24 research outputs found
Using Sputter Deposition to Increase CO Tolerance in a Proton-Exchange Membrane Fuel Cell
Placing a layer of Ru atop a Pt anode increases the carbon monoxide tolerance of proton-exchange membrane fuel cells when oxygen is added to the fuel stream. Sputter-deposited Ru filter anodes composed of a single Ru layer and three Ru layers separated by Nafion-carbon ink, respectively, were compared to Pt, Pt:Ru alloy, and an ink-based Ru filter anodes. The amount of Pt in each anode was 0.15 mg/cm2 and the amount of Ru in each Ru-containing anode was 0.080 mg/cm2. For an anode feed consisting of hydrogen, 200 ppm CO, and 2% O2 (in the form of an air bleed), all Ru filter anodes outperformed the Pt:Ru alloy. The performance of the Pt + single-layer sputtered Ru filter was double that of the Pt:Ru alloy (0.205 vs. 0.103 A/cm2 at 0.6 V). The performance was also significantly greater than that of the ink-based Ru filter (0.149 A/cm2 at 0.6 V). Within the filter region of the anode, it is likely that the decreased hydrogen kinetics of the Ru (compared to Pt) allow for more of the OHads formed from oxygen in the fuel stream to oxidize adsorbed CO to CO2
The Ursinus Weekly, December 2, 1968
Arts Forum held; 4 foreign students featured on panel • Board OKs student members on committees; Student Senate endorses SFARC resolution • Camino real scheduled for December 6th • Mandrake concert is hit; Rock group shows profit • Editorial: Our play; The larger issue • Letters to the editor • Tradition vs. change • Herberg sees anomic moral crisis; Fun morality termed other directed • SFARC minutes • Opinion: Speaker fails to prove dilemma • Freeland Hall: Don\u27t let it be forgot • Senior looks at Freeland: Can Library replace Freeland\u27s primacy? • Search into history substantiates claim of second oldest graduate that Freeland was everything • Instructor asks what do students really want? • Now is the time to unite • WRUC increases wattage to allow greater service • USGA discusses Black Alliance • Students to decide on two government proposals • Pratt art show opens at Ursinus • PNE Folk Fest held; U.C. talent featured • U.C. sponsors Career Days • Howard honored for achievements • Gurzynski\u27s men win title; Albert leads UC to championship • Soccer team edges LaSalle after losing to Haverford • Flowers win intramural crown with 6-0 victory over Sig Rho • Whatley lauds squad; predicts progress • Bears destroy Haverford; Shuman wins Maxwell Award • All Stars will visit Glassboro • Greek gleaningshttps://digitalcommons.ursinus.edu/weekly/1167/thumbnail.jp
The Ursinus Weekly, December 19, 1968
Messiah presented by Ursinus choir; Performances draw SRO audiences • Frat system & houses favored by students; 12% thumbs down! • 878 enrolled in U.C. Evening School • YM-YWCA supports SFARC investigation • Editorial: Activities chaos rolls on • Drama in real life • Student long-term planning committee report • Letters to the editor • Flu strikes East; U.C. still healthy • A memory with pillars • A Christmas story • Murmurs from within • Exchange • Faculty portrait: Mr. Sharp; Hangup on social problems overshadows intellectual quest • UC pranks: They\u27re all in good fun; Was Freeland ghost really Dr. Helfferich? • Many of greatest pranks took place in Chapel • Doctors Yost and Parsons recall Ursinus shenanigans of yesteryear; Boycotts, pigs, moths make hits • Protheatre makes hit debut in New Theatre production • Opinion: Open letter to Byron Jackson • Greek gleanings • Winning doesn\u27t count but being clean-shaven does • Snellbelles open against Moravian • Outweighed, but still fighting • Bears to face area teams, will see many super sophs • Women\u27s wrestling wound-up • Quiet revolution topic of discussion • Dr. Lewis announces $1000 trust fund • Blacks\u27 non-recognition: one topic for USGAhttps://digitalcommons.ursinus.edu/weekly/1168/thumbnail.jp
Inter-rater reliability of categorical versus continuous scoring of fish vitality: does it affect the utility of the reflex action mortality predictor (RAMP) approach?
Scoring reflex responsiveness and injury of aquatic organisms has gained popularity as predictors of discard survival. Given this method relies upon the individual interpretation of scoring criteria, an evaluation of its robustness is done here to test whether protocol-instructed, multiple raters with diverse backgrounds (research scientist, technician, and student) are able to produce similar or the same reflex and injury score for one of the same flatfish (European plaice, Pleuronectes platessa) after experiencing commercial fishing stressors. Inter-rater reliability for three raters was assessed by using a 3-point categorical scale (‘absent’, ‘weak’, ‘strong’) and a tagged visual analogue continuous scale (tVAS, a 10 cm bar split in three labelled sections: 0 for ‘absent’, ‘weak’, ‘moderate’, and ‘strong’) for six reflex responses, and a 4-point scale for four injury types. Plaice (n = 304) were sampled from 17 research beam-trawl deployments during four trips. Fleiss kappa (categorical scores) and intra-class correlation coefficients (ICC, continuous scores) indicated variable inter-rater agreement by reflex type (ranging between 0.55 and 0.88, and 67% and 91% for Fleiss kappa and ICC, respectively), with least agreement among raters on extent of injury (Fleiss kappa between 0.08 and 0.27). Despite differences among raters, which did not significantly influence the relationship between impairment and predicted survival, combining categorical reflex and injury scores always produced a close relationship of such vitality indices and observed delayed mortality. The use of the continuous scale did not improve fit of these models compared with using the reflex impairment index based on categorical scores. Given these findings, we recommend using a 3-point categorical over a continuous scale. We also determined that training rather than experience of raters minimised inter-rater differences. Our results suggest that cost-efficient reflex impairment and injury scoring may be considered a robust technique to evaluate lethal stress and damage of this flatfish species on-board commercial beam-trawl vessels
Guidelines for Diagnosis and Management of Infective Endocarditis in Adults: A WikiGuidelines Group Consensus Statement.
IMPORTANCE
Practice guidelines often provide recommendations in which the strength of the recommendation is dissociated from the quality of the evidence.
OBJECTIVE
To create a clinical guideline for the diagnosis and management of adult bacterial infective endocarditis (IE) that addresses the gap between the evidence and recommendation strength.
EVIDENCE REVIEW
This consensus statement and systematic review applied an approach previously established by the WikiGuidelines Group to construct collaborative clinical guidelines. In April 2022 a call to new and existing members was released electronically (social media and email) for the next WikiGuidelines topic, and subsequently, topics and questions related to the diagnosis and management of adult bacterial IE were crowdsourced and prioritized by vote. For each topic, PubMed literature searches were conducted including all years and languages. Evidence was reported according to the WikiGuidelines charter: clear recommendations were established only when reproducible, prospective, controlled studies provided hypothesis-confirming evidence. In the absence of such data, clinical reviews were crafted discussing the risks and benefits of different approaches.
FINDINGS
A total of 51 members from 10 countries reviewed 587 articles and submitted information relevant to 4 sections: establishing the diagnosis of IE (9 questions); multidisciplinary IE teams (1 question); prophylaxis (2 questions); and treatment (5 questions). Of 17 unique questions, a clear recommendation could only be provided for 1 question: 3 randomized clinical trials have established that oral transitional therapy is at least as effective as intravenous (IV)-only therapy for the treatment of IE. Clinical reviews were generated for the remaining questions.
CONCLUSIONS AND RELEVANCE
In this consensus statement that applied the WikiGuideline method for clinical guideline development, oral transitional therapy was at least as effective as IV-only therapy for the treatment of IE. Several randomized clinical trials are underway to inform other areas of practice, and further research is needed
Protecting Important Sites for Biodiversity Contributes to Meeting Global Conservation Targets
Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as ‘important sites’). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with>50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45–1.14% annually since 1950 for IBAs and 0.79–1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends
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Averting biodiversity collapse in tropical forest protected areas
The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon¹⁻³. With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses⁴⁻⁹. As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world’s major tropical regions. Our analysis reveals great variation in reserve ‘health’: about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.Keywords: Ecology, Environmental scienc
Beating the Stoner criterion using molecular interfaces.
Only three elements are ferromagnetic at room temperature: the transition metals iron, cobalt and nickel. The Stoner criterion explains why iron is ferromagnetic but manganese, for example, is not, even though both elements have an unfilled 3d shell and are adjacent in the periodic table: according to this criterion, the product of the density of states and the exchange integral must be greater than unity for spontaneous spin ordering to emerge. Here we demonstrate that it is possible to alter the electronic states of non-ferromagnetic materials, such as diamagnetic copper and paramagnetic manganese, to overcome the Stoner criterion and make them ferromagnetic at room temperature. This effect is achieved via interfaces between metallic thin films and C60 molecular layers. The emergent ferromagnetic state exists over several layers of the metal before being quenched at large sample thicknesses by the material's bulk properties. Although the induced magnetization is easily measurable by magnetometry, low-energy muon spin spectroscopy provides insight into its distribution by studying the depolarization process of low-energy muons implanted in the sample. This technique indicates localized spin-ordered states at, and close to, the metal-molecule interface. Density functional theory simulations suggest a mechanism based on magnetic hardening of the metal atoms, owing to electron transfer. This mechanism might allow for the exploitation of molecular coupling to design magnetic metamaterials using abundant, non-toxic components such as organic semiconductors. Charge transfer at molecular interfaces may thus be used to control spin polarization or magnetization, with consequences for the design of devices for electronic, power or computing applications (see, for example, refs 6 and 7)