Prevalence of Blackleg and Pathogenicity Groups of Leptosphaeria maculans in North Dakota.

Blackleg, caused by Leptosphaeria maculans, was first reported on canola (Brassica napus) in North Dakota in 1991. In 2003, L. maculans strains of previously unreported pathogenicity groups (PG) were discovered in the region. Since then, however, little has been known about the prevalence of L. maculans in the state. The objectives of this study, therefore, were to characterize the prevalence of blackleg and of L. maculans PGs in North Dakota. Prevalence was assessed in 2004, 2007, and 2009 in 572 fields. PG determination for 216 L. maculans isolates retrieved from blackleg symptomatic stems during that period was achieved on a set of B. napus differential cultivars. Blackleg prevalence increased from 28% in 2004 to 63 and 74% in 2007 and 2009, respectively. Similarly, the number of fields with blackleg incidences >30% increased from 4% in 2004 to 12 and 23% in 2007 and 2009, respectively. In all years, PG-4 was the predominant group, while PG-2, once predominant, accounted for <2% of isolates. Increase in the prevalence and incidence of blackleg as well as the frequency of virulent PGs over the last 10 years is a serious threat to the canola industry of the region.

Simulation and source identification of X-ray contrast media in the water cycle of Berlin.

This article describes the development of a model to simulate the fate of iodinated X-ray contrast media (XRC) in the water cycle of the German capital, Berlin. It also handles data uncertainties concerning the different amounts and sources of input for XRC via source densities in single districts for the XRC usage by inhabitants, hospitals, and radiologists. As well, different degradation rates for the behavior of the adsorbable organic iodine (AOI) were investigated in single water compartments. The introduced model consists of mass balances and includes, in addition to naturally branched bodies of water, the water distribution network between waterways and wastewater treatment plants, which are coupled to natural surface waters at numerous points. Scenarios were calculated according to the data uncertainties that were statistically evaluated to identify the scenario with the highest agreement among the provided measurement data. The simulation of X-ray contrast media in the water cycle of Berlin showed that medical institutions have to be considered as point sources for congested urban areas due to their high levels of X-ray contrast media emission. The calculations identified hospitals, represented by their capacity (number of hospital beds), as the most relevant point sources, while the inhabitants served as important diffusive sources. Deployed for almost inert substances like contrast media, the model can be used for qualitative statements and, therefore, as a decision-support tool.

Comparative evaluation and economic potential of ecorational versus chemical insecticides for crucifer flea beetle (Coleoptera: Chrysomelidae) management in Canola.

From 2001 to 2004, field studies were conducted to evaluate the effect of the ecorational insecticides SpinTor (spinosad), BotaniGard (Beauveria bassiana), Neemix (azadirachtin), and Surround (kaolin) against crucifer flea beetle on canola, Brassica napus L., at the cotyledon stage. The ecorational treatments were compared with a standard foliar chemical insecticide, Capture (bifenthrin), and the chemical seed treatment insecticide Helix XTra (thiamethoxam). This study indicated that flea beetle injury was lower for Helix XTra, Capture, and the ecorational insecticide SpinTor. SpinTor was less effective when flea beetle populations were relatively high (200-300 per trap-week). Yields for chemical insecticide treatments were always greater than SpinTor, with differences being the smallest (68-374 kg/ha) at low levels of flea beetle feeding injury. Differences were greatest when canola seedling injury was high (775-1,364 kg/ha). Yield differences between the conventional insecticides and BotaniGard, Neemix, and Surround were 119-439 and 61-2,248 kg/ha at low and high flea beetle feeding injury, respectively. Although yield differences between SpinTor and chemical insecticides were relatively small at lower levels of flea beetle injury, net losses ranged from $47 to $151/ha when SpinTor was used as an alternative to a standard chemical seed treatment, Helix XTra. This suggests that SpinTor would not be a viable alternative to the chemical insecticide. Net losses ranged from $30 to $266/ha when BotaniGard, Neemix, and Surround were used as alternatives to the seed treatment.

Distribution and Severity of Pasmo on Flax in North Dakota and Evaluation of Fungicides and Cultivars for Management.

Pasmo, caused by Septoria linicola, reduces flax (Linum usitatissimum) yield in the Canadian provinces of Manitoba and Saskatchewan, but little is known about its distribution and effect on yield in North Dakota. Field surveys for pasmo were conducted in 74 and 87 flax fields across 19 and 23 North Dakota counties in 2002 and 2003, respectively. The surveys indicated that pasmo was present in 17 and 18 counties in 2002 and 2003, respectively. County mean plant incidences ranged from 0 to 21% and 0 to 84.5% in 2002 and 2003, respectively. County mean pasmo severity ranged from 0 to 38.8% and 0 to 29.3% in 2002 and 2003, respectively. Significant (P ≤ 0.07) positive Pearson correlations were detected between total rainfall accumulated for June to August and pasmo severity in 2002 and 2003 and for rainfall and pasmo incidence in 2003. Field trials were conducted to determine the effect of fungicides and flax cultivars on pasmo severity and flax yield. Pasmo severity was significantly (P ≤ 0.05) reduced with azoxystrobin and sulfur fungicides compared with the untreated control. Flax yields were significantly (P ≤ 0.05) greater in azoxystrobin- and prothioconazole-treated plots than in the untreated control plots. Cv. Omega had significantly lower pasmo severity than the other three cultivars, but cv. Rahab 94 had the greatest yield of all the cultivars. Based on the results presented, pasmo is an important disease of flax in North Dakota, and its distribution is widespread throughout the flax-production region. Fungicides such as azoxystrobin and prothioconazole appear to be excellent potential tools for pasmo management.

Older people and AIDS: quantitative evidence of the impact in Thailand.

Discussions of the AIDS epidemic rarely consider the impact on older people except as infected persons. Virtually no systematic quantitative assessments exist of the involvement of parents or other older generation relatives in the living and caretaking arrangements of persons with AIDS in either the West or the developing world. We assess the extent of such types of involvement in Thailand, a country where substantial proportions of elderly parents depend on adult children for support and where co-residence with an adult child is common. Interviews with local key informants in the public health system in rural and urban communities provided quantitative information on a total of 963 adult cases who either had died of AIDS or were currently symptomatic. The results indicate that a substantial proportion of persons with AIDS move back to their communities of origin at some stage of the illness. Two-thirds of the adults who died of an AIDS-related disease either lived with or adjacent to a parent by the terminal stage of illness and a parent, usually the mother, acted as a main caregiver for about half. For 70%, either a parent or other older generation relative provided at least some care. The vast majority of the parents were aged 50 or more and many were aged 60 or older. This extent of older generation involvement appears to be far greater than in Western countries such as the US. We interpret the difference as reflecting the contrasting epidemiological and socio-cultural situations in Thailand and the West. The fact that older people in Thailand, and probably many other developing countries, are extensively impacted by the AIDS epidemic through their involvement with their infected adult children has important implications for public health programs that address caretaker education and social and economic support.

Sexual activity among older Thais: the influence of age, gender and health.

This study examines sexual activity among the population aged 50 and over in Thailand in relation to age, gender and health status. It is the first study of older persons based on a large nationally representative survey in any non-Western or developing country. The results indicate substantial proportions of older married Thais remain sexually active, but at lower levels than found in Western countries. Sexual activity and desire decline steadily with age for both married men and women but at any given age both are lower for women. Overall, the sexual desire of husbands is a far more important determinant of marital sexual activity than that of wives. Poor health depresses activity and desire but does not account for the decline of either with age. For the majority of older married Thai men and women behavior and desires are concordant. Discordance levels for married women exceed those for men, however, and arise primarily from being active but lacking desire. Possible reasons for lower sexual activity relative to Western countries are considered. Implications for the quality of life of older persons and the AIDS epidemic are discussed together with methodological lessons for research on older age sexual behavior.

Studying living arrangements of the elderly: lessons from a quasi-qualitative case study approach in Thailand.

The present study explores aspects of living arrangements of the elderly in Thailand and how they relate to intergenerational support exchanges as revealed by a quasi-qualitative case study approach. The study describes some of the challenges this topic poses for measurement if surveys are used. These include difficulties in appropriately defining a household and identifying its members, treating coresidence as a continuum, taking account of the complex links to non-coresident children and kin, recognizing that similar living arrangements can have different meanings, viewing living arrangements as part of an evolving process, and recognizing the potential sensitivity of the topic to respondents. Careful and informed design of survey questionnaires can increase their ability to accurately reflect the underlying complex reality. However, there are also relevant critical issues for which surveys are not well suited. Although the study is specific to Thailand, many of the same issues are likely to arise in the research on elderly elsewhere as well.

Deconstructing population momentum.

PIP: Population momentum is extremely important in understanding the dynamics of population growth and its consequences for population policy. Although momentum is discussed in almost every introductory population course, its demographic components and their policy implications are easily misunderstood. Population momentum refers to the fact that the future growth of any population will be influenced by its present age distribution. Such momentum is the reason why replacement-level fertility does not immediately translate into zero population growth. Discussions of future population growth routinely mention that even if world fertility falls to replacement level, momentum will cause population to continue to increase for some time. Fertility and death rates need to be understood in order to understand population momentum. The effects of positive and negative momentum upon populations at replacement-level fertility are discussed.^ieng

The demography of Asian ageing: past accomplishments and future challenges.

PIP: Fertility decline and the consequent population aging that follows are likely to be the most important demographic developments in Asia during the past and future halves of the century. Despite the inextricable link of these two phenomena, government planners and policy makers view them quite differently. The aim of this article is to review some of the accomplishments of demographic research on Asian aging and discuss some of the challenges that it shall face in the coming decades of the new century. It offers a basic demographic analysis of the population aging of Asia over the last half of the century and is anticipated to happen in the next 50 years, in comparison with the experience of the West. This paper also looks at the social and economic demography of the region with its aging population and the role of these surveys in monitoring the situation of the older population and promoting their well being. Moreover, it explores selected issues which deserve the attention of the population research community in Asia, including development and well being of the elderly, identifying the elderly in need, gender and aging, and the impact of AIDS on the older generations.^ieng

Can prostitutes marry? Thai attitudes toward female sex workers.

This study explores popular attitudes towards female sex workers in Thailand by examining the general public's perceptions of a prostitute's ability to marry based on focus group data. The tentative conclusion emerging from our findings that the general public believes sex workers can marry is that a relative lack of severe or lasting social stigma is an important part of a Thai context that facilitates recruitment into prostitution and permits it to persist on a widespread scale. We interpret this conclusion in terms of the broader value system in Thai society. Although our findings are implicitly comparative in nature, a lack of comparable information from other countries on how those who provide commercial sex are viewed by the general population prevents a more definitive conclusion. There is an obvious need for research on this topic as well as on how sex workers view themselves, and how this translates into actual behavior. Data set used: focus group transcripts from the project "The influence of primary female partners and male peers on male extramarital sexual behavior in Thailand".

Family size and children's education in Vietnam.

Data from the nationally representative 1994 Inter-Censal Demographic Survey are used to examine the association between family size and children's schooling in Vietnam. The data provide information on several education measures for all children over age 10, including children no longer residing in the household. Although a clear inverse bivariate association between family size and children's school attendance and educational attainment is evident, multivariate analysis controlling for urban/rural residence, region, parents' education, household wealth, and child's age, reveals that much of this association, especially that predicting educational attainment, is attributable to these other influences. Moreover, much of the effect that remains after statistical adjustment for the other influences is seen mainly at the largest family sizes. We consider the implications of these findings for current population policy in Vietnam and the possible features of the Vietnamese context that might account for the modest association.

In the company of friends: peer influence on Thai male extramarital sex.

We explore some of the key social dynamics underlying patterns of male extramarital heterosexual behavior in Thailand. We analyze transcripts of focus group discussions and focused individual interviews conducted during 1993 and 1994 with married men and women living in both urban and rural areas of central Thailand. We discern several pathways of peer influence on extramarital commercial sex patronage that are common across our sites and interpret these peer effects in light of contemporary theories of social influence and sexual behavior.

Family support and living arrangements of Thai elderly.

PIP: This study examined family support for the elderly in Thailand. Data were obtained from the Survey of the Welfare of Elderly in Thailand (SWET), a 1995 nationally representative sample of 4486 persons aged over 60 years. Findings were compared to 1986 and 1994 surveys of the elderly. All survey populations lived in private households. Findings indicate that in the 1990 census 76-77% of the elderly lived with one of their children. This figure was 74.2% in the 1995 SWET and 79.7% in the 1986 Socio-Economic Consequences of the Aging Population in Thailand (SECAPT) survey. In 1995, 4.4% were elderly with no children, a slight increase over 1986 and 1994 data. In 1995, 11.9% lived with a spouse only and 4.3% lived alone. Around 90%, in 1986 and 1995, coresided with a child or saw a child daily. 84.%, in 1995, coresided or lived next door to a child. In 1995, 50.7% lived with an ever-married child, and 33.2% lived with a single child. 36.3% lived with a son, and 49.3% lived with a daughter. More elderly lived with an ever-married daughter than an ever-married son (34% vs. 20%). Almost 50% of the Thai elderly lived in a 3-generation household. Many more non-coresident children gave food or clothes in exchanges with parents. Daily or weekly exchanges occurred mostly for those who lived near their parents. Yearly exchanges were fairly frequent. Money exchanges flowed in both directions, although children were more likely to be givers. Most elderly maintained at least occasional social contact with a variety of kin. In 1990, only 1.8% of the elderly lived in institutions, of which 86% were monks in temples.^ieng

Living arrangements, patrilineality and sources of support among elderly Vietnamese.

PIP: This study examined social support for the elderly in Ho Chi Minh (HCM) City and Hanoi, Viet Nam, in 1996. The sample included the main towns and provinces surrounding the cities. Two major findings were that the family was the main source of social security for the elderly. Almost 75% of the elderly in Hanoi, and 80% in HCM City, lived with at least 1 adult child. Parents were more likely to live with a married son. Most of the remaining elderly lived in close proximity to adult children. Over 50% of the elderly lived in households with at least 3 generations, regardless of their location in the north or the south. Older elderly were more likely to live in 3-generation households. 5-6% of the elderly lived alone or with a spouse and did not live near an adult child. Living alone was more prevalent in rural areas and among women. In both regions, almost 60% were female and over 50% were aged under 70 years. 56.6-61.8% were currently married; 37.3-38.1% were widowed. The elderly functioned within a strong patrilineal system. The proportion of male children who lived with a parent divided by the proportion of female children living with a parent (patrilineal ratio) was at least 3 times higher in Hanoi, urban towns, and rural areas in the Red River Delta, than in HCM City and its environs. There was substantial variation in non-family support. A higher proportion of elderly in Hanoi received pensions and social welfare benefits. The elderly in the south were less likely to name themselves or their spouses as the main sources of family income.^ieng

Reproductive preferences and fertility trends in post-transition Thailand.

Two large national surveys in 1988 and 1933 provide new evidence on trends in family-size preferences in Thailand at a time when the Thai fertility transition is reaching its conclusion. Although the average preferred number of children has continued to decline, a resistant lower bound of two children is found for the vast majority of respondents, stemming, apparently, from a pervasive, although not inflexible, desire to have one child of each sex. Moreover, new evidence from birth-registration data indicates that the decline in the total fertility rate appears to have leveled off at about replacement level. These findings challenge the view that fertility in Thailand will continue to fall well below replacement level, and contradict recently expressed alarmist predictions of population decline in the foreseeable future.

PIP: Estimations, based primarily on the 1990 census, that Thailand's total fertility rate fell below replacement level in the late 1980s sparked alarm about extinction of the Thai race and calls to abandon public subsidies for family planning. Recent low total fertility is considered a temporary phenomenon, however, related to the rapid rise in age at marriage and first birth. Birth registration data suggest that the fertility decline levelled off, probably close to replacement level, during the first half of the 1990s and fertility is unlikely to fall below two children. Although the 1988 and 1993 Social Attitudes Toward Children Surveys documented a consistent trend toward declining family size preferences (64% of 1993 respondents, and 74% of women under 30 years of age, stated a preference for two children), only 5% desired fewer than two children. This lower limit of two children prevailed across regional, educational, and socioeconomic categories and appears to reflect a desire to have a child of each sex. In 1993, three-quarters of married women under 30 years of age expressed a preference for one son and one daughter. Despite this preference, Thai couples who fail to achieve this goal generally subordinate gender ideals to the prevailing preferred limit of two children. Although the Thai Government has succeeded in exhorting couples to reduce their family size, any abandonment of subsidized family planning programs could have a deleterious impact on poor families in rural areas.

Fertility and family planning in Vietnam: evidence from the 1994 Inter-censal Demographic Survey.

Results from the 1994 Vietnam Inter-censal Demographic Survey reveal substantial change over recent years in reproductive behavior and attitudes. Fertility has continued to decline to a level not far above a total fertility rate of three children per woman. Compared with the late 1980s, contraceptive knowledge has broadened and contraceptive prevalence has increased, reaching a level of 65 percent of currently married women of reproductive age. The dominance of the IUD among modern methods has been reduced somewhat. Stated family-size preferences have shifted noticeably downward. Recently married women indicate that they want only 2.3 children, on average, suggesting that fertility will continue to fall in coming years. These findings suggest that Vietnam is in the midst of a transition that will lead to low levels of fertility in the near future.

Infant feeding practices in Viet Nam.

PIP: Data from the 1988 Vietnam Demographic and Health Survey and the 1994 Demographic Survey are used to determine the trends in breast feeding and amenorrhea among ever married women of reproductive age. Life table procedures are used to calculate monthly probabilities of weaning. Then five month moving averages of equal weight are computed for observed monthly probabilities of weaning. The smoothed probabilities are used to calculate the cumulative proportion weaned at successive monthly ages. Breast feeding is universal in Vietnam. Infants are put to the breast earlier when delivery occurs at home. Almost all children are breast fed through the first six months, and 80% are breast fed for a year. The median duration was 15.3 months in the 1988 survey and 15.9 months in the 1994 survey based on life table methods. Calculations based on current status methods were slightly higher for both years. Rural women tended to breast feed longer than urban women. Children who had mothers working in agriculture were breast fed longer than children whose mothers had other occupations. Socioeconomic factors did not correlate well with breast feeding duration. Findings indicate that over 66% of breast fed infants aged under 3 months were given plain water, and over 90% of infants aged 3-5 months were given plain water. Fresh cow's milk is not given to Vietnamese infants. Juices were given to children aged older than 6 months. Sugar water was given to younger infants. The introduction of supplemental liquids was more common in urban areas. Few infants during the first few months of life were given solid or mushy foods. But by 4 months of age, 50% of infants were given solid or mushy foods, and the practice was more common in rural areas. The urban-rural gap closed by 6 months of age. Over 90% of infants received solids at 9 months. It is expected that modernization will negatively impact on breast feeding.^ieng

Introduction.

This special issue of theJournal of Cross-Cultural Gerontology contains a series of articles on the living arrangements of the elderly in four Asian countries (the Philippines, Singapore, Taiwan, and Thailand) as revealed in qualitative data provided by focus group discussions. These four countries are characterized by a mix of similarities and differences that makes comparison between them especially interesting. Focus group methodology, as discussed in detail in the following separate article, is a promising approach for research in social gerontology.

Focus groups as a qualitative method for crosscultural research in social gerontology.

The focus group approach for collecting qualitative data can be usefully applied in social gerontological studies, both in a single setting and cross-culturally. The experiences of the research terms participating in the Comparative Study of Asian Elderly in employing focus groups are described, and their advantages and disadvantages as a general method for gathering basic qualitative data are discussed. While the method has promise, it also should be recognized that conducting focus group research within the context of a comparative study compounds the considerable time, effort, and funds that focus group research for basic social science already requires.