Disentangling historical signal and pollinator selection on the micromorphology of flowers: an example from the floral epidermis of the Nymphaeaceae.

The family Nymphaeaceae includes most of the diversity among the ANA-grade angiosperms. Among the species of this family, floral structures and pollination strategies vary. The genus Victoria, as well as subgenera Lotos and Hydrocallis in Nymphaea, present night-blooming, scented flowers pollinated by scarab beetles. Such similar pollination strategies have led to macromorphological similarities among the flowers of these species, which could be interpreted as homologies or convergences based on different phylogenetic hypotheses about the relationships of these groups. We employed scanning electron microscopy of floral epidermis for seven species of the Nymphaeaceae with contrasting pollination biology to identify the main characters of the floral organs and the potential homologous nature of the structures involved in pollinator attraction. Moreover, we used transmission electron microscopy to observe ultrastructure of papillate-conical epidermis in the stamen of Victoria cruziana. We then tested the phylogenetic or ecological distribution of these traits using both consensus network approaches and ancestral state reconstruction on fixed phylogenies. Our results show that the night-blooming flowers present different specialisations in their epidermis, with V. cruziana presenting the most elaborate floral anatomy. We also identify for the first time the presence of conical-papillate cells in the order Nymphaeales. The epidermal characters tend to reflect phylogenetic relationships more than convergence due to pollinator selection. These results point to an independent and parallel evolution of scarab pollination in Nymphaeaceae and demonstrate the promise of floral anatomy as a phylogenetic marker. Moreover, they indicate a degree of sophistication in the anatomical basis of cantharophilous flowers in the Nymphaeales that diverges from the most simplistic views of floral evolution in the angiosperms.

The use of olive mill wastes for the control of root-knot nematodes.

The suppressive effect of olive mill wastes was tested in a field experiment in sandy soil, infested by Meloidogyne incognita, in the Province of Lecce, southern Italy. The field was subdivided in 12 m2 plots distributed at random in four blocks. Treatment consisted of different dosages (10, 20 and 40 t/ha) of two composts prepared with either exhausted or fresh olive pomace or raw extraction sewage at rate of 40 or 80 m3/ha. There were four untreated control plots and four plots on which the granular 5% formulation of fenamiphos had been broadcast incorporated into the soil at the rate of 300 Kg/ha, one week before planting the tomato cv. Tondino di Zagaria. All treatments statistically increased tomato yields with respect to the control. Conversely, the root gall index, assessed according to a scale from 0 (no gall at all) to 5 (root system of reduced size and deformed by large galls), was significantly reduced in all treated plots. Also soil populations of the root-knot nematode declined, significantly compared to the control, except in the soil treated with the lowest doses of raw sewage or exhausted pomace compost.

Depressive symptoms among women receiving welfare.

Using data from an ongoing study of welfare recipients and their preschool-aged children, this study examined levels and correlates of self-reported depressive symptoms, and factors predicting transition off welfare assistance, among 173 low-income, single, African American mothers. Forty percent reported symptom levels that are likely to indicate a diagnosis of clinical depression, and very few had received any mental health services. Mothers who had lived as children in households that received AFDC, who had received AFDC themselves for more than five years, who perceived less social support to be available to them, and who reported more life stressors, had significantly higher levels of depressive symptoms. Controlling for these factors associated with depression, women with higher symptom levels were slightly less likely to stop receiving AFDC tor some period of time over the two years of the study, but were no less likely to work or attend school. Implications of these findings for the development of programs and services for families on welfare are discussed.

Do marriage problems affect fathering more than mothering? A quantitative and qualitative review.

The important question of whether marital problems disrupt fathering more than mothering is addressed in (a) a quantitative review of evidence on marital conflict and parenting in intact families, and (b) a qualitative review of research on mother and father involvement with their children following divorce. We conclude that (a) there is limited evidence that, relative to mothering, fathering is more likely to be affected by marital conflict, but suggest that (b) marital status (i.e., divorce) affects fathering notably more than it affects mothering. We further suggest that marital problems may disrupt father involvement which, in turn, weakens the quality of father-child relationships; there likely are multiple alternative pathways through which marriage problems affect parenting, including both "spillover" and "compensation"; researchers need to examine more carefully how marital problems disrupt coparenting; child age and gender may moderate linkages between the parental and marital subsystems; and coparenting, marital happiness, and the institution of marriage itself may be essential first avenues of intervention for those who wish to improve or maintain fathers' involvement with their children.

Health of our nation's children.

This report describes the health of children 17 years of age and under in the United States. The report discusses overall health status, prevalence of psychological disorders, access to health care and rates of health care utilization, characteristics of other family-controlled health variables, and family structure as it relates to health. All estimates are shown according to age of child as well as selected demographic and socioeconomic characteristics of the family and health characteristics of the child. Particular attention is paid to age-, race-, and income-related disparities in the health of children. Estimates are based on data from the 1988 National Health Interview Survey on Child Health.

The effects of intracage ventilation on microenvironmental conditions in filter-top cages.

Filter-top cages, while effective in reducing cross contamination by particulate material including microbes, can also cause accumulation of the waste gases carbon dioxide and ammonia as well as increased intracage relative humidity. A prototype system which provided each cage with 23 air changes per hour through a nozzle inserted in the filter lid was evaluated. The ventilated cageing system was effective in reducing intracage carbon dioxide, ammonia and relative humidity levels. Mean weekly carbon dioxide levels were 2900 ppm lower, ammonia levels 240 ppm lower and intracage relative humidity levels 8% lower in the ventilated cages than in unventilated controls.