Parents may provide many types of support to their grown children. Parents aged 40 to 60 (N = 633) reported the support they exchange with each child over age 18 (n = 1,384). Mothers and fathers differentiated among children within families, but provided emotional, financial, and practical help on average every few weeks to each child. Offspring received most assistance when they: (a) had greater needs (due to problems or younger age) or (b) were perceived as more successful. Parents received more from high achieving offspring. Findings support contingency theory; parents give more material and financial support to children in need. Motivation to enhance the self or to assure support later in life may explain support to high achieving offspring. Keywordsfamily; intergenerational relations; intergenerational transfers; parent child relations; social support; transition to adulthood Popular culture laments that young people today remain dependent on their parents, and recent news reports indicate how expensive and time consuming grown children have become (Briggs, 2008;Haughney, 2007). Research partially supports these claims, with studies indicating that more help flows downstream from parents to children rather than upstream to parents (at least until parents suffer declines of old age; Grundy, 2005;Soldo & Hill, 1995;Zarit & Eggebeen, 2002). Yet, there is little research specifically examining the types of support exchanged among parents and each of their young adult offspring.The first purpose of this study was to examine the range of support middle-aged parents provide grown children. By examining different types of support parents provide to each grown child, we can better understand when parents: (a) simply pass along potential future inheritance via financial transfers inter-vivo, (b) assist children's transitions into adulthood with advice and emotional support, (c) engage in socialization characteristic of friendship, or (d) provide a combination of these forms of support. The second purpose of this study was to understand factors that account for different support exchanges. That is, we were interested whether types of support vary by offspring's characteristics (offspring's needs and achievements) within families. We also examined parent characteristics (resources and demands) and support reciprocity (e.g., parents give more to offspring who provide them with more support) to garner a fuller portrait of parental support of grown children. NIH Public Access Types of SupportWe know little about the scope of support parents provide young adult children. Social support includes financial transmissions, practical support, advice, information, guidance, emotional support, and companionship (Antonucci, 2001;Vaux, 1988;Wills & Shinar, 2000). Studies of parent-child relationships have focused primarily on financial and practical support, however. Parents provide considerable material support to young adult offspring (McGarry & Schoeni, 1997;Schoeni & Ross, 2005). Studies also have found that parents pr...

The question of how individuals acquire and allocate resources to maximize fitness is central in evolutionary ecology. Basic information on prey selection, search effort, and capture rates are critical for understanding a predator's role in its ecosystem and for predicting its response to natural and anthropogenic disturbance. Yet, for most marine species, foraging interactions cannot be observed directly. The high costs of thermoregulation in water require that small marine mammals have elevated energy intakes compared to similar-sized terrestrial mammals [1]. The combination of high food requirements and their position at the apex of most marine food webs may make small marine mammals particularly vulnerable to changes within the ecosystem [2-4], but the lack of detailed information about their foraging behavior often precludes an informed conservation effort. Here, we use high-resolution movement and prey echo recording tags on five wild harbor porpoises to examine foraging interactions in one of the most metabolically challenged cetacean species. We report that porpoises forage nearly continuously day and night, attempting to capture up to 550 small (3-10 cm) fish prey per hour with a remarkable prey capture success rate of >90%. Porpoises therefore target fish that are smaller than those of commercial interest, but must forage almost continually to meet their metabolic demands with such small prey, leaving little margin for compensation. Thus, for these "aquatic shrews," even a moderate level of anthropogenic disturbance in the busy shallow waters they share with humans may have severe fitness consequences at individual and population levels.

No abstract

In sperm whales (Physeter catodon L. 1758) the nose is vastly hypertrophied, accounting for about one-third of the length or weight of an adult male. Norris and Harvey [in Animal Orientation and Navigation, NASA SP-262 (1972), pp. 397-417] ascribed a sound-generating function to this organ complex. A sound generator weighing upward of 10 tons and with a cross-section of 1 m is expected to generate high-intensity, directional sounds. This prediction from the Norris and Harvey theory is not supported by published data for sperm whale clicks (source levels of 180 dB re 1 microPa and little, if any, directionality). Either the theory is not borne out or the data is not representative for the capabilities of the sound-generating mechanism. To increase the amount of relevant data, a five-hydrophone array, suspended from three platforms separated by 1 km and linked by radio, was deployed at the slope of the continental shelf off Andenes, Norway, in the summers of 1997 and 1998. With this system, source levels up to 223 dB re 1 microPa peRMS were recorded. Also, source level differences of 35 dB for the same click at different directions were seen, which are interpreted as evidence for high directionality. This implicates sonar as a possible function of the clicks. Thus, previously published properties of sperm whale clicks underestimate the capabilities of the sound generator and therefore cannot falsify the Norris and Harvey theory.

No abstract

SUMMARYSynchronized video and high-frequency audio recordings of two trained harbour porpoises searching for and capturing live fish were used to study swimming and echolocation behaviour. One animal repeated the tasks blindfolded. A splash generated by the fish being thrown into the pool or -in controls -by a boat hook indicated prey and stimulated search behaviour. The echolocation sequences were divided into search and approach phases. In the search phase the porpoises displayed a clear range-locking behaviour on landmarks, indicated by a distance-dependent decrease in click interval. Only in trials with fish was the search phase followed by an approach phase. In the initial part of the approach phase the porpoises used a rather constant click interval of around 50 ms. The terminal part started with a sudden drop in click interval at distances around 2-4 m. Close to the prey the terminal part ended with a buzz, characterized by constant click intervals around 1.5 ms. The lag time in the search and the initial part of the approach phase seems to be long enough for the porpoise to process echo information before emitting the next click (pulse mode). However, we assume that during the buzz lag times are too short for pulse mode processing and that distance information is perceived as a 'pitch' with a 'frequency' corresponding to the inverse of the two-way transit time (pitch mode). The swimming speed of the animal was halved when it was blindfolded, while the click intervals hardly changed, resulting in more clicks emitted per metre swum.

Tensions are normative in the parent and adult child relationship, but there is little research on the topics that cause the most tension or whether tensions are associated with overall relationship quality. Adult sons and daughters, aged 22 to 49, and their mothers and fathers (N = 158 families, 474 individuals) reported the intensity of different tension topics and relationship quality (solidarity and ambivalence) with one another. Tensions varied between and within families by generation, gender and age of offspring. In comparison to tensions regarding individual issues, tensions regarding the relationship were associated with lower affective solidarity and greater ambivalence. Findings are consistent with the developmental schism hypothesis, which indicates that parent-child tensions are common and are the result of discrepancies in developmental needs which vary by generation, gender, and age. Keywords parent-child; tensions; ambivalence; solidarity; conflict; interpersonal problemsThe parent-child relationship is one of the most long-lasting and emotionally intense social ties. Although often positive and supportive, this tie also includes feelings of irritation, tension, and ambivalence (Luescher & Pillemer, 1998). Indeed, parents and their children report experiencing tensions long after children are grown (Clarke, Preston, Raksin, & Bengtson, 1999;Fingerman, 1996;Morgan, 1989;Shaw, Krause, Chatters, Connell, & Ingersoll-Dayton, 2004;Talbott, 1990). There is a lack of information, however, regarding the topics that generate more intense tensions for parents and their adult children, and whether mothers, fathers, and their sons and daughters report tensions of similar intensity. In addition, it is unclear whether tensions are associated with the overall quality of the relationship. Describing variations in perceptions of tensions and whether tensions are associated with relationship quality among Correspondence should be addressed to Kira S. Birditt, Institute for Social Research, University of Michigan, 426 Thompson St., Ann Arbor, MI., 48104-2321, E-mail: kirasb@isr.umich.edu.. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association and its Council of Editors disclaim any responsibility or liabilities for errors or omissions of this manuscript version, any version derived from this manuscript by NIH, or other third parties. The published version is available at http://www.apa.org/journals/pag/ An earlier version of this article was presented at the Gerontological Society of America meeting, Dallas, TX, November, 2006 parents and adult children is crucial due to implications this tie may hold for overall quality of life, depressive symptoms, and health (Fingerman, Pitzer, Lefkowitz, Birditt, & Mroczek, in press;Lowenstein, 2007;Silverstein & Bengtson, 1997...

The objective of the study was to develop a scintigraphic method for measurement of airway mucociliary clearance in small laboratory rodents such as the mouse. Previous investigations have characterized the secretory cell types present in the mouse airway, but analysis of the mucus transport system has been limited to in vitro examination of tissue explants or invasive in vivo measures of a single airway, the trachea. Three methods were used to deposit insoluble, radioisotopic colloidal particles: oropharyngeal aspiration, intratracheal instillation, and nose-only aerosol inhalation. The initial distribution of particles within the lower respiratory tract was visualized by gamma-camera, and clearance of particles was followed intermittently over 6 h and at the conclusion, 24 h postdelivery. Subsets of mice underwent lavage for evidence of tissue inflammation, and others were restudied for reproducibility of the methods. The aspiration and instillation methods of delivery led to greater distributions of deposited activity within the lungs, i.e., approximately 60--80% of the total respiratory tract radioactivity, whereas the nose-only aerosol technique attained a distribution of 32% to the lungs. However, the aerosol technique maximized the fraction of particles that cleared the airway over a 24-h period, i.e, deposited onto airway epithelial surfaces and cleared by mucociliary function such that lung retention at 24 h averaged 57% for delivery by aerosol inhalation and > or =80% for the aspiration or intratracheal instillation techniques. Particle delivery methods did not cause lung inflammation/injury with use of inflammatory cells and chemoattractant cytokines as criteria. Scintigraphy can discern particle deposition and clearance from the lower respiratory tract in the mouse, is noninvasive and reproducible, and includes the capability for restudy and lung lavage when time course or chronic treatments are being considered.