Intercellular signaling as visualized by endogenous calcium-dependent bioluminescence

Bioluminescence in the hydrozoan coelenterate Obelia results from calcium activation of a photoprotein contained in light-emitting cells (photocytes) scattered in the animal's endoderm. The influx of calcium into nonluminescent endodermal cells through conventional voltage-dependent calcium channels is required for the excitation-luminescence coupling. Our results suggest that the subsequent diffusion of this calcium, via gap junctions, into the neighboring photocytes triggers a localized luminescence response. Following intense stimulation, the local rise in calcium elicits a secondary wave of luminescence that is supported by a voltage-independent calcium permeability mechanism in the photocyte plasma membrane. These two mechanisms for elevating internal calcium in light-emitting cells can account for the spatial and temporal features of intracellular luminescence in Obelia.     

Historical aspects of the early Soviet/Russian manned space program.

Human spaceflight was one of the great physiological and engineering triumphs of the 20th century. Although the history of the United States manned space program is well known, the Soviet program was shrouded in secrecy until recently. Konstantin Edvardovich Tsiolkovsky (1857-1935) was an extraordinary Russian visionary who made remarkable predictions about space travel in the late 19th century. Sergei Pavlovich Korolev (1907-1966) was the brilliant "Chief Designer" who was responsible for many of the Soviet firsts, including the first artificial satellite and the first human being in space. The dramatic flight of Sputnik 1 was followed within a month by the launch of the dog Laika, the first living creature in space. Remarkably, the engineering work for this payload was all done in less than 4 wk. Korolev's greatest triumph was the flight of Yuri Alekseyevich Gagarin (1934-1968) on April 12, 1961. Another extraordinary feat was the first extravehicular activity by Aleksei Arkhipovich Leonov (1934-) using a flexible airlock that emphasized the entrepreneurial attitude of the Soviet engineers. By the mid-1960s, the Soviet program was overtaken by the United States program and attempts to launch a manned mission to the Moon failed. However, the early Soviet manned space program has a preeminent place in the history of space physiology.     

Water level fluctuations in Lake Baringo,Kenya, during the 19th and 20th centuries: Evidence from lake sediments

This article presents a fossil diatom-based, semi-quantitative reconstruction of water level fluctuations for Lake Baringo over the past 200 years as a consequence of climatic variations. A 285 cm long sediment core sample was collected using a Rod-Operated Single-drive Stationary Piston corer. Lake level was inferred using indices based on the proportion of planktonic to benthic diatom taxa (P/B ratio). The sediment archive presented distinct zones dominated by planktonic and benthic diatom flora. An initial transgression in the early 19th century was characterised as a shallow water environment dominated by planktonic Aulacoseira spp. This was a response to extreme drought during the late 18th to early 19th century. Mid-19th century was defined by a high lake stand. The late 19th to early 20th centuries experienced low water level following the widely documented aridity at the time. The mid-20th century was marked by a spectacular rise in water level that coincided with remarkably wet years during the early 1960s and late 1970s. The first decade of the 21st century witnessed widespread changes in water level. The proxy records show that lake ramping and drawdown over the years follow approximately 50-year climatic cycles.     

Invasions by the Late Blight Pathogen: Renewed Sex and Enhanced Fitness

Introductions of Phytophthora infestans, the oomycete plant pathogen responsible for late blight of potato and tomato, have had devastating human impacts wherever they have occurred. This pathogen was apparently sequestered in central Mexico until the mid-19th century, when introductions into the USA and Europe led to a series of crop failures – the most notable of which resulted in the Irish potato famine. A second series was documented in the late 20th century. There were terrible effects also from the second set of introductions, but no population was as vulnerable as the Irish peasants in the mid-19th century. Examination and comparison of these introductions has taught us that we must be prepared for the invasion of species that are more fit than the current population.     

Archaeobotanical analysis of radiocarbon-dated plant remains with special attention to <Emphasis Type="Italic">Secale cereale</Emphasis> (rye) cultivation at the medieval village of Mankby in Espoo (Finland)

Several urban medieval sites in Finland (ad 1000–1500) have been archaeobotanically investigated, but until now only a few rural medieval settlements have been studied. Therefore, many aspects of the crops and agricultural methods of medieval villages in Finland still remain unknown. At the 12th to mid-16th century medieval village of Mankby, Espoo, a systematic sampling for archaeobotanical material was carried out. The analysed samples derived from hearths, building contexts and medieval field layers etc. The archaeobotanical material was carbonised, and it consisted mostly of conifer needles, cereal grains and weed seeds. Secale cereale (rye) and Hordeum vulgare (barley) were the only crop species found, Secale being the most frequent. Seeds of Bromus secalinus (rye brome) and achenes of Centaurea cyanus (cornflower), which are associated with autumn sown winter cereal crops, were also present. The archaeobotanical material shows areas of activity linked to storing crops, as well as cultivation within the village boundaries. Based on radiocarbon dated grains, cultivation of the fields started in the 12th century and continued until the abandonment of the village in 1556. Archaeobotanical material from Mankby has been compared to other contemporary sites in Finland, and differences between the sites can be seen. Results from Mankby have added to our knowledge of medieval agriculture, past areas of activity and economic conditions within the village.     

Programmed cell death: history and future of a concept

Cell death was observed and understood since the 19th century, but there was no experimental examination until the mid-20th century. Beginning in the 1960's, several laboratories demonstrated that cell death was biologically controlled (programmed) and that the morphology was common and not readily explained (apoptosis). By 1990 the genetic basis of programmed cell death had been established and the first components of the cell death machinery (caspase 3, bcl-2 and Fas) had been identified, sequenced, and recognized as highly conserved in evolution. The rapid development of the field has given us substantial understanding of how cell death is achieved. However, capitalizing on our knowledge for therapeutic purposes requires us to learn much more about how a cell commits to death, as well as recognizing that apoptosis may be the most common and efficient means of death, but that there are alternative pathways that can result in cell death even when the conventional pathway is blocked. Interestingly enough, many of the arguments and missteps in the history of the field were anticipated by Claude Bernard, and his warnings and recommendations remain valid today.     

The biological standard of living in 19th century Mexico and in the American West

During the mid-19th century, the United States acquired Texas and large parts of Mexican territory with the vast Mexican-born population. This paper considers the biological standard of living of the part of this population that was incarcerated in American prisons. We use their physical stature as a proxy for their biological welfare. These data confirm earlier results which showed that adult heights tended to stagnate in Mexico during the late-19th century despite considerable social and political turmoil. While there is some evidence of a decline in height among youth, the decline is slight (<1 cm). As in other 19th century samples, farmers were the tallest. Americans were taller than Mexican prisoners by about 2 cm.     

Hindcasting of nutrient loadings from its catchment on a highly valuable coastal lagoon: the example of the Fleet, Dorset, UK, 1866–2004

Background

Nutrient loadings from its catchment upon The Fleet, a highly valuable coastal lagoon in Southern England, were hindcast for the period AD 1866–2004, using a catchment model, export coefficients, and historical data on land use changes, livestock numbers, and human population. Agriculture was the main nutrient source throughout, other inputs representing minor contributions. Permanent pasture was historically the main land use, with temporary grassland and cereals increasing during the mid-20th century. Sheep, the main 19th century livestock, were replaced by cattle during the 1930s.

Results

Total nitrogen loadings rose from ca 41 t yr-1 during the late 19th century to 49–54 t yr-1 for the mid-20th, increasing to 98 t yr-1 by 1986. Current values are ca 77 t yr-1. Total phosphorus loads increased from ca 0.75 t yr-1 for the late 19th century to ca 1.6 t yr-1 for the mid-20th, reached ca 2.2 t yr-1 in 1986, and are now ca 1.5 t yr-1. Loadings rose most rapidly between 1946 and 1988, owing to increased use of inorganic fertilisers, and rising sheep and cattle numbers. Livestock were the main nutrient source throughout, but inputs from inorganic fertilisers increased after 1946, peaking in 1986. Sewage treatment works and other sources contribute little nitrogen, but ca 35% of total phosphorus. Abbotsbury Swannery, an ancient Mute Swan community, provides ca 0.5% of total nitrogen, and ca 5% of total phosphorus inputs.

Conclusion

The Fleet has been grossly overloaded with nitrogen since 1866, climaxing during the 1980s. Total phosphorus inputs lay below 'permissible' limits until the 1980s, exceeding them in inner, less tidal parts of the lagoon, during the 1940s. Loadings on Abbotsbury Bay exceeded 'permissible' limits by the 1860s, becoming 'dangerous' during the mid-20th century. Phosphorus stripping at point sources will not significantly reduce loadings to all parts of the lagoon. Installation of 5 m buffer strips throughout the catchment and shoreline will marginally affect nitrogen loadings, but will reduce phosphorus inputs to the West Fleet below 'permissible' limits. Only a combination of measures will significantly affect Abbotsbury Bay, where, without effluent diversion, loadings will remain beyond 'permissible'.     

Seed Physiology: Its History from antiquity to the beginning of the 20th century

Seed physiology, especially seed germination, has intrigued the human mind since antiquity, partly out of curiosity, partly because of practical reasons. Theophrastus could be called the father of seed physiology since he already described many of the facts and problems which up to this day are being investigated by seed physiologists. Most of the other ancient authors writing about natural history or agriculture (Columella, Varro, Pliny the elder, Virgil) added little to Theophrastus’ all encompassing knowledge of seed physiology. The 1700 years from the first century A.D. to the end of the 18th century were a “black out” (Johansen, 1951) of seed physiology. At the beginning of the 19th century people like Schleiden, Amici, Brown and Hofmeister first understood structure and function of ovule, embryo sac and pollen tube whereas fertilization and double fertilization were only detected at the end of the 19th century by Strasburger, Nawaschin and Guignard. The physiology and biochemistry of seed maturation were first investigated by Sachs and Pfeffer, two great masters of modern plant physiology. In modern times our detailed knowledge of the effect of external factors on seed germination is due to the many authors working at the end of the 19th and the beginning of the 20th centuries. Our knowledge of the impact of temperature on germination derives mainly from the investigations of Sachs, De Vries and Haberlandt, and of light from those of Caspary, Cieslar, Heinricher and Kinzel. The action spectrum of light was first investigated by Cieslar, and Flint and McAllister whereas the most important discovery of the effect of light on germination (and on many other physiological phenomena), the R-FR photoreversible system, was made by Borthwick et al. leading later to the discovery of the phytochrome. The first germination inhibiting and stimulating substances were found by Siegmund and Lehman. The long history of seed physiology should make today’s seed physiologists conscious of the fact that they stand on the “shoulders of giants.”     

Phylogenetic analysis with multiple markers indicates repeated loss of the adult medusa stage in Campanulariidae (Hydrozoa, Cnidaria)

The Campanulariidae is a group of leptomedusan hydroids (Hydrozoa, Cnidaria) that exhibit a diverse array of life cycles ranging from species with a free medusa stage to those with a reduced or absent medusa stage. Perhaps the best-known member of the taxon is Obelia which is often used as a textbook model of hydrozoan life history. However, Obelia medusae have several unique features leading to a hypothesis that Obelia arose, in a saltational fashion, from an ancestor that lacked a medusa, possibly representing an example of a rare evolutionary reversal. To address the evolution of adult sexual stages in Campanulariidae, a molecular phylogenetic approach was employed using two nuclear (18S rDNA and calmodulin) and two mitochondrial (16S rDNA and cytochrome c oxidase subunit I) genes. Prior to the main analysis, we conducted a preliminary analysis of leptomedusan taxa which suggests that Campanulariidae as presently considered needs to be redefined. Campanulariid analyses are consistent with morphological understanding in that three major clades are recovered. However, several recognized genera are not monophyletic calling into question some "diagnostic" features. Furthermore, ancestral states were reconstructed using parsimony, and a sensitivity analysis was conducted to investigate possible evolutionary transitions in life-history stages. The results indicate that life-cycle transitions have occurred multiple times, and that Obelia might be derived from an ancestor with Clytia-like features.     

Socioeconomic, demographic and legal influences on consanguinity and kinship in northern coastal Sweden 1780-1899

Most studies on consanguinity have been conducted on contemporary populations and have focused on the prevalence and types of preferred intra-familial marriage. With its comprehensive birth, marriage and deaths records dating back to the late 17th century, and the legal bar on first cousin marriage removed in the mid-19th century, Sweden offers unique opportunities to examine the factors that determine by whom, where and why consanguineous marriages were contracted. The present study covers the period 1780-1899 and presents a detailed portrait of cousin and sibling exchange marriages in the Skellefte? region of northern coastal Sweden. The combined prevalence of first, second and third cousin marriage increased from 2.3% in 1790-1810 to 8.8% in 1880-1899, and multi-generation consanguinity also increased significantly over the study period. The distribution and prevalence of first cousin marriages was strikingly non-random, with a significantly greater propensity for consanguinity among land-owning families, especially involving first-born sons, within specific pedigrees, and in a number of more remote inland communities. Additional factors associated with a greater likelihood of consanguineous marriage included physical or mental disability among males, and among females the prior birth of an illegitimate child. Besides the inherent interest in the social and demographic structure of this region of northern Sweden during the course of the 19th century, in future studies it will be important to determine the degree to which the observed patterns of consanguineous and sibling exchange marriages in these past generations could have influenced present-day genetic structure.     

Overview of human population-genetic studies in Bosnia and Herzegovina during the last three centuries: history and prospective

Modern Bosnia and Herzegovina is a multi-ethnic and multi-religion country, with a very stormy history. Certain archaeological findings indicate continuous population of its territory since the Paleolithic. In time, vast number of different factors jointly influenced fascinating diversity of local human populations. A great number of small, more or less isolated, indigenous populations, make this area quite attractive for population-genetic surveys of different levels and approaches. Austro-Hungarian military physicians conducted the very first known bio-anthropological analyses of Bosnia-Herzegovina population at the end of the 19th century. Thus, the first step towards resolving the genetic structures of local B&H human populations was made. The studies that followed (conducted throughout most of the 20th century) were primarily based on the observation of various phenotypic traits. This stage was followed by the examination of various cytogenetic and fundamental DNA based molecular markers. The efforts undertaken over the last three centuries revealed "human genetic treasure" in Bosnia and Herzegovina. However, even now, after all the studies that were conducted, many interesting features remain to be discovered and described within the existing local human populations.     

Plant identification credibility in ethnobotany: a closer look at Polish ethnographic studies

In Italy, malaria was an endemic disease that was eradicated by the mid-20th century. This paper evaluates the prophylactic and therapeutic remedies used by folk medicine to cure malaria in Calabria (southern Italy). The data has been collected by analysing works of physicians, ethnographers, folklorists and specialists of the study of Calabrian history between the end of the 19th century and the 20th century. The data collected have allowed us to describe the most common cures used by the Calabrian people to treat malaria and the most evident symptoms of this disease, such as intermittent fever, hepato-spleenomegaly, asthenia and dropsy. This approach uncovered a heterogeneous corpus of empirical, magical and religious remedies, which the authors have investigated as evidences of past "expert medicine" and to verify their real effectiveness in the treatment of malaria.     

Global warming and alternative causes of decline in arctic-alpine and boreal-montane lichens in North-Western Central Europe

Lichens are thought to be sensitive indicators of global warming, as the spread of several thermophilous epiphytes in north-western Central Europe has been attributed to late 20th century warming. In the present paper, the potential contribution of late 20th century warming to the decline of arctic-alpine and boreal-montane lichen species is analyzed. Relevant ecological groups of lichens include terricolous heathland species, saxicolous species of exposed rock outcrops and boulder fields as well as epiphytes of mountain forests. These three groups of lichens experienced significant declines before the onset of late 20th century warming in the 1970s. These declines can be attributed to the abandonment of traditional land use systems in the case of the heathland lichens, increased recreational use of the exposed summits usually inhabited by cold-tolerant saxicolous lichens, and to high atmospheric SO₂ levels in the mid-20th century, but are probably not directly connected to global warming.     

The gene pool of the Belgorod oblast population: changes in the endogamy indices of district populations with time

Changes in the endogamy indices of district populations of the Central Chernozem region of Russia during the past 100 years were studied. The size of an elementary population in this region increased from that of a rural municipality in the mid-20th century to that of an administrative district in the late 20th century.     

Genetics behind barbed wire: Masuo Kodani, émigré geneticists, and wartime genetics research at Manzanar relocation center

This article explores the sociopolitical backdrop of genetics research during the politically turbulent decades of the mid-20th century that saw the persecution, displacement, and relocation of unpopular minorities in both the United States and Europe. It explores how geneticists in the United States accommodated these disruptions through formal and informal émigré networks and how the subsequent war affected their research programs and their lives. It does so by focusing on the career and life of geneticist Masuo Kodani, who, as a Japanese American, found himself conducting unexpected cytogenetics research in Manzanar, a "relocation center," or internment camp, located in the California desert, after the attack on Pearl Harbor. After the war, Kodani's subsequent career continued to be shaped by his experiences as a Japanese American and by the specific skills as a cytogeneticist that he demonstrated at a critical period in the history of 20th-century genetics. His many relocations in search of employment culminated in his work with the Atomic Bomb Casualty Commission on human chromosomes, for which he is best known.     

The gene pool of the belgorod oblast population: Changes in the endogamy indices of district populations with time

Changes in the endogamy indices of district populations of the Central Chernozem region of Russia during the past 100 years were studied. The size of an elementary population in this region increased from that of a rural municipality in the mid-20th century to that of an administrative district in the late 20th century.