bluuebunny/crossref_metadata_2025 huggingface dataset:
Linking the physiologic and phylogenetic successions in free‐living bacterial communities along an estuarine salinity gradient
Authors: del Giorgio Paul A. , Bouvier Thierry C.
Published: June 2010

In this paper we assess whether the bacterial compositional succession that occurs along an estuarine salinity gradient is accompanied by changes in both community and single‐cell metabolic activity in the free‐living bacterioplankton. In addition, we explore whether up‐ and downstream estuarine communities, which are dominated by different phylogenetic groups, show distinct patterns in single‐cell activity and characteristics. We have characterized the physiological succession of the bacterioplankton along the salinity gradient in the Choptank River Estuary (Maryland), using a combination of indices of single‐cell activity, which include respiratory activity, membrane polarization and integrity, and DNA and RNA contents, combined with flow cytometry. We have also measured bacterioplankton community production, respiration, and growth efficiency along the estuary. Our data suggest that the sharp phylogenetic succession that occurs within the fresh to saltwater transition region is accompanied by profound metabolic changes both at the single‐cell and community levels and that the phylogenetic succession occurs together with measurable physiological stress. The different indices of single‐cell characteristics that we have used converge to suggest that within the fresh to saltwater transition zone, there is generalized decline in growth and possibly a loss of activity and even significant cell mortality. At the community level, these changes in singlecell physiology at the site of the phylogenetic succession appear to translate into a generalized decline in bacterial growth efficiency with a decrease in bacterial growth and production but an actual increase in bacterial carbon consumption. Our data also suggest that different phylogenetic groups may have intrinsically different levels of single‐cell activity or at least respond differently to the activity assays that we currently use.
Viruses causing lysis of the toxic bloom‐forming alga Heterosigma akashiwo(Raphidophyceae) are widespread in coastal sediments of British Columbia, Canada
Authors: Lawrence Janice E. , Chan Amy M. , Suttle Curtis A.
Published: June 2010

Viruses that infect and cause lysis of the toxic alga Heterosigma akashiwo are abundant and widespread in the Strait of Georgia, Canada, and adjacent inlets during the summer months when blooms of this alga occur. Because viruses are subjected to many mechanisms of removal and their host is intermittently dormant, the persistence of viruses may be dependent on environmental reservoirs. We extracted pore water from sediments collected in the Strait of Georgia and screened for the presence of infectious agents that cause lysis of H. akashiwo. Lytic agents were widespread throughout the study region, being detected in 17 of 20 sites surveyed. Lytic agents were present in sediments ranging from highly organic to clay‐rich and were retrieved from cores taken at water depths of 25−285 m. The highest concentration of lytic agents was found at the sediment‐water interface; however, lytic agents were found as deep as 40 cm below the sediment‐water interface. Examination of agents isolated from various sites revealed virus‐like particles ~50 nm in diameter. These are similar to other virus‐like particles that have been isolated that infect this alga. This suggests that the most abundant lytic agents in the sediments are viruses and that these viruses may be long‐lived once buried in the sediments. The widespread presence of viral‐size lytic agents that infect H. akashiwo is consistent with viral infection being a mortality agent of this alga in the overlying waters and suggests that they may play in important role in regulating their population dynamics.
Sedimentological evidence of an increase in Pseudo‐nitzschia (Bacillariophyceae)abundance in response to coastal eutrophication
Authors: Parsons Michael L. , Dortch Quay
Published: June 2010

Pseudo‐nitzschia H. Peragallo, a marine planktonic diatom genus containing some species capable of producing the neurotoxin domoic acid, is often documented in extremely high concentrations in the northern Gulf of Mexico in the plume of the Mississippi River, especially when river flow and nutrient inputs are high. Limited historical data suggest that Pseudo‐nitzschia abundance has increased in the northern Gulf of Mexico since the 1950s. Five sediment cores were collected and analyzed to test whether Pseudo‐nitzschia increases coincided with increasing nutrient concentrations in the Mississippi River, thereby suggesting a cause‐effect relationship. Pseudo‐nitzschia abundance increased in all five cores, correlating significantly with increasing nitrate fluxes and decreasing silicate to nitrate ratios. A diatom dissolution index, based partly on scanning electron microscopic analysis of the fine structure of Pseudo‐nitzschia and other lightly silicified diatom valves preserved in the sediment, indicates that the increase in Pseudo‐nitzschia abundance appears to reflect a response to eutrophication rather than diagenesis. This study provides evidence for a possible link between coastal eutrophication and harmful algal blooms.
Assessing the impact of a recent predatory invader: The population dynamics, vertical distribution, and potential prey of Cercopagis pengoi in Lake Ontario
Authors: BenoÍt Hugues P. , Johannsson Ora E. , Warner David M. , Sprules W. Gary , Rudstam Lars G.
Published: June 2010

The predatory impacts of Cercopagis pengoi, a planktivorous cladoceran first observed in Lake Ontario in 1998, were assessed by examining patterns in the distribution and population dynamics of macrozooplankton. Specifically, we determined the vertical distribution of C. pengoi in Lake Ontario with respect to other zooplankton species and possible biotic and abiotic controlling factors and used seasonal time series of potential prey species, both before and after C. pengoi invasion, to make inferences about predatory impacts of C. pengoi. The highest abundances of C. pengoi generally occurred at the bottom of the epilimnion or at the top of the metalimnion, and strong diel vertical migration was not observed. The vertical distribution of cyclopoid and calanoid nauplii and copepodids was deeper in 1999 than had historically been observed, which suggest possible avoidance of C. pengoi or localized predatory depletion. Seasonal analyses of normalized biomass size spectra from the Bay of Quinte supported an impact of C. pengoi on organisms <0.1 µg dry weight. The hypothesized predatory effect on juvenile copepods was supported by an analysis of seasonal time series, where we observed that high abundances of C. pengoi coincided with marked decreases in these groups. Consequently, the presence of C. pengoi likely decreases the production of juvenile copepods both through direct predation and through a shift of copepod vertical distribution to colder waters. Among the cladocerans, only Bosmina longirostris abundance declined in the presence of C. pengoi in the analysis of seasonal time series.
Climatological phytoplankton chlorophyll and sea surface temperature patterns in continental shelf and slope waters off the northeast U.S. coast
Authors: Yoder James A. , Schollaert Stephanie E. , O'Reilly John E.
Published: June 2010

Satellite‐derived chlorophyll estimates from the Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) and Coastal Zone Color Scanner (CZCS), a large archive of in situ near‐surface chlorophyll data, and satellite sea surface temperature (SST) measurements were used to quantify spatial and seasonal variability of near‐surface chlorophyll and SST in middle shelf to slope waters off the coast of the U.S. Northeast. The results of empirical orthogonal function (EOF) analysis on normalized monthly fields (after temporal and spatial means were removed) show that all three chlorophyll climatologies have similar mode 1 temporal and spatial patterns in these waters. Mode 1, which explains about half of the total variability in monthly climatological images, shows that shelf waters in the Gulf of Maine (GOM) are out of phase with the mid‐Atlantic bight (MAB), with seasonally high chlorophyll concentrations in winter in the MAB and in summer in the GOM. The three chlorophyll climatologies begin to differ at higher modes (modes 2 and 3), although SeaWiFS and in situ climatologies keep similar features through mode 3. Higher modes in both SST and chlorophyll are related to the effects of tidal mixing on Georges Bank, differences in seasonal stratification between the southwestern and northeastern GOM, and the importance of the spring bloom in MAB outer shelf waters and western GOM. SST patterns during the CZCS and SeaWiFS eras are very similar, and this indicates that the observed differences between results obtained with these two sensors are probably not caused by differences in physical processes during the two satellite eras.
Examination of coupling between primary and secondary production in a river‐dominated estuary: Apalachicola Bay, Florida, U.S.A.
Authors: Chanton Jeffrey , Lewis F. Graham
Published: June 2010

To examine the influence of river‐borne organic material on estuarine communities, we conducted a dual stable isotope study in an estuary heavily influenced by alluvial runoff. Despite significant alluvial influence, secondary production in Apalachicola Bay depends more upon estuarine primary production than upon a detrital food web supported by floodplain primary production. Two simple mixing models, floodplain‐marine and floodplain‐estuarine, indicated that the upper limits for the contribution of terrestrial organic matter to estuarine consumer diets averaged 37, 25, and 27% and 20, 19, and 25% for East Bay, Cat Point, and Dry Bar, respectively. Systematic δ13C variation of consumer organisms was found for differing locations and attributed to increasing influence of terrestrial organic matter and 13C‐depleted dissolved inorganic carbon (DIC) closer to the river mouth. The δ34S data exhibited significant variation with river flow that was attributed to an admixture of terrestrial floodplain detritus with estuarine and marine organic matter. Both δ13C and δ34S isotope data demonstrated clear distinctions between benthic and water column feeding types. Our results suggest that the estuary is dependent on riverine inflows to provide floodplain detritus during the high‐flow period and dissolved nutrients for estuarine primary productivity during the low‐flow season. Any alteration of river hydrology may adversely affect estuarine secondary production, especially during the low‐flow period when the estuary is dependent on input of dissolved nutrients to maintain a high level of primary productivity.
Phosphorus cycling in the North Pacific Subtropical Gyre using cosmogenic 32P and 33P
Authors: Benitez-Nelson Claudia R. , Karl David M.
Published: June 2010

The North Pacific Subtropical Gyre (NPSG) has been hypothesized to be in transition from a nitrogen (N)‐limited system to one predominantly limited by phosphorus (P) as a result of a two‐decade‐long selection for N2‐fixing organisms. In this study, the naturally occurring cosmogenic radioisotopes, 32P (half‐life = 14.3 d) and 33P (halflife = 25.3 d), were measured and 33P/32P activity ratios were used to estimate radioactive P residence times at Sta. ALOHA (22°45′N, 158°00′W) in the NPSG from February 1999 to July 2000. The 33P/32P activity ratio in the total dissolved P pool varied considerably but systematically; high ratios correlated with periods of enhanced primary production (14C incorporation). Marine particulate 33P/32P activity ratios were similar to those found in the source (i.e., rain). Smaller size classes had longer apparent residence times. The observation that the activity ratio of 33P/32P closely follows primary production suggests that atmospherically derived 32P and 33P atoms track the most “bioavailable” pool of P within the NPSG ecosystem. These preferred substrates were removed from the dissolved phase via plankton uptake during periods of high productivity. Our results suggest that the soluble nonreactive P pool, which is substantially larger than the soluble reactive P pool, is a potentially important source of P to organisms and that its utilization can vary significantly on scales of weeks to months.
Prey resource use by coexistent hydromedusae from Friday Harbor, Washington
Authors: Costello J. H. , Colin S. P.
Published: June 2010

Prey selection patterns were quantified for a sympatric group of hydromedusae from Friday Harbor, WA. Selection patterns varied between species, but were largely replicable between sample dates and resembled dietary patterns found in similar studies from neighboring regions. Ambush‐foraging medusae (Aglantha digitale, Sarsia tubulosa, and Proboscidactyla flavicirrata) fed primarily on crustacean and ciliated prey but the dietary niches of these hydromedusan species centered on different fractions of the available plankton. Consequently, little dietary overlap occurred between the ambush foraging hydromedusae. In contrast, the dietary niches of cruising predators (Aequorea victoria, Mitrocoma cellularia, and Phialidium gregarium) overlapped substantially because those species all fed on similar soft‐bodied prey such as eggs and appendicularians. These results have two important implications for trophic patterns involving medusae. First, different mechanisms of prey encounter and capture used by hydromedusae (ambush vs. cruising patterns) result in important interspecific dietary differences and, hence, trophic roles of the medusae. Second, whereas cruising medusae may consume similar prey and hence form a feeding guild, ambush‐foraging medusae may experience substantially less prey overlap and, for the community examined here, do not experience potentially strong feeding competition from other medusan species.
Benthic photosynthesis in an acidic mining lake (pH 2.6)
Authors: Koschorreck Matthias , Tittel Jörg
Published: June 2010

Natural neutralization of acidic mining lakes is usually limited by the availability of organic carbon. We investigated whether benthic photosynthesis could contribute to primary production in an acidic mining lake (pH 2.6). The occurrence and light dependence of benthic photosynthesis in the lake was investigated using oxygen microelectrodes. Oxygen microprofiles measured in light and darkness were significantly different, indicating photosynthetic activity. The photic zone was 300 μm thick and the highest photosynthetic activity was found at the sediment surface, which was covered by a dense layer of diatoms. These algae, predominantly Eunotia spp. and Pinnularia obscura, were found to be adapted to low light intensities. The community compensation irradiance was 6.8 μE m−2 s−1, corresponding to an annual mean compensation depth of 1.8 m. These results imply that 13% of the lake area could have a net efflux of oxygen from the sediment. Even at an irradiance as low as 1.2 μE m−2 s−1, photosynthetic activity was detected. The relatively low light requirements for benthic photosynthesis in this acidic environment may be due to an efficient absorption of red light, the dominant wavelength available in this ferric iron‐rich lake. Our results suggest that benthic photosynthesis can play an important role in the biogeochemistry of acidic mining lakes.
Temporal mapping of phytoplankton assemblages in Lake Geneva: Annual and interannual changes in their patterns of succession
Authors: Anneville Orlane , Souissi Sami , Ibanez Frédéric , Ginot Vincent , Druart Jean Claude , Angeli Nadine
Published: June 2010

The implementation of a conservation program since the early 1980s resulted in a reduction in phosphorus concentrations in Lake Geneva. However, in the 1990s, phytoplankton biomass increased again, almost reaching the high values recorded during the period of greatest P loading. The structural changes in the phytoplankton of Lake Geneva over the past 25 yr have been analyzed using a recently developed statistical method based on hierarchical clustering and Bayesian probabilities. This method has been used to identify phytoplankton assemblages and to map annual and interannual successional patterns simultaneously. Characteristic species were identified for each cluster after calculation of their relative species fidelity and specificity indices. Six distinct phytoplankton assemblages were identified, and although the way species are organized into communities remains unclear, the seasonal patterns of succession are consistent with the C‐S‐R adaptive strategies and are characteristic of temperate lakes. This pattern broadly recurred over the years, but was markedly influenced by both human activity and regional climatic changes: The warmer winters and springs recorded in Europe since 1988 led to an earlier clear‐water phase. In the 1990s, the earlier and deeper depletion of dissolved inorganic phosphorus led to colonization in the summer by large species tolerant of low light levels and that could develop deeper in the water column, where phosphorus was still abundant. Their size made them less vulnerable to grazing losses, which favors their accumulation and lead to an unexpected high biomass in recent years.
Oxygen transfer across the air‐water interface by natural convection in lakes
Authors: Schladow S. Geoffrey , Lee Minhee , Hürzeler Bernhard E. , Kelly Peter B.
Published: June 2010

Oxygen transfer associated with natural convection in lakes and reservoirs was examined in a series of laboratory experiments. A thin, cool surface water layer (2–3 mm in thickness) was formed by chilling the air overlying a tank of surface area 0.6 m2 and depth 0.6 m. The surface water layer became gravitationally unstable, resulting in the formation of negatively buoyant thermal plumes, which penetrated through the total depth of the water column. The spatial distribution of oxygen concentration at the air‐water interface in the tank was visualized using a fluorescence imaging technique to quantify the oxygen transfer driven by only natural convection. Pyrenebutyric acid (PBA) at a concentration of 3.0 x 10-6 mole L-1 was used as the fluorophore, and the quenching of the fluorescence by oxygen was used to produce a spatial distribution of dissolved oxygen. A light plane was generated across the tank by the refraction of a laser light beam, and two‐dimensional images were continuously acquired with an intensified charge coupled‐device (ICCD) camera. Analysis of these images revealed the sinking of cooled water to transport oxygen, and the experiments enabled the quantification of the oxygen transferred from the air into water at a range of heat fluxes. The results confirm that vertical penetration of cold‐dense water can be a significant source of oxygen for lakes and reservoirs.
Cell‐specific detection of phosphorus stress in Trichodesmium from the Western North Atlantic
Authors: Dyhrman Sonya T. , Webb Eric A. , Anderson Donald M. , Moffett James W. , Waterbury John B.
Published: June 2010

The low phosphorus concentrations observed in the western North Atlantic and the western Central Atlantic suggest that phosphorus bioavailability may limit Trichodesmium productivity and N2 fixation. However, the degree to which the concentration and composition of the total phosphorus pool affects actual bioavailability is poorly understood. To better examine how phosphorus bioavailability may constrain primary production and marine N2 fixation, we have developed a molecular diagnostic tool for quickly detecting the phosphorus status of the diazotroph Trichodesmium. This diagnostic method uses a commercially available substrate to fluorescently tag cells expressing the phosphate‐regulated enzyme, alkaline phosphatase. Using this diagnostic tool, we were able to distinguish phosphorus‐replete from phosphorus‐stressed Trichodesmium populations along a transect from Grand Bahama Island to Bermuda in November 2000.
Uptake and efflux of 64Cu by the marine cyanobacterium Synechococcus (WH7803)
Authors: Croot Peter L. , Bengt Karlson , van Elteren J. T. , Kroon J. J.
Published: June 2010

The uptake and efflux of 64Cu was studied in the marine cyanobacterium Synechoccous strain WH7803 (DC2). Uptake followed classical Michaelis∐Menten type kinetics in metal∐buffered seawater. The maximum uptake rate, Vmax, was 0.236 ± 0.016 × 10−18 mol Cu cell−1 h−1, with the half∐saturation constant, KS, of 10−10.81±0.11 mol L−1. An efflux mechanism was also observed in WH7803, whose growth was inhibited by high internal Cu concentrations. Efflux of Cu enabled WH7803 to maintain homeostasis for Cu at typical seawater ambient free copper concentrations ([Cu𠀫]f). The sensitivity of WH7803 growth to Cu was related to a simple inability to regulate internal Cu concentrations when external concentrations were >10−11 mol L−1.
Microzooplankton grazing on Prorocentrum minimum and Karlodinium micrum in Chesapeake Bay
Authors: Johnson Matthew D. , Rome Michelle , Stoecker Diane K.
Published: June 2010

Potential grazing rates on the bloom forming dinoflagellates Prorocentrum minimum and Karlodinium micrum were measured in Chesapeake Bay during summer (2000). Cultured P. minimum and K. micrum cells were fluorescently labeled with 5‐chloromethylfluoroscein diacetate and introduced to <200 mm filtered water. Microzooplankton grazing was assessed by measuring the disappearance of labeled prey over time. Grazing on P. minimum and K. micrum was highest between lower oligohaline to midmesohaline regions of the open bay, where microzooplankton biomass was greatest. In June, grazing rates on P. minimum were high at all stations, apparently because of naked (NHD) and thecate heterotrophic dinoflagellates. In July, grazing pressure on P. minimum was related to aloricate oligotrich and choreotrich biomass (r2 = 0.5107, p = 0.030), whereas g for K. micrum was correlated with Oxyrrhis marina (r2 = 0.7217, p = 0.004) abundance. In August, grazing on P. minimum was correlated with abundance of the NHD Gyrodinium spp. (r2 = 0.6621, p = 0.006) and Polykrikos kofoidii (r2 = 0.6617, p = 0.010) abundance. Microzooplankton biomass peaked within the mesohaline regions of Chesapeake Bay during all months, and these assemblages were dominated by heterotrophic dinoflagellates. On the basis of these results, microzooplankton grazing is an important loss to P. minimum and K. micrum populations in Chesapeake Bay.
Airborne hyperspectral detection of microbial mat pigmentation in Rangiroa atoll (French Polynesia)
Authors: Andréfouët1 Serge , Payri Claude , Hochberg Eric J. , Che Lydie Mao , Atkinson Marlin J.
Published: June 2010

The pigmentation of a cyanobacterial mat located in Rangiroa atoll (French Polynesia) was characterized using low‐altitude (500 m) Compact Airborne Spectrometer Imager hyperspectral measurements. Peaks in second and fourth derivatives of the reflective absorptance can be explained by chlorophyll and carotenoid pigments, which were independently identified by high‐pressure liquid chromatography. Phycobilin pigments were also detected from airborne measurements. The study confirms the extensibility of derivative spectroscopy from in vivo to highresolution remote sensing measurements for biology and geochemistry investigations in marine communities.
Ocean color remote sensing of seagrass and bathymetry in the Bahamas Banks by high‐resolution airborne imagery
Authors: Dierssen Heidi M. , Zimmerman Richard C. , Leathers Robert A. , Downes T. Valerie , Davis Curtiss O.
Published: June 2010

New coastal ocean remote sensing techniques permit benthic habitats to be explored with higher resolution than ever before. A mechanistic radiative transfer approach is developed that first removes the distorting influence of the water column on the remotely sensed signal to retrieve an estimate of the reflectance at the seafloor. The retrieved bottom reflectance is then used to classify the benthos. This spectrally based approach is advantageous because model components are separate and can be evaluated and modified individually for different environments. Here, we applied our approach to quantitatively estimate shallow‐water bathymetry and leaf area index (LAI) of the seagrass Thalassia testudinum for a study site near Lee Stocking Island, Bahamas. Two high‐resolution images were obtained from the ocean portable hyperspectral imager for low‐light spectroscopy (Ocean PHILLS) over the study site in May 1999 and 2000. A combination of in situ observations of seafloor reflectance and radiative transfer modeling was used to develop and test our algorithm. Bathymetry was mapped to meter‐scale resolution using a site‐specific relationship (r2 = 0.97) derived from spectral ratios of remote sensing reflectance at 555 and 670 nm. Depth‐independent bottom reflectance was retrieved from remote sensing reflectance using bathymetry and tables of modeled water column attenuation coefficients. The magnitude of retrieved bottom reflectance was highly correlated to seagrass LAI measured from diver surveys at seven stations within the image (r2 = 0.88–0.98). Mapped turtlegrass LAI was remarkably stable over a 2‐yr period at our study site, even though Hurricane Floyd swept over the study site in September 1999.
Spatial and temporal variation in spectral reflectance: Are seagrass species spectrally distinct?
Authors: Fyfe S. K.
Published: June 2010

The spectral signatures of the seagrasses Zostera capricorni, Posidonia australis, and Halophila ovalis were investigated to determine whether species could be discriminated by remote sensing. The spectral reflectance of fouled and unfouled leaf samples collected from marine and brackish habitats at three estuaries in southeastern Australia were measured in the field with a spectroradiometer during each season in 1999 and 2000. Seagrass species were spectrally distinct regardless of whether the leaves were fouled by epibionts and despite spatial and temporal variability in the reflectance of each species. The visible wavelengths that penetrate water coincide with the regions of maximum absorption and characteristic reflectance by plant photosynthetic and accessory pigments. Strong and consistent differences in reflectance between species were recorded in the green wavelengths at 530–580 nm with additional discrimination in the regions 520–530 nm and 580–600 nm and at the red chlorophyll absorption trough at 686–700 nm. Species discrimination should be possible in the remote sensing of benthic aquatic vegetation using a hyperspectral sensor that has narrow bands centered on pigment‐related spectral features in the visible wavelengths. The detection of statistically significant differences in intraspecific reflectance associated with the year, season, estuary, and habitat of sample collection suggests a potential for monitoring seagrass health and estuarine water quality. This study has produced the first spectral library of aquatic plant species to take into account the range of spectral variability expected for the species under natural conditions. The results provide a sound basis for future mapping of seagrass species in Australia.
A remote sensing method for resolving depth and subpixel composition of aquatic benthos
Authors: Hedley John D. , Mumby Peter J.
Published: June 2010

The problem of subpixel heterogeneity in cover types has been addressed in terrestrial environments by the application of linear spectral unmixing techniques. However, in aquatic systems the interceding depth of water causes the apparent reflectance of the substrate to diverge from a linear model, and if depth is unknown these methods cannot be applied. A new technique is presented in which the conventional spectral unmixing method has been modified to calculate depth at each pixel in addition to the proportions of substrate type. The technique requires knowledge of the reflectance spectra of m pure substrata in n (n ≫ m) spectral bands at depth 0 and the water diffuse attenuation coefficients for the site in the same bands. Depth, z, can be entirely unknown. The method is comparable to “classical” spectral unmixing and proceeds by performing a Gaussian elimination for endmember quantities and then solving the remaining nonlinear function of z for f(z) = 0 by successive approximation. Computer‐based models are used to test the technique with realistic water diffuse attenuation coefficients and random spectra and actual spectra of coral reef substrata. The robustness of the technique is assessed against three forms of introduced error: measurement errors on the spectra to be unmixed, differences between the true endmember spectra and those used in the analysis, and measurement error on the water diffuse attenuation coefficients. The results of these tests imply the technique is sufficiently robust for use on real data. Furthermore, spectral unmixing of aquatic systems appears to be relatively insensitive to inaccuracies in depth estimation and offers great utility for benthic mapping.
The State of State Biomarker Testing Insurance Coverage Laws
Authors: Lin Grace A. , Coffman Janet M. , Phillips Kathryn A.
Published: May 2024

This Viewpoint discusses laws mandating insurance coverage of biomarker testing to broaden access to care for patients with cancer.
Disclosure Is an Essential Component of Ethical Practice
Authors: Raz Mical , Gupta-Kagan Josh , Asnes Andrea G.
Published: May 2024

This Viewpoint explains the role of child abuse pediatricians and makes specific recommendations for communicating their role in medical care.
Report on the 2nd international molecular biosciences PhD and postdoc conference 2023: The emerging challenge – environmental impacts on human health
Authors: Baumann Franziska , Mariani Andrea
Published: May 2024

The 2nd International FEBS‐IUBMB‐ENABLE Molecular Biosciences PhD and Postdoc Conference was held from 23rd to 25th November 2023 in Cologne, Germany. Over 240 participants from 31 different countries came together at the University of Cologne to follow the two‐day scientific symposium and the career day. This year's topic was “The emerging challenge – environmental impacts on human health”. In four different sessions, eight renowned keynote speakers presented their current research. By offering flash and short talks, 39 participants were able to present their work in front of a big audience. Scientific exchange and networking were encouraged during the two poster sessions, during breaks, and the conference dinner. On the Career Day, a career fair was held and participants could attend workshops as well as career chats to improve their job prospects. The success of the series will be continued during the next conference edition: “Artificial Intelligence – Reshaping biomedical and healthcare research”, which will take place 4th to 6th December 2024 in Singapore.
Basal bark herbicide treatment of Lonicera maackii (Amur honeysuckle) is effective regardless of application timing, with limited nontarget effects on native plant diversity
Authors: Hogan Katharine F. E. , Baker Kaleb , Bach Elizabeth M. , Barber Nicholas A.
Published: May 2024

Managers tasked with controlling invasive species require effective methods that are quick and easy to use without inflicting extensive nontarget damage, while also being compatible with other scheduled management responsibilities. Lonicera maackii (Amur honeysuckle) is a non‐native shrub that has invaded eastern and midwestern North American deciduous forests, altering ecosystem function and reducing biodiversity.

This study explores prescribed fire and seasonal basal applications of triclopyr ester as control methods and examines the extent of nontarget damage. We used paired‐split plots to implement basal bark treatments in different seasons within burned and unburned units, and we tracked individual L. maackii to determine mortality and hyperlocal impacts of management.

Basal bark treatments killed 98.4% of L. maackii across seasonal timings. Nontarget plant cover declined similarly for all herbicide application seasons, but there were some signs of recovery within 4 years, and the early‐ and late spring treatments were less affected overall. Species richness showed biologically small but statistically different declines across treatment times. Prescribed fire did not impact L. maackii mortality or interact with herbicide efficacy.

Basal bark applications of triclopyr are an effective means of L. maackii control regardless of application timing, which allows managers to implement it at their convenience to avoid interfering with other management tasks that have time constraints.
Structural Evolution of Liquid Metals and Alloys
Authors: Krishnamurthi Vaishnavi , Vaillant Pierre H. A. , Mata Jitendra , Nguyen Chung Kim , Parker Caiden J. , Zuraiqi Karma , Bryant Gary , Chiang Ken , Russo Salvy P. , Christofferson Andrew J. , Elbourne Aaron , Daeneke Torben
Published: May 2024

Low‐melting liquid metals are emerging as a new group of highly functional solvents due to their capability to dissolve and alloy various metals in their elemental state to form solutions as well as colloidal systems. Furthermore, these liquid metals can facilitate and catalyze multiple unique chemical reactions. Despite the intriguing science behind liquid metals and alloys, very little is known about their fundamental structures in the nanometric regime. To bridge this gap, this work employs small angle neutron scattering and molecular dynamics simulations, revealing that the most commonly used liquid metal solvents, EGaIn and Galinstan, are surprisingly structured with the formation of clusters ranging from 157 to 15.7 Å. Conversely, noneutectic liquid metal alloys of GaSn or GaIn at low solute concentrations of 1, 2, and 5 wt%, as well as pure Ga, do not exhibit these structures. Importantly, the eutectic alloys retain their structure even at elevated temperatures of 60 and 90 °C, highlighting that they are not just simple homogeneous fluids consisting of individual atoms. Understanding the complex soft structure of liquid alloys will assist in comprehending complex phenomena occurring within these fluids and contribute to deriving reaction mechanisms in the realm of synthesis and liquid metal‐based catalysis.
Scalable Precise Nanofilm Coating and Gradient Al Doping Enable Stable Battery Cycling of LiCoO2 at 4.7 V
Authors: Yao Jia , Li Yuyu , Xiong Tiantian , Fan Yameng , Zhao Lingfei , Cheng Xiangxin , Tian Yunan , Li Lele , Li Yan , Zhang Wen , Yu Peng , Guo Pingmei , Yang Zehui , Peng Jian , Xue Lixing , Wang Jiazhao , Li Zhaohuai , Xie Ming , Liu Huakun , Dou Shixue
Published: May 2024

The quest for smart electronics with higher energy densities has intensified the development of high‐voltage LiCoO2 (LCO). Despite their potential, LCO materials operating at 4.7 V faces critical challenges, including interface degradation and structural collapse. Herein, we propose a collective surface architecture through precise nanofilm coating and doping that combines an ultra‐thin LiAlO2 coating layer and gradient doping of Al. This architecture not only mitigates side reactions, but also improves the Li+ migration kinetics on the LCO surface. Meanwhile, gradient doping of Al inhibited the severe lattice distortion caused by the irreversible phase transition of O3−H1−3−O1, thereby enhanced the electrochemical stability of LCO during 4.7 V cycling. DFT calculations further revealed that our approach significantly boosts the electronic conductivity. As a result, the modified LCO exhibited an outstanding reversible capacity of 230 mAh g−1 at 4.7 V, which is approximately 28 % higher than the conventional capacity at 4.5 V. To demonstrate their practical application, our cathode structure shows improved stability in full pouch cell configuration under high operating voltage. LCO exhibited an excellent cycling stability, retaining 82.33 % after 1000 cycles at 4.5 V. This multifunctional surface modification strategy offers a viable pathway for the practical application of LCO materials, setting a new standard for the development of high‐energy‐density and long‐lasting electrode materials.
Protonation of an Imine‐linked Covalent Organic Framework for Efficient H2O2 Photosynthesis under Visible Light up to 700 nm
Authors: Zhu Qiong , Shi Li , Li Zhuo , Li Guisheng , Xu Xiaoxiang
Published: May 2024

Covalent organic frameworks (COFs) are promising photocatalysts for H2O2 production from water via oxygen reduction reaction (ORR). The design of COFs for efficient H2O2 production indubitably hinges on an in‐depth understanding of their ORR mechanisms. In this work, taking an imine‐linked COF as an example, we demonstrate that protonation of the functional units such as imine, amine, and triazine, is a highly efficient strategy to upgrade the activity levels for H2O2 synthesis. The protonation not only extends the light absorption of the COF but also provides proton sources that directly participate in H2O2 generation. Notably, the protonation simplifies the reaction pathways of ORR to H2O2, i.e. from an indirect superoxide radical (
) mediated route to a direct one‐step two‐electron route. Theoretical calculations confirm that the protonation favors H2O2 synthesis due to easy access of protons near the reaction sites that removes the energy barrier for generating *OOH intermediate. These findings not only extend the mechanistic insight into H2O2 photosynthesis but also provide a rational guideline for the design and upgradation of efficient COFs.
Medicinal attributes of thienopyrimidine scaffolds incorporating the aryl urea motif as potential anticancer candidates via VEGFR inhibition
Authors: Farag Myrna A. , Kandeel Manal M. , Kassab Asmaa E. , Faggal Samar I.
Published: May 2024

Worldwide, cancer is a major public health concern. It is a well‐acknowledged life‐threatening disease. Despite numerous advances in the understanding of the genetic basis of cancer growth and progression, therapeutic challenges remain high. Human tumors exhibited mutation or overexpression of several tyrosine kinases (TK). The vascular endothelial growth factor receptor (VEGFR) is a TK family member and is well known for tumor growth and progression. Therefore, VEGF/VEGFR pathway inhibition is an appealing approach for cancer drug discovery. This review will discuss the structure‐based optimization of thienopyrimidines incorporating the aryl urea moiety to develop scaffolds of potent anticancer activity via VEGFR inhibition published between 2013 and 2023. Increasing knowledge of probable scaffolds that can act as VEGFR inhibitors might spur the hunt for novel anticancer medications that are safer, more effective, or both.
Results of the multicenter early feasibility study (EFS) of the Renata Minima stent as treatment for branch pulmonary artery stenosis and coarctation of aorta in infants
Authors: Berman Darren P. , Morray Brian , Sullivan Patrick , Shahanavaz Shabana , Zahn Evan M.
Published: May 2024

Background

Stent implantation has become standard of care in older children and adults for treatment of branch pulmonary artery stenosis (BPAS) and coarctation aorta (CoAo). There are no stents approved or available for infants that have the potential to be dilated to adult diameters. The Minima stent was designed to fulfill this unmet need.

Methods

Multicenter, prospective, nonrandomized early feasibility study evaluating safety and effectiveness of the Minima stent for treatment of BPAS and CoAo. Primary endpoints included: (1) successful deployment across lesion, (2) stenosis relief defined by an increase in angiographic diameter of >50% and (3) freedom from stent explant, embolization or migration at 30 days and 6 months.

Results

Between 2/2022 and 5/2022, 10 pts underwent Minima stent implantation with a median age and weight of 9 months (4–43 months) and 7.6 kg (5.1−16.9 kg). Procedural success and predefined stenosis relief was achieved in all cases (CoAo [n = 4], BPAS [n = 6]). Adverse events occurred in 3 pts: transient diminished lower extremity pulse (n = 2), distal stent on‐balloon displacement successfully managed in the catheterization suite (n = 1). There were no deaths or major adverse events. All patients were free from stent explant and migration at 30 days and 6 months with no evidence for significant restenosis at latest follow‐up.

Conclusions

Implantation of the Renata Minima stent was safe and effective for the treatment of BPAS and CoAo in this small cohort of infants and young children during early follow‐up. Based on these early results, an expanded study with longer follow‐up is warranted.
Phosphodiesterase 5A regulates the vomeronasal pump in mice
Authors: Lippner Dennean S. , Xu Jiang , Ma Siqi , Reisert Johannes , Zhao Haiqing
Published: May 2024

The vomeronasal organ (VNO) is a specialized chemoreceptive structure in many vertebrates that detects chemical stimuli, mostly pheromones, which often elicit innate behaviors such as mating and aggression. Previous studies in rodents have demonstrated that chemical stimuli are actively transported to the VNO via a blood vessel‐based pumping mechanism, and this pumping mechanism is necessary for vomeronasal stimulation in behaving animals. However, the molecular mechanisms that regulate the vomeronasal pump remain mostly unknown. In this study, we observed a high level of expression of phosphodiesterase 5A (PDE5A) in the vomeronasal blood vessel of mice. We provided evidence to support the potential role of PDE5A in vomeronasal pump regulation. Local application of PDE5A inhibitors—sildenafil or tadalafil—to the vomeronasal organ (VNO) reduced stimulus delivery into the VNO, decreased the pheromone‐induced activity of vomeronasal sensory neurons, and attenuated male–male aggressive behaviors. PDE5A is well known to play a role in regulating blood vessel tone in several organs. Our study advances our understanding of the molecular regulation of the vomeronasal pump.
Harnessing enviromics to predict climate‐impacted high‐profile traits to assist informed decisions in agriculture
Authors: Zhang Bosen , Hauvermale Amber L. , Zhang Zhiwu , Thompson Alison , Neely Clark , Esser Aaron , Pumphrey Michael , Garland‐Campbell Kimberly , Yu Jianming , Steber Camille , Li Xianran
Published: May 2024

Modern agriculture is a complex system that demands real‐time and large‐scale quantification of trait values for evidence‐based decisions. However, high‐profile traits determining market values often lack high‐throughput phenotyping technologies to achieve this objective; therefore, risks of undermining crop values through arbitrary decisions are high. Because environmental conditions are major contributors to performance fluctuation, with the contemporary informatics infrastructures, we proposed enviromic prediction as a potential strategy to assess traits for informed decisions. We demonstrated this concept with wheat falling number (FN), a critical end‐use quality trait that significantly impacts wheat market values but is measured using a low‐throughput technology. Using 8 years of FN records from elite variety testing trials, we developed a predictive model capturing the general trend of FN based on biologically meaningful environmental conditions. An explicit environmental index that was highly correlated (r = 0.646) with the FN trend observed from variety testing trials was identified. An independent validation experiment verified the biological relevance of this index. An enviromic prediction model based on this index achieved accurate and on‐target predictions for the FN trend in new growing seasons. Two applications designed for production fields illustrated how such enviromic prediction models could assist informed decision along the food supply chain. We envision that enviromic prediction would have a vital role in sustaining food security amidst rapidly changing climate. As conducting variety testing trials is a standard component in modern agricultural industry, the strategy of leveraging historical trial data is widely applicable for other high‐profile traits in various crops.
Taxonomy of performance shaping factors in manufacturing: A systematic literature review
Authors: Jha Prameet Ranjan , Di Pasquale Valentina , Saleem Jason J. , Wang Xiaomei
Published: May 2024

Human error in manufacturing can have substantial consequences, including loss of life, injuries, productivity, and financial losses. Human reliability analysis (HRA) methods can be used to evaluate the likelihood of human error in manufacturing tasks and identify potential sources of error. Performance shaping factors (PSFs) are internal and external factors that influence human performance and can affect the likelihood of human reliability estimates in HRA methods. Understanding the impact of PSFs on human performance in manufacturing is essential for developing effective strategies to minimize the likelihood of human error and improve the safety and efficiency of manufacturing processes. This systematic review scrutinizes the literature on PSFs within manufacturing, highlighting HRA applications. Using the PRISMA protocol, studies from 2000 to 2024 across engineering and psychology were examined, culminating in the analysis of 35 pertinent works. The review identifies and contrasts various PSF taxonomies from established HRA methods like SPAR‐H, HEART, CREAM, and THERP, revealing their diverse applications in different manufacturing settings. The review also uncovers a tendency to devise taxonomies through the lens of experts' domain knowledge, particularly tailored to discrete manufacturing contexts. A critical gap is observed in the lack of a uniform PSF framework, with the current literature reflecting a disparate understanding of PSFs' roles, definitions, and interrelations. This absence is further pronounced by the inadequate integration of human factors in the dialogue surrounding Industry 4.0. The analysis points to the necessity of harmonizing PSFs to better assess human reliability amid technological integration. The findings emphasize the need for an industry‐specific PSF framework that aligns with the intricacies of manufacturing operations, thus enabling more accurate HRA outcomes and informing strategies for error reduction and process optimization.
Socioeconomic determinants of the double burden of malnutrition among women of reproductive age in sub‐Saharan Africa: A cross‐sectional study
Authors: Okyere Joshua , Budu Eugene , Aboagye Richard Gyan , Seidu Abdul‐Aziz , Ahinkorah Bright Opoku , Yaya Sanni
Published: May 2024

Background and Aim

The positioning of eliminating all forms of malnutrition within the spirit of the Sustainable Development Goals and the adoption of the United Nations resolution for a Decade of Action on Nutrition are a testament to strong global commitment to combat the double burden of malnutrition (DBM). Yet, there is a knowledge gap in sub‐Saharan Africa (SSA) regarding the influence of socioeconomic status on DBM. We investigated the associative effect of socioeconomic status on DBM in SSA.

Methods

Data for the study were extracted from the most recent Demographic and Health Surveys (DHS) of 29 countries in SSA conducted from 2010 to 2020. Bivariate and multivariate logistic regression models were fitted to examine the association between socioeconomic status and DBM. The results were presented using adjusted odds ratio (aOR) and 95% confidence interval (CI).

Results

Children of obese mothers were less likely to be stunted compared to those born to mothers who were not overweight/obese [aOR = 0.70; 95% CI = 0.66−0.77]. The odds of stunting increased with wealth index, with children born to poorest mothers having the highest odds compared to those born to richest mother [aOR = 1.79; 95% CI = 1.64−1.95]. The odds of stunting among children was highest among those born to mothers with no formal education compared to those whose mothers had higher education [aOR = 2.73; 95% CI = 2.34−3.18].

Conclusion

DBM among children in SSA is predicted by maternal level of education, and wealth status. These results underscore the urgency of tailored interventions and policies that address DBM among women of reproductive age, with a particular focus on the socioeconomic disparities in SSA. To effectively combat this pressing public health issue, it is imperative to direct efforts towards empowering women to attain higher levels of education and to implement strategies that consider the specific needs of women across varying socioeconomic statuses.