Fertility in Pakistan during the 1970s

Evidence of trends in fertility and related variables in Pakistan during the 1970s is analyzed using data from 2 comparable surveys: the 1975 Pakistan Fertility Survey (PFS) and the 1979-80 Population, Labor Force and Migration Survey (PLM). Both suggest that fertility was fairly constant, with a total fertility rate around 7.0 until the 5-year period preceding the surveys (1970-74 and 1975-79, respectively), during which it declined abruptly. The apparent date of the decline is thus conflicting. The evidence of recent decline in each survey is likely to be spurious, the result of systematic distortions in the reporting of dates. The present research finds evidence that fertility as measured by age-specific and marital age-specific rates did not change in Pakistan during the 1970s, except for a decline in age group 15-19 as a result of delayed marriage. An analysis of levels and trends in selected components of fertility indicates that all subgroups, except literate women, show a rise in the average age at marriage of the order of 1/2 a year or so. Differentials between subgroups are in the expected direction, with literate women marrying later than illiterate ones and women in urban areas marrying later than those in rural areas. There is no notable change in the % of children being breastfed; however, the average duration of breastfeeding shows a non-trivial decline in all subgroups. Nonetheless prolonged breastfeeding is still the general practice. Current use of contraception at the time of the 2 surveys actually declined by 1980, while knowledge, reported ever-use, and fertility preferences all moved in a pronatalist direction. The lessons of this study are primarily methodological. In particular, the analysis of fertility change in the future in Pakistan will require either more reliable reporting of birth histories, or the continued piecing together of 2 or more surveys.     

French marine policy in the 1970s and 1980s

Abstract

France, hitherto more “continental”; than “maritime,”; increasingly developed its ocean activities in the 1970s and 1980s. This article describes the different sectors of its marine activities and evolvement of a different outlook concerning the sea. Important events such as the 1976 Proclamation and subsequent implementation of the French 200‐nautical mile Exclusive Economic Zone, and 1981 formation of a new Socialist government in France after 23 years of uninterrupted “Gaullist”; rule, offered a unique opportunity to restructure marine policy. The new Ministry of the Sea was intended to integrate marine policy and cater to a developing ocean “constituency.”; It was eventually downgraded to a “Secrétariat d'Etat,”; but its impact was undeniably important.     

Ethnic segregation in Birmingham in the 1960s and 1970s

This article argues that assimilationist theory (seen as a specific instance of process theory) had a profound impact on immigration studies in the United States from the 1920s into the 1960s, but that this mode of conceptualization has been subsequently challenged theoretically by developments in social history. Specifically, exegetical evidence is offered for viewing the challenge as hinging on a reconceptualization of the meaning of culture and the role of social actors in creating their own history. The case is made by examining in depth two exemplars of immigration research published in different time‐periods: for the assimilationist model, W. I. Thomas et al.’s Old World Traits Transplanted, and from the new social history, John Bodnar's The Transplanted. To illustrate the impact of assimilationist thought on scholarship for nearly a half century, analyses are provided of a select number of ‘classic’ studies written between the respective appearances of the two aforementioned books.     

Spatial and Temporal Variations of Crop Fertilization and Soil Fertility in the Loess Plateau in China from the 1970s to the 2000s

Increased fertilizer input in agricultural systems during the last few decades has resulted in large yield increases, but also in environmental problems. We used data from published papers and a soil testing and fertilization project in Shaanxi province during the years 2005 to 2009 to analyze chemical fertilizer inputs and yields of wheat (Triticum aestivum L.) and maize (Zea mays L.) on the farmers'' level, and soil fertility change from the 1970s to the 2000s in the Loess Plateau in China. The results showed that in different regions of the province, chemical fertilizer NPK inputs and yields of wheat and maize increased. With regard to soil nutrient balance, N and P gradually changed from deficit to surplus levels, while K deficiency became more severe. In addition, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium increased during the same period. The PFP of N, NP and NPK on wheat and maize all decreased from the 1970s to the 2000s as a whole. With the increase in N fertilizer inputs, both soil total nitrogen and alkali-hydrolysis nitrogen increased; P fertilizer increased soil available phosphorus and K fertilizer increased soil available potassium. At the same time, soil organic matter, total nitrogen, alkali-hydrolysis nitrogen, available phosphorus and available potassium all had positive impacts on crop yields. In order to promote food safety and environmental protection, fertilizer requirements should be assessed at the farmers'' level. In many cases, farmers should be encouraged to reduce nitrogen and phosphate fertilizer inputs significantly, but increase potassium fertilizer and organic manure on cereal crops as a whole.     

The net flux of carbon from agricultural soils in Canada 1970–2010

Changes in soil organic carbon (SOC) in agricultural soils influence soil quality and greenhouse gas concentrations in the atmosphere. Land use, management practices, soil characteristics, and climate influence such changes. Using the Century model we estimated the rate of SOC change in agricultural soils of Canada for the period 1970 to 2010. This estimation was based on the estimated SOC change for 15% of the 1250 agriculturally designated soil landscape of Canada (SLC) polygons. Simulations were carried out for two to five crop rotations and for conventional and no‐tillage. The results indicate that the agricultural soils in Canada, whose SOC are currently very close to equilibrium, will stop being a net source of CO₂ and will become a sink by the year 2000. Rates of carbon change for the years 1970, 1990, and 2010 were estimated to be ?67, ? 39, and 11 kgC ha^?1. The rate of decline in the carbon content of agricultural soils in Canada has slowed considerably in the 1990s as a result of an increase in the adoption of no‐tillage management, a reduction in the use of summer fallowing, and an increase in fertilizer application. We estimate that the proportion of agricultural land storing SOC will have increased from 17% in 1990 to 53% by the year 2000.     

Active abdominal tuberculosis in Canada in 1970-81.

We reviewed all 341 cases of abdominal tuberculosis reported in Canada between 1970 and 1981. Over the study period abdominal tuberculosis accounted for a stable proportion (0.8%) of all reported cases of tuberculosis in Canada. Its incidence declined steadily. It was more common in women, in native Indians and in people born in Asia. Detailed records of the 55 cases reported to Statistics Canada from British Columbia and of an additional 31 cases not reported to Statistics Canada (usually because they involved concomitant disease elsewhere, notably the lungs) were studied. Five of the 55 cases reported to Statistics Canada had been reported incorrectly. Of the 81 cases in British Columbia 51% involved peritonitis, 21% ileocecal disease, 20% anorectal disease, 10% mesenteric lymphadenitis, 1% disease of the sigmoid colon and 1% disease of the liver. The rate of bacteriologic confirmation was low (51%).     

Norway's law of the sea policy in the 1970s

Abstract

The Norwegian government has stated that creating a new international law of the sea is a foreign policy matter of the highest political priority in the period 1978–1981. A reasonable explanation might be the close correlation that normally exists between the political significance and the economic importance of issues and the area on which they impinge. As to Norway, it should suffice to point to the fact that the country ranks fifth among the merchant marine nations of the world, takes the fifth largest fish catch, and has sovereignty over the biggest continental shelf in Europe. Against this background, the author discusses the hypothesis that economic factors are the guiding hand in Norwegian ocean policy. However, the conclusion reached is that economic factors play a rather modest role in explaining this policy and that the reasons behind it are to be found at the intersection between economic interests, security policies, jurisdiction, the protection of resources and the environment as they are reflected in the rather peculiar situation of the North.     

A divergent pattern of the sex difference in life expectancy: Sweden and Japan, early 1970s-late 1990s

For most of the 20th century the sex gap in life expectancy in the industrialized countries has widened in favor of women. By the early 1980s a reversal in the long-term pattern of this differential had occurred in some countries, where it reached a maximum and thereafter followed a declining trend. Of particular interest to the present investigation is the anomalous experience of Japan, where unlike other high-income countries the female advantage in life expectancy has been expanding. We contrast the case of Japan with that of Sweden, where, like many other high-income nations, the sex differential in longevity has been narrowing in recent years. We observe that in Sweden, until the early 1980s, the sex gap in life expectancy (female-male) exceeded that of Japan; but this situation reversed in subsequent periods, when the Swedish differential narrowed and that of Japan widened. A decomposition analysis indicates that these divergent patterns since 1980 have resulted mainly from larger than expected reductions in male mortality in Sweden due to heart disease and from accidents and violence, lung cancer and "other" cancers. In Japan, death rates for men and women from heart disease--which is a leading cause of death--have tended to decline more or less at the same pace since the early 1980s; and with regard to lung cancer, and "other" neoplasms, male death rates in Japan have been rising while those of women have either declined or risen more slowly. Moreover, during the 1990s, male and female suicide rates rose in Japan, but the rates for men went up faster. Altogether, the net effect of these divergent mortality trends for men and women in Japan underlie much of the observed widening of its sex differential in longevity in recent years.     

试析光合作用的研究动向

光合作用被称为＂地球上最重要的化学反应＂和＂生命界最重大的顶极创造之一＂,在生物演化、生物圈形成和运转及人类诞生与经济和社会的可持续发展等过程中都处于非常关键的地位。从最近召开的国际和国内光合作用会议来看,当前进行的研究呈现出领域越来越宽广、层次越来越深入、技术越来越先进的特点;研究重点集中在探讨光合作用反应机理、结构与功能,揭示光合机构组装、运转与调节机制及光合作用与人类可持续发展3个方面。