Including Oxygen Concentration Research Articles

Ubiquitous but unique: Water depth and oceanographic attributes shape methane seep communities

AbstractIn the past decade, thousands of previously unknown methane seeps have been identified on continental margins around the world. As we have come to appreciate methane seep habitats to be abundant components of marine ecosystems, we have also realized they are highly dynamic in nature. With a focus on discrete depth ranges across the Cascadia Margin, we work to further unravel the drivers of seep‐associated microbial community structure. We found highly heterogenous environments, with depth as a deterministic factor in community structure. This was associated with multiple variables that covaried with depth, including surface production, prevailing oxygen minimum zones (OMZs), and geologic and hydrographic context. Development of megafaunal seep communities appeared limited in shallow depth zones (~ 200 m). However, this effect did not extend to the structure or function of microbial communities. Siboglinid tubeworms were restricted to water depths > 1000 m, and we posit this deep distribution is driven by the prevailing OMZ limiting dispersal. Microbial community composition and distribution covaried most significantly with depth, but variables including oxygen concentration, habitat type, and organic matter, as well as iron and methane concentration, also explained the distribution of the microbial seep taxa. While members of the core seep microbiome were seen across sites, there was a high abundance of microbial taxa not previously considered within the seep microbiome as well. Our work highlights the multifaceted aspects that drive community composition beyond localized methane flux and depth, where environmental diversity adds to margin biodiversity in seep systems.

Research on time-varying degradation of RC buildings coupled environmental effects and corrosion-induced damage from multi-scale

Corrosion of steel reinforcement in reinforced concrete (RC) buildings is influenced by several factors, including oxygen content, chloride ion diffusion, concrete damage, and humidity. A numerical method is presented to evaluate the long-term structural performance of RC buildings under environmental conditions, which takes into account the impact of steel corrosion-induced damage from multi-scale. The macro-index used for calculation is the level of reinforcement corrosion-induced damage, which considers the inter-connected effects of oxygen content, chloride ion, moisture transport, mechanical stresses, and corrosion uncertainties. In the case of RC beams, corrosion tends to occur more severely on the outer edge near concrete surface. When the corrosion factor is taken as 1.0, the calculated compression side corrosion rate of RC beam agrees well with experimental results. Due to the influence of multiple factors, the corrosion of tension-side reinforcement exhibits some degree of variability. Furthermore, the corrosion of tension-side longitudinal reinforcement in RC beams gradually intensifies from beam ends towards mid-span, with corrosion at mid-span being particularly significant. The relationship between corrosion rate and corrosion time obtained from tests falls within the range of calculation results, and the calculated results from micro-scale align favorably with tests conducted to measure crack width.

HOTFLOOR: A benthic chamber system to simulate warming on the seafloor

AbstractThe frequency of abnormally warm water events is increasing not only in surface waters, but also in subsurface layers, with major impacts on benthic ecosystems. Previous insights on heatwave effects have been obtained through field observations or manipulative laboratory experiments. Here, we introduce a system capable of inducing elevated water temperatures in benthic habitats in situ over several days. The system consists of a commercially available electric boiler, usually applied in domestic underfloor heating, and custom‐designed benthic acrylic glass chambers connected to individual thermostats. Furthermore, the chambers are semi‐open, allowing constant water exchange, maintaining otherwise near‐natural conditions, including oxygen concentrations, while the temperature is elevated. The water exchange can be stopped to facilitate incubations measuring changes in benthic fluxes. We conducted a 15‐d trial study in July 2021 on a bare‐sediment habitat at 2.5 m depth, exposing five chambers to water temperatures 5°C above ambient temperatures for 6 d and comparing with five control chambers. In this assessment, we demonstrate that the temperature control and stability were reliable while maintaining natural oxygen conditions. The modular character of the system permits adaptations for various benthic habitats, facilitating the investigation of elevated temperatures in situ for future climate change scenarios.

Exploring species-level infant gut bacterial biodiversity by meta-analysis and formulation of an optimized cultivation medium

In vitro gut cultivation models provide host-uncoupled, fast, and cost-efficient solutions to investigate the effects of intrinsic and extrinsic factors impacting on both composition and functionality of the intestinal microbial ecosystem. However, to ensure the maintenance and survival of gut microbial players and preserve their functions, these systems require close monitoring of several variables, including oxygen concentration, pH, and temperature, as well as the use of a culture medium satisfying the microbial nutritional requirements. In this context, in order to identify the macro- and micro-nutrients necessary for in vitro cultivation of the infant gut microbiota, a meta-analysis based on 1669 publicly available shotgun metagenomic samples corresponding to fecal samples of healthy, full-term infants aged from a few days to three years was performed to define the predominant species characterizing the “infant-like” gut microbial ecosystem. A subsequent comparison of growth performances was made using infant fecal samples that contained the most abundant bacterial taxa of the infant gut microbiota, when cultivated on 18 different culture media. This growth analysis was performed by means of flow cytometry-based bacterial cell enumeration and shallow shotgun sequencing, which allowed the formulation of an optimized growth medium, i.e., Infant Gut Super Medium (IGSM), which maintains and sustains the infant gut microbial biodiversity under in vitro growth conditions. Furthermore, this formulation was used to evaluate the in vitro effect of two drugs commonly used in pediatrics, i.e., acetaminophen and simethicone, on the taxonomic composition of the infant gut microbiota.

P345 The relationship between virulence of Candida albicans and environmental oxygen concentration

Poster session 3, September 23, 2022, 12:30 PM - 1:30 PMObjectives Candida species are known to colonize human skins and mucous membranes, and cause candidemia under various immunosuppressive conditions. Among these Candida species, C. albicans is reported to be the most frequently isolated species, and could colonize on skins, vaginas, gastrointestinal tracts, and medical devices. Environmental factors including oxygen concentration is thought to affect the capability of colonization and virulence of Candida species; however, most previous research was performed under aerobic condition, and few research focused on hypoxic conditions imitating inside the human bodies. Given these backgrounds, we performed murine experiments by culturing C. albicans under various oxygen conditions to evaluate the effect of environmental oxygen concentration on virulence. Through our studies, we aimed to clarify the actual behavior of C. albicans in the human body.MethodsIn this study, female C57BL/6 mice, 7-8 weeks old, were used and injected via lateral tail vein to cause C. albicans dissemination. Mice were divided into 4 groups according to the pre-culture conditions: aerobic, microaerobic (5% oxygen concentration), microaerobic (1% oxygen concentration), and anaerobic. Under each oxygen condition, C. albicans was grown at 37°C for 2 days on yeast extract peptone dextrose (YPD) agar and then incubated in YPD broth for 16-24 h. After incubation, C. albicans was collected, washed, resuspended in sterile PBS, and injected into each mouse at ∼2.5 × 105 colony-forming units. In this study, one reference strain (SC5314) and one clinically isolated strain (from bloodstream infection) were used. These infected mice were euthanatized 2 or 4 days after injection, and organ (kidneys and brain) fungal burdens were evaluated.ResultsThe kidneys’ fungal burdens were significantly higher in the microaerobic groups than those in the aerobic or anaerobic groups 2 and 4 days after injection. There were no significant differences between 5% oxygen concentration pre-cultured group and 1% oxygen concentration pre-cultured group. On gross examination, disseminated lesion formations were visible in the kidneys of the microaerobic groups. Similarly, the fungal burdens of brain were significantly higher in the microaerobically pre-cultured groups than in the aerobically or anaerobically pre-cultured groups. This tendency was similar for both the reference and clinically isolated strain.ConclusionOur results indicated that C. albicans could become more virulent under hypoxia, especially under microaerobic conditions. We assumed that some virulence factors of C. albicans were elevated under microaerobic conditions. These results implicated that C. albicans could become more virulent under hypoxic conditions in human bodies. In the future, we will continue to evaluate factors related to this change in virulence and pathological analysis of infected organs.

A full year of turbulence measurements from a drift campaign in the Arctic Ocean 2019–2020

Ocean turbulent mixing is a key process in the global climate system, regulating ocean circulation and the uptake and redistribution of heat, carbon, nutrients, oxygen and other tracers. In polar oceans, turbulent heat transport additionally affects the sea ice mass balance. Due to the inaccessibility of polar regions, direct observations of turbulent mixing are sparse in the Arctic Ocean. During the year-long drift expedition “Multidisciplinary drifting Observatory for the Study of Arctic Climate” (MOSAiC) from September 2019 to September 2020, we obtained an unprecedented data set of vertical profiles of turbulent dissipation rate and water column properties, including oxygen concentration and fluorescence. Nearly 1,700 profiles, covering the upper ocean down to approximately 400 m, were collected in sets of 3 or more consecutive profiles every day, and complemented with several intensive sampling periods. This data set allows for the systematic assessment of upper ocean mixing in the Arctic, and the quantification of turbulent heat and nutrient fluxes, and can help to better constrain turbulence parameterizations in ocean circulation models.

Multiple-Vessel-Based Blood Gas Profiles Analysis Revealed the Potential of Blood Oxygen in Mammary Vein as Indicator of Mammary Gland Health Risk of High-Yielding Dairy Cows.

Simple SummaryThe objective of the study was to realize the function of blood gas parameter in relation to the health of high-yielding dairy cows. The study showed that most blood gas parameters differ across the three vessels (coccygeal artery, coccygeal vein, and mammary vein). The associations of oxygen-related variables in the mammary vein are negatively correlated with the levels of malondialdehyde, lactate dehydrogenase, and plasmin in the milk. In the present study, we used blood gas profile to identify the mammary gland health condition in lactating dairy cows.The blood gas profile is a routine method in the rapid disease diagnosis of farm animals, yet its potential in evaluating mammary health status of dairy cows remains to be investigated. This study was conducted to learn the potential of the blood gas parameter regarding the mammary gland health status in lactating dairy cows. Twenty animals were divided into two groups, the H-SCC group (milk SCC > 122 k/mL) and L-SCC group (milk SCC < 73.8 k/mL), to compare blood gas profiles from different blood vessels and to identify the key parameters associated with milk somatic cell count. H-SCC cows are higher in malondialdehyde content, but lower in SOD and T-AOC activities in the milk, compared to the L-SCC group. In terms of blood gas parameters, most differ across the three vessels, including K+, CO2 pressure, O2 pressure, HCO3−, base excess in the extracellular fluid compartment, and saturation of O2. The Pearson correlation analysis showed that oxygen-related variables in the mammary vein, including oxygen concentrations, O2 pressure, and saturation of O2, are negatively correlated with levels of malondialdehyde, lactate dehydrogenase, and plasmin in the milk. Our study revealed that oxygen-related variables in the mammary vein can be a marker in suggesting mammary-gland health status in high-yielding cows.

Clinical Study on Pathogenic Factors and Screening Strategies of Retinopathy of Prematurity

Objective: To investigate the incidence of retinopathy of prematurity (ROP), analyze the risk factors of ROP, and put forward effective screening strategies, to reduce its incidence. Background: Retinopathy of prematurity (ROP) is an eye disease that can happen in new born premature (born early) babies or have weigh less than 3 pounds at birth. ROP happens when abnormal blood vessels grow in the retina. There are multiple risk factors, which are causing the ROP. In our study we will analyses the risk factors of ROP. Methods: From February 2016 to August 2021, 190 premature infants in the neonatal intensive care unit (NICU) who received inpatient care and ophthalmic screening was selected as study subjects. ROP group (n = 32) and non-ROP group (n = 158) were selected, and the clinical data of the two groups were compared. Including oxygen concentration, mechanical ventilation, broncho pulmonic dysplasia, delivery mode (cesarean section, vaginal delivery), blood transfusion, anemia, gestational diabetes, gestational hypertension, fetal distress, preterm birth weight, gestation age, etc. Women were divided into two groups according to whether they had gestational diabetes mellitus (GDM) or not: gestational diabetic (n = 38) and non-gestational diabetics (n = 152). Age, pregnancy times, birth times, oxygen inhalation, birth weight, and gestational age were compared between the two groups. The X2 test for counting data and the t-test for measuring data are then conducted according to the distribution characteristics of the data, The correlation analysis between ROP and a single risk factor was performed by chi-square test, and the analysis of the correlation between many risk factors and ROP was conducted by Logistic regression analysis. Results: 1) The incidence of ROP in the GDM group was higher than that in the non-GDM group (P P > 0.05). 3) Univariate analysis showed that oxygen use, birth weight, gestational age, bronchopulmonary dysplasia, pregnancy-induced hypertension, and fetal distress in the ROP group and non-ROP group were statistically significant (P P > 0.05). 4) Logistic multivariate analysis showed that oxygen use, gestational hypertension, diabetes mellitus during pregnancy, fetal distress, bronchopulmonary dysplasia, birth weight, and gestational age were the main risk factors for ROP. Conclusion: 1) Gestational diabetes mellitus is a high-risk factor for ROP. 2) Oxygen inhalation, birth weight, and gestational age are related to the occurrence and development of ROP. 3) In determining the initial screening time for ROP.

Effects of Hypoxia on Cerebral Microvascular Angiogenesis: Benefits or Damages?

Cerebrovascular microcirculation is essential for maintaining the physiological functions of the brain. The brain can be protected from stress injury by remodeling the microcirculation network. Angiogenesis is a type of cerebral vascular remodeling. It is an effective approach to improve the blood flow of the cerebral microcirculation, which is necessary for preventing and treating various neurological disorders. Hypoxia is one of the most important regulators of angiogenesis, affecting the sprouting, proliferation, and maturation stages of angiogenesis. Moreover, hypoxia negatively affects cerebral vascular tissue by impairing the structural and functional integrity of the blood-brain barrier and vascular-nerve decoupling. Therefore, hypoxia has a dual effect on blood vessels and is affected by confounding factors including oxygen concentration, hypoxia duration, and hypoxia frequency and extent. Establishing an optimal model that promotes cerebral microvasculogenesis without causing vascular injury is essential. In this review, we first elaborate on the effects of hypoxia on blood vessels from two different perspectives: (1) the promotion of angiogenesis and (2) cerebral microcirculation damage. We further discuss the factors influencing the dual role of hypoxia and emphasize the benefits of moderate hypoxic irritation and its potential application as an easy, safe, and effective treatment for multiple nervous system disorders.

Advanced approach for oxygen transport and crystallization front calculation in Cz silicon crystal growth

Modeling of oxygen transport during Czochralski (Cz) silicon crystal growth still is a big challenge due to oxygen evacuation from the melt free surface, affected by strong anisotropy of turbulent mass transport. To predict the crystal oxygen concentration and crystallization front geometry with reasonable accuracy usually a 3D unsteady LES or DNS approach is required which demands significant computation resources and time. We present a new steady turbulence model using the extended hypothesis for modeling the Reynolds stress tensor, which accounts for different mechanisms of Reynolds stresses anisotropy and can be used in fast 2D engineering calculations. Several 8″ silicon crystals were grown in EKZ 3500 furnace with varying operating parameters. Wafers have been cut from different parts of the crystals and analyzed using the Fourier-transform infrared spectroscopy (FTIR) for oxygen concentration in facilities of Fraunhofer CSP and iTechSolar. The comparison between experimental and calculated results, which include oxygen concentration and interface deflection, is discussed in details. Time-averaged Reynolds stress tensor components as well as the turbulent heat fluxes components are compared between unsteady LES and steady RANS approaches.

Does Oxygen Content Play a Role in Spontaneous Closure of Perimembranous Ventricular Septal Defects?

(1) Background: the impact of a series of laboratory parameters (haemoglobin, haematocrit, foetal haemoglobin, peripheral oxygen saturation, iron, transferrin, ferritin, and albumin) on perimembranous ventricular septal defects spontaneous healing was tested. (2) Methods: one hundred and seven patients were enrolled in the study (57% males; mean age 2.1 ± 0.4 years) and were subsequently subdivided into two groups: self-healing (n = 36) and in need of intervention (n = 71). Self-healing subjects were defined on the basis of an absence of residual shunts at colorDoppler across the previous defect. (3) Results: no statistically significant differences were reported in the size of perimembranous ventricular septal defects between the two groups (p = ns). Conversely, prevalence of anaemia was significantly higher in those requiring intervention than in the self-healing group (p < 0.03), while haemoglobin, iron, ferritin, and albumin levels were lower (p < 0.001, p < 0.05, p < 0.02, p < 0.007, respectively). In multivariable linear regression analysis, only haemoglobin and albumin were found to be associated with spontaneous closure (p < 0.005 and p < 0.02, respectively). In multiple logistic regression analysis, haemoglobin independently increased the probability of self-healing of perimembranous ventricular septal defects (p = 0.03). All patients needing an interventional closure of perimembranous ventricular septal defects presented with haemoglobin <12.7 g/dL. (4) Conclusion: the self-resolution of perimembranous ventricular septal defects seems to rely on numerous factors, including oxygen content, which is likely to promote cell proliferation as well as tissue regeneration. Haemoglobin blood concentration seems to influence the natural history of perimembranous ventricular septal defects and improvement of anaemia by supplementation of iron intake might represent a simple and reliable method to promote self-healing.

Effects of reuse on the properties of tantalum powders and tantalum parts additively manufactured by electron beam powder bed fusion

The cost of additively manufactured tantalum parts can be effectively lowered by reusing or recycling tantalum powder. To evaluate the effects of reuse of the tantalum powder on the properties of tantalum parts and scaffolds, this study investigated the characteristics of tantalum powder during cycling, including oxygen content, particle morphology, apparent density, tap density, and flowability. Besides, the influence of reuse time on the mechanical properties of electron beam powder bed fusion (EB-PBF) fabricated tantalum parts and scaffolds was studied with tantalum powder reused more than 30 cycles. The results indicated that particle size distribution of the tantalum powder was nearly unchanged with the increase of cycle number, accordingly apparent density, tap density, and fluidity. While the powder became less spherical with increasing reuse times and some particles showed noticeable distortion and rough surface after being reused 25 times. Moreover, the oxygen content of the tantalum powder increased progressively with increasing reuse times, leading to the decrease of plasticity of the dense tantalum after 15 reuse cycles, and some potential micro-defects appeared in the tantalum samples fabricated from EB-PBF process. However, the tensile strength of dense tantalum parts was not sensitive to the number of uses within the research range.

An Experimental Study on Kerosene Spray Combustion Under Conventional and Hot-Diluted Conditions

ABSTRACT The combustion of kerosene spray under hot-diluted conditions and conventional conditions was experimentally investigated. By examining flame photographs, chemiluminescence images, and in-field temperature measurements, the separate effect of different variables including oxygen concentration, temperature and velocity of the co-flowing air, fuel flow rate and injection pressure, and eventually the type of spray nozzle on multiple parameters such as flame stability, structure, luminosity, temperature field, and qualitative CH radical distribution, as well as HCO and NO2 with lower precision, in the reaction region, have been studied. It was observed that an increment in injection pressure and co-flow temperature enhances the spray flame stability, while dilution exacerbates it. Also, a solid cone spray pattern with a lower spray angle has better stability than hollow cone ones with a higher spray angle. Moreover, it was noted that liquid fuels, compared to gaseous fuels, require higher preheating temperatures, for the same dilution level, to engender a stable flame. For combustion of spray in conventional conditions, a double-flame structure was observed consisting of a bluish section at the leading edge emerging into a yellowish sooting trail. An increase in co-flow velocity, as well as injection pressure, strengthens the inner flame front, whereas raising the co-flow temperature or diluting the oxidant, deteriorates the inner flame front. In the case of highly preheated air (without dilution), the flame liftoff height is reduced to as close to the atomizer as a few millimeters, forming a single flame structure similar to gaseous flames. In this case, the peak temperature was considerably higher than the conventional combustion, yet the gain was much lower than the preheating level. Combined effects of preheating and dilution alter the spray flame structure in a way that the flame volume is reduced, the temperature field has become more homogeneous, the peak temperature is limited to less than 1500 K, and temperature fluctuations have significantly decreased, seemingly approaching MILD combustion regime conditions.

Mixed Ionic-Electronic Conductivity, Redox Behavior and Thermochemical Expansion of Mn-Substituted 5YSZ as an Interlayer Material for Reversible Solid Oxide Cells.

Manganese-substituted 5 mol.% yttria-stabilized zirconia (5YSZ) was explored as a prospective material for protective interlayers between electrolyte and oxygen electrodes in reversible solid oxide fuel/electrolysis cells. [(ZrO2)0.95(Y2O3)0.05]1−x[MnOy]x (x = 0.05, 0.10 and 0.15) ceramics with cubic fluorite structure were sintered in air at 1600 °C. The characterization included X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), thermogravimetry and dilatometry in controlled atmospheres, electrical conductivity measurements, and determination of oxygen-ion transference numbers by the electromotive force (EMF) technique. Mn-substituted 5YSZ solid solutions exhibit variable oxygen nonstoichiometry with manganese cations in a mixed 2+/3+ oxidation state under oxidizing conditions. Substitution by manganese gradually increases the extent of oxygen content variation on thermal/redox cycling, chemical contribution to thermal expansion and dimensional changes on reduction. It also deteriorates oxygen-ionic conductivity and improves p-type electronic conductivity under oxidizing conditions, leading to a gradual transformation from predominantly ionic to prevailing electronic transport with increasing x. Mn2+/3+→Mn2+ transformation under reducing atmospheres is accompanied by the suppression of electronic transport and an increase in ionic conductivity. All Mn-substituted 5YSZ ceramics are solid electrolytes under reducing conditions. Prolonged treatments in reducing atmospheres, however, promote microstructural changes at the surface of bulk ceramics and Mn exsolution. Mn-substituted 5YSZ with 0.05 ≤ x < 0.10 is considered the most suitable for the interlayer application, due to the best combination of relevant factors, including oxygen content variations, levels of ionic/electronic conductivity and thermochemical expansion.

Influencing factors and mechanisms involved in the ignition of low-rank coal: Implications for spontaneous combustion

Understanding the ignition mechanism of spontaneous combustion is critical for preventing it. In this work, the effects of different test conditions including oxygen concentration, heating rate, oxidation carrier gas flow rate, and sample amount on the ignition temperature were studied with a thermal gravimetric analyzer. Further, the effects of coal properties on the ignition temperature were also investigated using 15 different low-rank coals. A heterogenous ignition model was proposed that small amount of active species is the key material leading to ignition. The heterogenous ignition mechanism well explained the complex effects of test conditions and coal properties on the ignition temperature of low-rank coal. Finally, an empirical formula for predicting the ignition temperature was derived for the rapid assessment of the spontaneous combustion potential.

Macrofaunal diversity and community structure of the DeSoto Canyon and adjacent slope

Northern Gulf of Mexico canyons are centers of organic matter accumulation and biodiversity, but studies of their finer-scale (sub-100 km) ecological patterns are scarce. Detailed sampling of macrofauna within the DeSoto Canyon was undertaken along 3 depth transects on the canyon wall, axis, and adjacent slope. Sediment, terrain, and water mass parameters were also compiled for the same stations. Within the canyon, macrofaunal abundance decreased, evenness increased, and richness followed the expected parabolic curve with depth, peaking at 1100 m. Cluster analysis identified 3 canyon depth groups that conformed to established bathymetric boundaries for the non-canyon Gulf of Mexico slope: Group I at &lt;500 m, Group II at 669-1834 m, and Group III at &gt;2000 m. Explanatory environmental models indicate that canyon community structure was strongly correlated with oxygen concentration and fluorescence, with a weaker potential influence from any of salinity, particulate organic carbon, sediment organic carbon, or slope. Comparisons of the habitats indicated that abundances were highest on the canyon wall. Slope community structure differed from that of either of the canyon habitats. Environmental models consisted of single variables including oxygen concentration, sediment organic carbon, slope, and temperature with similar explanatory values. Community differences within the canyon and between the canyon and adjoining slope contradict previous findings of a single faunal zone for the whole study area. Factors that may contribute to inter-habitat heterogeneity include potential hydrocarbon seepage, organically enriched sediment deposits along channels, or remnant influence from the Deepwater Horizon spill, warranting more research into this dynamic ecosystem.

Single-cell expression profiles of ACE2 and TMPRSS2 reveals potential vertical transmission and fetus infection of SARS-CoV-2.

Morbidity and mortality of coronavirus disease 2019 (COVID-19) is age-dependent. It remains unclear whether vertical severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs during pregnancy and how such infection will affect fetal development. Here, we performed single-cell transcriptomic analysis of placenta and other tissues from fetuses in comparison with those from adults using public-available datasets. Our analysis revealed that a very small proportion of trophoblast cells expressed the Angiotensin I Converting Enzyme 2 (ACE2) gene, suggesting a low possibility of vertical transmission of SARS-CoV-2 from mother to fetus during pregnancy. We found that the fetal adrenal gland, heart, kidney and stomach were susceptible to SARS-CoV-2 infection, because these organs contained cell clusters that expressed high levels of the ACE2 gene. In particular, a higher proportion of ACE2-expressing cell clusters in the adrenal gland and kidney also expressed the Transmembrane Serine Protease 2 (TMPRSS2) gene compared with other organs. Surprisingly, ACE2-expressing type II alveolar (AT2) equivalent cells were absent in fetal lungs. This is in sharp contrast to adult lungs. As ACE2 expression is regulated by various conditions, including oxygen concentration, inflammation and smoking, caution is warranted to avoid triggering potential ACE2 expression in fetal and placental tissue.

Distribution of planktonic foraminifera in the subtropical South Atlantic: depth hierarchy of controlling factors

Abstract. Temperature appears to be the best predictor of species composition of planktonic foraminifera communities, making it possible to use their fossil assemblages to reconstruct sea surface temperature (SST) variation in the past. However, the role of other environmental factors potentially modulating the spatial and vertical distribution of planktonic foraminifera species is poorly understood. This is especially relevant for environmental factors affecting the subsurface habitat. If such factors play a role, changes in the abundance of subsurface-dwelling species may not solely reflect SST variation. In order to constrain the effect of subsurface parameters on species composition, we here characterize the vertical distribution of living planktonic foraminifera community across an east–west transect through the subtropical South Atlantic Ocean, where SST variability was small, but the subsurface water mass structure changed dramatically. Four planktonic foraminifera communities could be identified across the top 700 m of the transect. Gyre and Agulhas Leakage surface faunas were predominantly composed of Globigerinoides ruber, Globigerinoides tenellus, Trilobatus sacculifer, Globoturborotalita rubescens, Globigerinella calida, Tenuitella iota, and Globigerinita glutinata, and these only differed in terms of relative abundances (community composition). Upwelling fauna was dominated by Neogloboquadrina pachyderma, Neogloboquadrina incompta, Globorotalia crassaformis, and Globorotalia inflata. Thermocline fauna was dominated by Tenuitella fleisheri, Globorotalia truncatulinoides, and Globorotalia scitula in the west and by G. scitula only in the east. The largest part of the standing stock was consistently found in the surface layer, but SST was not the main predictor of species composition either for the depth-integrated fauna across the stations or at individual depth layers. Instead, we identified a pattern of vertical stacking of different parameters controlling species composition, reflecting different aspects of the pelagic habitat. Whereas productivity appears to dominate in the mixed layer (0–60 m), physical properties (temperature, salinity) become important at intermediate depths and in the subsurface, a complex combination of factors including oxygen concentration is required to explain the assemblage composition. These results indicate that the seemingly straightforward relationship between assemblage composition and SST in sedimentary assemblages reflects vertically and seasonally integrated processes that are only indirectly linked to SST. It also implies that fossil assemblages of planktonic foraminifera should also contain a signature of subsurface processes, which could be used for paleoceanographic reconstructions.

Hatchetfishes (Stomiiformes: Sternoptychidae) biodiversity, trophic ecology, vertical niche partitioning and functional roles in the western Tropical Atlantic

Species of the family Sternoptychidae (hatchetfishes) occur worldwide and play critical roles by sequestering carbon, recycling nutrients, and acting as a key trophic link between epipelagic primary consumers and higher trophic levels in marine ecosystems. Nevertheless, basic knowledge on their ecology is still lacking and their functional ecology remains understudied with respect to composition, organization, functions and environment interactions. Here we integrated comprehensive information collected in the western Tropical Atlantic on the diversity, abundance, distribution and trophic ecology of hatchetfishes, including physicochemical features of their habitats and extensive carbon and nitrogen stable isotope data on its main prey groups. On this basis we defined five functional groups of hatchetfishes with different diet preference, isotopic composition, and vertical abundance peaks and reveal a possible high resource partitioning. Additionally, these species might have a different feeding tie chronology. Hence, hatchetfishes segregate in different ecological groups responding differently to environmental constraints including oxygen concentration and presenting diverse functional roles. As deep-sea species that migrate to epipelagic waters, hatchetfishes may play a key role in the transfer of sub-surface photoassimilated carbon to deeper waters, a pathway through which the effects of climate change at the surface are transferred to the deep ocean. Moreover, as consumers of gelatinous organisms, these species convert “gelatinous energy” into “fish energy” readily usable by higher trophic levels, including endangered and commercially important species. This is a crucial trophic relationship that has been historically underestimated due to methodology limitations (e.g., quickly digested gelatinous organisms were probably underestimated in previous studies, based solely on stomach contents). Considering in ecosystem models this trophic relationship, as well as the functional organization of hatchetfishes, is important to properly answer key ecological questions including resource use, carbon transportation, and influence of mesopelagic community in climate change process.

Control and design of biosystems.

Biosystems are dynamic networks driven by cross-scale interactions between molecules, cells, tissues, organs and organisms. Recent advances in our understanding of the spatiotemporal regulation and organization of biosystems have stimulated exploration of novel approaches to control and design biosystems at multiple biological scales. Such new approaches include artificial cell synthesis, generation of embryoids/organoids, reconstitution and manipulation of life events such as aging and reproduction, and multidisciplinary approaches using theoretical and engineering technologies. These control-and-design methodologies are expected to open up a new avenue to understanding life events as well as to provide the basis for novel design strategies in medical sciences. This review issue of DGD aims at collecting current results on such challenges. Hayashi, Shimamoto, and Nagamatsu (2020) review environmental factors involved in the control of oocyte dormancy, including oxygen concentrations and ECM-mediated mechanical stress. Uncovering the mechanism of oocyte dormancy will contribute to design novel approaches in reproductive biology and therapy. Hagiwara and Isabel (2020) introduce recent advancements in engineering technologies to control the microenvironment during cell culture, which will provide experimental advantages for maturing organoids as well as for measuring their self-organization process. Funano, Tanaka, and Tanaka (2020) describe a newly developed methodology for designing cell patterns on a dish/substrate at a high resolution of under a few micrometers with long-term stability, and also mention those biological applications. Naoki and Matsui (2020) introduce theoretical approaches to investigate noise-resistant spatial-patterning mechanisms during organ development, taking somitogenesis as an example. Seirin-Lee (2020) also reviews, from the theoretical perspective, the mechanism of cell polarity formation, which plays a critical role in controlling asymmetric cell division. This issue is based on the discussions during the RIKEN BDR symposium 2019 “Control and Design of Biosystems” held on March 25th to 27th, 2019 in RIKEN Center for Biosystems Dynamics Research, Kobe, Japan. RIKEN BDR was launched on April 1, 2018, as a new RIKEN center succeeding the Center for Developmental Biology, Center for Life Science Technologies, and Quantitative Biology Center. The BDR symposium continues in the footsteps of the RIKEN CDB symposium series that was launched in 2003, to foster the global and timely scientific exchange among researchers in the fields of biological studies related with all life stages.