Measured Growth Rates Research Articles

Nucleation delay in water-saturated rhyolite during decompression in shallow volcanic systems and its implications for ascent dynamics

We developed a model of feldspar nucleation delay during decompression in water-saturated rhyolite based on classical nucleation theory (CNT). With the thermodynamic and kinetic parameters proposed in this study, the model agrees with the experimental results of this study to within a factor of two. To account for the variety of conditions encountered by magma during ascent, we propose expanding the model, developed in this study for isothermal decompression, to a wider range of pressures and temperatures (i.e. non-isothermal conditions). We present new measurements of feldspar growth rates during decompression in water-saturated rhyolite, emphasizing the importance of accurately calculating the nucleation delay in order to estimate growth rates. Using these data, we propose a method for estimating the ascent rate of water-saturated rhyolite based on the nucleation delay of feldspar microlites. The findings of this study hold the promise of a better understanding of volcanic timescales during magma ascent in the conduit, as well as the possibility of extending our model to more complicated scenarios with changing pressure and temperature.

Stroke Severity and Early Ischemic Changes Predict Infarct Growth Rate and Clinical Outcomes in Patients With Large‐Vessel Occlusion

Background The infarct growth rate (IGR) measures ischemic stroke progression and varies among patients. Clinicoradiological phenotypes of IGR are poorly understood. We evaluated the association of presentation stroke severity and early ischemic changes with infarct progression in patients who underwent successful thrombectomy. Methods This is a retrospective cohort observational study of consecutive endovascular therapy patients with anterior circulation large‐vessel occlusion strokes and successful reperfusion (modified Thrombolysis in Cerebral Ischemia≥2b) from 2 comprehensive stroke centers. National Institutes of Health Stroke Scale and Alberta Stroke Program Early CT [Computed Tomography] Score (ASPECTS) were scored at admission. IGR was defined as the final infarct volume after endovascular therapy divided by the time from stroke onset to successful reperfusion. We used the Youden J index to identify the optimal IGR cutoff to stratify fast and slow progressors. A multivariate logistic regression was used to identify variables associated with a fast IGR and clinical outcomes. Results A total of 212 patients were included in the study. The optimal IGR threshold was 3.2 mL/h, and 135 patients (63.6%) were classified as fast progressors. Presentation National Institutes of Health Stroke Scale score (odds ratio [OR], 1.12; 95% CI, 1.06–1.19) and ASPECTS (OR, 0.56; 95% CI, 0.41–0.73) were accurate predictors of a fast IGR after adjusting for significant confounders. For each 1‐point increase in National Institutes of Health Stroke Scale score at admission, the likelihood of being a fast progressor increased by 12%; for each 1‐point increase in ASPECTS, the likelihood of being a fast progressor decreased by 44%. In the early window (≤6 hours), all patients with ASPECTS <7 were identified as fast progressors. Conclusions This study shows that National Institutes of Health Stroke Scale score and ASPECTS at presentation could predict fast versus slow IGR in patients receiving endovascular therapy.

GrowFruit: An IoT-Based Radial Growth Rate Monitoring Device for Fruit

GrowFruit is an Internet of Things-based low-cost real-time radial growth-rate measurement device for fruit or stem. The working principle is measuring the growth of multiple crops up to 128 different inputs utilizing a single Texas Instrument-based 32-bit ultra-low-power microcontroller. The system utilizes Flex sensors, each of 4.5 in. to measure the change of circumference of the crop. The bending angle of the Flex sensor generates voltage, and via ADC, is fed to the microcontroller in the form of a digital signal. With the help of the Quectel M95 GSM modem, the microcontroller sends the signal to the cloud for storage and analysis of the growth rate data. As the system measures the perimeter changes of fruits or stems, more precise growth information is obtained.

Measurements and simulations of microtubule growth imply strong longitudinal interactions and reveal a role for GDP on the elongating end.

Microtubule polymerization dynamics result from the biochemical interactions of αβ-tubulin with the polymer end, but a quantitative understanding has been challenging to establish. We used interference reflection microscopy to make improved measurements of microtubule growth rates and growth fluctuations in the presence and absence of GTP hydrolysis. In the absence of GTP hydrolysis, microtubules grew steadily with very low fluctuations. These data were best described by a computational model implementing slow assembly kinetics, such that the rate of microtubule elongation is primarily limited by the rate of αβ-tubulin associations. With GTPase present, microtubules displayed substantially larger growth fluctuations than expected based on the no GTPase measurements. Our modeling showed that these larger fluctuations occurred because exposure of GDP-tubulin on the microtubule end transiently 'poisoned' growth, yielding a wider range of growth rates compared to GTP only conditions. Our experiments and modeling point to slow association kinetics (strong longitudinal interactions), such that drugs and regulatory proteins that alter microtubule dynamics could do so by modulating either the association or dissociation rate of tubulin from the microtubule tip. By causing slower growth, exposure of GDP-tubulin at the growing microtubule end may be an important early event determining catastrophe.

Rapid, Automated Measurement of Dynamic Size Distributions and Size-Dependent Growth Rates of Crystal Ensembles within Microfluidic Flow Cells

Rapid, Automated Measurement of Dynamic Size Distributions and Size-Dependent Growth Rates of Crystal Ensembles within Microfluidic Flow Cells

​Growth Performance and Biometry of Nellore Brown Lambs from Birth to Weaning under Different Systems of Rearing

Background: Among the three varieties of Nellore sheep, Nellore brown was most popular among the shepherds of Telangana state. The research on the performance of the other two varieties i.e. Palla and Dora was done extensively in their home tract but less data was available about performance of Nellore brown under different system of rearing. The growth rate of lambs was highest from birth to weaning in their life. The system of rearing can influence both growth rate and biometrical measurements of the lamb. The performance of the lambs during this stage influence the productive and reproductive performance in the lifetime. Methods: Sixty Nellore brown ewes (1.5 - 2 years) were selected from Sheep unit, Livestock Research Station, Mamnoor, Telangana for the present study. The lambs born in intensive (G1, lambs born N= 14), Semi-intensive (G2, lambs born N= 14) and Extensive (G3, lambs born N= 12) system of rearing were used to study the growth performance and biometry of lambs from birth to weaning. Result: The birth weight (kg) of lambs in G1 and G2 groups were significantly (P less than 0.01) higher than lambs in G3 group. The weaning body weight (Kg) was significantly higher (P less than 0.01) in G1 group as compared to weaning body weights in G2 and G3 group. The mean average ADG (gm) of lambs from birth to weaning was significantly (P less than 0.01) higher in G1 (105.4±0.19) followed by G2 (97.9±0.14) and G3 (92.8±0.07) group. The mean pin shoulder length (cm) of lambs at birth in G1 group was higher than G2 and G3 group but had a significant (P less than 0.05) difference with the only G3 group. In G1 group, the mean heart girth (cm) of lambs from15th day to weaning was significantly (P less than 0.01) higher than G2 and G3 groups. The mean gain in paunch girth from birth to weaning in lambs of three groups was nearly 19 cm and had no significant (P less than 0.05) difference between groups.

Influence of Deposition Strategies on Residual Stress in Wire + Arc Additive Manufactured Titanium Ti-6Al-4V

Wire + arc additive manufacturing (WAAM) is a modern manufacturing process that has opened new possibilities for rapid builds and reductions in material wastage. This paper explores residual stress in WAAM Ti-6Al-4V walls built using three different deposition strategies: single bead, parallel path, and oscillation path. The effect of interlayer hammer peening and interlayer temperature was investigated for the single bead walls. We also examined the residual stress in compact-tension (C(T)) coupons extracted from large builds (walls) with crack orientation either parallel with or perpendicular to the build direction. This type of sample is often used for the measurement of the fatigue crack growth rate. The contour method was used for experimental determinations of residual stress. In addtion, residual stress in the C(T) coupons was estimated by finite element (FE) analysis. A good agreement was achieved between the contour method and FE analysis. The oscillation-path wall had the lowest residual stress values. For the single bead walls built with various process conditions, residual stress was significantly reduced after removing the substrate. A interlayer temperature of 110 °C resulted in much higher residual stress values in the wall (both tensile and compressive) compared to the continuous build, with much higher interlayer temperature.

Stannous chloride as a tool for mercury stripping in contaminated streams: Experimental assessment of toxicity in an invertebrate model species

The chronic toxicity of an innovative Hg water treatment system using tin (Sn) (II) chloride (SnCl2) followed by air stripping was assessed through measurements of survival, growth, and reproduction rate in the freshwater cladoceran Ceriodaphnia dubia, a model species for toxicity testing. We first calculated the concentrations of Hg causing 25% reduction in survival and reproduction (Lethal or Inhibition Concentrations, or LC25 and IC25, for survival and reproduction, respectively) through exposure to aqueous Hg at concentrations ranging from 0 to 25,000 ng L−1. Then, we treated media (DMW and natural stream water) contaminated with Hg at LC25 and IC25 concentrations with SnCl2 at a Sn:Hg stoichiometric ratio of 8:1 and air stripping and exposed C. dubia to this Sn-amended media. Our results showed that Hg significantly affected survival, reproduction rates and impaired growth. SnCl2-treatment removed 100% of the Hg from the media at all concentrations tested with no deleterious effects on survival, growth and reproduction. Our results confirmed the efficacy of SnCl2 in removing aqueous Hg from stream water and showed that the added Sn did not impact C. dubia at the concentrations tested, supporting the suitability of SnCl2-based treatments in appropriate Hg-contaminated environments.

Environmental Dependence of Competitive Fitness in Rifampin-Resistant rpoB Mutants of Bacillus subtilis.

RNA polymerase (RNAP) is a highly conserved macromolecular machine that contributes to the flow of genetic information from genotype to phenotype. In Bacillus subtilis, mutations in the rpoB gene encoding the β-subunit of RNAP have been shown to alter a number of global phenotypes, including growth, utilization of unusual nutrient sources, sporulation, germination, and production of secondary metabolites. In addition, the spectrum of mutations in rpoB leading to rifampin resistance (Rifr) can change dramatically depending upon the environment to which B. subtilis cells or spores are exposed. RifrrpoB mutations have historically been associated with slower growth and reduced fitness; however, these assessments of fitness were conducted on limited collections of mutants in rich laboratory media that poorly reflect natural environments typically inhabited by B. subtilis. Using a novel deep-sequencing approach in addition to traditional measurements of growth rate, lag time, and pairwise competitions, we demonstrated that the competitive advantages of specific rpoB alleles differ depending on the growth environment in which they are determined. IMPORTANCE Microbial resistance to antibiotics is a growing threat to public health across the world. Historically, resistance to antibiotics has been associated with reduced fitness. A growing body of evidence indicates that resistance to rifampin, a frontline antibiotic used to treat mycobacterial and biofilm-associated infections, may increase fitness given an appropriate environment even in the absence of the selective antibiotic. Here, we experimentally confirm this phenomenon by directly comparing the fitness of multiple rifampin-resistant mutants of Bacillus subtilis in rich LB medium and an asparagine minimal medium. Our research demonstrates that the fitness cost of rifampin resistance can vary greatly depending upon the environment. This has important implications for understanding how microbes develop antimicrobial resistance in the absence of antibiotic selection.

Acquired resistance to irradiation or docetaxel is not associated with cross-resistance to cisplatin in prostate cancer cell lines

PurposePlatinum chemotherapy can be considered to treat metastatic castration-resistant prostate cancer (mCRPC) with features of neuroendocrine differentiation. However, platinum compounds are generally only applied after the failure of multiple prior-line treatment options. This study investigated whether acquired resistance against ionizing radiation or docetaxel chemotherapy—two commonly applied treatment modalities in prostate cancer—influences the cisplatin (CDDP) tolerance in mCRPC cell line models.MethodsAge-matched parental as well as radio- or docetaxel-resistant DU145 and PC-3 cell lines were treated with CDDP and their sensitivity was assessed by measurements of growth rates, viability, apoptosis, metabolic activity and colony formation ability.ResultsThe data suggest that docetaxel resistance does not influence CDDP tolerance in all tested docetaxel-resistant cell lines. Radio-resistance was associated with sensitization to CDDP in PC-3, but not in DU145 cells. In general, DU145 cells tolerated higher CDDP concentrations than PC-3 cells regardless of acquired resistances. Furthermore, non-age-matched treatment-naïve PC-3 cells exhibited significantly different CDDP tolerances.ConclusionLike patients, different mCRPC cell lines exhibit significant variability regarding CDDP tolerance. The presented in vitro data suggest that previous radiation treatment may be associated with a moderate sensitization to CDDP in an isogenic and age-matched setting. Therefore, previous radiotherapy or docetaxel chemotherapy might be no contraindication against initiation of platinum chemotherapy in selected mCRPC patients.

Stress corrosion crack propagation affected by microstructures for nuclear steam turbine rotor steels in the simulated environment

The propagation behavior of stress corrosion cracking (SCC) for two CrNiMoV steels in the simulated environment of low-pressure nuclear steam turbine rotor was systematically investigated by microstructural characterizations, electrochemical measurements, slow strain rate tensile tests, and crack growth rate (CGR) measurements. The results showed that both the corrosion susceptibility and stress corrosion susceptibility increased with the increase of localized residual strain, yield strength, and the decrease of grain size. With the higher stress corrosion susceptibility, the SCC CGR of Steel A was higher than Steel B in the corrosive solution at 80 °C, however, at 180 °C the SCC CGR of Steel A was lower than Steel B under the lower applied K. The change of SCC CGR was strongly affected by crack branches, crack deflections and plastic deformation during the SCC propagation, which may have some correlations with the microstructural distribution.

UV exposure causes energy trade-offs leading to increased chytrid fungus susceptibility in green tree frog larvae.

Levels of ultraviolet (UV) radiation have increased in many parts of the world due to the anthropogenic destruction of the ozone layer. UV radiation is a potent immunosuppressant and can increase the susceptibility of animal hosts to pathogens. UV radiation can directly alter immune function via immunosuppression and photoimmunotolerance; however, UV may also influence pathogen defences by affecting the distribution of energy resources among competing physiological processes. Both defence against UV damage and repair of incurred damage, as well as the maintenance of immune defences and responding to an immune challenge, are energetically expensive. These competing demands for finite energy resources could trade off against one another, resulting in sub-optimal performance in one or both processes. We examined the potential for a disease-related energy trade-off in green tree frog (Litoria caerulea) larvae. Larvae were reared under high- or low-UV conditions for 12weeks during which time we measured growth rates, metabolic rate and susceptibility to the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd). We found that larvae exposed to high levels of UV radiation had higher rates of energy expenditure than those exposed to low UV levels; however, UV exposure did not affect growth rates or developmental timings. Larvae exposed to high UV radiation also experienced greater Bd infection rates and carried a higher infection burden than those not exposed to elevated UV radiation. We propose that the increased energetic costs of responding to UV radiation were traded off against immune defences to protect larval growth rates. These findings have important implications for the aetiology of some Bd-associated amphibian declines, particularly in montane environments where Bd infections are most severe and where UV levels are highest.

Transplantation Tests of Precious Coral Fragments Using Small-sized Artificial Substratum.

Since the Roman era, precious corals have been used to make ornaments worldwide, and their demand has recently increased. As a basic study for artificial cultivation, we transplanted Corallium japonicum fragments. In 2016 and 2017, 132 fragments approximately 3-5 cm in length were attached to small-sized artificial substratums using marine epoxy on land. These artificial substratums, acting as transplant substrates, were then transported and sunk to a depth approximately 100 m off the coast of Otsuki Town and Tosashimizu City, Kochi Prefecture, where precious corals once flourished. From six months to three years post-submersion, we successfully recovered the transplanted substrates and found a total of 107 fragments (81%). We confirmed that 106 of these fragments were alive 177 to 936 days after transplantation. Although we could not measure growth rates due to the initial damage caused by the transplantation, we observed growth in coenenchyme tissues, new polyps and new branches in the 104 surviving fragments. This result suggests there is great potential to artificially multiply precious corals, which could aid in the development of a sustainable precious coral industry.

Combined approach for fatigue crack characterisation in metals

In this work a comprehensive characterisation of the fatigue crack growth of an Al 2024 alloy is presented. A powerful Christopher-James-Patterson (CJP) model is used for multi-parameter characterisation of the crack state at a few different locations through the fatigue crack growth. The CJP model of crack tip displacements and stress fields was proposed in order to better capture the influences on the applied elastic stress field of the plastic enclave that is generated around a growing fatigue crack. The model does this through a set of elastic stresses applied at a notional elastic-plastic boundary, and it has been shown to accurately model plastic zone shape and size, whilst its ability to predict the effective range of stress intensity factor during a fatigue cycle has been verified. Thus, the model can predict the driving force component of the crack and additional components that account for different shielding mechanisms. CJP model is combined with full-field non-contact Digital Image Correlation (DIC) so that the model can be fed at any moment with real experimental information. The results are then correlated with Paris law data for Al 2024 alloy through Scanning Electron Microscopy (SEM) observations of the fracture surface. In this work the effect of crack length and load level are thoroughly studied and validated with fatigue crack growth rate measurements.

Growth rate measurements of Chlorella vulgaris in a photobioreactor by Neubauer-improved counting chamber and densitometer

The depletion of fossil fuel sources and increased CO2 emissions has triggered intensive research to discover renewable energy sources. With the Low Carbon Scenario, the role of renewable energy will increase to 58% in 2050. As a renewable energy source, bioethanol is environmentally friendly which can substitute gasoline. Currently, the third-generation bioethanol production technology from microalgae is still being developed. Chlorella vulgaris is one of the microalgae types with high carbohydrate content and is easy and fast to cultivate. This study aims to evaluate the growth rate of C. vulgaris cultivated in a bubble column photobioreactor using artificial seawater aerated with pure CO2. Two LED tube lights were used with 12 h light and 12 dark cycles for 12 - 13 days. Microalgae culture population was measured every 24 h using a Neubauer-improved counting chamber and a microscope equipped with a digital camera. The results showed that the maximum specific growth rate,/max, was found to be 0.344 d1, and the highest concentration of 1.88 x107 cells mL1 occurred on day 7. Moreover, the microalgae populations were also measured using a densitometer. Since the calculation of the cell population used secondary data from the literature, the results were less accurate than those of the counting chamber.

Leaf Induction Impacts Behavior and Performance of a Pollinating Herbivore

Flowering plants use volatiles to attract pollinators while deterring herbivores. Vegetative and floral traits may interact to affect insect behavior. Pollinator behavior is most likely influenced by leaf traits when larval stages interact with plants in different ways than adult stages, such as when larvae are leaf herbivores but adult moths visit flowers as pollinators. Here, we determine how leaf induction and corresponding volatile differences in induced plants influence behavior in adult moths and whether these preferences align with larval performance. We manipulated vegetative induction in four Nicotiana species. Using paired induced and control plants of the same species with standardized artificial flowers, we measured foraging and oviposition choices by their ecologically and economically important herbivore/pollinator, Manduca sexta. In parallel, we measured growth rates of M. sexta larvae fed leaves from control or induced plants to determine if this was consistent with female oviposition preference. Lastly, we used plant headspace collections and gas chromatography to quantify volatile compounds from both induced and control leaves to link changes in plant chemistry with moth behavior. In the absence of floral chemical cues, vegetative defensive status influenced adult moth foraging preference from artificial flowers in one species (N. excelsior), where females nectared from induced plants more often than control plants. Plant vegetative resistance consistently influenced oviposition choice such that moths deposited more eggs on control plants than on induced plants of all four species. This oviposition preference for control plants aligned with higher larval growth rates on control leaves compared with induced leaves. Control and induced plants of each species had similar leaf volatile profiles, but induced plants had higher emission levels. Leaves of N. excelsior produced the most volatile compounds, including some inducible compounds typically associated with floral scent. We demonstrate that vegetative plant defensive volatiles play a role in host plant selection and that insects assess information from leaves differently when choosing between nectaring and oviposition locations. These results underscore the complex interactions between plants, their pollinators, and herbivores.

Effects of Dietary Shifts on Ontogenetic Development of Metabolic Rates in Age 0 Lake Sturgeon (Acipenser fulvescens).

AbstractIn many fish species, ontogenetic dietary shifts cause changes in both quantitative and qualitative intake of energy, and these transitions can act as significant bottlenecks in survival within a given year class. In the present study, we estimated routine metabolic rate (RMR) and forced maximum metabolic rate (FMR) in age 0 lake sturgeon (Acipenser fulvescens) on a weekly basis from 6 to 76 days posthatch (dph) within the same cohort of fish. We were particularly interested in the period of dietary transition from yolk to exogenous feeding between 6 and 17 dph and as the fish transitioned from an artemia-based diet to a predominantly bloodworm diet between 49 and 67 dph. Measurement of growth rate and energy density throughout indicated that there was a brief period of growth arrest during the transition from artemia to bloodworm. The highest mass-specific RMR (mg O2 kg-1 h-1) recorded throughout the first 76 d of development occurred during the yolk sac phase and during transition from artemia to bloodworm. Similarly, diet transition from artemia to bloodworm-when growth arrest was observed-increased scaled RMR (i.e., mg O2 kg-0.89 h-1), and it did not significantly differ from scaled FMR. Log-log relationships between non-mass-specific RMR or FMR (i.e., mg O2 h-1) and body mass significantly changed as the growing fish adapted to the nutritional differences of their primary diet. We demonstrate that dietary change during early ontogeny has consequences for growth that may reflect altered metabolic performance. Results have implications for understanding cohort and population dynamics during early life and effective management for conservation fish hatcheries.

Isolasi dan aktivitas antibakteri jamur endofit pada mangrove Avicennia marina dari Pulau Payung Kabupaten Banyuasin Sumatera Selatan

Isolation of endophytic fungus is the growth of endophytic fungus on new media to obtain the type of endophytic fungus. One of the mangrove plants containing endophytic fungi is Avicennia marina mangroves taken from Payung Island of South Sumatera. This study aims to isolate and identify the type of endophytic fungus, measure the growth rate of isolate diameter and know the antibacterial activity. Methods of this study include identification, growth rate measurement of isolate diameter for seven days and endophytic fungal activity test as antibacterial using Paper Disc method. The results of this study obtained five isolates with three types of endophytic fungi from each root part, stems and leaves of Aspergillus ochraceus , Aspergillus flavus and Aspergillus niger . The lag phase of these three fungi occurs from day of planting until the first day for one day, the exponential phase from the first day until the sixth day for five days, and the stationary phase on the sixth day to the seventh for one day for Aspergillus ochraceus and Aspergillus niger fungi while for Aspergillus flavus fungi yet occur stationary phase. The highest antibacterial activity with inhibit zone was shown by A. flavus fungal isolates ranging from 13,79 ± 1,26 mm for S. aureus and 11,86 ± 1,48 mm for E. coli bacteria, whereas the lowest inhibition zone was indicated by fungal isolates A. ochraceus 8,01 ± 0,45 mm for S. aureus bacteria and 9,34 ± 1,25 mm for E. coli bacteria.

Isolasi dan aktivitas antibakteri jamur endofit pada mangrove Avicennia marina dari Pulau Payung Kabupaten Banyuasin Sumatera Selatan

Isolation of endophytic fungus is the growth of endophytic fungus on new media to obtain the type of endophytic fungus. One of the mangrove plants containing endophytic fungi is Avicennia marina mangroves taken from Payung Island of South Sumatera. This study aims to isolate and identify the type of endophytic fungus, measure the growth rate of isolate diameter and know the antibacterial activity. Methods of this study include identification, growth rate measurement of isolate diameter for seven days and endophytic fungal activity test as antibacterial using Paper Disc method. The results of this study obtained five isolates with three types of endophytic fungi from each root part, stems and leaves of Aspergillus ochraceus, Aspergillus flavus and Aspergillus niger. The lag phase of these three fungi occurs from day of planting until the first day for one day, the exponential phase from the first day until the sixth day for five days, and the stationary phase on the sixth day to the seventh for one day for Aspergillus ochraceus and Aspergillus niger fungi while for Aspergillus flavus fungi yet occur stationary phase. The highest antibacterial activity with inhibit zone was shown by A. flavus fungal isolates ranging from 13,79 ± 1,26 mm for S. aureus and 11,86 ± 1,48 mm for E. coli bacteria, whereas the lowest inhibition zone was indicated by fungal isolates A. ochraceus 8,01 ± 0,45 mm for S. aureus bacteria and 9,34 ± 1,25 mm for E. coli bacteria.

Structural fatigue and fracture of shape memory alloy actuators: Current status and perspectives

Shape Memory Alloy (SMA)-actuators are efficient, simple, and robust alternatives to conventional actuators when a small volume and/or large force and stroke are required. The analysis of their failure response is critical for their design in order to achieve optimum functionality and performance. Here, (i) the existing knowledge base on the fatigue and overload fracture response of SMAs under actuation loading is reviewed regarding the failure micromechanisms, empirical relations for actuation fatigue life prediction, experimental measurements of fracture toughness and fatigue crack growth rates, and numerical investigations of toughness properties and (ii) future developments required to expand the acquired knowledge, enhance the current understanding, and ultimately enable commercial applications of SMA-actuators are discussed.