氮供给对中度水分胁迫的番茄植株渗透调节的影响

对造成水分亏缺的沙土盆栽的番茄植株 (Lycopersionexcalentum Mill)设置了 3种施氮水平 ,研究其对渗透调节的影响。采用每日滴灌的方式 ,使植株保持在田间持水量水平的土壤中 ,直至胁迫发生。每处理灌溉量为 1 0 0ml,氮 0 (N0 )处理为荷格兰特 (Hoagland)培养液 ;氮 1(N1 )处理为Hoagland培养液加 60mmolNO-3 ;氮 2 (N2 )处理 :为Hoagland培养液加 1 1 0mmolNO-3 。停止灌溉 3d后 ,叶片渗透调节百分率 (叶片实际渗透势占供水良好状态下叶片渗透势的百分数 )分别为N0植株 44%,N1植株 63%,N2植株 2 9%。停止供水 8d后的百分率与之相似。在停止供水 3d后 ,对一些植株恢复每天灌溉。当胁迫解除结束时 (灌溉 8d后 ) ,叶片渗透势较低 ( - 1 .8MPa) ,在Nl中仍保持着渗透调节的状态 ( 39%) ,这与水势降低的情况下 ,膨压的保持有关。结果表明 ,N1处理可能具有增强番茄植株避脱水性和耐脱性的效应     

Efficiency and the Fix Revisited: Informal Relations and Mock Routinization in a Nonprofit Nursing Home

Participant observation in a nonprofit nursing home reveals that informal patterns of work routinization depart markedly from official procedures designed to protect the health and safety of workers and residents. Six aspects of the informal organization of work are found to correspond closely to patterns observed by Roy (1954): the mismatch between time and tasks, the development of new (informal) skills, the institutionalization of rule-breaking, negative effects on quality, the collaboration of shop-level supervision, and workers’ experience of managerial irrationality. However, whereas classic manufacturing studies emphasized upper management's periodic attempts to force compliance to official rules and routines, here upper management engages only in symbolic interventions, collaborating with workers and nursing home residents in the “mock routinization” of work. The article concludes by showing how, in the context of contradictory external workplace regulation, all three parties to the labor process of the contemporary nursing home experience mock routinization as compatible with their own interests.

Semiparametric inference for the recurrent events process by means of a single-index model

In this paper, we introduce new parametric and semiparametric regression techniques for a recurrent event process subject to random right censoring. We develop models for the cumulative mean function and provide asymptotically normal estimators. Our semiparametric model which relies on a single-index assumption can be seen as a dimension reduction technique that, contrary to a fully nonparametric approach, is not stroke by the curse of dimensionality when the number of covariates is high. We discuss data-driven techniques to choose the parameters involved in the estimation procedures and provide a simulation study to support our theoretical results.     

Non‐parametric Copula Estimation Under Bivariate Censoring

In this paper, we consider non‐parametric copula inference under bivariate censoring. Based on an estimator of the joint cumulative distribution function, we define a discrete and two smooth estimators of the copula. The construction that we propose is valid for a large range of estimators of the distribution function and therefore for a large range of bivariate censoring frameworks. Under some conditions on the tails of the distributions, the weak convergence of the corresponding copula processes is obtained in l^∞([0,1]²). We derive the uniform convergence rates of the copula density estimators deduced from our smooth copula estimators. Investigation of the practical behaviour of these estimators is performed through a simulation study and two real data applications, corresponding to different censoring settings. We use our non‐parametric estimators to define a goodness‐of‐fit procedure for parametric copula models. A new bootstrap scheme is proposed to compute the critical values.     

RENT CREATION AND RENT SHARING: NEW MEASURES AND IMPACTS ON TOTAL FACTOR PRODUCTIVITY

This analysis proposes new measures of rent creation and rent sharing and assesses their impact on productivity on cross‐country‐industry panel data. We find first that: (1) anticompetitive product market regulations positively affect rent creation and (2) employment protection legislation boosts hourly wages, particularly for low‐skill workers. However, we find no significant impact of this employment legislation on rent sharing, as the hourly wage increases are offset by a negative impact on hours worked. Second, using regulation indicators as instruments, we find that rent creation and rent sharing both have a substantial negative impact on total factor productivity. (JEL E22, E24, O30, L50, O43, O47, C23)     

Back to Basics

Nonprofits are under increased accountability pressures to demonstrate their effectiveness. Output measurement (how much is produced) is disregarded as simplistic. Emphasis is made instead on measuring outcomes (changes in the lives of beneficiaries) or impacts (effects developed relative to the mission of the nonprofit, or the overall public good), and a growing portion of organizations state that they measure these effects. However, we question the assumption that outputs such as the number of beneficiaries served are being adequately measured. We first review existing research gaps on results measurement practices and discuss the main types of obstacles to the quality and utility of evaluation data. In this context, we argue for the need to reground nonprofit evaluation in the profound knowledge available about beneficiary populations. We discuss the potential and limitations of reach, a basic output indicator that is defined as the number of individuals directly affected by a nonprofit, and explore the organizational drivers of reach measurement. Evidence from 2,229 nonprofits shows they still lack adequate data on the beneficiaries they serve, face relevant conceptual and practical hurdles when trying to identify them, and are significantly influenced by organizational factors in their capacity to track them. Our research not only shows that nonprofits fail to adequately measure outputs, but also that measuring the number of beneficiaries served and how they are served is not as straightforward as outcome and impact advocates suggest. Practitioners and funders are reminded of the need to place beneficiaries at the core of their evaluation efforts.     

The raise estimator estimation,inference, and properties

Several methods using different approaches have been developed to remedy the consequences of collinearity. To the best of our knowledge, only the raise estimator proposed by García et al. (2010 García, C.B., García, J., Soto, J. (2010). The raise method: An alternative procedure to estimate the parameters in presence of collinearity. Qual. Quantity 45(2):403–423.[Crossref], [Web of Science ®] , [Google Scholar]) deals with this problem from a geometric perspective. This article fully develops the raise estimator for a model with two standardized explanatory variables. Inference in the raise estimator is examined, showing that it can be obtained from ordinary least squares methodology. In addition, contrary to what happens in ridge regression, the raise estimator maintains the coefficient of determination value constant. The expression of the variance inflation factor for the raise estimator is also presented. Finally, a comparative study of the raise and ridge estimators is carried out using an example.     

Computing the <Emphasis Type="Italic">k</Emphasis>-resilience of a synchronized multi-robot system

The vertex arboricity va(G) of a graph G is the minimum number of colors the vertices can be colored so that each color class induces a forest. It was known that \(va(G)\le 3\) for every planar graph G. In this paper, we prove that \(va(G)\le 2\) if G is a planar graph without intersecting 5-cycles.     

What Men Who Have Sex With Men in Peru Want in Internet-Based Sexual Health Information

We aimed to gather information among gay men regarding their preferences for online sexual health information; 1,160 Peruvian MSM, 18 years or older, completed an online survey hosted on www.tunexo.org. The mean age was 26.8 years. Around 90% had post–high school education. The self-reported HIV prevalence was 12.3%. The acceptability of sexual health content was greater in the most highly educated group. The highest rated topics and services of interest were those related to improving sexual and mental health. The least educated group was significantly more interested in “getting prevention messages on mobiles” compared to men with the highest level of education (71% vs. 52%; p < 0.001). Men’s sexual health was of more interest to the 30–39-year-old group compared to the 18–24-year-old one (97% vs. 87%; p = 0.005). Future Web-based interventions related to sexual health among targeted groups of MSM in Peru can be tailored to meet their preferences.     

Interior Immigration Enforcement and Political Participation of U.S. Citizens in Mixed-Status Households

The 2000s have witnessed an expansion of interior immigration enforcement in the United States. At the same time, the country has experienced a major demographic transformation, with the number of U.S. citizens living in mixed-status households—that is, households where at least one family member is an unauthorized migrant—reaching 16 million. U.S. citizens living in mixed-status households are personally connected to the struggles experienced by their unauthorized family members. For them, immigration policy is likely to shape their current and future voting behavior. Using data from the 2002–2014 Current Population Survey Voting and Registration Supplements, we examine whether intensified immigration enforcement has affected the political engagement of U.S. citizens living in mixed-status households. We find that immigration enforcement has chilled their electoral participation by lowering their propensity to register by 5 %; however, it has not visibly affected their voting propensity among those registered. Importantly, their lower voting registration likelihood does not seem to reflect indifference for community and public matters, given that it has been accompanied by greater involvement in civic forms of political participation, such as volunteering. Understanding how immigration policy affects the political participation of a fast-growing segment of the electorate is imperative because they will inevitably constitute a rapidly rising political force in future elections.