Recent trends in homeownership

The homeownership rate began to trend upward in 1995 after years of being relatively constant, near 64 percent. This article describes recent changes in the share of U.S. housing that is owner-occupied and explores the reasons for the surprising rise over the past decade. Explanations that have been offered include demographics, low mortgage rates, changes in housing policy, and innovations in the mortgage financial market. Of all these explanations, the most plausible one is that innovations in the financial markets increased access to mortgage finance, mainly by reducing downpayment constraints and allowing younger people to buy homes.Home ownership

Bayesian estimates of free energies from nonequilibrium work data in the presence of instrument noise

The Jarzynski equality and the fluctuation theorem relate equilibrium free energy differences to non-equilibrium measurements of the work. These relations extend to single-molecule experiments that have probed the finite-time thermodynamics of proteins and nucleic acids. The effects of experimental error and instrument noise have not previously been considered. Here, we present a Bayesian formalism for estimating free-energy changes from non-equilibrium work measurements that compensates for instrument noise and combines data from multiple driving protocols. We reanalyze a recent set of experiments in which a single RNA hairpin is unfolded and refolded using optical tweezers at three different rates. Interestingly, the fastest and farthest-from-equilibrium measurements contain the least instrumental noise, and therefore provide a more accurate estimate of the free energies than a few slow, more noisy, near-equilibrium measurements. The methods we propose here will extend the scope of single-molecule experiments; they can be used in the analysis of data from measurements with AFM, optical, and magnetic tweezers.Comment: 8 page

A PESCA ILEGAL DO TAMBAQUI NOS RIOS NEGRO, SOLIMÕES E AMAZONAS: UMA ANÁLISE DOS EFEITOS DA LEI DO DEFESO

Due to the decline in fish stocks in Brazil, mainly in the Amazon Basin, the Closed Fishing Season Law was implemented to help fisheries recover and protect fish habitat. Tambaqui (Colossoma macropomum) is one of the main overexploited fish species and there is concern about its decline in many Amazonian rivers. Therefore, in order to investigate the effectiveness of the Closed Fishing Season Law as it applies to tambaqui, seizure data compiled by IBAMA (Brazilian Institute of Environmental Protection) was analyzed for the period 1993 to 2012 (20 years) for the Negro, Solimões and Amazonas rivers.  Although the results of this study showed variations in the volume of tambaqui seizures among the three different rivers analyzed over a 20-year period, these variations were small in comparison to the differences found between the 10-year periods before and after implementation of the Closed Fishing Season Law. Overall, there was a 24.4% decrease in the volume of tambaqui seized after implementation of the Law, which can be attributed to a number of possible reasons: 1) reduction of tambaqui stocks in the area of study; 2) occurrence of great floods and dry periods influenced by the natural phenomena El Niño and La Niña, which strongly affected fish stocks in 2002-2003 and 2009, respectively; 3) poor enforcement of regulations, due to reductions in IBAMA personnel and; 4) difficult to patrol such a large area, including many remote locations. However, notwithstanding the noted overall decrease, the results suggest that implementation of the Closed Fishing Season Law with its corresponding compensation payments to fishers did not end up dramatically improving the protection of tambaqui stocks and may have even encouraged more people to enter into the fishery to benefit from the payments. Keywords: Fishery stocks; fisheries; closed season compensation.Com o declínio dos estoques pesqueiros no Brasil, sobretudo na bacia Amazônica, foi criada a Lei do Defeso para auxiliar na recuperação dos estoques pesqueiros e na proteção de seus ambientes. O tambaqui (Colossoma macropomum) é uma das espécies de peixes mais sobreexplotada, onde já se reconhece a sua diminuição em muitos rios da Amazônia. Sendo assim, com o foco de investigar a eficácia do emprego da Lei do Defeso e sua aplicabilidade na defesa do tambaqui, dados das apreensões registradas pelo IBAMA (Instituto Brasileiro do Meio Ambiente) foram analisados para o período de 1993 a 2012 (20 anos), ocorridas nos rios Negro, Solimões e Amazonas. Os resultados mostraram que incidiram variações no número de apreensões de tambaquis entre os diferentes rios estudados durante o período de 20 anos, mas essas variações foram fracas, quando comparadas aos períodos de 10 anos antes e após a criação da Lei do Defeso. No entanto, foi registrado também, uma diminuição de 24,4% no número de infrações após a implementação da referida Lei, o que pode ser atribuído a várias possibilidades: 1) diminuição dos estoques da espécie na área do estudo; 2) ocorrência de grandes cheias e secas influenciadas por fenômenos naturais como o El Niño e a La Niña, que impactaram fortemente os estoques de peixes nos períodos de 2002-2003 e 2009, respectivamente; 3) reduzido efetivo de pessoal fiscalizador, em virtude da diminuição do efetivo de pessoal no IBAMA; e 4) dificuldades em fiscalizar regiões muito extensas, incluindo os locais remotos. Sendo assim, mesmo com a perceptível queda no número de apreensões de tambaqui na região do estudo, os resultados sugerem que o emprego da Lei do Defeso e do seu referido seguro para os pescadores, não alcançaram a finalidade desejada, e ainda, podem estar influenciando negativamente na sustentabilidade dos estoques de tambaquis da região, principalmente pelo incentivo ao ingresso de novos pescadores em virtude da oferta do seguro.Palavras-chave: Estoque pesqueiro, pescarias, seguro defeso

A study of stone arch bridge’s flood reliability through a surrogate model approach

Europe’s historic masonry arch bridges are culturally and economically significant, but their long-term safety must be ensured. Scour effects are the most common cause of collapse, so it is necessary to carry out structural assessments to mitigate the risk and prevent potential failures. In this study, a metamodel-based method was used to determine the probability of failure of an existing stone arch bridge in Portugal due to local and contraction scour on the abutments. Non-linear finite element analysis supported the calculation of the reliability index, which took into account the soil-structure interaction and the failure mechanism. The variables with the greatest influence on the load-carrying capacity of the structure were identified and a surrogate model was implemented. Fragility curves were then derived based on the surrogate model, using scour depth as a measure of intensity and load factor as an engineering requirement parameter. The results of the study indicate that the load capacity of the numerical model is compromised when the scour depth of 1.5 m reaches the base of the foundation. As a result, stability problems and settlements are observed in the model. At a depth of 2.5 m, the soil reaches its ultimate bearing capacity.This research was carried out at the University of Minho in close collaboration with ‘Infraestruturas de Portugal (IP)’, the Portuguese Authority responsible for the conservation of bridges. This work was partially funded by: (i) national funds through the FCT - Foundation for Science and Technology, under grant agreements ‘PD/BD/143142/ 2019’ attributed to the first author and ‘2022.09751.BD’ attributed to the second author; and (ii) FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/ 04029/2020

Standardization is superior to traditional methods of teaching open vascular simulation

ObjectivesStandardizing surgical skills teaching has been proposed as a method to rapidly attain technical competence. This study compared acquisition of vascular skills by standardized vs traditional teaching methods.MethodsThe study randomized 18 first-year surgical residents to a standardized or traditional group. Participants were taught technical aspects of vascular anastomosis using femoral anastomosis simulation (Limbs & Things, Savannah, Ga), supplemented with factual information. One expert instructor taught a standardized anastomosis technique using the same method each time to one group over four sessions, while, similar to current vascular training, four different expert instructors each taught one session to the other (traditional) group. Knowledge and technical skill were assessed at study completion by an independent vascular expert using Objective Structured Assessment of Technical Skill (OSATS) performance metrics. Participants also provided a written evaluation of the study experience.ResultsThe standardized group had significantly higher mean overall technical (95.7% vs 75.8%; P = .038) and global skill scores (83.4% vs 67%; P = .006). Tissue handling, efficiency of motion, overall technical skill, and flow of operation were rated significantly higher in the standardized group (mean range, 88%-96% vs 67.6%-77.6%; P < .05). The standardized group trended to better cognitive knowledge (mean, 68.8% vs 60.7%; P = .182), creation of a secure knot at the toe of the anastomosis, fashioning an appropriate arteriotomy, better double-ended suture placement at the heel of the anastomosis (100% vs 62.7%; P = .07), and accurate suture placement (70% vs 25%; P = .153). Seventy-two percent of participant evaluations suggested a preference for a standardized approach.ConclusionsThis study demonstrates the feasibility of open vascular simulation to assess the effect of differing teaching methods on performance outcome. Findings from this report suggest that for simulation training, standardized may be more effective than traditional methods of teaching. Transferability of simulator-acquired skills to the clinical setting will be required before open simulation can be unequivocally recommended as a major component of resident technical skill training

Reflections of Communication Skills after Practicing Telehealth Physical Activity Screening Evaluations: Qualitative Study

The Disconnect Between Patients and Providers Have you had a healthcare visit where: - You didn’t feel heard - Your concerns weren’t fully addressed - You didn’t follow the advice give

Impact of initiating carvedilol before angiotensin-converting enzyme inhibitor therapy on cardiac function in newly diagnosed heart failure

ObjectivesThe purpose of this research was to evaluate the therapeutic value of initiating a beta-blocker before an angiotensin-converting enzyme inhibitor (ACEI) in the treatment of heart failure.BackgroundAlthough ACEI and carvedilol produce benefits in heart failure, whether the order of initiation of therapy determines the impact on left ventricular (LV) function and New York Heart Association functional class (NYHA FC) has not been determined.MethodsA single-center, prospective, randomized, open-label study was performed. We evaluated whether initiation of therapy with carvedilol either before (n = 38) or after (n = 40) perindopril therapy in newly diagnosed patients in NYHA FC II to III heart failure with idiopathic dilated cardiomyopathy, with the addition of the alternative agent after six months, determined subsequent changes in NYHA FC and LV function (echocardiography and radionuclide ventriculography). Study drugs were titrated to maximum tolerable doses.ResultsThere were no differences in baseline characteristics between the study groups. After 12 months 11 patients died (6 in the group where the ACEI was initiated). At 12 months the group receiving carvedilol as initial therapy achieved a higher tolerable dose of carvedilol (43 ± 17 mg vs. 33 ± 18 mg, p = 0.03); a lower dose of furosemide (p &lt; 0.05); and better improvements in symptoms (NYHA FC, p &lt; 0.002), LV ejection fraction (radionuclide: 15 ± 16% vs. 6 ± 13%, p &lt; 0.05; echocardiographic, p &lt; 0.01), and plasma N-terminal pro-brain natriuretic peptide concentrations (p &lt; 0.02).ConclusionsAs opposed to the conventional sequence of drug use in the treatment of heart failure, initiation of therapy with carvedilol before an ACEI results in higher tolerable doses of carvedilol and better improvements in FC and LV function

Heavy Neutral Gauge Bosons at the LHC in an Extended MSSM

Searching for heavy neutral gauge bosons Z', predicted in extensions of the Standard Model based on a U(1)' gauge symmetry, is one of the challenging objectives of the experiments carried out at the Large Hadron Collider. In this paper, we study Z' phenomenology at hadron colliders according to several U(1)'-based models and in the Sequential Standard Model. In particular, possible Z' decays into supersymmetric particles are included, in addition to the Standard Model modes so far investigated. We point out the impact of the U(1)' group on the MSSM spectrum and, for a better understanding, we consider a few benchmarks points in the parameter space. We account for the D-term contribution, due to the breaking of U(1)', to slepton and squark masses and investigate its effect on Z' decays into sfermions. Results on branching ratios and cross sections are presented, as a function of the MSSM and U(1)' parameters, which are varied within suitable ranges. We pay special attention to final states with leptons and missing energy and make predictions on the number of events with sparticle production in Z' decays, for a few values of integrated luminosity and centre-of-mass energy of the LHC.Comment: 53 pages, 23 figures, 25 tables. One Feynman diagram fixed, results and conclusions unchange

Fire behavior modeling for operational decision-making

Simulation frameworks are necessary to facilitate decision-making to many fire agencies. An accurate estimation of fire behavior is required to analyze potential impact and risk. Applied research and technology together have improved the implementation of fire modeling, and decision-making in operational environments.Dr Cardil acknowledges the support of Technosylva USA and Wageningen University in his research stays in the USA and the Netherlands to develop this work. The authors of this paper acknowledges the support of the EUfunded PYROLIFE project (Reference: 860787; https://pyrolife.lessonsonfire.eu/), a project in which a new generation of experts will be trained in integrated wildfire management