Faster Growth Rate Research Articles

Effect of post-weld heat treatment on microstructure and mechanical properties of induction roll welded joint for A283GRC steel and 5052 aluminum alloy

Steel-aluminum transition joints are commonly produced through explosive welding and friction welding techniques, serving to link aluminum pressure vessels with steel pipes within cold boxes in air separation unit. This study investigates the impact of PWHT on the microstructure and mechanical properties of steel-aluminum transition joints created via IRW, utilizing A283GRC steel and 5052 aluminum alloy as substrates. The findings suggest that the types of intermetallic compounds (IMCs) in IRW joints remain unchanged before and after heat treatment. The thickness of interfacial IMCs increases with higher annealing temperature and longer annealing time, with a faster growth rate at higher annealing temperatures. After PWHT, the grain size near the interface of the joint on the steel side decreased, with the most significant decrease observed when annealed at 300 °C for 2 hours. While cracks in the interface zone gradually diminish or disappear with PWHT, excessive heat treatment temperature or duration may result in new transverse cracks. At an annealing temperature of 200 °C, there is limited growth range for IMCs and noticeable repair effect on cracks within the interface region. When annealed at 300 °C and 400 °C, there is a decrease in joint hardness compared to before heat treatment levels, and this decreasing rate accelerates with higher annealing temperature and longer duration. Following annealing at 300 °C for 2 hours, the shear strength of the sample reached 70.52 MPa, which is 32% higher than that before heat treatment. Overall findings suggest that the annealing temperature exerts a more pronounced impact on the mechanical properties of joints in comparison to the annealing duration across the investigated time and temperature ranges. The fracture mode exhibited by the samples before and after heat treatment in IRW is characterized by a mixed fracture mode. However, the predominant fracture mode observed without heat treatment is brittle fracture, whereas after heat treatment, ductile fracture becomes the primary mode of fracture.

Determining the rate-limiting processes for cell division in Escherichia coli.

A critical cell cycle checkpoint for most bacteria is the onset of constriction when the septal peptidoglycan synthesis starts. According to the current understanding, the arrival of FtsN to midcell triggers this checkpoint in Escherichia coli. Recent structural and in vitro data suggests that recruitment of FtsN to the Z-ring leads to a conformational switch in actin-like FtsA, which links FtsZ protofilaments to the cell membrane and acts as a hub for the late divisome proteins. Here, we investigate this putative pathway using in vivo measurements and stochastic cell cycle modeling at moderately fast growth rates. Quantitatively upregulating protein concentrations and determining the resulting division timings shows that FtsN and FtsA numbers are not rate-limiting for the division in E. coli. However, at higher overexpression levels, they affect divisions: FtsN by accelerating and FtsA by inhibiting them. At the same time, we find that the FtsZ numbers in the cell are one of the rate-limiting factors for cell divisions in E. coli. Altogether, these findings suggest that instead of FtsN, accumulation of FtsZ in the Z-ring is one of the main drivers of the onset of constriction in E. coli at faster growth rates.

Rotating culture regulates the formation of HepaRG-derived liver organoids via YAP translocation.

Liver organoid serves as an alternative model for liver pathophysiology in carbohydrate or lipid metabolism and xenobiotic metabolism transformation. Biomechanical cues including spaceflight mission can affect liver organoid construction and their related functions, but their underlying mechanisms are not fully understood yet. Here, a rotating cell culture device, namely Rotating Flat Chamber (RFC), was specifically designed for adhering cells or cell aggregated to elucidate the effects of altered gravity vector on HepaRG-derived liver organoids construction. The organoids so formed under RFC presented the fast growth rate and large projection area. Meanwhile, the expressions of two pluripotency markers of SOX9 and CD44 were enhanced. This finding was positively correlated with the increased YAP expression and nuclear translocation as well as the elevated α4β6-integrin expression. Inhibition of YAP expression and nuclear translocation decreased the expression of SOX9 and CD44 under RFC, thereby attenuating the pluripotency of HepaRG-derived liver organoids. In conclusion, we proposed a novel liver organoid construction method using rotating culture, by which the pluripotency of liver organoids so constructed is mediated by α4β6-integrin and YAP translocation. This work furthered the understanding in how the gravity vector orientation affects the construction of liver organoids and the related mechanotransductive pathways.

Comparison of the Effects of Antibiotic Sensitivity and Physical Parameters on the Growth of <i>Burkholderia cepacia</i> complex and <i>Burkholderia cenocepacia</i>

B<i>urkholderia cepacia</i> complex (Bcc) has been tied to various FDA drug recalls over the past years. It was found that these bacteria can survive on a broad range of molecules in oxygenic and anoxygenic environments as well as sterilized and non-sterilized environments. The main research question focused on how physical requirements and antibiotics can be used to control Bcc and <i>B. cenocepacia </i>growth. Four replicates of TSB tubes that had pH 4, 6, 7, and 8 were inoculated with Bcc and <i>B. cenocepacia</i> and incubated overnight at 4, 20, 25, 37, and 85°C. The transmission readings of the broth cultures were measured to estimate bacterial growth using a Genesys 2 spectrophotometer. The Kirby-Bauer test was performed using Polymyxin, Ticarcillin, Ticarcillin with Clavulanic acid, Penicillin, Ampicillin, Chloramphenicol, Tetracycline, Erythromycin, and Streptomycin. The E-test was performed using gradient strips of Cefiderocol (C) l (0.016-256 mg/L) and Imipenem-relebactam (IR) (0.002/4-32/4 mg/L). The antibiotic dilution test was performed for Chloramphenicol and Tetracycline after observing larger zones of inhibitions with the Kirby-Bauer test. There was no visible growth of Bcc and <i>B cenocepacia</i> at 4°C and 85 °C at any pH and pH 4 across the temperatures. However, subcultures showed bacterial growth the following day. The growth rates increased significantly at 25 and 37°C as well as pH 6 and 7. The average diameters of the zones of inhibitions of PXB, TCC, TIC, C30, and TE30 for Bcc were 1.3, 3.7, 3.1, 2.0, and 1.16 mm and for <i>B. cenocepacia</i> were 0, 1.2, 1.3, 1.1, and 1.6 mm, respectively. Both Bcc and <i>B. cenocepacia</i> were resistant to P10, AM10, E15, and S10. MIC for the E-test of Bcc and <i>B. cenocepacia</i> for IR and C were 0.67 and 10 and 0.88 and 0. 016. mg/L, respectively. MIC and MBC for the dilution test of the C30 and TE30 for Bcc were 1 and 8 and 64 and 128 and <i>B. cenocepacia</i> 8 and 128 and 16 and 128 µg/ml. These bacteria had faster growth rates with no significant difference in their growth under the various temperature and pH conditions used. The research concluded that both Bcc and <i>B. cenocepacia</i> can grow in typical storage conditions such as 4°C and pH 4, without showing any visible signs of growth. This study showed that <i>B. cenocepacia</i> has significantly higher resistance to antibiotics than Bcc. These results are beneficial for developing strategies to prevent <i>Burkholderia</i> cross-contamination in clinical environments.

Alternatively activated macrophages are associated with faster growth rate in vestibular schwannoma

Abstract The variability in vestibular schwannoma growth rates greatly complicates clinical treatment. Management options are limited to radiological observation, surgery, radiotherapy and, in specific cases, bevacizumab therapy. As such, there is a pressing requirement for growth restricting drugs for vestibular schwannoma. This study explored potential predictors of vestibular schwannoma growth in depth, highlighting differences between static and growing vestibular schwannoma to identify potential therapeutic targets. High dimensional imaging was used to characterise the tumour microenvironment of four static and five growing vestibular schwannoma (indicated by volumetric change < 20% or ≥ 20% per year, respectively). Single cell spatial information and protein expression data from a panel of 35 tumour immune-targeted antibodies identified specific cell populations, their expression profiles, and their spatial localisation within the tumour microenvironment. Growing vestibular schwannoma contained significantly more proliferative and non-proliferative alternatively activated tumour-associated macrophages per mm2 compared to static vestibular schwannoma. Furthermore, two additional proliferative cell types were identified in growing and static vestibular schwannoma: transitioning monocytes and Programmed Cell Death Ligand 1 (PD-L1+) Schwann cells. In agreement, growing vestibular schwannoma were characterised by a tumour microenvironment composed of immune-enriched, proliferative neighbourhoods, whereas static vestibular schwannoma were composed of tumour-enriched, non-proliferative neighbourhoods. Finally, classically activated macrophages significantly co-localised with alternatively activated macrophages in static vestibular schwannoma, but this sequestration was reduced in growing vestibular schwannoma. This study provides a novel, spatial characterisation of the immune landscape in growing vestibular schwannoma, whilst highlighting the need for new therapeutic targets that modulate the tumour immune microenvironment.

Functional differences between herbs and woody species in a semiarid Mediterranean plant community: A whole‐plant perspective on growth, nutrient‐use and size

Abstract Despite decades of research, a comprehensive understanding of trait coordination at the whole‐plant level remains elusive. Furthermore, while the link between above‐ground growth rates and leaf traits related to nutrient use is well established, much less is known about the below‐ground compartment. Herbs and woody species exhibit distinct above‐ground growth and nutrient‐use strategies, but whether these differences extend to root traits below‐ground remains unclear. We carried out a common garden experiment with 23 perennials (7 herbs and 16 woody species) coexisting in a Mediterranean shrubland and measured 17 above‐ground and below‐ground traits related to growth, nutrient use and size. We analysed the links between growth rate and nutrient use focusing especially on roots and considering potential differences between herbs and woody species. We also combined plant size data from experimental juveniles and field‐sampled adults to determine the effects of life stage on whole‐plant phenotypic integration. We found a significant relationship between growth rates (both above‐ground and below‐ground) and root nutrient‐use strategies. Root diameter was negatively associated to growth rate only in herbs. Specific root area and root tissue density were positively and negatively correlated with growth rate, respectively, in both herbs and woody species. Moreover, we found significant differences in roots traits between herbs and woody species. Plant growth rate and root nutrient‐use strategies were both positively associated to plant size (height and above‐ground diameter) in juveniles, while a negative relationship was observed in adults. Our work provides insights on the links between whole‐plant growth rate and nutrient‐use strategies in species from a dry Mediterranan shrubland. Specifically, we show that whole‐plant growth rate is strongly associated to root traits, with more acquisitive root nutrient‐use strategies related to faster growth rates, which in turn translated to greater plant size in juveniles but smaller in adults. Our results also highlight root functional differences and contrasting patterns of whole‐plant phenotypic integration between herbs and woody species, offering deeper insights into species coexistence in species‐rich dry Mediterranean environments. Read the free Plain Language Summary for this article on the Journal blog.

Descriptive embryological insights of the colorectum of quail embryos with concern to its functional morphology

BackgroundQuail is an interesting emerging bird species gaining attention in developmental embryology research due to its small size, quick lifespan, and fast growth rate. These characteristics make quail an ideal model for examining the development of the gastrointestinal tract. Consequently, the embryonic development of the colorectum was conducted to provide a comprehensive understanding of its functions in digestion, absorption, and immunity.MethodologyThe morphological anatomy and microscopical structure of the colorectal wall of 74 embryos were studied using light and scanning electron microscopy (SEM). Histologically, the embryos were collected and dissected to extract the intestine. The samples were then fixed in 10% neutral buffer formalin for a minimum of 24 h, and in 2.5% glutaraldehyde buffer formalin for semithin processing and scanning electron microscopy.ResultsThe wall of the embryonic colorectum on the hatching day consisted of three layers; mucosa, muscularis externa, and serosa. Mucosa was a simple layer of columnar enterocytes interspersed with goblet cells that appeared as cub-like shaped cells. Additionally, two ganglionic plexuses were also developed in the colorectal wall; Auerbach plexus (among the colorectal tunica muscularis) and Meissner plexus (submucosal plexus).ConclusionThe morphological characteristics of the quail colorectum at different ages were closely related to its functional features.

Repeat airborne laser scanning to assess canopy height changes in tropical montane forests

Abstract. Tropical montane forests are vital ecosystems globally, preserving biodiversity, carbon stocks, and capturing moisture. We employed two airborne laser scanning (ALS) data sets to study changes in montane forest canopy heights in the Taita Hills, Kenya between 2014/2015 and 2022. We studied two forests, Ngangao (129 ha) and Yale (57 ha), which encompassed both indigenous montane forest and exotic plantations. First, forest types were mapped using field observations and aerial imagery, and then, canopy height changes were analysed using canopy height models at spatial resolution (i.e. the cell size) ranging from 1 m to 20 m. The results revealed overall increase in canopy height in the studied forests, with considerable spatial variation between the forest segments and main tree species. Planted exotic tree species, particularly eucalyptus but also pine and cypress, exhibited faster growth rates than native tree species. Point density differences between the ALS data sets can cause bias to estimation of canopy height changes. However, we observed that reducing the cell size of the canopy height models from 1 m to 10 m and 20 m, decreased the positive trend between point density difference and overestimation of canopy height change due to higher point density of more recent ALS data set. These findings contribute to our understanding on spatial complexity of montane forest ecosystems dynamics and help informing forest monitoring and development of management strategies for fragmented forests in montane regions.

Forest Aboveground Biomass Estimation Based on Unmanned Aerial Vehicle-Light Detection and Ranging and Machine Learning.

Eucalyptus is a widely planted species in plantation forests because of its outstanding characteristics, such as fast growth rate and high adaptability. Accurate and rapid prediction of Eucalyptus biomass is important for plantation forest management and the prediction of carbon stock in terrestrial ecosystems. In this study, the performance of predictive biomass regression equations and machine learning algorithms, including multivariate linear stepwise regression (MLSR), support vector machine regression (SVR), and k-nearest neighbor (KNN) for constructing a predictive forest AGB model was analyzed and compared at individual tree and stand scales based on forest parameters extracted by Unmanned Aerial Vehicle-Light Detection and Ranging (UAV LiDAR) and variables screened by variable projection importance analysis to select the best prediction method. The results of the study concluded that the prediction model accuracy of the natural transformed regression equations (R2 = 0.873, RMSE = 0.312 t/ha, RRMSE = 0.0091) outperformed that of the machine learning algorithms at the individual tree scale. Among the machine learning models, the SVR prediction model accuracy was the best (R2 = 0.868, RMSE = 7.932 t/ha, RRMSE = 0.231). In this study, UAV-LiDAR-based data had great potential in predicting the AGB of Eucalyptus trees, and the tree height parameter had the strongest correlation with AGB. In summary, the combination of UAV LiDAR data and machine learning algorithms to construct a predictive forest AGB model has high accuracy and provides a solution for carbon stock assessment and forest ecosystem assessment.

Comparative study on growth performance and nutritional quality of Eriocheir sinensis between Liaohe River strain and Yangtze River strain under rice field culture environment

This study investigated the similarities and differences in catch rates, growth performance, proximate composition, amino acid content, and fatty acid profiles between the Yangtze River crab and the Liaohe River crab in rice aquaculture systems in northern China. A three-month culture experiment was conducted for the Yangtze River crab and the Liaohe River crab in a rice located at longitude 124.82° and latitude 43.50°. The results revealed that Liaohe River crab had higher catch rate and faster growth rates than Yangtze River crab, and the female crab had earlier ovaries. The edible tissues of Liaohe River crabs contain higher crude protein and fat contents, featuring a more reasonable amino acid composition and structure. Meanwhile, the gonads of male and female Yangtze River crabs had higher PUFA content. In conclusion, under the conditions of this experiment, the Liaohe River crab demonstrated a significant growth advantage.

Enhancing the Stereocomplex Crystallization of PLLA/PDLA Symmetric Blend by Controlling the Degree of Molecular Chain Entanglement

In order to enhance the content of stereocomplex crystals (SC) in poly L-lactic acid (PLLA)/poly D-lactic acid (PDLA) symmetric blend, thereby improving the defects of low crystallinity and poor heat resistance of polylactic acid (PLA)-based materials, the samples with different entanglement degrees were prepared by freezing extration method. The critical overlap concentration of the blend system was quantitatively obtained using an Ubbelohde viscometer. Based on this concentration, samples with a series of concentration gradient were prepared to control the different degrees of molecular chain entanglement inside. The results indicated that the chain disentanglement could greatly increase the content of SC in the blend, whether in the precipitation crystallization or the melt crystallization process. Especially after the isothermal crystallization for 30min at 130oC, the L/D-0.1 sample with the highest degree of disentanglement almost only formed SC, accounting for 95.2% of the total crystallinity. Samples with lower entanglement degree had more crystal nuclei and faster growth rate of formed spherulites. For completely entangled sample L/D-50, the crystal nucleus of homo-crystalls (HC) could be considered as SC. Besides, the Vicat softening temperature (VST) of L/D-0.1 sample increased from 79.9oC of L/D-50 sample to 103.8oC with an obvious increase of 24.9oC. All these results provide new ideas for improving the performance of PLA-based materials and show promising development prospects of green and sustainable polymers.

Analysis of the Ni-5%at.W Alloy Substrate Texture Evolution at Different Strain Levels Using the EBSD Technique.

In this paper, the texture evolution of the Ni-5%W alloy baseband with different strain variables (εvM = 3.9, 4.9, and 5.1) during rolling and annealing was studied using the electron back scattering diffraction (EBSD) technique. The results indicate that after high-temperature annealing at 1150 °C, all three strain levels of the alloy substrates can achieve a strong cubic texture, with a content exceeding 99% (<10°). However, the texture evolution trajectory is significantly influenced by the strain level. When the content of cubic texture in the alloy substrates under strain levels of 3.9 and 5.1 is the same, significant temperature differences exist. Additionally, the different strain levels result in varying nucleation rates and growth rates of cubic texture in the Ni-5%W alloy substrates. The study reveals that in the alloy substrates under strain levels of 3.9 and 4.9, recrystallized cubic grain nuclei grow within a layered structure, resulting in larger grain sizes and lower nucleation rates. In contrast, in the alloy substrates under a strain level of 5.1, recrystallized cubic grain nuclei form from small equiaxed grains, leading to higher nucleation rates but smaller grain sizes, competing with random orientations. In the later stages of nucleation, recrystallized grains in the alloy substrates under a strain level of 5.1 exhibit a significant size advantage, rapidly growing by engulfing randomly oriented grains. Compared to the alloy substrates with lower strain levels, the recrystallized cubic grains in the alloy substrates under a strain level of 5.1 have higher nucleation rates and faster growth rates.

Chromosome level genome assembly of giant freshwater prawn (Macrobrachium rosenbergii)

The giant freshwater prawn (Macrobrachium rosenbergii) has many advantages in aquaculture, such as fast growth rate, short breeding cycle and good nutrition, which makes it a freshwater shrimp with high economic value. Herein, high-quality chromosome-level genome of both female and male prawns were obtained by combining Illumina paired-end sequencing, PacBio single molecule sequencing technique and High-through chromosome conformation capture (Hi-C) technologies. In ZZ male prawn, a final contig assembly of 3118.58 Mb with a N50 length of 956,237 bp was obtained. In WW female prawn, a final contig assembly of 3333.31 Mb with a N50 length of 1,143,555 bp was obtained. The assembled genome sequences from prawns were anchored to 59 chromosomes. Moreover, the sex chromosomes including W chromosome and Z chromosome were generated in prawn with the length of 36.23 Mb and 27.33 Mb, respectively. The sequence similarity of Z chromosome and W chromosome reached to 74.90%. The high-quality genome resource will be useful for further molecular breeding and functional genomic research of giant freshwater prawns.

E-Waste and Hazardous Elements: A Comprehensive Study of Chemical Components and Environmental Threats

Electronic waste, or "e-waste," has grown significantly as a result of the exponential rise of electronic gadgets and is currently one of the waste streams with the fastest rate of growth in the world. Many dangerous substances, such as organic pollutants like brominated flame retardants and heavy metals like lead, mercury, and cadmium, can be found in e-waste. The chemical components of e-waste are thoroughly analyzed in this work, with an emphasis on the identification, measurement, and health and environmental effects of these hazardous materials. According to study, e-waste improper disposal and unofficial recycling can release dangerous substances into the environment, posing a major risk to human health including endocrine disruption and neurological damage. This can result in soil, water, and air contamination. The results highlight the necessity of more advanced recycling technology, stringent laws, and environmentally friendly design principles in order to reduce these hazards. This study adds to the expanding body of information on e-waste and urges immediate action to mitigate the risks that electronic trash poses to the environment and public health.

The efficacy of crossbreeding on reproductive and productive performance in New Zealand White and Flemish Giant rabbits

Crossbreeding is a well-established practice in livestock production aimed at improving reproductive and productive traits. This study evaluated the effects of crossbreeding on rabbits, focusing on comparisons between purebred Flemish Giant (n = 10), New Zealand White (n = 23), and their crossbred offspring (n = 27). Various parameters, including litter size, body weight, growth rate, and mortality, were assessed. The results demonstrated that crossbred rabbits presented a 15% faster growth rate than purebred rabbits, along with the lowest mortality rate and highest total meat output. This phenomenon, attributed to hybrid vigour, effectively blends the large frame of the Flemish Giant with the good litter size of the New Zealand White. Furthermore, statistical analyses, including ANOVA and Tukey‒Kramer’s honestly significant test, confirmed the significant effects of breed class on productivity, body weight, and carcass yield. Growth curves estimated using the Gompertz model highlighted the superior performance of crossbred rabbits under semiarid conditions. Notably, crossbreeding resulted in offspring with the highest dressing percentage and overall improved performance, offering potential advantages for rabbit producers worldwide.

Impacts of Carbon Sequestration Projects on Household Income, and Consumption Expenditure of Smallholder Farmers in Meru County, Kenya

Mitigation of climate change has led to the initiation of carbon sequestration projects in the developing countries in compliance with the Kyoto protocol of 1997. The protocol goal was for industrialized countries to reduce their greenhouse emission by funding carbon projects in developing countries. The study focused on voluntary carbon projects involving smallholder farmer practicing agroforestry. The impacts of these projects on farmers’ household income and consumption expenditure were evaluated. A survey and quasi-experimental research design targeting 207 smallholder farmers was conducted in three wards within Igembe South Sub- County namely Athiru Gaiti, Akachiu and Kiegoi/Antubochiu. Data was collected from secondary sources and primary sources. The data was analyzed using propensity matching techniques. The results showed participation in the carbon sequestration program has a significant impact on the income (t= -3.8081 w/df 205, p=0.0002) at a significant level 0.05. Consumption expenditure of the participant was also significant (t= -4.7034 w/df 205, p= 0.0000). Exotic tree species were more preferred to indigenous trees species. Grevillea robusta (A. Cunn. Ex R. Br) although naturalized, was the most preferred exotic tree species (33.9%) while (17%) of the respondents planted Cussonia holstii (Harms ex Engl.) - an indigenous tree species. Income status of majority (86%, f=77/90) farmers participating in the carbon program increased. Expenditure status of majority (68%, f=61/90) of participating farmers in the project also increased. Savings, inflation, alternative uses led to decrease in consumption expenditure. The study recommends the carbon sequestration project be expanded in more areas, conduction of awareness campaigns to reach more farmers, increase of the carbon credit amount paid to the farmer, the project proponent and partners to continue assisting farmers with tree seedlings for free. The study also recommends use of multipurpose exotic tree species since they have a fast growth rate

Green Technology Innovation and Carbon Emission Performance of the Middle Reaches of the Yangtze River Urban Agglomeration: Mechanism and Spatio-Temporal Evolution

Amid the increasingly severe global climate change situation, green technology innovation has become an important means to promote carbon reduction and achieve the transition to a low-carbon economy. This study aims to systematically analyze the relationship between green technology innovation and carbon emission performance in the urban agglomeration of the middle reaches of the Yangtze River, exploring the degree of coupling and coordination between different cities. Utilizing data from 2011 to 2021, we employ methods such as the Coupling Coordination Degree Model and fixed effects model to achieve our objectives. Our findings reveal that both green technology innovation and carbon emission performance in this region are on an upward trend; however, the growth rate of green technology innovation showed a slowdown in 2021. Notably, there are disparities in the coupling coordination degree among cities, with economically developed areas exhibiting a faster growth rate. Moreover, green technology innovation significantly enhances carbon emission performance, and heterogeneity tests indicate that this impact is even more pronounced in cities with weaker environmental regulations. Despite regional differences, the overall trend remains positive.

The life (history), diet and death of the blackspot shark (Carcharhinus sealei) from South-east Asia

Context The blackspot shark (Carcharhinus sealei) is a small-bodied coastal shark often incidentally caught in fisheries across South-east Asia. Aims This study aimed to document the species’ biology, ecology, fisheries and markets to inform conservation. Methods In total, 103 blackspot sharks from Indonesia (n = 101) and Singapore (n = 2) were examined to determine biological parameters (growth rate, age at maturity, reproductive traits and diet). An interview with a Singaporean seafood supplier gave insight to population trends, fisheries and markets. Key results Males attained a maximum age of 9 years, the smallest mature individual measured 709-mm stretched total length (STL), with 50% reaching maturity at 6.15 years. Females attained a maximum age of 11 years, the smallest mature individual measured 730 mm STL, with 50% reaching maturity at 6.12 years. The species has an overall growth rate (k) of 0.37 year−1. Reproduction was asynchronous, with only two pups produced per litter. Crustaceans dominated the diet of juveniles, whereas bony fishes and cephalopods dominated the diets of adult males and adult females respectively. Conclusions Blackspot sharks have a moderately fast growth rate, but a late age-at-maturity and a low fecundity. Diet differed between the sexes as well as adults and juveniles. Implications The low fecundity and late maturity of blackspot sharks increase their vulnerability to exploitation. Blackspot sharks are now listed on CITES-Appendix II, but mortality may remain high because they are reportedly often caught incidentally.

Growth and shrinkage of tissue sheets on substrates: buds, buckles, and pores

Abstract Many tissues take the form of thin sheets, being only a single cell thick, but millions of cells wide. &amp;#xD;These tissue sheets can bend and buckle in the third dimension. In this work, we investigated the growth and shrinkage of suspended and supported tissue sheets using particle-based simulations. We construct a minimum model, combining particle-based tissue growth and meshless membrane models, to simulate the growth of tissue sheets with mechanical feedback. Free suspended growing tissues exhibit wrinkling when growth is sufficiently fast. Conversely, tissues on a substrate form buds when the adhesion to the substrate is weak and/or when the friction with the substrate is strong. These buds undergo a membrane-mediated attraction and subsequently fuse. The complete detachment of tissues from the substrate and straight buckled bump formation are also obtained at very weak adhesion and/or fast growth rates. In the tissue shrinkage, tissue pores grow via Ostwald ripening and coalescence. The reported dynamics can also be applied in research on the detachment dynamics of different tissues with weakened adhesion.

Coastal &lt;i&gt;Synechococcus&lt;/i&gt; strains can exploit low oxygen habitats

We found that PhycoErythrin-rich &lt;i&gt;Synechococcus&lt;/i&gt; achieved faster growth rates (µ), across the spectral bandwidths from 405 – 730 nm, under 2.5 µM [O&lt;sub&gt;2&lt;/sub&gt;], characteristic of Oxygen Minimum Zones (OMZs), than under 250 µM [O&lt;sub&gt;2&lt;/sub&gt;], whereas PhycoCyanin-rich strain showed generally similar µ under 2.5 and 250 µM [O&lt;sub&gt;2&lt;/sub&gt;]. For PhycoCyanin- and PhycoErythrin-rich &lt;i&gt;Synechococcus&lt;/i&gt;, µ showed also positive linear responses to both Phycobiliproteins:Chlorophyll &lt;i&gt;a&lt;/i&gt;, and to cumulative diel PSII electron flux, although the relations vary across strain and [O&lt;sub&gt;2&lt;/sub&gt;]. Electron transport downstream of Photosystem II was generally higher for both PhycoCyanin- and PhycoErythrin-rich strains under 250 µM [O&lt;sub&gt;2&lt;/sub&gt;], since cyanobacteria show strong capacity for electron flow away from PSII to O&lt;sub&gt;2&lt;/sub&gt;, particularly under excess excitation. Even though electron transport was faster under 250 µM [O&lt;sub&gt;2&lt;/sub&gt;], the PhycoErythrin-rich strain showed a higher growth yield of electron transport under 2.5 µM [O&lt;sub&gt;2&lt;/sub&gt;]. PhycoErythrin-rich &lt;i&gt;Synechococcus&lt;/i&gt; are currently typically found at greater depths, and lower light, than are PhycoCyanin-rich strains, but we suggest that the PhycoErythrin-rich strains are actually limited to lower light by an interaction between light and full air-saturated [O&lt;sub&gt;2&lt;/sub&gt;]. In expanding Oxygen Minimum Zones PhycoErythrin-rich strains will likely exploit higher light niches, across a wider spectral range.