26 research outputs found

    The Effect of Water Turbulence and Stocking Density on Mactromeris Polynyma Growth and Survival in a Subtidal Nursery Setting

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    The Arctic surfclam, Mactromeris polynyma, while native to the Maine coast is generally found only in deep water. The market for these clams has historically been restricted to their use in Asian cuisine. In an attempt to improve the declining clamming industry in Downeast Maine the Downeast Institute (DEI) is attempting to cultivate Mactromeris in a similar way as other shellfish already being cultivated. This study examined growth and survival of cultured Arctic surfclam juveniles at a sheltered site (Inner Mud Hole Cove 44.4852778, -67.5863889) and a more exposed site located approximately 650 m away at the mouth of the cove. It was hypothesized that the more sheltered site might present more favorable conditions for growth and survival (more food, less stress due to wave action). In addition, the study examined intraspecific density on surfclam growth and survival. In previous studies (Beal et al., 2016, unpubl.) clams stocked at lower densities tended to show higher survival and growth. Clams were stocked at either 40 or 20 per tray in this experiment

    Enhancing the activity of oxygen-evolution and chlorine-evolution electrocatalysts by atomic layer deposition of TiO₂

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    We report that TiO₂ coatings formed via atomic layer deposition (ALD) may tune the activity of IrO₂, RuO₂, and FTO for the oxygen-evolution and chlorine-evolution reactions (OER and CER). Electrocatalysts exposed to ∼3–30 ALD cycles of TiO₂ exhibited overpotentials at 10 mA cm⁻² of geometric current density that were several hundred millivolts lower than uncoated catalysts, with correspondingly higher specific activities. For example, the deposition of TiO₂ onto IrO₂ yielded a 9-fold increase in the OER-specific activity in 1.0 M H₂SO₄ (0.1 to 0.9 mA cm_(ECSA)⁻² at 350 mV overpotential). The oxidation state of titanium and the potential of zero charge were also a function of the number of ALD cycles, indicating a correlation between oxidation state, potential of zero charge, and activity of the tuned electrocatalysts

    Enhancing the activity of oxygen-evolution and chlorine-evolution electrocatalysts by atomic layer deposition of TiO₂

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    We report that TiO₂ coatings formed via atomic layer deposition (ALD) may tune the activity of IrO₂, RuO₂, and FTO for the oxygen-evolution and chlorine-evolution reactions (OER and CER). Electrocatalysts exposed to ∼3–30 ALD cycles of TiO₂ exhibited overpotentials at 10 mA cm⁻² of geometric current density that were several hundred millivolts lower than uncoated catalysts, with correspondingly higher specific activities. For example, the deposition of TiO₂ onto IrO₂ yielded a 9-fold increase in the OER-specific activity in 1.0 M H₂SO₄ (0.1 to 0.9 mA cm_(ECSA)⁻² at 350 mV overpotential). The oxidation state of titanium and the potential of zero charge were also a function of the number of ALD cycles, indicating a correlation between oxidation state, potential of zero charge, and activity of the tuned electrocatalysts

    Carbon-sensitive pedotransfer functions for plant available water

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    Currently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute\u27s North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had predictions of θAWHC that were similarly accurate compared with Saxton and Rawls when tested on samples from the National Soil Characterization database. Further, the new pedotransfer functions showed substantial effects of soil calcareousness and SOC on θAWHC. For an increase in SOC of 10 g kg–1 (1%) in noncalcareous soils, an average increase in θAWHC of 3.0 mm 100 mm–1 soil (0.03 m3 m–3) on average across all soil texture classes was found. This SOC related increase in θAWHC is about double previous estimates. Calcareous soils had an increase in θAWHC of 1.2 mm 100 mm–1 soil associated with a 10 g kg–1 increase in SOC, across all soil texture classes. New equations can aid in quantifying benefits of soil management practices that increase SOC and can be used to model the effect of changes in management on drought resilience

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Synthesis and Structure of [Fe(TPA)Cl2](ClO4) and [{Fe(TPA)Cl}2O](ClO4)2 Where TPA = Tris-(2-pyridylmethyl)amine

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    Abstract: [Fe(TPA)Cl2](ClO4), where TPA is tris-(2-pyridylmethyl)amine, crystallizes in the orthorhombic space group P212121 with Z = 4, a = 8.6264(10) Å, b = 15.459(3) Å, and c = 16.008(3) Å. The structure was determined at 110 K from 4333 reflections (3520 observed) with R = 0.041 (Rw = 0.082). The iron is pseudo-octahedral with the two chloride ions cis. The Fe-Cl bond trans to the tertiary amine is shorter. [{Fe(TPA)Cl}2O](ClO4)2 exhibits two polymorphic monoclinic forms, and the monohydrate also crystallizes in a monoclinic form. For the P21/c polymorph, Z = 2, a = 10.839(2) Å, b = 15.956(3) Å, c = 12.416(2) Å, β = 107.024(10)°, and the structure was determined at 95 K from 6514 reflections (3974 observed) with R = 0.052 (Rw = 0.099). For the C2/c polymorph, Z = 4, a = 20.5023(17) Å, b = 15.2711(13) Å, c = 16.1069(11) Å, β = 124.465(4)°, and the structure was determined at 161 K from 6250 reflections (3130 observed) with R = 0.0632 (Rw = 0.1229). For the hydrate, P21/n, Z = 4, a = 16.201(2) Å, b = 16.980(3), c = 16.451(3), β = 112.234(5)°, and the structure was determined at 100 K from 12,745 reflections (6600 observed) with R = 0.097 (Rw = 0.190). In each of the [{Fe(TPA)Cl}2O]2+ units, each iron is pseudo-octahedral with the chloride and oxide ions cis. The oxide bridge is linear, and the two chlorides are anti. The Fe-N distance for the pyridyl ring trans to the oxide bridge is quite long due to the trans influence of the oxide. Graphic Abstract: The X-ray structures of [Fe(TPA)Cl2](ClO4), where TPA is tris-(2-pyridylmethyl)amine, and three polymorphs of dimeric [{Fe(TPA)Cl}2O](ClO4)2 are presented and discussed. [Figure not available: see fulltext.

    Syntheses and Structures of [Fe(TPA)X2](ClO4) and [{Fe(TPA)Y}2O](ClO4)2 Where TPA = Tris-(2-pyridylmethyl)amine, X = N3, or Br, and Y = N3, Br, NCO, or NCS

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    [Fe(TPA)(N3)2](ClO4) and [Fe(TPA)Br2](ClO4), where TPA is tris-(2-pyridylmethyl)amine, crystallize in the monoclinic space group P21/c with a = 8.7029(5) Å, b = 19.168(1) Å, c = 13.5728(7) Å, β = 101.472(3)°, and a = 8.944(3) Å, b = 16.578(6) Å, c = 15.108(6) Å, β = 103.18(2)°, respectively. The structures were determined at 150 K from 3397 reflections (1426 observed) with R = 0.063 (Rw = 0.097), and at 115 K from 5617 reflections (2261 observed) with R = 0.057 (Rw = 0.065), respectively. In both cases, the iron is pseudo-octahedral with the two halide/pseudohalide ions cis. The Fe–X bond trans to the tertiary amine is shorter. The structures of [{Fe(TPA)X}2O](ClO4)2 where X = N3, Br, NCO, and two polymorphic forms of NCS, are also reported. The azide derivative [CH3CN solvate, monoclinic P21/n, a = 11.8038(11) Å, b = 22.547(2) Å, c = 17.344(2) Å, β = 106.972(4)°, determined at 100 K from 8972 reflections (4404 observed) with R = 0.087 (Rw = 0.145)] has two distinct Fe environments—the tertiary amine is cis to the oxido bridge at one site and is trans to the oxido bridge at the other site; the trans Fe–N3° distance is longer. Both the Br and NCO derivatives are monoclinic, C2/c [with a = 16.1480(17), b = 17.2036(13), c = 16.8521(12), β = 111.204(10), data collected at 293 K, 3753 reflections (2404 observed), R = 0.069 (Rw = 0.151), and a = 15.7470(9), b = 18.2270(11), c = 16.8950(8), β = 110.666(3), data collected at 90 K, 5392 reflections (3028 observed), R = 0.064 (Rw = 0.091), respectively]. Both polymorphs of the NCS derivative are monoclinic—one is P21/c and the other P21/n [a = 11.075(2), b = 15.436(2), c = 12.351(2), β = 95.528(7), data collected at 90 K, 5378 reflections (4345 observed), R = 0.068 (Rw = 0.198), and a = 12.396(2), b = 15.428(3), c = 44.505(8), β = 95.211(7), data collected at 110 K, 16,527 reflections (6540 observed), R = 0.069 (Rw = 0.105), respectively]. For the Br, NCO and NCS dimers, each iron of the [{Fe(TPA)X}2O]2+ unit is pseudo-octahedral with the halide/pseudohalide and oxide ions cis. The oxide bridge is linear, and the two halides/pseudohalides are anti. The ranking of trans influence of the ligands is O2− ≫ Br− \u3e Cl− \u3e N3− \u3e NCO− ≥ NCS− \u3e pyridyl \u3e tertiary amine and the ranking of cis influence of the ligands is O2− ≫ N3− \u3e NCO− \u3e Cl− ≥ Br− \u3e NCS−. Graphical Abstract: The X-ray structures of two monomeric [Fe(TPA)(X)2](ClO4), where TPA is tris-(2-pyridylmethyl)amine and X = N3, and Br, and four dimeric [{Fe(TPA)Y}2O](ClO4)2, where Y =N3, Br, NCO, and NCS are presented and discussed. [Figure not available: see fulltext.
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