放开生育政策,促进人口长期均衡发展

通过描述我国人口低生育水平低惯性增长以及人口变化趋势,讨论了人口结构严重失衡对我国经济社会国防国力的消极影响。同时指出,新形势下,完善人口政策必须从改变思想观念开始;必须从放开生育政策,废除现行计划生育政策开始。唯有这样才能实现人口长期均衡发展的目标。     

灾难事件对生育率的影响：历史经验与现实思考

纵观人类历史,任何一次重大灾难事件都会导致生育率波动变化。灾难事件周期与生育率变动的一般规律为:生育率在灾难事件发生短期内会受挫下降,灾难事件恢复中期内回升反弹,灾后长周期内则回归灾难事件前的变动大趋势。从外在因素的影响看,灾难事件范围越广,波及人口越多且致死率越高,生育率波动越剧烈,疫情和与环境有关的灾难事件可能会对生育能力产生负面影响。从内在因素的影响看,灾害发生地的经济发展水平、教育水平与家庭经济能力、人口年龄结构以及政府的应对能力等会影响生育率波动幅度,但不会改变波动方向。通过影响机制分析,初步观察新冠肺炎疫情所造成的生育率下降是高死亡数量带来的心理冲击、经济衰退、停工停产以及对未来生活预期不明朗和信心减弱综合作用的结果。     

社会流动机制的转变对农村生育率的影响

随着我国由计划经济向市场经济转型、从传统社会向现代社会转变,农民的社会流动机制发生了变迁。社会流动机制的转变必然导致经济、社会诸多变量的变动,而经济和社会变量的变化又影响着生育行为。本文从宏观层面探讨了社会流动机制的变迁对农村生育率的影响。     

Socially disadvantaged women's views of barriers to feeling safe to engage in decision-making in maternity care

BackgroundAlthough midwifery literature suggests that woman-centred care can improve the birthing experiences of women and birth outcomes for women and babies, recent research has identified challenges in supporting socially disadvantaged women to engage in decision-making regarding care options in order to attain a sense of control within their maternity care encounters.ObjectiveThe objective of this paper is to provide an understanding of the issues that affect the socially disadvantaged woman's ability to actively engage in decision-making processes relevant to her care.Research designThe qualitative approach known as Interpretative Phenomenological Analysis was used to gain an understanding of maternity care encounters as experienced by each of the following cohorts: socially disadvantaged women, registered midwives and student midwives. This paper focuses specifically on data from participating socially disadvantaged women that relate to the elements of woman-centred care-choice and control and their understandings of capacity to engage in their maternity care encounters.FindingsSocially disadvantaged women participants did not feel safe to engage in discussions regarding choice or to seek control within their maternity care encounters. Situations such as inadequate contextualised information, perceived risks in not conforming to routine procedures, and the actions and reactions of midwives when these women did seek choice or control resulted in a silent compliance. This response was interpreted as a consequence of women's decisions to accept responsibility for their baby's wellbeing by delegating health care decision-making to the health care professional.ConclusionThis research found that socially disadvantaged women want to engage in their care. However without adequate information and facilitation of choice by midwives, they believe they are outsiders to the maternity care culture and decision-making processes. Consequently, they delegate responsibility for maternity care choices to those who do belong; midwives. These findings suggest that midwives need to better communicate a valuing of the woman's participation in decision-making processes and to work with women so they do have a sense of belonging within the maternity care environment. Midwives need to ensure that socially disadvantaged women do feel safe about having a voice regarding their choices and find ways to give them a sense of control within their maternity care encounters.     

我国出口果蔬食品农残控制现状及其发展趋势

文章综述了我国果蔬中农药残留污染的现状、农残控制状况及发展趋势,并提出了预防和控制果蔬中农药残留的措施,突破国外技术壁垒,扩大我国果蔬食品出口。     

浅谈专业课的教学

专业课教学中的趣味性及授课方式的巧妙性,能激发学生的学习兴趣,营造轻松、愉快的学习氛围。     

大股东控制影响公司现金持有量的实证分析

 本文结合我国上市公司所面临的内部治理机制特点及外部治理环境,从大股东行为的视角对公司现金持有量的影响因素进行实证分析。在加入年度控制变量、行业控制变量和公司财务特征控制变量后,对三项反映大股东行为特征的因素,即大股东持股比例、大股东属性和制度环境因素对公司现金持有量的影响进行了检验。结果表明,第一大股东持股比例较高的公司持有较多的现金,大股东的高持股比例是其占用企业资金侵占中小股东利益的基础。与国有企业相比,民营企业因遭受较强的外部融资约束而持有较高水平的现金。此外,制度环境的发展程度与公司现金持有水平正相关,表明制度环境较好地区的公司持有较多的现金。     

HIV testing,perceptions of AIDS risk,and condom use motivation among US women

As STD infections including HIV increase in the United States, it has become increasingly important to policy makers to ascertain the extent to which knowledge and perceptions of AIDS risk affect an individual's probability of altering their sexual or contraceptive behavior to avoid infection. This paper examines the extent to which women's perceptions of their own and their partners' risk of HIV infection affects the probability of using a condom for protection against sexually transmitted diseases. This paper also examines the extent to which HIV testing may affect motivation for condom use. Crosstabulations reveal that prophylactic condom use is more prevalent among women who have been tested for HIV and increase as perceptions of their chance (and their partner's chance) of being positive increases. The multivariate results from this study indicate that having an HIV test significantly predicts the likelihood of using a condom for STD prevention for US women. Furthermore, women who perceive themselves to be at least somewhat likely to be HIV positive have a higher probability of using a condom to prevent sexually transmitted disease, and women who perceive their partners to be HIV positive are twice as likely as other women to use a condom for STD prevention. However, women who consider themselves likely to be HIV positive are no more likely to use a condom than those who consider themselves not at risk.     

A Warning Zone Method for the Multiperiod Cost Variance Investigation Problem

This paper develops a warning zone approach to make variance investigation decisions for a multiperiod process. The assumed cost generation process varies between an in-control and out-of-control state. These states cannot be directly observed, but must be inferred from the reported cost variances. Using the warning zone method of inference, the manager investigates the process whenever an upper threshold is exceeded or a lower threshold is exceeded for two consecutive periods. A four-state Markov chain models the resulting decision process. Steady state probabilities are derived for this chain and are used to obtain explicit formulas for the effectiveness and efficiency of the decision process. These formulas permit computation of the cost savings attainable by the warning zone method. Compared to other decision rules, the warning zone method is much simpler than the theoretically optimal Bayesian revision method, but uses more information than the Markovian control limit method. Numerical comparison of results shows that the warning zone method usually captures most of the available cost savings, even in cases where the Markovian control limit method does not perform well.     

A Bayesian Approach for Analyzing Results of Vehicle Collision Tests

Certain motor vehicle safety standards stipulate a collision test speed and a set of performance criteria that vehicles must satisfy during or after the collision test. For example, Federal Motor Vehicle Safety Standard 301 requires a 30 mile per hour (mph) barrier collision and specifies a certain maximum allowable limit on the total spillage of fuel. Vehicle designs are required to meet this standard; however, when collision tests are conducted at speeds higher than the standard, vehicles do not always satisfy the performance criteria. This paper develops a mathematical model for estimating the probability of meeting the standard by using a Bayesian framework to incorporate engineering judgment with collision test results. The model is based on the idea that there are random features to a vehicle's ability to meet performance standards in a collision, especially at such elevated speeds. Example calculations are included to illustrate the estimation of the probability of meeting the standard and to compare it with a maximum likelihood approach.