Pollen specialization by solitary bees in an urban landscape

Many polylectic bee species are known to specialize locally on one or a few pollen types to increase foraging efficiency. What is relatively unknown is how different landscapes influence foraging decisions, and whether habitat alteration, such as that resulting from urbanization, influences broad-scale foraging activities of bees. This study evaluates the type and diversity of pollen collected by two solitary bees that are common in Toronto, Ontario, Canada, the native Osmia pumila and the exotic O. caerulescens, sampled in trap nests set up in urban parks and gardens. We found that the dominant pollen in every successful brood cell was either of one widespread, cosmopolitan lawn-invasive plant species (Trifolium repens) or one of two wind-pollinated tree genera (Quercus spp. and Betula spp.). In combination, these three represented more than 90 % of all pollen collected by each bee species. Despite considerable overlap in the dominant pollen types collected by each bee species, the exotic O. caerulescens was significantly more specialized than the native O. pumila. Brood cells with Betula as the dominant pollen type were more pollen species-rich than those cells having Trifolium or Quercus as dominant, perhaps a result of the comparatively low protein content in Betula pollen.     

A Social Networks Approach to Public Relations on Twitter: Social Mediators and Mediated Public Relations

This study proposes theoretical and practical frameworks to systematically examine mediated public relations in social media spaces. We applied a social network conceptual framework to identify and characterize social mediators that connect the US State Department with its international public. The results showed that social mediators vary in terms of their formality and interdependence. Formal social mediators were primarily US government agencies while informal social mediators were nongovernmental organizations (NGOs) and individuals. Notably, relationships with populations in the Middle East and North Africa were mediated primarily by informal actors, and formal mediators played a key role in connecting the public with everywhere else in the world. Government-related formal mediators and informal social mediators showed similar levels of bilateral relationships. In contrast, news media, the most traditional public relations mediators, were rarely found as social mediators and demonstrated the most unilateral relationships.     

A Theoretical Comparison of Relational Maintenance and Closeness as Mediators of Family Communication Patterns in Parent-Child Relationships

This investigation sought to elaborate Koerner and Fitzpatrick’s theory of family communication by testing two theoretical models of family communication patterns (FCP), child-to-parent inclusion of the other in the self (IOS), and relational maintenance. Participants included 374 young adults recruited from two universities in different regions of the United States. Results best supported a model positioning maintenance as a mediator of the association between FCP and IOS, as compared to an alternative model with IOS as a mediator of the association between FCP and maintenance. These findings extend Koerner and Fitzpatrick’s theory by highlighting communication as the means by which overarching family schemas influence relationship-specific schemas; additionally, they commend the self-expansion model as a useful theoretical approach to relational maintenance behavior in family contexts.     

Intergenerational Remote Exergaming with Family and Friends for Health and Leisure

Global guidelines for physical activity are not being met by most of the world’s youths, adults, and older adults. Family and friends who engage in physical activity across generations derive emotional, social, cognitive, and physical benefits from their interaction. Youths depend on adult assistance to travel long distances, adults are encumbered with obligations to work, and older adults often live more than 200 miles from their extended families. Intergenerational physical activity is difficult because generations are distant and lead busy lifestyles. Remotely played exergames can connect family and friends for intergenerational physical activity. Internet exergaming can help to make physical activity convenient and enjoyable as well as eliminate the effect of distance on playing with family and friends.     

Work and breastfeeding decisions are jointly determined for higher socioeconomic status US mothers

We study postpartum decisions about paid work and breastfeeding using a simultaneous equations model. For our sample of higher socioeconomic status mothers, we find a joint decision process for three sets of decisions modeled: work leave duration and duration of any, as well as of exclusive, breastfeeding, and daily work hours and daily breastfeedings at infant age 3 months. We find that returning to paid work 1 week earlier reduces any breastfeeding duration by about two-thirds of a week while extending breastfeeding by a week delays work participation by about one-third of a week. We find larger elasticities for decisions involving daily work hours and number of breastfeedings at 3 months than for work leave duration and any breastfeeding duration and the smallest elasticities for duration of exclusive breastfeeding and work leave. This marks the first study to find a joint decision-making process for postpartum work and breastfeeding decisions and suggests that, in addition to increased leave impacting breastfeeding behaviors, successful breastfeeding promotion policies can have nontrivial impacts on the US labor market.     

Looking for homogeneous groups of respondents and nonrespondents using latent class analysis

Concerns about decreasing response rates have led to many nonresponse studies. Unfortunately, usually only a limited amount of data is available on nonrespondents. Linking administrative data makes information available on all the sampled units including nonrespondents. Statistics Netherlands has constructed a database in which several administrative records and several surveys are connected. In this explorative study we use this dataset to look for homogenous groups of respondents and nonrespondents in survey research using latent class cluster analysis. Latent class techniques can provide insight into the problem of selective nonresponse and currently under-represented societal groups. We identify four different latent classes in a recent Dutch survey and replicate the findings for the same survey conducted 4 years later. Two of the types of sampled units have above-average response rates and the other two have below-average response rates. We also evaluate various latent class models with other response outcomes to gain insight into the contact and cooperation process.     

Potential strategies to avoid progestogen-induced premenstrual disorders

Non-hormonal approaches to premenstrual syndrome (PMS) treatment such as selective serotonin reuptake inhibitors are by no means effective for all women and frequently we must resort to endocrine therapy. During many of the hormonal approaches, PMS-like symptoms can be introduced or re-introduced during the necessary cyclical or continuous progestogen component of the therapy. This is seen with combined oral contraception, progestogen only contraception, progestogen therapy for heavy menstrual bleeding and endometriosis, sequential hormone replacement therapy and any therapeutic strategy for premenstrual syndrome where it is necessary to provide endometrial protection, including estrogen suppression of ovulation or add-back during gonadotrophin releasing hormone suppression. The link to progestogen is very often missed by health professionals. When the pattern of symptoms mimics the cyclicity of PMS, it is termed progestogen-induced premenstrual disorder. The need to use progestogen to protect the endometrium from the proliferative actions of estrogen can pose insurmountable difficulties in managing premenstrual disorders. In the absence of any really useful evidence, nearly all practice in this area depends on clinician experience. We cannot afford to wait for adequate research evidence to be produced - it never will - and so we must rely on empirical findings, clinical experience, theoretical strategies and common sense.     

Slope effect on pushing forces

In some occupations pushing forces are frequent when performed on horizontal ground and are standardized (ISO 2002). In special cases employees are obliged to grow container on slopes and the strains are poorly investigated. The objective of this work is to measure forces required to push garbage container on horizontal and inclined at 0, 4, 11 and 16 % grounds. Sudden and significant increases in heart rate reflect the possible risk of heart overload in long displacements. This study proposes realistic limits and provides a simple and protective tool for a group of employees without distinction of age or gender. These limits can even be reduced to a quasi-linear model where push 200 kg is the maximum for 0% slope and 60 kg for 10% slope.