SARS-CoV2 (COVID-19) infection: is fetal surgery in times of national disasters reasonable?

Even though the global COVID-19 pandemic may affect how medical care is delivered in general, most countries try to maintain steady access for women to routine pregnancy care, including fetal anomaly screening. This means that, also during this pandemic, fetal anomalies will be detected, and that discussions regarding invasive genetic testing and possibly fetal therapy will need to take place. For patients, concerns about Severe Acute Respiratory Syndrome-Corona Virus 2 will add to the anxiety caused by the diagnosis of a serious fetal anomaly. Yet, also for fetal medicine teams the situation gets more complex as they must weigh up the risks and benefits to the fetus as well as the mother, while managing a changing evidence base and logistic challenges in their healthcare system.     

Population structure of two deep-sea hydrothermal vent gastropods from the Juan de Fuca Ridge, NE Pacific

The gastropods Lepetodrilus fucensis and Depressigyra globulus are abundant faunal components of animal communities at deep-sea hydrothermal vents along the Juan de Fuca Ridge in the NE Pacific. The population structure and recruitment pattern of both species were studied using modal decomposition of length–frequency distributions. Gastropod populations were collected from Axial Volcano and Endeavour Segment in 2002 and 2003. Polymodal size–frequency distributions, particularly at Axial Volcano vent sites, suggest a discontinuous recruitment pattern for D. globulus. In contrast, there were no distinct peaks visible in the distributions of L. fucensis, suggesting a continuous recruitment pattern for this species. For both species, distributions were positively skewed towards the smaller length–classes, implying post-settlement mortality is high. However, variations in growth, due to short- and long-term variability in environmental conditions in the hydrothermal vent habitat, as well as biological interactions, may also be influencing the distribution and abundance of subsequent life-history stages. Using maximum shell lengths from populations of known ages, the growth rate of L. fucensis was estimated as 9.6 μm day⁻¹, indicating adulthood would be reached in ∼1 year. Our results suggest that, despite occupying the same habitat, abundance and population structure are regulated by different biotic and abiotic processes in L. fucensis and D. globulus.     

Photosynthetic resource-use efficiency and demographic variability in desert winter annual plants

We studied a guild of desert winter annual plants that differ in long-term variation in per capita reproductive success (lb, the product of per capita survival from germination to reproduction, l, times per capita reproduction of survivors, b) to relate individual function to population and community dynamics. We hypothesized that variation in lb should be related to species' positions along a trade-off between relative growth rate (RGR) and photosynthetic water-use efficiency (WUE) because lb is a species-specific function of growing-season precipitation. We found that demographically variable species have greater RGR and greater leaf carbon isotope discrimination (Delta, a proxy inversely related to WUE). We examined leaf nitrogen and photosynthetic characteristics and found that, in this system, variation in Delta is a function of photosynthetic demand rather than stomatal regulation of water loss. The physiological characteristics that result in low Delta in some species may confer greater photosynthetic performance during the reliably moist but low temperature periods that immediately follow winter rainfall in the Sonoran Desert or alternatively during cool periods of the day or early growing season. Conversely, while species with high Delta and high RGR exhibit low leaf N, they have high biomass allocation to canopy leaf area display. Such trait associations may allow for greater performance during the infrequent conditions where high soil moisture persists into warmer conditions, resulting in high demographic variance. Alternatively, high variance could arise from specialization to warm periods of the day or season. Population dynamic buffering via stress tolerance (low RGR and Delta) correlates negatively with buffering via seed banks, as predicted by bet-hedging theory. By merging analyses of population dynamics with functional trait relationships, we develop a deeper understanding of the physiological, ecological, and evolutionary mechanisms involved in population and community dynamics.     

Global-scale environmental transport of persistent organic pollutants

In order to realistically simulate both chemistry and transport of atmospheric organic pollutants, it is indispensable that the applied models explicitly include coupling between different components of the global environment such as atmosphere, hydrosphere, cryosphere and soil system. A model with such properties is presented.

The atmospheric part of the model is based on the equations in a general contravariant form which permits easy changes of the coordinate system by redefining the metric tensor of a specifically employed coordinate system. Considering a need to include explicitly the terrain effects, the terrain following spherical coordinate system is chosen from among many possible coordinate systems. This particular system is a combination of the Gal-Chen coordinates, commonly employed in mesoscale meteorological models, and the spherical coordinates, typical for global atmospheric models.

In addition to atmospheric transport, the model also simulates the exchange between air and different types of underlying surfaces such as water, soil, snow, and ice. This approach permits a realistic representation of absorption and delayed re-emission of pollutants from the surface to the atmosphere and, consequently, allows to capture hysteresis-like effects of the exchange between the atmosphere and the other components of the system. In this model, the most comprehensive numerical representation of the exchange is that for soil. In particular, the model includes a realistic soil module which simulates both diffusion and convection of a tracer driven by evaporation from the soil, precipitation, and gravity.

The model is applied to a long-term simulation of the transport of pesticides (hexachlorocyclohexanes in particular). Emission fluxes from the soil are rigorously computed on the basis of the realistic data of the agricultural application. All four modelled systems, i.e. atmosphere, soil, hydrosphere and cryosphere, are driven by objectively analysed meteorological data supplemented, when necessary, by climatological information. Therefore, the verification against the observed data is possible. The comparison of the model results and the observations taken at remote stations in the Arctic indicates that the presented global modelling system is able to capture both trends and short-term components in the observed time series of the concentrations, and therefore, provides a useful tool for the evaluation of the source–receptor relationships.     

Differentiation in low molecular weight organic acids exudation into rhizosphere and their creation in Ulmus laevis Pall organs treated by As – pot experiment

Two-year old Ulmus laevis Pall (U. laevis) seedlings were cultivated in a three-month hydroponic experiment with inorganic (aresenite – As(III) and arsenate – As(V)) and organic (dimethylarsenic acid – DMA(V)) arsenic forms, at 0.06 and/or 0.6?mM concentrations. Further, the profile and content of total low molecular weight organic acids (LMWOAs) were investigated in the rhizosphere, roots and leaves of U. laevis. Obtained results showed that the addition of As(III) or As(V) individually or in a mixture led to increased LMWOAs concentration in the rhizosphere, especially of oxalic and malonic acids, in comparison to the control, while in roots the overall content of the profiled LMWOAs decreased. In both rhizosphere and roots, addition of the DMA(V) form resulted in the inhibition of LMWOAs exudation into the rhizosphere and their creation in plant roots. Leaves were characterised by a higher content of LMWOAs than in the rhizosphere and roots for all experimental systems, where the profile and content of LMWOAs was strictly correlated with the analysed As forms. Our study indicated that creation of LMWOAs in U. laevis organs and their exudation to the rhizosphere could be responsible for the As toxicity tolerance of the plants.     

Residues of fluoroquinolones in marine aquaculture environment of the Pearl River Delta, South China

Concentrations and distributions of selected fluoroquinolones (norfloxacin, ciprofloxacin and enrofloxacin) in water, sediments and nine kinds of fish species collected from 6 sites in two marine aquaculture regions of the Pearl River Delta, China, were analyzed by using high-performance liquid chromatography with fluorescence detector (HPLC). The results showed that the concentrations of ciprofloxacin and enrofloxacin were below the limits of quantification (LOQ) in all water samples except for norfloxacin. Norfloxacin and ciprofloxacin concentrations ranged from 1.88 to 11.20 ng g⁻¹ dry wt, 0.76–2.42 ng g⁻¹ dry wt in sediments collected from the Dapeng’ao region (sites 1–3) and ranged from 2.31 to 4.75 ng g⁻¹ dry wt, 1.26–1.76 ng g⁻¹ dry wt in sediments collected from the Hailing Island region (sites 4–6), respectively. However, no enrofloxacin was found in all sediment samples. The three fluoroquinolones (FQs) were detected in all fish samples, and the concentrations were higher in liver tissues than those in muscle tissues. The levels of norfloxacin were higher than ciprofloxacin and enrofloxacin in both liver and muscle tissues. Among the nine marine fish species, Siganus fuscescens from Hailing Island had a significantly high level of norfloxacin in liver tissue (254.58 ng g⁻¹ wet wt), followed by Sparus macrocephalus (133.15 ng g⁻¹ wet wt) from Dapeng’ao, and the lowest value was Lutianus argentimaculatus (5.18 ng g⁻¹ wet wt) from Hailing Island. The obtained results of FQs in present study do not represent a risk to the human health in Guangdong coastal area, based on the maximum residue limits (MRLs) established by Chinese Government and the acceptable daily intake (ADI) recommended by the Food and Agriculture Organization and World Health Organization (FAO/WHO).     

Shaving of axillary hair has only a transient effect on perceived body odor pleasantness

In contrast to other apes, humans have relatively greater amounts of armpit hair, which is thought to retain signaling molecules. Although armpit shaving is widespread cross-culturally, its effect on body odor has been little investigated. In four experiments, we tested the effect of shaving and the subsequent regrowth of axillary hair. Armpit odors were collected from men who regularly shaved (group S) or who had never shaved (group N) their armpits before. The samples were subsequently rated by women for intensity, pleasantness, and attractiveness. In Experiments I, II (group N) and III, subjects firstly shaved one armpit and then let the hair regrow over 6 or 10 weeks. In Experiments I, II (group S) and IV, subjects shaved both armpits before the sampling and subsequently shaved one armpit during the same period, leaving the second armpit unshaved. Odors of the shaved armpits were rated more pleasant, attractive, and less intense compared to the unshaved armpits (Experiment I (group N)). However, no significant differences found in Experiments II and III (group N) suggest the effect of shaving is relatively minor. Moreover, there were no significant differences in odor comparing unshaved armpits with armpits after 1 week of regrowth (Experiments I, II (group N) and III) or comparing regularly shaved armpits with armpits after 1 or 3 weeks of regrowth (Experiments I, II (group S) and IV). The odor of shaved armpits was rated significantly more attractive compared to the armpits where hair had been regrowing for 6 or 10 weeks.     

Life-history correlates of extinction risk and recovery potential

Extinction risk is inversely associated with maximum per capita population growth rate (r(max)). However, this parameter is not known for most threatened species, underscoring the value in identifying correlates of r(max) that, in the absence of demographic data, would indirectly allow one to identify species and populations at elevated risk of extinction and their associated recovery potential. We undertook a comparative life-history analysis of 199 species from three taxonomic classes: Chondrichthyes (e.g., sharks; n = 82), Actinopterygii (teleost or bony fishes; n = 47), and Mammalia (n = 70, including 16 marine species). Median r(max) was highest for (and similar between) terrestrial mammals (0.71) and teleosts (0.43), significantly lower among chondrichthyans (0.26), and lower still in marine mammals (0.07). Age at maturity was the primary (and negative) correlate of r(max). In contrast, although body size was negatively correlated with r(max) in chondrichthyans and mammals, evidence of an association in teleosts was equivocal, and fecundity was not related to r(max) in fishes, despite recurring assertions to the contrary. Our analyses suggest that age at maturity can serve as a universal predictor of extinction risk in fishes and mammals when r(max) itself is unknown. Moreover, in contrast to what is generally expected, the recovery potential of teleost fishes does not differ from that of terrestrial mammals. Our findings are supportive of the application of extinction-risk criteria that are based on generation time and that are independent of taxonomic affinity.