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1.
Phys Rev Lett ; 132(11): 110601, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38563919

RESUMO

Simulators can realize novel phenomena by separating them from the complexities of a full physical implementation. Here, we put forward a scheme that can simulate the exotic statistics of D(S_{3}) non-Abelian anyons with minimal resources. The qudit lattice representation of this planar code supports local encoding of D(S_{3}) anyons. As a proof-of-principle demonstration, we employ a classical photonic simulator to encode a single qutrit and manipulate it to perform the fusion and braiding properties of non-Abelian D(S_{3}) anyons. The photonic technology allows us to perform the required nonunitary operations with much higher fidelity than what can be achieved with current quantum computers. Our approach can be directly generalized to larger systems or to different anyonic models, thus enabling advances in the exploration of quantum error correction and fundamental physics alike.

3.
Nat Chem Biol ; 13(6): 655-659, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28394885

RESUMO

The recently realized biochemical phenomenon of energy conservation through electron bifurcation provides biology with an elegant means to maximize utilization of metabolic energy. The mechanism of coordinated coupling of exergonic and endergonic oxidation-reduction reactions by a single enzyme complex has been elucidated through optical and paramagnetic spectroscopic studies revealing unprecedented features. Pairs of electrons are bifurcated over more than 1 volt of electrochemical potential by generating a low-potential, highly energetic, unstable flavin semiquinone and directing electron flow to an iron-sulfur cluster with a highly negative potential to overcome the barrier of the endergonic half reaction. The unprecedented range of thermodynamic driving force that is generated by flavin-based electron bifurcation accounts for unique chemical reactions that are catalyzed by these enzymes.


Assuntos
Elétrons , Flavina-Adenina Dinucleotídeo/análogos & derivados , Flavinas/metabolismo , Modelos Biológicos , Sítios de Ligação , Transporte de Elétrons , Flavina-Adenina Dinucleotídeo/química , Flavina-Adenina Dinucleotídeo/metabolismo , Flavinas/química
4.
Phys Rev Lett ; 120(15): 150602, 2018 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-29756899

RESUMO

In thermodynamics, quantum coherences-superpositions between energy eigenstates-behave in distinctly nonclassical ways. Here we describe how thermodynamic coherence splits into two kinds-"internal" coherence that admits an energetic value in terms of thermodynamic work, and "external" coherence that does not have energetic value, but instead corresponds to the functioning of the system as a quantum clock. For the latter form of coherence, we provide dynamical constraints that relate to quantum metrology and macroscopicity, while for the former, we show that quantum states exist that have finite internal coherence yet with zero deterministic work value. Finally, under minimal thermodynamic assumptions, we establish a clock-work trade-off relation between these two types of coherences. This can be viewed as a form of time-energy conjugate relation within quantum thermodynamics that bounds the total maximum of clock and work resources for a given system.

5.
Worldviews Evid Based Nurs ; 15(5): 368-376, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30160011

RESUMO

BACKGROUND: Effective pain management is unlikely to occur without consistent and timely assessments. To improve assessment and management of pain, ward-based pain resource nurses were introduced in 2007 to facilitate hospital-wide evidence-based practice changes using three key targets. One-year post implementation of this quality improvement project, promising results were revealed. AIMS: The purpose of this study, 8 years post implementation, was to (a) evaluate sustained practice improvements in pain assessment and management, (b) assess current pain resource nurse knowledge and attitudes to pain, (c) explore characteristics of the pain resource nurse role, as well as (d) any perceived contextual changes regarding study findings. METHODS: A mixed-methods approach was used to address study aims. Quantitative data were collected from documentation audits and a "Knowledge and Attitudes Survey Regarding Pain." Qualitative interviews explored the characteristics of the pain resource nurse role, and a focus group discussion explored the context of change. RESULTS: Significant improvements were observed for the documentation of pain scores on admission and for each nursing shift. Survey results highlighted potential knowledge deficits in key practice areas, even though interview findings suggested that pain resource nurses provided a resource for peers, raised awareness of best practice, and imparted knowledge to other ward staff. An important facilitator for the pain resource nurse role was the ongoing collaboration and support from specific pain teams, and barriers to engage in the role were competing workload priorities, and limited awareness among other ward staff. LINKING EVIDENCE TO ACTION: Implementing and sustaining evidence-based practice change in clinical practice is challenging. Ongoing evaluation is necessary for identifying the long-term implications of practice improvement interventions and issues that influence the adoption of evidence-based practice. Strategies to address barriers, and to increase awareness and engagement of the pain resource nurse role with wider collaboration require further investigation.


Assuntos
Manejo da Dor/normas , Medição da Dor/estatística & dados numéricos , Percepção , Especialidades de Enfermagem/normas , Documentação/métodos , Documentação/normas , Documentação/estatística & dados numéricos , Prática Clínica Baseada em Evidências/métodos , Prática Clínica Baseada em Evidências/normas , Prática Clínica Baseada em Evidências/tendências , Grupos Focais , Humanos , Enfermeiras e Enfermeiros/psicologia , Enfermeiras e Enfermeiros/estatística & dados numéricos , Manejo da Dor/enfermagem , Medição da Dor/enfermagem , Medição da Dor/normas , Pesquisa Qualitativa , Inquéritos e Questionários
6.
J Anim Ecol ; 85(4): 973-81, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27061175

RESUMO

Foraging modalities (e.g. passive, sit-and-wait, active) and traits are plastic in some species, but the extent to which this plasticity affects interspecific competition remains unclear. Using a long-term laboratory mesocosm experiment, we quantified competition strength and the plasticity of foraging traits in a guild of generalist predators of arthropods with a range of foraging modalities. Each mesocosm contained eight passively foraging pink sundews, and we employed an experimental design where treatments were the presence or absence of a sit-and-wait foraging spider and actively foraging toad crossed with five levels of prey abundance. We hypothesized that actively foraging toads would outcompete the other species at low prey abundance, but that spiders and sundews would exhibit plasticity in foraging traits to compensate for strong competition when prey were limited. Results generally supported our hypotheses. Toads had a greater effect on sundews at low prey abundances, and toad presence caused spiders to locate webs higher above the ground. Additionally, the closer large spider webs were to the ground, the greater the trichome densities produced by sundews. Also, spider webs were larger with than without toads and as sundew numbers increased, and these effects were more prominent as resources became limited. Finally, spiders negatively affected toad growth only at low prey abundance. These findings highlight the long-term importance of foraging modality and plasticity of foraging traits in determining the strength of competition within and across taxonomic kingdoms. Future research should assess whether plasticity in foraging traits helps to maintain coexistence within this guild and whether foraging modality can be used as a trait to reliably predict the strength of competitive interactions.


Assuntos
Comportamento Apetitivo , Bufonidae/crescimento & desenvolvimento , Comportamento Competitivo/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Aranhas/fisiologia , Animais , Drosera , Ecossistema
7.
J Am Chem Soc ; 137(42): 13556-65, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26436715

RESUMO

We report the first direct electrochemical characterization of the impact of oxygen on the hydrogen oxidation activity of an oxygen-tolerant, group 3, soluble [NiFe]-hydrogenase: hydrogenase I from Pyrococcus furiosus (PfSHI), which grows optimally near 100 °C. Chronoamperometric experiments were used to probe the sensitivity of PfSHI hydrogen oxidation activity to both brief and prolonged exposure to oxygen. For experiments between 15 and 80 °C, following short (<200 s) exposure to 14 µM O2 under oxidizing conditions, PfSHI always maintains some fraction of its initial hydrogen oxidation activity; i.e., it is oxygen-tolerant. Reactivation experiments show that two inactive states are formed by interaction with oxygen and both can be quickly (<150 s) reactivated. Analogous experiments, in which the interval of oxygen exposure is extended to 900 s, reveal that the response is highly temperature-dependent. At 25 °C, under sustained 1% O2/ 99% H2 exposure, the H2oxidation activity drops nearly to zero. However, at 80 °C, up to 32% of the enzyme's oxidation activity is retained. Reactivation of PfSHI following sustained exposure to oxygen occurs on a much longer time scale (tens of minutes), suggesting that a third inactive species predominates under these conditions. These results stand in contrast to the properties of oxygen-tolerant, group 1 [NiFe]-hydrogenases, which form a single state upon reaction with oxygen, and we propose that this new type of hydrogenase should be referred to as oxygen-resilient. Furthermore, PfSHI, like other group 3 [NiFe]-hydrogenases, does not possess the proximal [4Fe3S] cluster associated with the oxygen tolerance of some group 1 enzymes. Thus, a new mechanism is necessary to explain the observed oxygen tolerance in soluble, group 3 [NiFe]-hydrogenases, and we present a model integrating both electrochemical and spectroscopic results to define the relationships of these inactive states.


Assuntos
Hidrogenase/química , Hidrogenase/metabolismo , Oxigênio/química , Pyrococcus furiosus/enzimologia , Hidrogênio/química , Oxirredução , Temperatura
9.
Gen Comp Endocrinol ; 214: 62-7, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25745815

RESUMO

Direct-developing frogs lack, wholly or in part, a wide range of larval features found in metamorphosing species and form adult-specific features precociously, during embryogenesis. Most information on thyroid regulation of direct development relies on hormone manipulations; the ontogeny of many thyroid axis components has not been fully described. This analysis examines differentiation of the median eminence of the hypothalamus and production of thyroid-stimulating hormone (TSH) by the pituitary of the direct-developing frog Eleutherodactylus coqui. The median eminence is established two-thirds of the way through embryogenesis. Cells immunoreactive to human TSHß antibodies are first detected during embryogenesis and quantitative changes in TSHß-IR cells resemble those in metamorphosing amphibians. Formation of the median eminence of the hypothalamus and TSHß production by the pituitary precede or coincide with morphological changes during embryogenesis that occur during metamorphosis in biphasic anurans. Thus, while the onset of neuroendocrine regulation has changed during the evolution of direct development, it is likely that these thyroid axis components still mediate the formation of adult features.


Assuntos
Anuros/embriologia , Encefalopatias/patologia , Eminência Mediana/patologia , Metamorfose Biológica/fisiologia , Hipófise/embriologia , Glândula Tireoide/embriologia , Tireotropina/metabolismo , Animais , Anuros/metabolismo , Encefalopatias/metabolismo , Diferenciação Celular , Feminino , Técnicas Imunoenzimáticas , Larva/crescimento & desenvolvimento , Larva/metabolismo , Masculino , Eminência Mediana/metabolismo , Hipófise/metabolismo , Glândula Tireoide/metabolismo
10.
Phys Rev Lett ; 113(2): 020402, 2014 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-25062143

RESUMO

The quantum steering ellipsoid of a two-qubit state is the set of Bloch vectors that Bob can collapse Alice's qubit to, considering all possible measurements on his qubit. We provide an elementary construction of the ellipsoid for arbitrary states, calculate its volume, and explain how this geometric representation can be made faithful. The representation provides a range of new results, and uncovers new features, such as the existence of "incomplete steering" in separable states. We show that entanglement can be analyzed in terms of three geometric features of the ellipsoid and prove that a state is separable if and only if it obeys a "nested tetrahedron" condition.

11.
J Sex Marital Ther ; 40(4): 294-308, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23905759

RESUMO

Research on nonparaphilic hypersexual behavior has increased in recent years. In the present article, the authors conducted a methodological review of empirical studies that evaluated a treatment for nonparaphilic hypersexual behavior. The authors reviewed several characteristics of the extant studies, including the participants, research designs, treatments evaluated, assessment of nonparaphilic hypersexual behavior, and outcomes. Despite several attempts to explore treatments aimed at attenuating the symptoms of nonparaphilic hypersexual behavior, the findings from this review indicate that much of the outcome research in the field contains significant methodological limitations. The authors conclude by offering recommendations to enhance future outcome research among investigators working with hypersexual populations.


Assuntos
Terapia Conjugal/métodos , Disfunções Sexuais Psicogênicas/diagnóstico , Disfunções Sexuais Psicogênicas/terapia , Cônjuges , Feminino , Humanos , Relações Interpessoais , Libido , Masculino
12.
Sci Total Environ ; 914: 169941, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38199369

RESUMO

BACKGROUND: Microplastics (MPs) are found in all environments: aquatic, airborne, and terrestrial. While their presence is not disputed, their potential impacts are not yet known. OBJECTIVE: To undertake a pilot analysis of MP contamination in archaeological sediment samples, taken in the late 1980s from two archaeological excavation sites in the historic city of York (UK) as well as contemporary sources close to the same sites, with respect to the presence (if any), levels, and characteristics of any particles identified. METHODS: This study analysed pre-digested sediment samples as follows: n = 3 from Queens Hotel (QH) site and n = 3 Wellington Row (WR) contemporary core-source, and n = 3 QH and n = 3 WR archival-source samples, alongside procedural controls (n = 8), using µFTIR spectroscopy (size limitation of 5 µm) to detect and characterise any MPs present. RESULTS: In total, 66 MP particles consisting of 16 MP polymer types were identified across both site and contemporary/archived samples. The highest levels of MP particles, 20,588 MP/kg was identified at the lowest sample depth (∼7.35 m) at archived WR, 5910 MP/kg in the mid depth layer (∼5.85 m) at the contemporary QH site. Of the MPs detected in sediment samples overall, polytetrafluoroethylene (PTFE), polybutylene sulfone (PSU), and polypropylene: polyethylene (PE:PP) copolymer polymer types were most abundant; mainly fragmented and irregular shape. CONCLUSIONS: This is believed to be the first evidence of MP contamination in archaeological sediment (or soil) samples with polymers and size ranges measured and while accounting for procedural blanks. These results support the phenomenon of transport of MPs within archaeological stratigraphy, and the characterisation of types, shapes and size ranges identified therein. Through contamination, MPs may compromise the scientific value of archaeological deposits, and environmental proxies suspended within significant sediment, and as such represent a new consideration in the dynamism of, as well as arguments for preserving, archaeological deposits in situ.

13.
J Am Chem Soc ; 134(17): 7553-7, 2012 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-22512303

RESUMO

Formaldehyde-a rapid and reversible inhibitor of hydrogen evolution by [FeFe]-hydrogenases-binds with a strong potential dependence that is almost complementary to that of CO. Whereas exogenous CO binds tightly to the oxidized state known as H(ox) but very weakly to a state two electrons more reduced, formaldehyde interacts most strongly with the latter. Formaldehyde thus intercepts increasingly reduced states of the catalytic cycle, and density functional theory calculations support the proposal that it reacts with the H-cluster directly, most likely targeting an otherwise elusive and highly reactive Fe-hydrido (Fe-H) intermediate.


Assuntos
Clostridium acetobutylicum/enzimologia , Inibidores Enzimáticos/farmacologia , Formaldeído/farmacologia , Hidrogênio/metabolismo , Hidrogenase/antagonistas & inibidores , Metaloproteínas/antagonistas & inibidores , Monóxido de Carbono/metabolismo , Clostridium acetobutylicum/química , Hidrogenase/química , Hidrogenase/metabolismo , Ferro/química , Metaloproteínas/química , Metaloproteínas/metabolismo
14.
Phys Rev Lett ; 109(15): 150404, 2012 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-23102280

RESUMO

Perhaps the quantum state represents information about reality, and not reality directly. Wave function collapse is then possibly no more mysterious than a Bayesian update of a probability distribution given new data. We consider models for quantum systems with measurement outcomes determined by an underlying physical state of the system but where several quantum states are consistent with a single underlying state-i.e., probability distributions for distinct quantum states overlap. Significantly, we demonstrate by example that additional assumptions are always necessary to rule out such a model.

15.
Phys Rev Lett ; 108(11): 110403, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22540443

RESUMO

The amount of correlation attainable between the components of a quantum system is constrained if the system is closed. We provide some examples, largely from the field of quantum thermodynamics, where knowing the maximal possible variation in correlations is useful. The optimization problem it raises requires us to search for the maximally and minimally correlated states on a unitary orbit, with and without energy conservation. This is fully solvable for the smallest system of two qubits. For larger systems, the problem is reduced to a manageable, classical optimization.

16.
Ecotoxicology ; 21(2): 569-75, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22076028

RESUMO

While agrochemical pollution is thought to be an important conservation threat to carnivorous plants, the effects of insecticides on these taxa have not been quantified previously. Using a combination of lab- and field-based experiments, we tested the effects of commercial and technical grades of three widely used insecticides (carbaryl, lambda-cyhalothrin, and malathion) on survival and the expression of traits associated with carnivory of pink sundews (Drosera capillaris) and Venus flytraps (Dionaea muscipula). Commercial grades were generally more harmful than technical grades under lab and field conditions, but all three insecticides were capable of reducing both survival and the expression of traits associated with carnivory within recommended application rates. However, pink sundews appeared to be more susceptible to insecticides than Venus flytraps, perhaps because of larger numbers of digestive glands on the leaf surfaces. We make several recommendations for future research directions, such as examining the long-term effects of insecticides on carnivorous plant populations, for example in terms of growth rates and fitness. Additionally, future research should include representative species from a wider-range of carnivorous plant growth forms, and explore the mechanism by which insecticides are harming the plants. Given the effects we observed in the present study, we suggest that the use of insecticides should be carefully managed in areas containing vulnerable carnivorous plant species.


Assuntos
Carbaril/toxicidade , Carnivoridade/efeitos dos fármacos , Drosera/efeitos dos fármacos , Droseraceae/efeitos dos fármacos , Inseticidas/toxicidade , Malation/toxicidade , Nitrilas/toxicidade , Piretrinas/toxicidade , Carnivoridade/fisiologia , Drosera/crescimento & desenvolvimento , Droseraceae/crescimento & desenvolvimento , Longevidade/efeitos dos fármacos
17.
Insects ; 13(2)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35206683

RESUMO

Understanding the biodiversity and distribution of forensically relevant blowflies (Diptera: Calliphoridae) in a region can aid in legal investigations when insects are associated with remains. For this purpose, we conducted a 14-month-long blowfly survey at the Anthropology Research Facility (ARF) of the University of Tennessee in Knoxville, Tennessee. Traps baited with pork kidney were deployed for 24 h twice a month throughout the study. A total of 3180 adult blowflies were collected, comprising 13 species from 7 genera. Phormia regina (Meigen) and Lucilia coeruleiviridis (Macquart) were the predominant species collected from this survey, with collections representing 65.9% and 20.6%of total flies captured, respectively. In addition to relative abundance, we investigated blowfly community composition, species abundance, richness, and diversity by season. One state record was identified, with adult Protophormia terraenovae (Robineau-Desvoidy) being collected for the first time in Tennessee. Additionally, an earlier record of Chrysomya megacephala (Fabricius) in Tennessee was noted. These findings can be used to aid in legal investigations in the area and surrounding areas where work is limited, as well as to provide information on which forensically relevant species should be the subject of future research in the area.

18.
J Pers Assess ; 93(3): 225-34, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21516581

RESUMO

The study of humility has progressed slowly due to measurement problems. We describe a model of relational humility that conceptualizes humility as a personality judgment. In this set of 5 studies, we developed the 16-item Relational Humility Scale (RHS) and offered initial evidence for the theoretical model. In Study 1 (N = 300), we developed the RHS and its subscales--Global Humility, Superiority, and Accurate View of Self. In Study 2, we confirmed the factor structure of the scale in an independent sample (N = 196). In Study 3, we provided initial evidence supporting construct validity using an experimental design (N = 200). In Study 4 (N = 150), we provided additional evidence of construct validity by examining the relationships between humility and empathy, forgiveness, and other virtues. In Study 5 (N = 163), we adduced evidence of discriminant and incremental validity of the RHS compared with the Honesty-Humility subscale of the HEXACO-PI (Lee & Ashton, 2004).


Assuntos
Emoções , Testes de Personalidade/normas , Personalidade , Valores Sociais , Adolescente , Adulto , Análise Fatorial , Conflito Familiar , Feminino , Humanos , Masculino , Relações Pais-Filho , Estudantes , Universidades , Adulto Jovem
19.
Proc Biol Sci ; 277(1696): 3001-8, 2010 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-20462904

RESUMO

Several studies have demonstrated that competition between disparate taxa can be important in determining community structure, yet surprisingly, to our knowledge, no quantitative studies have been conducted on competition between carnivorous plants and animals. To examine potential competition between these taxa, we studied dietary and microhabitat overlap between pink sundews (Drosera capillaris) and wolf spiders (Lycosidae) in the field, and conducted a laboratory experiment examining the effects of wolf spiders on sundew fitness. In the field, we found that sundews and spiders had a high dietary overlap with each other and with the available arthropod prey. Associations between sundews and spiders depended on spatial scale: both sundews and spiders were found more frequently in quadrats with more abundant prey, but within quadrats, spiders constructed larger webs and located them further away from sundews as the total sundew trapping area increased, presumably to reduce competition. Spiders also constructed larger webs when fewer prey were available. In the laboratory, our experiment revealed that spiders can significantly reduce sundew fitness. Our findings suggest that members of the plant and animal kingdoms can and do compete.


Assuntos
Drosera/fisiologia , Aranhas/fisiologia , Animais , Comportamento Competitivo , Drosera/anatomia & histologia , Ecossistema , Comportamento Alimentar
20.
J Clin Psychol ; 66(1): 46-72, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19904806

RESUMO

This article evaluated the efficacy status of religious and spiritual (R/S) therapies for mental health problems, including treatments for depression, anxiety, unforgiveness, eating disorders, schizophrenia, alcoholism, anger, and marital issues. Religions represented included Christianity, Islam, Taoism, and Buddhism. Some studies incorporated a generic spirituality. Several R/S therapies were found to be helpful for clients, supporting the further use and research on these therapies. There was limited evidence that R/S therapies outperformed established secular therapies, thus the decision to use an R/S therapy may be an issue of client preference and therapist comfort.


Assuntos
Prática Clínica Baseada em Evidências , Transtornos Mentais/terapia , Religião , Espiritualidade , Humanos
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