Elevated fish densities extend kilometres from oil and gas platforms.

Thousands of offshore oil and gas platforms have been installed throughout the world's oceans and more structures are being installed as part of the transition to renewable energy. These structures increase the availability of ecological niches by providing hard substrate in midwater and complex 3D habitat on the seafloor. This can lead to 'hotspots' of biodiversity, or increased densities of flora and fauna, which potentially spill over into the local area. However, the distances over which these higher densities extend (the 'range of influence') can be highly variable. Fish aggregate at such structures, but the range of influence and any implications for wider fish populations, are unclear. We investigated the relationship between fish and platform areal densities using high resolution fisheries acoustic data. Data were collected in the waters surrounding the vessel exclusions zones around 16 oil and gas platforms in the North Sea, and throughout the wider area. We estimated densities of schooling fish using echo-integration, and densities of non-schooling fish using echo-counting. At 10 platforms, non-schooling fish densities were elevated near the platform relative to background levels in the equivalent wider area. The range of influence, defined here as the range to which fish densities were elevated above background, varied from 0.8 to 23 km. In areas of high platform density, fish schools were encountered more often, and non-schooling fish densities were higher, when controlling for other sources of environmental variation. This is the first time such long-range effects have been identified; previously, ranges of influence have been reported in the order of just 10s-100s of metres. These findings suggest that the environmental impact of these structures may extend further than previously thought, which may be relevant in the context of upcoming management decisions around the decommissioning of these structures.

Are extra locking bolts or fibular plating more important in extreme nailing of distal tibia fractures? A cadaveric biomechanical analysis.

OBJECTIVES: In far-distal extra-articular tibia fracture "extreme" nailing, debate surrounds the relative biomechanical performance of plating the fibula compared with extra distal interlocks. This study aimed to evaluate several constructs for extreme nailing including one interlock (one medial-lateral interlock), one interlock + plate (one medial-lateral interlock with lateral fibula compression plating), and two interlocks (one medial-lateral interlock and one anterior-posterior interlock). METHODS: Fifteen pairs of fresh cadaver legs were instrumented with a tibial nail to the physeal scar. A 1 cm segment of bone was resected from the distal tibia 3.5 cm from the joint and an oblique osteotomy was made in the distal fibula. We loaded specimens with three different distal fixation constructs (one interlock, one interlock + plate, and two interlocks) through 10,000 cycles form 100N-700 N of axial loading. Load to failure (Newtons), angulation and displacement were also measured. RESULTS: Mean load to failure was 2092 N (one interlock), 1917 N (one interlock + plate), and 2545 N (two interlocks). Linear mixed effects modeling demonstrated that two interlocks had a load to failure 578 N higher than one interlock alone (95 % CI, 74N-1082 N; P = 0.02), but demonstrated no significant difference between one interlock and one interlock + plate. No statistically significant difference in rates or timing of displacement >2 mm or angulation >10° were demonstrated. CONCLUSIONS: When nailing far-distal extra-articular tibia and fibula fractures, adding a second interlock provides more stability than adding a fibular plate. Distal fibula plating may have minimal biomechanical effect in extreme nailing.

Does the OTA Open Fracture Classification Align With the Gustilo-Anderson Classification? A Study of 2215 Open Fractures.

OBJECTIVES: To characterize the Orthopaedic Trauma Association Open Fracture Classification (OTA-OFC) and Gustilo-Anderson classification of open extremity fractures and determine if there is meaningful alignment between these grading systems. DESIGN: Retrospective case series. SETTING: Level I academic trauma center. PATIENT SELECTION CRITERIA: Adult patients with at least 1 operatively treated open extremity fracture and surgeon-assigned OTA-OFC and Gustilo-Anderson classification. OUTCOME MEASURES AND COMPARISONS: Frequency, distribution, and association measures of OTA-OFC category scores and Gustilo-Anderson classification types. RESULTS: Two thousand twenty-seven patients (mean age, 43.1 ± 17.5 years) with 2215 fractures were included. Gustilo-Anderson type I or II fractures (n = 961; 43%) most frequently had the least severe scores for all OTA-OFC categories. Type IIIA fractures (n = 978; 44%) were most often assigned intermediate scores for OTA-OFC Bone Loss (n = 564; 58%). Type IIIB fractures (n = 204, 9%) were most often assigned intermediate OTA-OFC Skin scores (n = 120; 59%). Type IIIC fractures (n = 72; 3%) were most often assigned the most severe OTA-OFC Arterial score (n = 60; 83%). In the multivariable model, OTA-OFC Contamination scores showed little association (ß = 0.05; 95% confidence interval [CI], 0.01-0.09) with Gustilo-Anderson classification severity. Conversely, higher OTA-OFC Arterial (ß = 0.50; 95% CI 0.44-0.56) and Skin (ß = 0.46; 95% CI, 0.40-0.51) scores were strongly associated with more severe Gustilo-Anderson classifications. CONCLUSIONS: OTA-OFC Contamination scores were weakly associated with Gustilo-Anderson classification severity for open fractures. The study findings suggest that the current Gustilo-Anderson classification does not adequately account for injury contamination, a known predictor of infection. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Photosynthesis re-wired on the pico-second timescale.

Photosystems II and I (PSII, PSI) are the reaction centre-containing complexes driving the light reactions of photosynthesis; PSII performs light-driven water oxidation and PSI further photo-energizes harvested electrons. The impressive efficiencies of the photosystems have motivated extensive biological, artificial and biohybrid approaches to 're-wire' photosynthesis for higher biomass-conversion efficiencies and new reaction pathways, such as H2 evolution or CO2 fixation1,2. Previous approaches focused on charge extraction at terminal electron acceptors of the photosystems3. Electron extraction at earlier steps, perhaps immediately from photoexcited reaction centres, would enable greater thermodynamic gains; however, this was believed impossible with reaction centres buried at least 4 nm within the photosystems4,5. Here, we demonstrate, using in vivo ultrafast transient absorption (TA) spectroscopy, extraction of electrons directly from photoexcited PSI and PSII at early points (several picoseconds post-photo-excitation) with live cyanobacterial cells or isolated photosystems, and exogenous electron mediators such as 2,6-dichloro-1,4-benzoquinone (DCBQ) and methyl viologen. We postulate that these mediators oxidize peripheral chlorophyll pigments participating in highly delocalized charge-transfer states after initial photo-excitation. Our results challenge previous models that the photoexcited reaction centres are insulated within the photosystem protein scaffold, opening new avenues to study and re-wire photosynthesis for biotechnologies and semi-artificial photosynthesis.

Point-of-Care Lung Ultrasound Predicts Severe Disease and Death Due to COVID-19: A Prospective Cohort Study.

The clinical utility of point-of-care lung ultrasound (LUS) among hospitalized patients with COVID-19 is unclear. DESIGN: Prospective cohort study. SETTING: A large tertiary care center in Maryland, between April 2020 and September 2021. PATIENTS: Hospitalized adults (≥ 18 yr old) with positive severe acute respiratory syndrome coronavirus 2 reverse transcriptase-polymerase chain reaction results. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All patients were scanned using a standardized protocol including 12 lung zones and followed to determine clinical outcomes until hospital discharge and vital status at 28 days. Ultrasounds were independently reviewed for lung and pleural line artifacts and abnormalities, and the mean LUS Score (mLUSS) (ranging from 0 to 3) across lung zones was determined. The primary outcome was time to ICU-level care, defined as high-flow oxygen, noninvasive, or invasive mechanical ventilation, within 28 days of the initial ultrasound. Cox proportional hazards regression models adjusted for age and sex were fit for mLUSS and each ultrasound covariate. A total of 264 participants were enrolled in the study; the median age was 61 years and 114 participants (43.2%) were female. The median mLUSS was 1.0 (interquartile range, 0.5-1.3). Following enrollment, 27 participants (10.0%) went on to require ICU-level care, and 14 (5.3%) subsequently died by 28 days. Each increase in mLUSS at enrollment was associated with disease progression to ICU-level care (adjusted hazard ratio [aHR], 3.61; 95% CI, 1.27-10.2) and 28-day mortality (aHR, 3.10; 95% CI, 1.29-7.50). Pleural line abnormalities were independently associated with disease progression to death (aHR, 20.93; CI, 3.33-131.30). CONCLUSIONS: Participants with a mLUSS greater than or equal to 1 or pleural line changes on LUS had an increased likelihood of subsequent requirement of high-flow oxygen or greater. LUS is a promising tool for assessing risk of COVID-19 progression at the bedside.

Synthetic biology and bioelectrochemical tools for electrogenetic system engineering.

Synthetic biology research and its industrial applications rely on deterministic spatiotemporal control of gene expression. Recently, electrochemical control of gene expression has been demonstrated in electrogenetic systems (redox-responsive promoters used alongside redox inducers and electrodes), allowing for the direct integration of electronics with biological processes. However, the use of electrogenetic systems is limited by poor activity, tunability, and standardization. In this work, we developed a strong, unidirectional, redox-responsive promoter before deriving a mutant promoter library with a spectrum of strengths. We constructed genetic circuits with these parts and demonstrated their activation by multiple classes of redox molecules. Last, we demonstrated electrochemical activation of gene expression under aerobic conditions using a novel, modular bioelectrochemical device. These genetic and electrochemical tools facilitate the design and improve the performance of electrogenetic systems. Furthermore, the genetic design strategies used can be applied to other redox-responsive promoters to further expand the available tools for electrogenetics.

3D-printed hierarchical pillar array electrodes for high-performance semi-artificial photosynthesis.

The rewiring of photosynthetic biomachineries to electrodes is a forward-looking semi-artificial route for sustainable bio-electricity and fuel generation. Currently, it is unclear how the electrode and biomaterial interface can be designed to meet the complex requirements for high biophotoelectrochemical performance. Here we developed an aerosol jet printing method for generating hierarchical electrode structures using indium tin oxide nanoparticles. We printed libraries of micropillar array electrodes varying in height and submicrometre surface features, and studied the energy/electron transfer processes across the bio-electrode interfaces. When wired to the cyanobacterium Synechocystis sp. PCC 6803, micropillar array electrodes with microbranches exhibited favourable biocatalyst loading, light utilization and electron flux output, ultimately almost doubling the photocurrent of state-of-the-art porous structures of the same height. When the micropillars' heights were increased to 600 µm, milestone mediated photocurrent densities of 245 µA cm-2 (the closest thus far to theoretical predictions) and external quantum efficiencies of up to 29% could be reached. This study demonstrates how bio-energy from photosynthesis could be more efficiently harnessed in the future and provide new tools for three-dimensional electrode design.

A switch in species dominance of a recovering pelagic ecosystem.

Although many marine ecosystems have been adversely impacted by human activities,1 some are now recovering due to reductions in fishing pressure.2-4 Here, we document the recovery of an ecosystem subjected to intense anthropogenic activity for over 200 years, the Clyde Sea.5 This region once had productive fisheries for herring (Clupea harengus) and other fish, but these disappeared at the turn of the century.6,7 Using acoustic surveys of the pelagic ecosystem, we found that the Clyde Sea supports 100 times as many forage fish as in the late 1980s. However, herring has now been replaced by sprat (Sprattus sprattus), despite virtually no fishing on herring for 20 years. A combination of a warming sea,6 bycatch of herring in the prawn (Nephrops norvegicus) fishery,8,9 and susceptibility of herring to poor recruitment may have contributed to this unexpected recovery. We compare this to similar unexpected "recoveries" involving unforeseen ecosystem effects, such as the return of hake (Merluccius merluccius) to the North Sea;10,11 the recent expansion of the pelagic squat lobster, "munida," (Pleuroncodes monodon) off Peru;12 and the increase in scallop (Placopecten magellanicus) numbers on Georges Bank.13 The lack of a current sprat fishery in the Clyde presents a unique opportunity to develop an alternative industry for its seafaring community: ecotourism. Charismatic megafauna (whales, dolphins, and seabirds) that people will pay to see14 will, in time-if not already15,16-be drawn in by the abundance of forage fish now present, further restoring the biodiversity of the region after centuries of overexploitation.

Phenazines as model low-midpoint potential electron shuttles for photosynthetic bioelectrochemical systems.

Bioelectrochemical approaches for energy conversion rely on efficient wiring of natural electron transport chains to electrodes. However, state-of-the-art exogenous electron mediators give rise to significant energy losses and, in the case of living systems, long-term cytotoxicity. Here, we explored new selection criteria for exogenous electron mediation by examining phenazines as novel low-midpoint potential molecules for wiring the photosynthetic electron transport chain of the cyanobacterium Synechocystis sp. PCC 6803 to electrodes. We identified pyocyanin (PYO) as an effective cell-permeable phenazine that can harvest electrons from highly reducing points of photosynthesis. PYO-mediated photocurrents were observed to be 4-fold higher than mediator-free systems with an energetic gain of 200 mV compared to the common high-midpoint potential mediator 2,6-dichloro-1,4-benzoquinone (DCBQ). The low-midpoint potential of PYO led to O2 reduction side-reactions, which competed significantly against photocurrent generation; the tuning of mediator concentration was important for outcompeting the side-reactions whilst avoiding acute cytotoxicity. DCBQ-mediated photocurrents were generally much higher but also decayed rapidly and were non-recoverable with fresh mediator addition. This suggests that the cells can acquire DCBQ-resistance over time. In contrast, PYO gave rise to steadier current enhancement despite the co-generation of undesirable reactive oxygen species, and PYO-exposed cells did not develop acquired resistance. Moreover, we demonstrated that the cyanobacteria can be genetically engineered to produce PYO endogenously to improve long-term prospects. Overall, this study established that energetic gains can be achieved via the use of low-potential phenazines in photosynthetic bioelectrochemical systems, and quantifies the factors and trade-offs that determine efficacious mediation in living bioelectrochemical systems.

High-throughput in situ experimental phasing.

In this article, a new approach to experimental phasing for macromolecular crystallography (MX) at synchrotrons is introduced and described for the first time. It makes use of automated robotics applied to a multi-crystal framework in which human intervention is reduced to a minimum. Hundreds of samples are automatically soaked in heavy-atom solutions, using a Labcyte Inc. Echo 550 Liquid Handler, in a highly controlled and optimized fashion in order to generate derivatized and isomorphous crystals. Partial data sets obtained on MX beamlines using an in situ setup for data collection are processed with the aim of producing good-quality anomalous signal leading to successful experimental phasing.

The Development of Biophotovoltaic Systems for Power Generation and Biological Analysis.

Biophotovoltaic systems (BPVs) resemble microbial fuel cells, but utilise oxygenic photosynthetic microorganisms associated with an anode to generate an extracellular electrical current, which is stimulated by illumination. Study and exploitation of BPVs have come a long way over the last few decades, having benefited from several generations of electrode development and improvements in wiring schemes. Power densities of up to 0.5 W m-2 and the powering of small electrical devices such as a digital clock have been reported. Improvements in standardisation have meant that this biophotoelectrochemical phenomenon can be further exploited to address biological questions relating to the organisms. Here, we aim to provide both biologists and electrochemists with a review of the progress of BPV development with a focus on biological materials, electrode design and interfacial wiring considerations, and propose steps for driving the field forward.

The second-language vocabulary trajectories of Turkish immigrant children in Norway from ages five to ten: the role of preschool talk exposure, maternal education, and co-ethnic concentration in the neighborhood.

Little research has explored how preschools can support children's second-language (L2) vocabulary development. This study keenly followed the progress of twemty-six Turkish immigrant children growing up in Norway from preschool (age five) to fifth grade (age ten). Four different measures of preschool talk exposure (amount and diversity of teacher-led group talk and amount and diversity of peer talk), as well as the demographic variables of maternal education and co-ethnic concentration in the neighborhood, were employed to predict the children's L2 vocabulary trajectories. The results of growth analyses revealed that maternal education was the only variable predicting children's vocabulary growth during the elementary years. However, teacher-led talk, peer talk, and neighborhood predicted children's L2 vocabulary skills at age five, and these differences were maintained up to age ten. This study underscores the importance of both preschool talk exposure (teacher-led talk and peer talk) and demographic factors on L2 learners' vocabulary development.

Ruthenium-catalyzed regiospecific borylation of methyl C-H bonds.

We report the regiospecific, ruthenium-catalyzed borylation of saturated terminal C-H bonds. Alkylboronates were obtained in 78-98% yields. The borylations of alkanes, trialkylamines, protected alcohols, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. In contrast to most organometallic C-H activation, the reactions of alkanes occurred in higher yields than the reactions of arenes. Reactions were conducted that probed steric and electronic effects on the alkyl borylation. These reactions showed that the borylation occurred preferentially at the methyl group that is least sterically hindered and most electron-deficient. Ruthenium compounds containing boryl ligands were synthesized, and one was characterized by X-ray crystallography. One of these compounds contained a rare bridging boryl ligand and served as a catalyst precursor for the borylation of octane.

Regiospecific functionalization of methyl C-H bonds of alkyl groups in reagents with heteroatom functionality.

We report the regiospecific, rhodium-catalyzed borylation of saturated terminal C-H bonds in molecules with existing functionality. Moderate to good yields were obtained with the organic substrate in excess and as limiting reagent. The borylations of trialkylamines, protected alcohols, protected ketones, and fluoroalkanes occurred regiospecifically at the methyl group that is least sterically hindered. Reactions were also conducted that probed electronic effects on the alkyl borylation. These reactions showed that the borylation occurred preferentially at the methyl group that is most electron-deficient. Methods to conduct tandem borylation of C-H bonds and conversion of the resulting boronate esters to alcohols, alkylarenes, and alkyltrifluoroborates were also developed.

Bimetallic carbonyl thiolates as functional models for Fe-only hydrogenases.

The anion [Fe(2)(S(2)C(3)H(6))(CN)(CO)(4)(PMe(3))](-) (2(-)) is protonated by sulfuric or toluenesulfonic acid to give HFe(2)(S(2)C(3)H(6))(CN)(CO)(4)(PMe(3)) (2H), the structure of which has the hydride bridging the Fe atoms with the PMe(3) and CN(-) trans to the same sulfur atom. (1)H, (13)C, and (31)P NMR spectroscopy revealed that HFe(2)(S(2)C(3)H(6))(CN)(CO)(4)(PMe(3)) is stereochemically rigid on the NMR time scale with four inequivalent carbonyl ligands. Treatment of 2(-) with (Me(3)O)BF(4) gave Fe(2)(S(2)C(3)H(6))(CNMe)(CO)(4)(PMe(3)) (2Me). The Et(4)NCN-induced reaction of Fe(2)(S(2)C(3)H(6))(CO)(6) with P(OMe)(3) gave [Fe(2)(S(2)C(3)H(6))(CN)(CO)(4)[P(OMe)(3)]](-) (4). Spectroscopic and electrochemical measurements indicate that 2H can be further protonated at nitrogen to give [HFe(2)(S(2)C(3)H(6))(CNH)(CO)(4)(PMe(3))](+) (2H(2)(+)). Electrochemical and analytical data show that reduction of 2H(2)(+) gives H(2) and 2(-). Parallel electrochemical studies on [HFe(2)(S(2)C(3)H(6))(CO)(4)(PMe(3))(2)](+) (3H(+)) in acidic solutions led also to catalytic proton reduction. The 3H(+)/3H couple is reversible, whereas the 2H(2)(+)/2H(2) couple is not, because of the efficiency of the latter as a proton reduction catalyst. Proton reduction is proposed to involve protonation of reduced diiron hydrides. DFT calculations establish that the regiochemistry of protonation is subtly dependent on the coligands but is more favorable to occur at the Fe-Fe bond for [Fe(2)(S(2)C(3)H(6))(CN)(CO)(4)(PMe(3))](-) than for [Fe(2)(S(2)C(3)H(6))(CN)(CO)(4)(PH(3))](-) or [Fe(2)(S(2)C(3)H(6))(CN)(CO)(4)[P(OMe)(3)]](-). The Fe(2)H unit stabilizes the conformer with eclipsed CN and PMe(3) because of an attractive electrostatic interaction between these ligands.

New class of diiron dithiolates related to the Fe-only hydrogenase active site: synthesis and characterization of [Fe2(SR)(2)(CNMe)7]2+.

Electron-rich polyisocyano derivatives Fe(2)(S(2)C(n)H(2n)(CO)(6-x)(CNMe)(x) (x approximately 4) undergo oxidatively induced (FeCp(2)(+)) reaction with additional CNMe to give [Fe(2)(SR)(2)(CNMe)(7)](PF(6))(2), a new class of iron thiolates. Crystallographic characterization established that the 34 e(-) dinuclear core resembles the oxidized (H(2)-binding) form of the active sites of the Fe-only hydrogenases, key features being the face-sharing bioctahedral geometry, the mu-CX ligand, and an Fe-Fe separation of 2.61 A. Oxidation of the phenylthiolate Fe(2)(SPh)(2)(CO)(2)(CNMe)(4) led to mononuclear [Fe(SPh)(CNMe)(5)](PF(6)), which is analogous to [Fe(2)(SR)(2)(CNMe)(10)](PF(6))(2) formed upon treatment of [Fe(2)(S(2)C(3)H(6))(CNMe)(7)](PF(6))(2) with excess CNMe.