Low Fertility (low + fertility)

Distribution by Scientific Domains


Selected Abstracts


Delayed Marriage and Very Low Fertility in Pacific Asia

POPULATION AND DEVELOPMENT REVIEW, Issue 3 2007
Gavin W. Jones
The general decline in fertility levels in Pacific Asia has in its vanguard countries where fertility rates are among the lowest in the world. A related trend is toward delayed marriage and nonmarriage. When prevalence of cohabitation in European countries is allowed for, levels of "effective singlehood" in many countries of Pacific Asia have run ahead of those in northern and western Europe. This raises questions about the extent to which delayed marriage has been implicated in fertility declines, and whether the same factors are leading both to delayed marriage and to lowered fertility within marriage. The article argues that involuntary nonmarriage is likely to be more common in Pacific Asia than in Western countries, and that resultant involuntary childlessness plays a substantial role in the low fertility rates currently observed. [source]


Bridewealth and Birth Control: Low Fertility in the Indonesian Archipelago, 1500,1900

POPULATION AND DEVELOPMENT REVIEW, Issue 2 2003
Peter Boomgaard
Before the onset of the present demographic transition, population growth in Indonesia had reached unprecedentedly high levels. This article demonstrates that such high levels were a recent phenomenon. Prior to 1900 rates of natural population increase were low to very low in most areas in Indonesia. This runs counter to expectations based on Hajnal's "Eastern marriage pattern," which could imply high growth levels in extended family areas, such as most Indonesian regions outside Java in the past. Usually, the low population growth rates in Southeast Asia are attributed to high mortality owing to high levels of violent conflict. It is argued that other factors contributing to such high levels of mortality should receive more attention. In this article it is also argued that low fertility rates, too, played a role in generating low rates of natural increase. The article discusses the influence of marriage patterns, household structure, methods of birth control, adoption, and slavery on fertility. [source]


Incidence of Error in Oestrus Detection Based on Secondary Oestrus Signs in a 24-h Tie-Stalled Dairy Herd with Low Fertility

REPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2009
RMSBK Ranasinghe
Contents Oestrus detection error and conception rates after AI based only on secondary oestrus signs were evaluated in a high yielding, 24-h tie-stalled dairy herd with low fertility, using milk progesterone profiles. Oestrus detection was based on the secondary oestrus signs such as restlessness, swelling, congestion of vulva and clear mucus discharge. Sixty eight AI conducted after observing the secondary oestrus signs in 44 animals were included in the study. Of the 68 AI, 53 (77.9%) were conducted in the follicular phase, and 13 (19.1%) and 2 (2.9%) were carried out in the luteal phase and during pregnancy, respectively. The overall error in oestrus detection based on milk progesterone profiles was 22.1%. The oestrus detection error did not differ significantly among different secondary oestrus signs. None of the AI conducted in the luteal phase resulted in conception, whereas 20.8% of AI conducted in the follicular phase resulted in conception. No significant difference in the conception rates among the groups of cows with different secondary oestrus signs was shown. The high incidence of oestrus detection error in this study might have been caused by the detection of cows in oestrus based only on secondary oestrus signs due to the confinement of animals. In conclusion, there was a high incidence of heat detection error in the 24-h tie-stalled dairy herd and oestrus detection based only on secondary oestrus signs resulted in low conception rate. [source]


Family Changes in the Context of Lowest-Low Fertility: The Case of Japan

INTERNATIONAL JOURNAL OF JAPANESE SOCIOLOGY, Issue 1 2008
Makoto Atoh
Abstract: Japan has currently one of the lowest-low fertility rates in the world. Low fertility in Japan is due to the extreme postponement of marriage and childbearing, and their weak recuperation in women in their 30s, as well as very low levels of cohabitation and extra-marital fertility. Both changing and unchanged aspects of families are related to lowest-low fertility in Japan. Although premarital sexual activities have increased, women's contraceptive initiative is very weak: they may be connected with weak partnership formation. "Parasite singles", "freeters", or "NEETs", probably related to weak family formation, have increased, but they may be connected with strong filial bondage derived from the traditional family system, i.e. Women have been normatively, educationally, and occupationally emancipated, but gender norms are currently divided in half among Japanese people, which may deter the revising of working conditions for women with children, leading to delaying family formation among working women. Lowest-low fertility conversely brings about family changes. Its direct effect is the increase of lifetime celibacy and childless couples, which may jeopardize the universality of families. Its indirect effect is through policy response to low fertility as well as labor shortages and population aging: recently, both family and labor policies have been strengthened to make it easier for working women to continue their jobs after marriage and childbirth, which might in turn promote family formation in Japan. [source]


,Low' fertility and population replacement in Scotland

POPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2007
John MacInnes
Abstract It has been argued that Scotland faces population ageing and decline that will have potentially serious economic and social consequences, and that the origin of these processes lie in its low and declining fertility rates. After considering alternatives to the total period rate measure of fertility, empirical evidence and theoretical argument about low fertility and its consequences is briefly reviewed. The paper argues that low fertility in general may not be the problem it is often purported to be, that Scotland has relatively high fertility, and that pro-natalist policies are neither desirable nor necessary. It suggests that low fertility and population ageing may be viewed as positive developments, and that within Europe, Scotland is distinguished more by its excess of early deaths than by any shortage of births. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Liveweight gains of lambs from Caucasian clover/ryegrass and white clover/ryegrass swards on soils of high and low fertility

GRASS & FORAGE SCIENCE, Issue 2 2007
A. D. Black
Summary The high nutritive value and persistence under a wide range of climatic and soil fertility conditions make Caucasian clover a potentially useful forage legume but there is little information about the performance of livestock grazing Caucasian clover/grass swards. This study compared liveweight gains of lambs grazing Caucasian clover/perennial ryegrass and white clover/perennial ryegrass swards on high fertility (Olsen P 20 mg L,1, SO4 -S 12 mg kg,1) and low fertility (Olsen P 11 mg L,1, SO4 -S 7 mg kg,1) soils from 1998 to 2001 in the South Island of New Zealand. Mean annual liveweight gains were 1178 kg ha,1 for Caucasian clover/perennial ryegrass and 1069 kg ha,1 for white clover/perennial ryegrass swards at high fertility compared with 1094 kg ha,1 and 1015 kg ha,1, respectively, at low fertility. There was a higher mean proportion of clover in Caucasian clover/perennial ryegrass (0·19) than white clover/perennial ryegrass (0·11) swards, but there were no differences in total herbage production between the two clover/perennial ryegrass swards. The mean concentration of crude protein in the herbage of Caucasian clover (302 g kg DM,1) was higher than that in white clover (287 g kg DM,1) and grass herbage (227 g kg DM,1). Estimated mean metabolizable energy concentrations in the herbage were 12·5 MJ kg DM,1 for the two clovers and 11·6 MJ kg DM,1 for grass herbage. The difference in liveweight gain between swards on soils of high and low fertility was associated with an increase in total herbage production of similar composition and nutritive value, giving a greater number of grazing days for the swards on soils of high than low fertility. [source]


Selective defoliation by sheep according to slope and plant species in the hill country of New Zealand

GRASS & FORAGE SCIENCE, Issue 4 2003
I. F. López
Abstract The objective of the study was to evaluate the grazing behaviour by sheep in hill country paddocks in New Zealand which had received two long-term fertilization and stocking rate treatments [high fertility,high stocking rate (HH); low fertility,low stocking rate (LL)]. Herbage accumulation and selective grazing were evaluated within low slope (LS), medium slope (MS) and high slope (HS) categories. Transects lines were placed and tillers of Agrostis capillaris and Lolium perenne in the LS category; A. capillaris, Anthoxanthum odoratum and L. perenne in the MS category; and A. capillaris and A. odoratum in the HS category were marked. The leaf length of each marked tiller was measured and used to determine selective grazing over 3 weeks during each season. The highest herbage accumulation rates were during spring and the lowest in summer and winter. The LS category showed the highest herbage accumulation rates and HS the lowest. Except for autumn, the marked tillers were more frequently grazed in the HH than in the LL paddock. During summer, autumn and spring, grazing frequency in the slope categories was in the order LS > MS > HS. During winter sheep did not discriminate between slope category. During summer, autumn and spring, sheep did not selectively graze the species studied but this was not the case during winter. Overall, sheep selectively grazed L. perenne. In all the seasons L. perenne consistently had the longest leaves but within species there was no consistent relationship between leaf length and probability of being grazed. Selective grazing changed through the year according to herbage accumulation rate. Sheep concentrated grazing in the category LS when herbage accumulation rate was high, but they did not discriminate between slope categories in winter when herbage accumulation rate was low. [source]


The Jewish Emigration from the Former Soviet Union to Germany

INTERNATIONAL MIGRATION, Issue 2 2002
Barbara Dietz
Since the end of the 1980s a massive emigration of Jews from the former Soviet Union (FSU) can be observed. Israel and the United States were the most important receiving countries, followed by Germany, a comparatively new immigration destination for Jews from the successor states of the USSR. One of the reasons the German Government allowed the admission of Jews from post-Soviet states was the Jewish community's claim that this immigration might rejuvenate the German Jewish population in the longer run. Using an index of demographic aging (Billeter's J), the following article examines if this has actually happened. Findings suggest that immigration actually initiated a process of rejuvenation in the Jewish population in Germany. However, it was reversed during the end of the 1990s because of an unaffected low fertility. [source]


Genetic identity of interspecific neighbours mediates plant responses to competition and environmental variation in a species-rich grassland

JOURNAL OF ECOLOGY, Issue 5 2007
JASON D. FRIDLEY
Summary 1Although outbreeding populations of many grassland plants exhibit substantial genetic and phenotypic variation at fine spatial scales (< 100 m2), the implications of local genetic diversity for community structure are poorly understood. Genetic diversity could contribute to local species diversity by mediating the effects of competition between species and by enhancing species persistence in the face of environmental variation. 2We assayed the performance of three genotypes each of a dominant tussock grass (Koeleria macrantha [Ledeb.] J.A. Schultes) and dominant sedge (Carex caryophyllea Lat.) derived from a single 10 × 10 m quadrat within a limestone grassland in Derbyshire, UK. Genotypes were grown in monoculture and grass,sedge mixtures of different genetic composition in two environments of contrasting fertility. Species mixtures also included one genotype of the subordinate forb Campanula rotundifolia L. 3When grown without neighbours, intraspecific genotypes responded similarly to environmental treatments. One genotype of the sedge performed worse in both environments than the other two sedge genotypes. 4When grown in species mixtures, genotype performance was significantly influenced by the genetic identity of the neighbouring species for both the sedge and the grass. At high fertility, differential genotype performance was not sufficient to alter the expectation of competitive exclusion of the sedge by the grass. However, at low fertility, the competitive dominant depended on the genetic identity of both the grass and the sedge. In addition, each genotype of the grass performed best next to a different genotype of the sedge, and the identity of the best genotype pairings switched with environment. 5Performance of a single genotype of the subordinate Campanula was not predictable by fertility alone, but by how fertility interacted with different neighbouring genotypes of both the grass and the sedge. 6Results support the hypothesis that the genetic identity of interspecific neighbours influences plant performance in multispecies assemblages and mediates species' responses to environmental variation. Such interactions could be a key factor in the contribution of local intraspecific genetic diversity to species diversity. [source]


Postzygotic incompatibilities between the pupfishes, Cyprinodon elegans and Cyprinodon variegatus: hybrid male sterility and sex ratio bias

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2006
C. TECH
Abstract I examined the intrinsic postzygotic incompatibilities between two pupfishes, Cyprinodon elegans and Cyprinodon variegatus. Laboratory hybridization experiments revealed evidence of strong postzygotic isolation. Male hybrids have very low fertility, and the survival of backcrosses into C. elegans was substantially reduced. In addition, several crosses produced female-biased sex ratios. Crosses involving C. elegans females and C. variegatus males produced only females, and in backcrosses involving hybrid females and C. elegans males, males made up approximately 25% of the offspring. All other crosses produced approximately 50% males. These sex ratios could be explained by genetic incompatibilities that occur, at least in part, on sex chromosomes. Thus, these results provide strong albeit indirect evidence that pupfish have XY chromosomal sex determination. The results of this study provide insight on the evolution of reproductive isolating mechanisms, particularly the role of Haldane's rule and the ,faster-male' theory in taxa lacking well-differentiated sex chromosomes. [source]


Importance of assemblage-level thinning: A field experiment in an alpine meadow on the Tibet plateau

JOURNAL OF VEGETATION SCIENCE, Issue 4 2006
Yanjiang Luo
Anon. (1998) Abstract Question: Which fraction of the decrease in species richness under fertilization can be explained by assemblage-level thinning? Location: An alpine meadow on the eastern Tibet plateau. Methods: 60-m2 plots were randomly assigned to a control or one of four levels of ammonium phosphate fertilizer. Treatments were repeated for three years. The effect of as semblage-level thinning was decided based on similarity in quadrats within and between fertilizing levels, bootstrap simulation based on random thinning of the high density (low production, low fertility) quadrats and correlation of species' biomass in low fertility and high fertility. Results: Fertilization increased production, reduced species richness and reduced density of individuals. Heavily fertilized quadrats are more similar in species composition in 2000 but less similar in 2001 and 2002. Rarefaction showed that a decrease in density can account for 32.3-42.9% decrease of species richness, but the simulated species richness is always significantly higher than the observed one. When production and species richness are similar at two levels of fertilization, species biomass in the higher fertility treatment is positively correlated with biomass at lower fertility. When the two fertilizer levels differed in production and species richness, there was no evidence of correlation in species biomass, suggesting that assemblage level thinning cannot explain all the loss of species. Conclusion: Although a decrease in density could explain much of the decrease (up to 42.9%) in species richness when this alpine meadow was fertilized, other important mechanisms such as interspecific competition cannot be ignored. Future studies should investigate the effect of assemblage level thinning on species diversity, and search for mechanisms responsible for a decrease in diversity. [source]


Validation of plant functional types across two contrasting landscapes

JOURNAL OF VEGETATION SCIENCE, Issue 2 2002
Michael Kleyer
Disturbance; Fertility; Logistic regression; Trait; Urban landscape Abstract. The validation of plant functional type models across contrasting landscapes is seen as a step towards the claim that plant functional types should recur regionally or even globally. I sampled the vegetation of an urban landscape on a range of sites representing gradients of resource supply and disturbance intensity. A group of plants with similar attributes was considered a ,functional type', if the species significantly co-occurred in a certain segment of the gradient plane of resource supply and disturbance intensity. Vegetative and regeneration traits were considered. A similar study was performed in a nearby agricultural landscape (Kleyer 1999). The logistic regression models from the urban landscape were applied to the data set of the agricultural landscape and vice versa. Although the overall environment of the two landscapes was very different, recurrent patterns of several functional types were found. At high fertility and high disturbance levels, annual species predominated with a persistent seed bank, high seed output, and short vertical expansion. When disturbances changed from below-ground to above-ground, the sexual regeneration mode was replaced by the vegetative mode, while vertical expansion remained low. At medium disturbance intensities, the vertical expansion and vegetative regeneration increased with fertility, while the seed bank remained mostly transient to short-term persistent and lateral expansion and sexual regeneration was intermediate. At low disturbances and low resource supplies, seed bank longevity, and vertical and lateral expansion tended to be long. Diversity of groups of plants with similar attributes was highest at intermediate disturbance levels and low fertility. These results correspond with Grime's humped-back model and Connell's intermediate disturbance hypothesis. [source]


Proteins of the accessory sex glands associated with the oocyte-penetrating capacity of cauda epididymal sperm from holstein bulls of documented fertility

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2007
Arlindo A. Moura
Abstract We previously reported that accessory sex gland fluid (AGF) from high fertility (HF) bulls influenced the oocyte-penetrating capacity of cauda epididymal sperm from low fertility (LF) bulls, based on in vitro fertilization (IVF) assays. The present study determined if AGF proteins were associated with these effects. Nineteen IVF assays with 12 bulls were grouped as follows. Group I (n,=,8): assays where sperm from LF bulls exposed to AGF from HF bulls had greater oocyte penetration than exposed to homologous AGF. Group II (n,=,7): sperm from LF bulls to AGF from HF bulls versus homologous AGF showed no significant differences. Group III (n,=,4): sperm from LF bulls treated with homologous AGF had greater fertility than sperm treated with AGF from HF bulls. Sire fertility was based on nonreturn rates (NNR) and AGF collected by artificial vagina from bulls with cannulated vasa deferentia. Two-dimensional SDS,PAGE maps of AGF were analyzed by PDQuest and proteins identified by tandem mass spectrometry and Western blots. Differences in spot intensity between AGF of HF and LF bulls were compared across groups of IVF assays (P,<,0.05). The expression of BSP A1/A2 and A3, BSP 30 kDa, clusterin, albumin, phospholipase A2 (PLA2), and osteopontin was greater in the AGF of HF bulls in Group I as compared to Groups II and III. Conversely, there was less nucleobindin in the AGF of HF bulls in Group I than in Groups II and III. This is the first report of nucleobindin (58 kDa/pI 5.6) in male reproductive fluids, using both immunoblots and mass spectrometry. Thus, the effect of AGF from HF bulls on epididymal sperm is likely the result of specific proteins expressed in the AGF. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source]


The Sex Ratio Transition in Asia

POPULATION AND DEVELOPMENT REVIEW, Issue 3 2009
Christophe Z. Guilmoto
This article adopts a comparative perspective to review the recent increase in the sex ratio at birth (SRB) across Asia. It first describes and compares the most recent birth statistics in Asia in order to identify commonalities in the gradual rise of SRBs observed from Armenia to South Korea. This comparison provides the basis for identifying specific transition patterns in the changes in SRBs. Their recent rise is then interpreted in a social and historical framework borrowed from fertility decline and based on three preconditions: access to sex-selection technology, preference for male births, and pressure from low fertility. On a broader plane, the process of growing imbalances in the sex composition of the population gives rise to a tragedy of the commons. This article indicates the factors that appear most likely to trigger a turnaround in this transitional demographic situation and to facilitate a return to biologically normal sex ratios in the future. [source]


An Imperfect Contraceptive Society: Fertility and Contraception in Italy

POPULATION AND DEVELOPMENT REVIEW, Issue 3 2009
Alessandra Gribaldo
Italy represents an unexpected and in some ways paradoxical outcome in terms of fertility control: a drop to one of the lowest birth rates in the world has been accompanied by continuing extensive use of traditional methods despite the availability of modern contraception. Using data from 349 interviews conducted in 2005,06 in four Italian cities, we argue that Italian women commonly achieve "unplanned" and desired conceptions through the use of withdrawal and natural methods. While data from other countries reveal similar notions of ambivalence surrounding pregnancy intentions and contraceptive use, Italy stands out for the surprising correlation between highly "managing" the conditions under which children are born and the socially commended approach of "letting births happen." Such results suggest the need to rethink theoretical understandings of low fertility. Through the use of non-technological methods, individuals manipulate culturally produced norms and beliefs about the appropriate time to have a child; simultaneously, their actions are embedded in larger cultural, economic, and political processes. [source]


Delayed Marriage and Very Low Fertility in Pacific Asia

POPULATION AND DEVELOPMENT REVIEW, Issue 3 2007
Gavin W. Jones
The general decline in fertility levels in Pacific Asia has in its vanguard countries where fertility rates are among the lowest in the world. A related trend is toward delayed marriage and nonmarriage. When prevalence of cohabitation in European countries is allowed for, levels of "effective singlehood" in many countries of Pacific Asia have run ahead of those in northern and western Europe. This raises questions about the extent to which delayed marriage has been implicated in fertility declines, and whether the same factors are leading both to delayed marriage and to lowered fertility within marriage. The article argues that involuntary nonmarriage is likely to be more common in Pacific Asia than in Western countries, and that resultant involuntary childlessness plays a substantial role in the low fertility rates currently observed. [source]


On Integrating Immigrants in Germany

POPULATION AND DEVELOPMENT REVIEW, Issue 3 2006
Article first published online: 8 SEP 200
Immigration to Germany in the decades following World War II made the Federal Republic the host of the largest number of immigrants in Europe. The size of the population with an immigration background is on the order of 15 million, nearly one-fifth of the total population. (Many of these are ethnic German returnees.) Although restrictive policies and a less dynamic economy in recent years slowed the annual number of immigrants and asylum seekers, the interrelated demographic influences of very low fertility, negative natural population increase, and population aging make continuing future immigration likely and, judged by influential domestic interests, desirable. Anxieties about inadequate integration of immigrants in German society are, however, apparently strongly felt by large segments of the native population. The "Grand Coalition" government that took office in November 2005 considers the formation of an effective policy of integration a high priority. On 14 July 2006 an "Integration Summit" was convened in the Chancellery with the active participation of representatives of immigrant groups. Chancellor Angela Merkel called the Summit "an almost historical event." Reproduced below in full is a non-official English translation of a government statement (entitled "Good coexistence,Clear rules") presented to the participants at the opening of the meeting. Intended as a "start of the development of a national integration plan," the statement highlights existing deficiencies of integration, especially problems with second- and third-generation immigrants: lack of mastery of the German language, weaknesses in education and training, high unemployment, lack of acceptance of the basic rules of coexistence, and violation of the law. The importance of these issues is underlined by a demographic fact noted in the statement: by 2010 it is expected that in Germany's large cities 50 percent of the population under age 40 will have an immigrant background. The statement recognizes the government's responsibility to help immigrants learn German and become better informed about the country's laws, culture, history, and political system. In turn, it demands reciprocal efforts from migrants living permanently and lawfully in Germany. The original German text of the statement is available at the Bundeskanzleramt home page: «http://www.bundesregierung.d» [source]


Vladimir Putin on Raising Russia's Birth Rate

POPULATION AND DEVELOPMENT REVIEW, Issue 2 2006
Article first published online: 26 JUN 200
The total fertility rate in what is now the Russian Federation has been below replacement level during much of the last 40 years. By the late 1990s it was barely above 1.2 children per woman. There may have been some recovery since: the United Nations estimate for 2000,05 is 1.33. Other reports set the 2004 rate at 1.17. Countries elsewhere in Europe have fertility levels that are equally low or even lower, but the Russian demographic predicament is aggravated by mortality that is exceptionally high by modern standards. Thus, despite large-scale net immigration (mostly due to return of ethnic Russians from other republics of the former Soviet Union), the population in the last decade-and-a-half has been shrinking: of late by some 700,000 persons per year. The United Nations medium estimate assumes a steady recovery of the total fertility rate to reach a level of 1.85 by 2050 and a considerable improvement in survival rates during that period,notably an increase in male life expectancy at birth of more than ten years. It also assumes further modest net immigration at a steady rate, amounting to a total of somewhat over 2 million by midcentury. Under these stipulations the projected population of Russia in 2050 would be 112 million,some 31 million below its present size. By that time, 23 percent of the population would be aged 65 and older. The government's concern with the demographic situation of the country and its intent to improve it have been manifest in various official statements, notably in the annual State of the Nation Address given by the president to the Federal Assembly (or State Duma). Formerly a subordinate theme (see the Documents item in the June 2005 issue of PDR), the issue constituted the centerpiece of the 2006 Address, delivered on 10 May in the Kremlin by President Vladimir Putin. Policies regarding health and mortality were given short shrift in the speech,road safety, bootleg alcohol, and cardiovascular diseases being singled out as areas of special concern. The president's remarks on immigration are of greater interest: immigration of skilled persons is to be encouraged. They must be educated and law-abiding and must treat the country's culture and national tradition with respect. The main focus of the address, however, was on the birth rate and policies to be introduced to raise it. (The need for an "effective demographic policy" as seen from the Kremlin was of course also voiced in the later stages of the Soviet era. See, for example, the excerpts from the addresses delivered by then Party Chairman Leonid Brezhnev and Premier Nikolai Tikhonov to the 26th Congress of the Communist Party of the Soviet Union in February 1981 that appear in the Documents item in the June 1981 issue of PDR.) In detail and specificity, and also in terms of the economic cost of the measures envisaged, Putin's speech is without parallel in addressing population policy matters by a head of state in Europe. The demo graphically relevant portion of the address is reproduced below in the English translation provided by the website of the president's office «http://www.kremlin.ru/eng». Calling Russia's demographic situation "the most acute problem facing our country today," Putin terms its causes as "well known," but lists only economic factors, presumably because these, at least in principle, lend themselves to remedial measures that the Russian government, its coffers now swollen with petrodollars, should be able to provide. His starkly economic interpretation of the problem of low fertility (in Russia apparently taking the form of convergence to a single-child pattern) may be overly optimistic. Causes of electing to have only one child may lie deeper than those Putin names: low incomes, inadequate housing, poor-quality health care and inadequate educational opportunities for children, and even lack of food. Putin's proposed policies to attack these problems in part consist of a major upgrading of existing child care benefits: to 1,500 roubles a month for the first child and 3,000 roubles for the second. The latter amount is roughly equivalent to US$113, a significant sum given Russian income levels. Maternity leave for 18 months at 40 percent of the mother's previous wage (subject to a ceiling) and compensation for the cost of preschool childcare round out the basic package proposed. Benefits are to be parity-dependent, highlighting the pronatalist intent of the measures. Thus the child benefit for the second child is to be twice as large as for the first, and payment for preschool childcare is to cover 20 percent of parental costs for the first, 50 percent for the second, and 70 percent for the third child. Putin mentions "young families" as recipients, but the payments are clearly directed to mothers. (Even the usually obligatory reference to western European,style paternity leave is missing.) The most innovative element of the proposed measures, however, is support for women who have a second birth. The state should provide such women (not the child, as called for in some European precedents) "with an initial maternity capital that will raise their social status and help resolve future problems." Citing expert opinion, Putin says that such support "should total at least 250,000 roubles [about $9,300] indexed to annual inflation." Evidently assuming, optimistically, that there will be many takers, Putin says that carrying out all these plans will require not only a lot of work but also "an immense amount of money." The measures are to be launched starting January 2007. [source]


The End of the Fertility Transition in the Developed World

POPULATION AND DEVELOPMENT REVIEW, Issue 3 2002
John Bongaarts
By the late 1990s the average period total fertility rate in the developed world had declined to 1.6, a level substantially lower than projected in the 1970s and 1980s. This article examines recent trends and patterns in fertility in the developed world with particular emphasis on the effects and implications of changes in the timing of childbearing. The main objective is to demonstrate that while fertility in these countries is indeed low, women's childbearing levels are not as low as period measures such as the total fertility rate suggest. To obtain a full understanding of the various dimensions of fertility change. several indicators are examined, including period and cohort fertility by birth order and childbearing preferences. An analysis of these indicators demonstrates that period fertility measures in many developed countries are temporarily depressed by a rise in the mean age at childbearing. The distortion of the TFR is as great as 0.4 births per woman in Italy and Spain. These effects have been present in many developed countries since the 1970s and could continue for years into the future. But tempo effects are temporary, and once the postponement of childbearing ends,as it eventually must,the corresponding fertility-depressing effect stops, thus putting upward pressure on period fertility. Countries with very low fertility and substantial tempo effects may well experience rises in fertility in the near future if the timing of childbearing stabilizes. Even if this happens, however, it seems unlikely that fertility will rebound to the replacement level. [source]


Uncertain Aims and Tacit Negotiation: Birth Control Practices in Britain, 1925,50

POPULATION AND DEVELOPMENT REVIEW, Issue 2 2000
Kate Fisher
Evidence from oral history interviews is used to suggest the need to reevaluate our understanding of the dynamics of fertility decisions and behavior in the first half of the twentieth century. Those interviewed stressed their vague and haphazard approach to contraceptive use, in sharp contrast to the dominant depiction in studies of fertility decline that emphasize the degree to which individuals made deliberate and calculated choices about family size based on an assessment of the costs and benefits of childrearing. Details of individual contraceptive strategies elucidate the complexities of birth control behavior: couples, lacking explicit aims for family limitation, adopted diverse methods of birth control, using them for different reasons, at different times, with varying degrees of determination and confidence and frequently with very little direct discussion or planning. Explicit articulation of aims was not a necessary prerequisite of the spread of birth control; accepted gender roles meant that responsibilities and obligations emerged gradually and tacitly. As a result, nevertheless, low fertility was effectively achieved. [source]


,Low' fertility and population replacement in Scotland

POPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2007
John MacInnes
Abstract It has been argued that Scotland faces population ageing and decline that will have potentially serious economic and social consequences, and that the origin of these processes lie in its low and declining fertility rates. After considering alternatives to the total period rate measure of fertility, empirical evidence and theoretical argument about low fertility and its consequences is briefly reviewed. The paper argues that low fertility in general may not be the problem it is often purported to be, that Scotland has relatively high fertility, and that pro-natalist policies are neither desirable nor necessary. It suggests that low fertility and population ageing may be viewed as positive developments, and that within Europe, Scotland is distinguished more by its excess of early deaths than by any shortage of births. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Incidence of Error in Oestrus Detection Based on Secondary Oestrus Signs in a 24-h Tie-Stalled Dairy Herd with Low Fertility

REPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2009
RMSBK Ranasinghe
Contents Oestrus detection error and conception rates after AI based only on secondary oestrus signs were evaluated in a high yielding, 24-h tie-stalled dairy herd with low fertility, using milk progesterone profiles. Oestrus detection was based on the secondary oestrus signs such as restlessness, swelling, congestion of vulva and clear mucus discharge. Sixty eight AI conducted after observing the secondary oestrus signs in 44 animals were included in the study. Of the 68 AI, 53 (77.9%) were conducted in the follicular phase, and 13 (19.1%) and 2 (2.9%) were carried out in the luteal phase and during pregnancy, respectively. The overall error in oestrus detection based on milk progesterone profiles was 22.1%. The oestrus detection error did not differ significantly among different secondary oestrus signs. None of the AI conducted in the luteal phase resulted in conception, whereas 20.8% of AI conducted in the follicular phase resulted in conception. No significant difference in the conception rates among the groups of cows with different secondary oestrus signs was shown. The high incidence of oestrus detection error in this study might have been caused by the detection of cows in oestrus based only on secondary oestrus signs due to the confinement of animals. In conclusion, there was a high incidence of heat detection error in the 24-h tie-stalled dairy herd and oestrus detection based only on secondary oestrus signs resulted in low conception rate. [source]


Effects of Glucose Concentration on in vitro Fertilization in BALB/c Mice

REPRODUCTION IN DOMESTIC ANIMALS, Issue 6 2003
HT Wu
Contents BALB/c mice are widely used in genetic, tumour and immunological studies. However, the mice demonstrate a lower reproduction rate, low fertility and small litters, because of their highly genetic homozygoisty. Based on in vitro fertilization (IVF), a routine technique for biomedical studies, it is worth to evaluate the effects to BALB/c mice on IVF efficiency. In order to test the genetic factor affecting the IVF efficiency of BALB/c, four reciprocal IVF tests of BALB/cByJ and FVB/NCrl mice were performed. The results showed that the average fertility of IVF sponsored by FVB/NCrl spermatozoa was 69.6%, but only 12.1% was obtained from BALB/cByJ strain. Effect of glucose contained in the culture medium to the IVF efficiency of BALB/cByJ was also evaluated. The results showed that the fertility of BALB/cByJ spermatozoa incubated with 0, 2.7, 5.5, 11.1 and 22.2 mm of glucose in the TYH medium were 6.8, 9.9, 13.9, 32.7 and 22.2%, respectively. It is showed that IVF efficiency of BALB/cByJ spermatozoa could be improved depending on the concentration of glucose in the IVF medium. According to the results, it is beleived that lower IVF of BALB/cByJ mice might be due to the genetic defect in spermatozoa and increasing glucose in the IVF medium which significantly affect the IVF efficiency of BALB/cByl via activating the spermatozoa. [source]


Would a Decrease in Fertility Be a Threat to Living Standards in Australia?

THE AUSTRALIAN ECONOMIC REVIEW, Issue 1 2002
Ross S. Ross S.
Falling rates of fertility in many countries have led to concerns that low fertility is a threat to future living standards. In this article we report simulations of living standards for Australia that take into account the effect of demographic change. These simulations show that reduced fertility would actually increase living standards, albeit by a small amount. We also present projections of government social outlays. These projections suggest that reductions in fertility will have an insignificant or tiny tax-disincentive effect on GDP, thereby reinforcing our conclusion that reductions in fertility are not a threat to future living standards. [source]


The ratio of campesterol to sitosterol that modulates growth in Arabidopsis is controlled by STEROL METHYLTRANSFERASE 2;1

THE PLANT JOURNAL, Issue 6 2001
Aurélie Schaeffer
Summary The Arabidopsis genome contains three distinct genes encoding sterol-C24-methyltransferases (SMTs) involved in sterol biosynthesis. The expression of one of them, STEROL METHYLTRANSFERASE 2;1, was modulated in 35S::SMT2;1 Arabidopsis in order to study its physiological function. Plants overexpressing the transgene accumulate sitosterol, a 24-ethylsterol which is thought to be the typical plant membrane reinforcer, at the expense of campesterol. These plants displayed a reduced stature and growth that could be restored by brassinosteroid treatment. Plants showing co-suppression of SMT2;1 were characterized by a predominant 24-methylsterol biosynthetic pathway leading to a high campesterol content and a depletion in sitosterol. Pleiotropic effects on development such as reduced growth, increased branching, and low fertility of high-campesterol plants were not modified by exogenous brassinosteroids, indicating specific sterol requirements to promote normal development. Thus SMT2;1 has a crucial role in balancing the ratio of campesterol to sitosterol in order to fit both growth requirements and membrane integrity. [source]