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The long-awaited second edition of the International Symposium on "Epigenome Network, Development and Reprogramming of Germ Cells" hosted by Hiroyuki Sasaki took place at the Kyushu University School of Medicine, in Fukuoka, Japan from 22 to 24 November 2010. This meeting brought together again the crème de la crème of the Japanese research community investigating germline development, reprogramming and genetic networks as well as eminent international scientists. Novel trend concepts including the "reprogramming expressway", "canalization", "licensing", "epigenetic barrier", "flex points" and "hydroxymethylation" were introduced and discussed in the context of development, reprogramming and pluripotency.

Myxococcus xanthus is remarkable among the prokaryotes because it has a developmental cycle that produces fruiting bodies. Many extracellular signals (A–E) orchestrate fruiting body formation. This update highlights recent work that has contributed to our current understanding of the C-signal and its role in fruiting body formation and morphogenesis.

International audience; Human and animal African trypanosomoses, or sleeping sickness and Nagana, are neglected vector-borne parasitic diseases caused by protozoa belonging to the Trypanosoma genus. Advances in proteomics offer new tools to better understand host-vector-parasite crosstalks occurring during the complex parasitic developmental cycle, and to determine the outcome of both transmission and infection. In this review, we summarize proteomics studies performed on African trypanosomes and on the interactions with their vector and mammalian hosts. We discuss the contributions and pitfalls of using diverse proteomics tools, and argue about the interest of pathogenoproteomics, both to generate advances in basic research on the best knowledge and understanding of host-vector-pathogen interactions, and to lead to the concrete development of new tools to improve diagnosis and treatment management of trypanosomoses in the near future.

Brewing was an important part of the medieval peasant economy. There are different views, however, about the nature and position of those who brewed. It has been suggested that brewing was an integral part of the household economy, that is, at the fully developed stage of the household and family, whilst others have connected brewing with the early stages of the life-cycle of individuals, before household formation. Either as part of the household economy or before household formation, brewing may have supplemented income from agrarian activity, whether from the direct holding of land, or from wages for work on the land. Brewing may also have been a feature of the sexual division of labour within the household. Moreover, it has been proposed that brewing was more important for the household economy of cottagers and lesser landholders than for the tenants of standard holdings, who, perhaps, needed to supplement their income less than the smaller landholders. When related to the life-cycle of individuals, however, brewing may have been undertaken more consistently by those who would later acquire land and would then divest themselves of brewing as a major part of their income, although Chayanov believed brewing to relate more widely to the developmental cycle of all peasant households. His perception was that brewing would have been necessary at that stage of household development where there were many mouths to feed and many hands to perform the labour, whereas, when the siblings left the household, the supplementary income from brewing would no longer be required. There are thus a number of issues involved in the question of who, in the main, brewed, and at what stage of their life-cycle they did so.

Although Americans have experienced many drug epidemics, the majority of which have ended within ten years of onset, they nevertheless believed that the use of smokable cocaine, which took the popular form of crack cocaine in 1984, would grow exponentially throughout the 1990s unless it was vigorously combated. However, in 1991 it appears that crack use is in decline even in the inner-city neighborhoods where it had been most entrenched, and that the decline is due more to natural controls than to the War on Drugs. The cyclical nature of drug epidemics, as well as their progression through regular stages, was again affirmed. The cocaine-smoking epidemic of 1981-1991 (which included crack) afforded the opportunity to research it in its entirety. In this article, the advantages of recognizing the developmental cycles of drug epidemics are outlined, the most important of which concerns the future. In the terminal stage of the developmental cycle of a drug epidemic, remaining abusers play a pivotal role. If humanely treated, they may serve as deterrents to future drug use: frustrated in current drug use, however, yet insensitively treated by the wider society, they may author the next epidemic.

Numerous bacterial proteins exert their function outside the prokaryotic cell. To this end, both Gram-negative and Gram-positive bacteria have evolved specialized mechanisms to transport their proteins to the bacterial supernatant or host cell cytoplasm, so called secretion systems. These different strategies will be briefly discussed, followed by an in depth description of the Type III secretion system, an efficient molecular syringe assisting Gram-negative bacteria in entrance, growth and survival in eukaryotic host cells. Topics addressed include classification and role of multiple Type III secretion systems, the mechanism of protein translocation into the host cell as well as substrate recognition and chaperoning. Chlamydiales have also been found to encode a Type III secretion system and associated effector proteins. In contrast to the genetic organization in other bacteria, the encoding genes are scattered throughout the genome. To date, no structural information is available on the chlamydial Type III secretion system. We therefore propose a model of the chlamydial Type III secretion system and summarize current knowledge on the role of Type III secretion in the different stages of the chlamydial developmental cycle.

The objective of this work was to show the substrates preference for oviposition of Ae. albopictus in the field, and its developmental cycle in laboratory. Insects were distributed in nine black plastic containers in the field, next to chicken coops, pigsties and jaboticaba trees. Paper coffee filters, wrapping paper cones and palettes of eucatex were, simultaneously, placed in every container. The observations were conducted twice a week for 120 days. After counting, eggs were transferred to disposable plastic cups, with 500mL capacity. Inside them, 350 mL of water were placed in order to propitiate the eclosion of larvae. Every plastic cup was properly identified with the date and type of substrate, and daily remarks were made for a 60 days period. We observed 29 postures in the field: nine in wrapping paper, nine in filter paper, and 11 in palettes. The average of eggs was 15.9 per oviposition. The larvae eclosion average was 11.2 and the adult development average was 9.9 per oviposition. The number of male and female insects was approximately one to one. There was no significant difference of oviposition of Ae. albopictus between the studied substrates. In the laboratory, the daily average of eggs per female was 2.09 ± 0.31. The incubation of the eggs lasted for 4.0 days. The average duration of larval instars was 1.4, 1.2, 1.3 and 2.7 days, respectively to 1°, 2°, 3° and 4° instars. The pupae instar lasted for 2.1 days. The average life expectancy for males and females was 60 and 75 days, respectively.

Publisher Summary This chapter presents several methodological considerations that are useful in determining reproductive periodicity. The oldest and most widely used quantitative method for estimating the reproductive activity is the gonad index (GI), also termed gonadosomatic index (GSI). Although not precise, the technique is particularly suitable for routinely handling large numbers of samples. The GI is calculated in several ways, but is usually defined as the ratio of the gonad wet weight to the wet weight of the body wall, test, or whole animal expressed as a percentage. Gonadal smears and/or histological sections of the gonads are widely used to estimate the reproductive status. Such data are not quantitative when the developmental cycle is merely divided into a series of maturity stages in a manner that may differ from that used by other investigators. The long-term rearing and monitoring of animals in the laboratory provides another way of assessing reproductive processes and spawning periodicities. However, compiling the data on gamete release in the laboratory constitutes a powerful tool only when the holding conditions simulate those of the natural environment.

A-09-11; International audience; Architectural descriptors were used to understand root system structure and development in white yam (Dioscorea rotundata Poir., Dioscoreaceae), a tuber monocot. Observations were made on seedlings and plant derived from tuber fragments, cultivated in greenhouses over a developmental cycle. This study demonstrated that both seedlings and plants derived from tubers have two distinct root systems that are highly organized. The first (seminal or tubercular) has been called the temporary root system which is small and short lived. The architectural unit here is made up of two root axis categories. The second (adventitious in both cases) has been called the definitive root system. It is larger and has a far longer lifespan than temporary root systems. The architectural unit here is made up of three root axis categories. Adventitious root systems are formed by structural repetitions of their own architectural unit. The temporary and definitive root systems possess the same structural and functional properties and become established and succeed one another in time following an identical developmental sequence. Neo tuber development is coupled with the root system development. Our results highlight to what extent it is important to study simultaneously the different parts of a root system in order to understand its development. This study confirms how architectural tools can be used to understand root system structure and development and prove accurate informations on root system development for use in agricultural management.

Scholars of the Chinese entrepreneurial ethic describe married women's primary entrepreneurial strategy as an indirect one—motivating sons to work hard for the family. Research in a community of overseas Chinese entrepreneurs, however, reveals diversity in married women's strategies. After cross-tabulating a number of variables, including family type, spatial organization, and firm size, this article concludes that firm size is the most influential factor with respect to women's strategies and roles. Its impact is explained in terms of the relationship of entrepreneurial ideology to Chinese family relationships and sex roles. [China, women, entre-preneurship, developmental cycle, sexual division of labor]

BackgroundThe chlamydial developmental cycle involves the alternation between the metabolically inert elementary body (EB) and the replicating reticulate body (RB). The triggers that mediate the interchange between these particle types are unknown and yet this is crucial for understanding basicChlamydiabiology.Presentation of the hypothesisWe have proposed a hypothesis to explain key chlamydial developmental events whereby RBs are replicating strictly whilst in contact with the host cell membrane-derived inclusion via type three secretion (T3S) injectisomes. As the inclusion expands, the contact between each RB and the inclusion membrane decreases, eventually reaching a threshold, beyond which T3S is inactivated upon detachment and this is the signal for RB-to-EB differentiation.Testing the hypothesisWe explore this hypothesis through the development of a detailed mathematical model. The model uses knowledge and data of the biological system wherever available and simulates the chlamydial developmental cycle under the assumptions of the hypothesis in order to predict various outcomes and implications under a number of scenarios.Implications of the hypothesisWe show that the concept ofin vitropersistent infection is not only consistent with the hypothesis but in fact an implication of it. We show that increasing the RB radius, and/or the maximum length of T3S needles mediating contact between RBs and the inclusion membrane, and/or the number of inclusions per infected cell, will contribute to the development of persistent infection. The RB radius is the most important determinant of whether persistent infection would ensue, and subsequently, the magnitude of the EB yield. We determine relationships between the length of the T3S needle and the RB radius within an inclusion, and between the RB radius and the number of inclusions per host cell to predict whether persistent infection or normal development would occur within a host cell. These results are all testable experimentally and could lead to significantly greater understanding of one of the most crucial steps in chlamydial development.

Trypanosoma congolense and T. simiae have been the two recognized species within the subgenus Nannomonas. T. congolense is pathogenic to cattle and the small ruminants but not to pigs, while T. simiae causes disease only in pigs. The two species are difficult to distinguish from each other because both share the same developmental cycle in the tsetse and are broadly similar morphologically. However, their isoenzyme and DNA characteristics are quite different. Even more confusing is the fact that T. congolense itself is composed of a num ber of “strains”, or types; historically the different types of T. congolense were often considered as separate species by different workers.

Experimental time courses often reveal a nonlinear behaviour. Analysing these nonlinearities is even more challenging when the observed phenomenon is cyclic or oscillatory. This means, in general, that the data describe a circular trajectory which is caused by periodic gene regulation. Nonlinear PCA (NLPCA) is used to approximate this trajectory by a curve referred to as nonlinear component. Which, in order to analyse cyclic phenomena, must be a closed curve hence a circular component. Here, a neural network with circular units is used to generate circular components. This circular PCA is applied to gene expression data of a time course of the intraerythrocytic developmental cycle (IDC) of the malaria parasite Plasmodium falciparum. As a result, circular PCA provides a model which describes continuously the transcriptional variation throughout the IDC. Such a computational model can then be used to comprehensively analyse the molecular behaviour over time including the identification of relevant genes at any chosen time point.

Identification of periodically expressed genes (PEGs) has been widely studied, but understanding how PEGs are distributed along chromosomes is largely unexplored. In this study we investigated chromosomal clusters of PEGs in stages of intraerythrocytic developmental cycle (IDC) of Plasmodium falciparum using the cDNA microarray data provided by the organizers of the Critical Assessment of Microarray Data Analysis (CAMDA) 2004 competition. To this end, we implemented an analysis consisting of three stages: first, fitting sinusoidal curves to the 46 time points to identify periodically expressed oligonucleoitides, second, using a support vector machine (SVM) to assign the periodically expressed oligonucleoitides to the four known developmental stages of the IDC, and third, defining stage-specific physically adjacent clusters and evaluating through permutation whether there were more clusters than expected by chance. We identified 2949 periodically expressed oligonucleoitides (2204 genes) where periodicity explained at least 70% of the variation over time, and 718, 624, 141, and 167 genes were assigned to the ring/early trophozoite, trophozoite/early schizont, schizont, and early ring stages, respectively, with at least 80% probability for stage prediction. Finally, we identified 312 clusters of two or more adjacent genes assigned to the same stage. Using a permutation-based method, we found that we observed more clusters of size five than expected by chance (p = 0.04). There was also a suggestion (p ∼ 0.10) of more clusters than expected for other cluster sizes. Our findings suggest that the expression of periodically expressed genes may be coordinated locally on chromosomes where there are clusters of genes within same stage, suggesting cis-regulation.

The influence of internal and external factors such as tree fruit load and elevation on ethylene biosynthesis and action was assessed during apple fruit development and ripening. Ethylene biosynthesis, as well as transcript accumulation of the hormone biosynthetic enzymes (MdACS1 and MdACO1), receptors (MdETR1 and MdERS1) and an element of the transduction pathway (MdCTR1), were evaluated in apples borne by trees with high (HL) and low (LL) fruit load. Orchards were located in two localities differing in elevation and season day degree sum. These parameters significantly affected the date of bloom and commercial harvest, and the length of the fruit developmental cycle. Trees from the low elevation (LE) bloomed and the fruit ripened earlier than those from the high elevation (HE), displaying also a shortened fruit developmental cycle. Dynamics of ethylene evolution was apparently not affected by elevation. The onset of ethylene evolution started 130 days after bloom (DAB) at both elevations. During early ripening, fruits from LL trees produced significantly more ethylene than those from HL trees. Expression analysis of MdACS1, MdACO1 and MdERS1 indicated that the transcript accumulation well correlated with ethylene evolution. MdCTR1 was expressed at constant level throughout fruit growth and development up to 130 DAB, thereafter, the transcript accumulation decreased up to commercial harvest, concurrently with the onset of ethylene evolution.

Eggs fertility rate and some biological aspects of the immature forms were studied on six Simulium species from ovipositions collected in natural breeding places located in rural area. The fertility was considerably high. For a total of 213 ovipositions containing 74,906 eggs, the average fertility rate was 99.13% with variation from 94 to 100%. The developmental cycle of the immature forms was observed from egg eclosion to adult emergence under temperature from 16.5 to 28ºC. In S. orbitale the life cycle duration was 30 to 32 days, for S. perflavum 32 to 35 days, for S. subnigrum 33 to 39 days, for S. inaequale 41 to 47 days, for S. pertinax 42 to 48 days, and finally, the longest duration was observed for S. distinctum to range 48 to 49 days.Foram estudados o índice de fertilidade de ovos de espécies de Simulium e o ciclo biológico das fases aquáticas em posturas trazidas de criadouro natural localizado na área rural. A fertilidade de ovos mostrou-se altíssima, das 213 posturas coletadas, contendo 74.906 ovos, o índice médio percentual geral foi de 99,13%. Entre as diferentes posturas, a variação oscilou de 94% a 100%. O ciclo biológico a partir da incubação do ovo até a emergência de adulto em Simulium orbitale foi de 30 a 32 dias; Simulium perflavum de 32 a 35 dias; Simulium subnigrum de 33 a 39 dias, Simulium inaequale de 41 a 47 dias; Simulium pertinax de 42 a 48 dias e Simulium distinctum de 48 a 49 dias em temperaturas com variação de 16,5ºC a 28ºC.

Some studies have demonstrated that a few biological systems are affected by weak, extremely low frequency (ELF) electromagnetic fields (EMFs), lower than 10 mT. However, to date there is scanty evidence of this effect on Protists in the literature. Due to their peculiarity as single-cell eukaryotic organisms, Protists respond directly to environmental stimuli, thus appearing as very suitable experimental systems. Recently, we showed the presence of propionylcholinesterase (PrChE) activity in single-cell amoebae of Dictyostelium discoideum. This enzyme activity was assumed to be involved in cell-cell and cell-environment interactions, as its inhibition affects cell aggregation and differentiation. In this work, we have exposed single-cell amoebae of D. discoideum to an ELF-EMF of about 200 microT, 50 Hz, for 3 h or 24 h at 21 degrees C. A delay in the early phase of the differentiation was observed in 3 h exposed cells, and a significant decrease in the fission rate appeared in 24 h exposed cells. The PrChE activity was significantly lower in 3 h exposed cells than in the controls, whereas 24 h exposed cells exhibited an increase in this enzyme activity. However, such effects appeared to be transient, as the fission rate and PrChE activity values returned to the respective control values after a 24 h stay under standard conditions.

We have attempted to present new information on the biology of the legionellae. Most new developments have focused on the events that follow host cell entry and lead to intracellular replication in macrophages or macrophage-like cell lines. However, we have also presented recent findings addressing the early events of invasion of nonphagocytic cells by L.pneumophila and the unusual role that the heat-shock protein Hsp60 may play in these early events. Readers may have grasped the wealth of potential knowledge that could be extracted from using the legionellae to model the pathogenesis and evolution of intracellular bacterial pathogens. In particular, the study of the recently discovered developmental cycle of L.pneumophila offers unique opportunities,as developmental cycles have been basically described only for obligate intracellular pathogens.

Chayanov's model of the peasant economy is based on autarkic nuclear family households. Expansion to the more complex households and kin groups common in peasant societies shows that the sharp changes Chayanov observed in the consumer/producer ratio over the domestic cycle are smoothed by the intergenerational structure of complex households and extended kin groups. This amelioration may be retarded by competition between constituent units. Understanding the dynamics of the developmental cycle and micropolitics of domestic groups is a useful correction to Chayanov's widely used formulation, especially in developing countries where complex kin structures are common.

Bdellovibrio are predatory bacteria that invade the periplasm of other Gram-negative bacteria where they undergo a complex developmental cycle that culminates in killing of the prey cell. Their intracellular niche allows Bdellovibrio to feed without competition and their lytic action can rapidly reduce bacterial populations, including pathogens, making these predatory bacteria interesting potential candidates for therapeutic applications. With the complete genome sequence for one Bdellovibrio strain now available, researchers now have an opportunity to evaluate the therapeutic potential of these predatory bacteria.

It is usual to divide organisms into two basic categories: unicellular and multicellular. However, looking at unicellular organisms such as bacteria and amoebae one can see their clear tendency to form multicellular structures, colonies and fruiting bodies [1–7]. Here we focus on pattern formation of Myxobacteria [8,9]. Myxobacteria are rod-shaped cells that glide (the precise mechanism is unknown) along their long axis. They exhibit a complex developmental cycle with individual and social phases. As long as there is sufficient food supply, vegetative cells prey, grow and divide as individuals or in small swarms. Under starvation conditions, bacteria start to act cooperatively, aggregate and finally build a multicellular structure, the fruiting body. Fruiting body formation is often preceded by a periodic pattern originally classified asoscillatory waves[10] and later namedrippling [11,12].

Bacteriophages are the viruses with either DNA or RNA as the genetic material.1 Phages have a developmental cycle within the host bacteria which can be lytic or lysogenic. The lytic cycle comprises has a series of events that subsequenty release daughter phage particles. Phage for a given bacterium can be isolated wherever that bacterium grows.2 The problem is not just isolating the phage against particular bacteria but in selecting the ones most likely to be useful for clinical application.

O objetivo dessa pesquisa foi avaliar a curva de desenvolvimento de frutos da cirigueleira. Para a avaliação do crescimento e maturação, as flores foram marcadas após a antese, e as colheitas dos frutos foram realizadas durante todo o período de desenvolvimento, visando às avaliações de diâmetro, comprimento, peso fresco, peso seco e volume. O ciclo de desenvolvimento da antese até o amadurecimento do fruto foi de 124 dias, sendo caracterizado pelo aumento dos pesos fresco e seco, volume, comprimento e diâmetro. O aumento do comprimento do fruto apresentou maior taxa de crescimento até aproximadamente 55 dias, seguido por um período de crescimento mais lento até 105 dias após a antese. O início da maturação do fruto ocorreu quando a taxa de crescimento foi mais lenta, em torno de 100 dias, enquanto o amadurecimento se iniciou aproximadamente aos 119 dias após a antese. The aim of this research was to evaluate the development profile of red mombin fruits. For the evaluation of growth and maturation, open flowers were marked after anthesis and fruits were sampled at regular intervals, and length, diameter, volume, and, fresh and dry weights were measured throughout the development following the growth of the fruits. Red mombin fruit developmental cycle, from anthesis to full ripening, lasted 124 days, characterized by the increase in fresh and dry weights, volume, length, and diameter. The growth period, mainly characterized by the increase in fruit length, had the highest growth rate until approximately 55 days, followed by a lower growth rate period from 55 to 105 days post-anthesis. Fruit maturation, which started when fruit growth rates slowed down, was set around 100 days and fruit ripening was initiated around 119 days post-anthesis.

Molineus torulosus (Molin, 1861) parasite of Cebus spp. from South America is redescribed in Cebus apella and C. olivecaeus (new host) from French Guyana with emphasis on the synlophe. During the maturation process, the larvae dwelt in the cysts carved alongside the external part of the small intestine. The turn-out of the mature worms and the laid eggs depended on the tissular organisation of cyst walls as the inflammatory process waned and fibrosis progressed to seal the cystic lumen. Adult worms entwine themselves in the cysts, live there permanently as their presence has never been evidenced in the intestinal lumen. They copulated, laid eggs, degenerated and died once entrapped by the fibrotic process. Laid eggs released in the intestinal lumen through a narrow channel ensured the continuation of the developmental cycle. However, erratic migration was possible via the vascular channels surrounding the cysts.

We used a photoactivatable, lipophilic reagent, 3′-(trifluoromethyl)-3-( m -[ 125 I]iodophenyl)diazirine, to label proteins in the outer membrane of elementary bodies of Chlamydia trachomatis LGV serovar L2 and mass spectrometry to identify the labeled proteins. The identified proteins were polymorphic outer membrane proteins E, G, and H, which were made late in the developmental cycle, the major outer membrane protein, and a mixture of 46-kDa proteins consisting of the open reading frame 623 protein and possibly a modified form of the major outer membrane protein.

A fundamental process in all organisms is their ability to regulate gene expression in response to developmental and environmental signals. In Chlamydia, changes in gene expression are closely linked to the presence or to undetectability of eukaryotic-like histones observed late in the parasites life cycle. It is becoming increasingly clear that these histone-like proteins are involved in macromolecular confirmation of DNA. However, their functional role(s) in chlamydial development and the underlying mechanism(s) involved in their degradation and dissociation are largely unknown. It is not surprising therefore that eukaryotic-like histones are a focus of intense research in several laboratories around the world. Recent studies on the interaction of eukaryotic- like histones with DNA, the role of phosphorylation and identification of a histone specific protease are beginning to unravel the mechanism of stage specific differentiation and gene expression in Chlamydia. In this article we review recent advances on the eukaryotic-like histones that have set the stage for elucidation of the chlamydial developmental cycle.

An Algal Order, the Dascycladales and a Family of higher plants, the Ranunculaceae, are used as examples for discussion on the robust nature and intrinsic wholeness of the order of organisms in time and space. The developmental cycle of species, both algae and buttercups, research on morphogenesis, a resultant mathematical model and hands-on experience of plant phenomena all provide discussion material on our experience of the origin of form and the action of genes in the context of organisms, species and wider taxonomic groupings.

Publisher Summary In this chapter, some of the better-studied examples of developmental cycles among bacteria are discussed, and then discusses the mechanisms that regulate these cycles. This chapter describes Cuulobucter crescentus for discussion as an example of a bacterium, with an extensively studied developmental cycle that is independent of environmental stress. The ease of synchronization and amenability to the genetic analysis of C. crescentus have allowed significant strides to be made in understanding the forces that drive its obligate developmental cycle. Development takes on many forms among the bacteria, from a natural part of the cell cycle as seen in C. crescentus to the sporulation pathways, initiated by stress in a variety of other organisms. Developmental programs are evident even in the prototypical bacterium of molecular biology, E .coli , as it responds to stress and enters or exits the stationary phase. Dissection of the factors, driving these programs in several different bacteria, is well underway, revealing in each case a complex network of signals temporally and spatially controlling gene expression. As the components, regulating development in bacteria, are understood at a molecular level, this fundamental knowledge should illuminate the basic principles that extend beyond the prokaryotic kingdom to aid in the understanding of the developmental processes in a variety of other organisms.

This monograph chapter pertains to a study of family structure over the life cycle in a Han ethnic population during the late Ming and early and middle Qing dynasties in China. It is argued that the frequency of a stem and joint family is dependent on the overlap of generations the size of the sibling set and the timing of family division. Data were obtained from genealogies in the Lin Shi and Wu lineages of Xiaoshan County Shaoxing Prefecture Zhejiang Province. Data were used to determine the potential for the formation of stem and joint families. The first Lin lineage settled during 1353-1433. The Lin genealogy was compiled in 1897 and includes the smallest number of entries (452). The Wu lineage was formed in the late 16th century and Wu Shouyou had five sons. The records include entries for 1078 men by 1904. The Shi lineage was formed in the 13th century from two sons of the founder. In 1888 there were 1994 full entries. The findings were similar to study findings from the 20th century. Everyone was part of a stem family (three generations) at one point in the life cycle. Most ordinary people spent time in joint families (two generations). Male marriage age is estimated by taking the mean interval between the births of the first and second surviving sons adjusting the interval for deaths of female births subtracting back to female marriage age and adding the average age difference. It is calculated that the mean age at marriage was 20.9 years for males in the Shi lineage and 22.4 years for the Wu. It appears that during the late Ming dynasty a man had a greater than 70% chance of being born while his grandfather was still alive. During the Qing dynasty the chances declined to 22-45%. In general around 70% of males had a chance of living in a stem family during the 17th and 18th centuries. This figure is considered an underestimate. The chance of being part of a joint family at some life cycle stage was about 50%.

The Streptomyces coelicolor sapA gene encodes a spore coat protein. The sapA promoter is regulated developmentally, with maximal expression occurring in aerial hyphae at a late stage of colonial development. The DNA sequences upstream from the transcription start point do not appear to fall into a previously described promoter class. One (or more) putative activation site, required for full activity, is eliminated when 5' deletions extend to between -178 and -72 bases upstream from the transcription start point. In addition, a downstream activation site is destroyed by removing sequences between positions +40 and +120, relative to the transcription start point, in the absence of an intact upstream region. However, temporal regulation of transcription initiation over the course of the life cycle is maintained faithfully in the absence of these elements, even in the smallest 18-bp sapAp fragment containing sequences from positions -8 to +10. Site-specific mutations around the transcriptional start points shift the timing of sapA expression to an earlier stage in the developmental cycle. These results sugges that a novel mechanism may be involved in Streptomyces late gene expression.

In recent years, concern about possible female reproductive and developmental toxicity due to environmental contaminants, such as PCBs, has been growing. Because this area of toxicology had not been emphasized prior to this time, there are many gaps in current knowledge about female developmental and reproductive toxicology and only a limited number of validated tests to assay effects of toxicants on various parts of the reproductive and developmental cycle. This article reviews the current state of knowledge on this topic and also explores a variety of techniques for assessing female reproductive and developmental toxicity. These include an assay of the state of intercellular communication among the embryo, fetus and placenta; protocols for assessing toxicity in early pregnancy; and techniques for evaluating the role of glutathione in protecting the conceptus from xenobiotics.

Development of the microfilariae of Brugia pahangi in the mammalian host is blocked until uptake by a mosquito vector when the developmental cycle is re-initiated. Comparison of the profile of polypeptides labelled in microfilariae cultured at mammalian temperature (37 degrees C) or mosquito temperature (28 degrees C) revealed a complex of low-molecular-weight proteins (18 kDa and 22-24 kDa) synthesized only in microfilariae at 37 degrees C. The synthesis of these proteins was also induced by transfer of microfilariae to 41 degrees C (i.e., heat shock conditions), suggesting that these are heat shock proteins. The expression of the small heat shock proteins in the Brugia life cycle is developmentally regulated, as they are not observed in the mature adult female. Their synthesis is strictly temperature dependent and is repressed upon transfer of the microfilariae to 28 degrees C.

Four species of mesostigmatic mites are reported from carabid beetles in Sweden. Of these, Antennoseius masoviae Sellnick and Iphidosoma fimetarium (J. Muller) occurred on more than one species. Deutonymphs of I. fimetarium have been found on all six Carabus spp. studied, on two Pterosticus spp. and on one Nebria sp. The host species are relatively large, their lengths ranging from 1–4 cm. Most of the deutonymphs were found under the elytra of the beetles. The number of deutonymphal I. fimetarium on the beetles increased from August to October. By that time the beetles start to hibernate in southern Sweden, and it became difficult to catch them in Barber traps. To follow the developmental cycle of I. fimetarium, beetles of the genus Carabus infested with deutonymphs were collected alive and kept in perspex containers in a regime to simulate natural winter conditions (4 to −2°C, 100% r.h.). The deutonymphs were active and mobile even at temperatures below freezing. At the end of January, the temperature was slowly increased to c. 8°C. In mid February, they showed signs of becoming distended. They were often seen on the prosternum and around the coxae of the beetles. At the end of February, the first deutonymph moulted to an adult. The adults are referable to the genus Stylochirus G. and R. Canestrini.

What have been interpreted to be three phases in the developmental cycle of an unidentified protistan parasite of Ruditapes decussatus from Portugal are described as a result of transmission electron microscopy. This parasite shows similarities to Perkinsus marinus; however, differences also exist.

Chlamydiae are intracellular bacterial parasites that develop and multiply within mucosal cells of humans and animals and amongst the most common sexually transmitted disease worldwide. If left untreated, infection with Chlamydia can lead to serious outcomes such as infertility, ectopic pregnancy and blinding trachoma due to tissue scarring. There are currently no vaccines available for these major diseases. Microbiological research on Chlamydia is advancing rapidly and recently mathematical models of the bacteria have been developed to assist understanding of the complex chlamydial developmental cycle. Here, we extend the current description of the chlamydial developmental cycle and review the models developed and their predictions about chlamydial pathogenesis. The computational techniques employed by these applications are outlined.

Introduction: Microdemography and the Modeling of Population Process in Late Imperial China Marriage among the Song Elite Fertility and Population Growth in the Lineages of Tongcheng County, 1520-1661 A Comparison of Lineage Populations in South China, ca. 1300-1900 Demographic Constraint and Family Structure in Traditional Chinese Lineages, ca. 1200-1900 Marriage, Mortality, and the Developmental Cycle in Three Xiaoshan Lineages A Century of Mortality in Liaoning Migration in Two Minnan Lineages in the Ming and Qing Periods

Le cycle de vie de Cowdria ruminantium a été étudié dans des cellules SBE 189 par microscopie classique et électronique. Des cultures ont été infectées avec un inoculum synchronisé et fixées et préparées entre 15 min et 111 h post-inoculation (PI). Après 12 h, de grands corps réticulaires seuls ou en petits groupes ont été identifiés dans des vacuoles intracytoplasmatiques entourées de membranes. Ils se développaient graduellement dans des corps réticulaires plus petits avec une structure interne plus granuleuse. De 66 à 75 h PI, il y avait une augmentation importante de la taille des colonies. La plupart des colonies contenaient des corps réticulaires, bien que quelques corps intermédiaires et opaques aux électrons aient été visibles. Des corps réticulaires solitaires extracellulaires avec une couche ressemblant au peptidoglycan ont été observés 84 h PI. Après 90 h, des corps intermédiaires et opaques aux électrons fussent présents en abondance et cela coïncidait avec la lyse des cellules de culture. Le cycle de développement de Cowdria ruminantium durait donc environ 4 jours, dans cette étude.

P OLYGYNY, WHICH IS THE MARRIAGE of a man to two or more women at the same time, has been reported for nearly all Native American societies. In all cases, however, only a small minority of men can participate in such arrangements, since the number of adult men and adult women in a human population is usually about the same. In North America, as elsewhere, polygyny is made possible by the marriage of women at a younger age than men, so that there are more women in the marriage pool at any one time, and by the normally higher mortalities of males from warfare and disease. From the perspective of Anglo-American culture, the motivation for polygyny in other societies is somewhat beclouded by myth. The pervasive Anglo-American idea that polygyny is sexually motivated on the part of the husband probably tells us more about the sexual fan

The vegetative and basidial development of Pachnocybe ferruginea was studied by light and electron microscopy. Caffeine was used during fixation to improve cytoplasmic clarity, and a flat-embedding method incorporating Mylar as a release agent was used. Uninucleate basidiospores have ornamented walls and germinate by forming germ tubes. Within 72 h of germination, colonies produce singular conidia and coenocytic apical cells with synchronously dividing nuclei. Basidiospore germination, and hyphal and basidial branching involve breaking of the wall, but sterigma initiation does not. Simple septal pores contain densely staining, pulley-wheel shaped structures. Septal and lateral walls of the same isolate vary in thickness when grown in broth or agar. Basidial and reproductive hyphal walls have conical-shaped cavities containing cytoplasmic projections. Rod-shaped ladder-like connections not previously described join outer mitochondrial membranes and cisternae of endoplasmic reticulum in reproductive hyphae. At different stages in prophase I, the nucleus contains synaptonemal complexes and structures resembling the central element are located in nucleolar regions. Vacuole development follows a specific pattern in the basidium from nuclear fusion to spore release. The results of these observations are compared with developmental patterns observed in other organisms and the evolutionary, phylogenetic, and functional significance is discussed.

In a recently proposed hypothesis for the transmission of Myxosoma cerebralis, the causative agent of salmonid whirling disease, it was suggested that there was a developmental cycle in tubificid worms culminating in actinosporean spores, which were infective to the fish. Results are presented here which do not support the actinosporean involvement in the life cycle. On addition of M. cerebralis spores to Tubifex tubifex colonized in sterilized medium, no significant change in the prevalence of Triactinomyxon dubium (i.e. T. gyrosalmo) was found. Although it is shown that these worms are capable of ingesting M. cerebralis spores, neither hatching of the spores nor further development within the worm has been observed. Field observations on the distribution of actinosporean species show no obvious correlation between the occurrence of T. dubium and M. cerebralis.