval 95%, p=0.000). When comparing LVAD placement to primary HT performance and re-do HT, a significant increase will continue to occur based on the thus-far determined growth rate across all age groups (p= 0.0001). Thus, suggestive that within the upcoming years, the number of LVADs placed will equal the amount of HT performed. Conclusions: With the continuance in evolution and improvement of LVADs in the AHF population and the uneven number of HT performed, this study outlines that the growing tendencies of MCS should be prioritized in lieu of HT availability or strategies to increase donation culture. The prioritization of MCS should aim for a better and comprehensive understanding of the role of these devices and adequate management in a long-term basis.Figure 1. LVAD, primary transplant and transplant repeat annual growth rate

Link between Energy Investment in Biosynthesis and Proteostasis: Testing the Cost-Quality Hypothesis in Insects.

The energy requirement for biosynthesis plays an important role in an organism's life history, as it determines growth rate, and tradeoffs with the investment in somatic maintenance. This energetic trait is different between painted lady (Vanessa cardui) and Turkestan cockroach (Blatta lateralis) due to the different life histories. Butterfly caterpillars (holometabolous) grow 30-fold faster, and the energy cost of biosynthesis is 20 times cheaper, compared to cockroach nymphs (hemimetabolous). We hypothesize that physiologically the difference in the energy cost is partially attributed to the differences in protein retention and turnover rate: Species with higher energy cost may have a lower tolerance to errors in newly synthesized protein. Newly synthesized proteins with errors are quickly unfolded and refolded, and/or degraded and resynthesized via the proteasomal system. Thus, much protein output may be given over to replacement of the degraded new proteins, so the overall energy cost on biosynthesis is high. Consequently, the species with a higher energy cost for biosyntheses has better proteostasis and cellular resistance to stress. Our study found that, compared to painted lady caterpillars, the midgut tissue of cockroach nymphs has better cellular viability under oxidative stresses, higher activities of proteasome 20S, and a higher RNA/growth ratio, supporting our hypothesis. This comparative study offers a departure point for better understanding life history tradeoffs between somatic maintenance and biosynthesis.

Growth rates of pelagic Sargassum species in the Mexican Caribbean

The recent recurring blooms of pelagic Sargassum spp. (sargasso) in the tropical Atlantic forming the Great Atlantic Sargasso Belt, are composed of distinct algal species and morphological forms, for which little understanding of basic development exists. Growth rate measurements across a range of environmental conditions in semi-controlled settings may aid in understanding the blooms. However, measuring the growth of this pelagic seaweed has proved to be challenging, as it tends to lose vigor in standard culturing systems. This work describes in-situ and ex-situ culture systems, that mimicked the pelagic condition by keeping the algae in motion. Growth rates measured in both systems were comparable, and in the same order of magnitude as those measured for sargasso in the Sargasso Sea. The morphotype VIII of the species S. natans, which became abundant with the blooms, had a higher in-situ growth rate (doubling time 17.9 – 26.3 d) than S. fluitans III (doubling time 25.6 – 83.3 d) under the studied conditions and temperatures (27–29 °C). Fertilizer addition to the in-situ trials did not result in higher growth rates, even though tissue content analysis showed that both N and P were taken up by the algae. In the ex-situ trials, S. natans VIII responded unfavorably to higher temperature (31 °C), whereas S. fluitans III did not. This preliminary study showed that both in-situ and ex-situ culture are feasible to determine growth rates of sargasso, paving the way for future (semi-) controlled studies on bloom dynamics in relation to abiotic and biotic conditions.