The occurrence of former heathland vegetation in the coastal areas of the south-east Baltic sea,in particular Lithuania: a review

Previously published pollen diagrams from the coastal area of the south-east Baltic Sea including parts of the Polish and Lithuanian peninsulas, Mierzeja Wilana (Frische Nehrung) and Kuri Nerija (Courland Spit) respectively, document the former presence of heathland vegetation and an associated burning practice. This type of human influence can be dated back to ca. 1200 B.P. at the latest, and was maintained until the 18th century. It is suggested that this former Calluna-dominated vegetation belonged to the known west to north-west European heathland vegetation. Several dwarf shrub taxa, such as Genista spp. and Erica tetralix, normally connected to heathland vegetation, may have had a former wider distribution.     

黄斑巨鳖分布的历史变迁

通过考古、文史和动物学文献的考证,对黄斑巨鳖Rafetus swinhoei分布的历史变迁进行了研究,该种历史上曾广泛分布于黄河、长江、太湖、钱塘江、红河、马江流域和台湾澎湖水道,这些区域历史上记录的"鼋"都应为黄斑巨鳖而非亚洲圆鳖Pelochelys cantorii。黄斑巨鳖在台湾澎湖水道仅记录于1万年前,主要是由于人为影响,黄河种群自11世纪后未再有记载,近代其分布区更是急剧缩小,长江中游种群于19世纪末即已绝灭,长江下游和钱塘江种群在20世纪中叶绝灭,太湖流域目前已野生绝灭,红河和马江流域分布区虽未有明显变化,但在最近30年中密度急剧下降,野生种群濒临灭绝。建议重点在红河流域开展研究和保护工作。红河与钱塘江之间是否有分布仍存疑问,需要进一步研究。     

Phylogeography, phylogeny and hybridization in trichechid sirenians: implications for manatee conservation

Abstract The three living species of manatees, West Indian (Trichechus manatus), Amazonian (Trichechus inunguis) and West African (Trichechus senegalensis), are distributed across the shallow tropical and subtropical waters of America and the western coast of Africa. We have sequenced the mitochondrial DNA control region in 330 Trichechus to compare their phylogeographic patterns. In T. manatus we observed a marked population structure with the identification of three haplotype clusters showing a distinct spatial distribution. A geographic barrier represented by the continuity of the Lesser Antilles to Trinidad Island, near the mouth of the Orinoco River in Venezuela, appears to have restricted the gene flow historically in T. manatus. However, for T. inunguis we observed a single expanding population cluster, with a high diversity of very closely related haplotypes. A marked geographic population structure is likely present in T. senegalensis with at least two distinct clusters. Phylogenetic analyses with the mtDNA cytochrome b gene suggest a clade of the marine Trichechus species, with T. inunguis as the most basal trichechid. This is in agreement with previous morphological analyses. Mitochondrial DNA, autosomal microsatellites and cytogenetic analyses revealed the presence of hybrids between the T. manatus and T. inunguis species at the mouth of the Amazon River in Brazil, extending to the Guyanas and probably as far as the mouth of the Orinoco River. Future conservation strategies should consider the distinct population structure of manatee species, as well as the historical barriers to gene flow and the likely occurrence of interspecific hybridization.     

Phylogeography and population genetics of the endangered Amazonian manatee, Trichechus inunguis Natterer, 1883 (Mammalia, Sirenia)

We used mitochondrial DNA control region sequences to examine phylogeography and population differentiation of the endangered Amazonian manatee Trichechus inunguis. We observe lack of molecular differentiation among localities and we find weak association between geographical and genetic distances. However, nested clade analysis supports restricted gene flow and/or dispersal with some long-distance dispersal. Although this species has a history of extensive hunting, genetic diversity and effective population sizes are relatively high when compared to the West Indian manatee Trichechus manatus. Patterns of mtDNA haplotype diversity in T. inunguis suggest a genetic disequilibrium most likely explained by demographic expansion resulting from secession of hunting and enforcement of conservation and protective measures. Phylogenetic analysis of T. manatus and T. inunguis haplotypes suggests that T. inunguis is nested within T. manatus, effectively making T. manatus a paraphyletic entity. Paraphyly of T. manatus and recent divergence times of T. inunguis and the three main T. manatus lineages suggest a possible need for a taxonomic re-evaluation of the western Atlantic Trichechus.     

The environmental and cultural contexts of the late Iron Age and medieval settlement in the Mazurian Lake District,NE Poland: combined palaeobotanical and archaeological data

Pollen analysis of sediments from three lakes and analysis of plant macroremains including charcoal from archaeological sites in the Mazurian Lake District provide new data for the reconstruction of vegetation changes related to human activity between the 1st and 13th century ad. At that time settlements of the Bogaczewo culture (from the turn of the 1st century ad to the first part of the 5th century ad), the Olsztyn Group (second part of the 5th century ad to the 7th or beginning of the 8th century ad), and the Prussian Galinditae tribes (8th/9th–13th century ad) developed. The most intensive woodland clearing occurred between the 1st and 6th/7th century ad. Presence of Cerealia-type, Secale cereale and Cannabis-type pollen, as well as macroremains of Hordeum vulgare, S. cereale, Triticum spelta, T. cf. monococcum, T. cf. dicoccum, Avena sp. and Panicum miliaceum documented local agriculture. High Betula representation synchronous with microcharcoal occurrence suggests shifting agriculture. After forest regeneration between c. ad 650 and 1100, the area was strongly deforested due to the early medieval occupation by Prussian tribes. The archaeobotanical examination of samples taken in a cemetery and a large settlement of the Roman Iron Age revealed strong differences in the taxonomic composition of the fossil plant remains. An absolute dominance of birch charcoal in the samples from the cemetery indicates its selective use for funeral pyre construction. There is a difference between cereals found in both contexts: numerous grains of Triticum have been found in the cemetery, while in the settlement crops were represented mostly by Secale and Hordeum. Grass tubers, belonging probably to Phleum pratense, are among the particularly interesting plant remains found in the cemetery.     

Low twinning rate and seasonal effects on twinning in a fertile population,the Hutterites

This paper analyzes from the mid 18th century to 1987 the birth records of the Dariusleut, one of the three subgroups of the Hutterite population. The aim of this study is to describe several aspects of the twinning rate in a fertile population. The overall rate of twinning was 0.90%:103 twins among all 11492 maternities. The rate peaked at the 7th birth order and at the maternal age of 40 years and over. Until the mid 19th century when the Hutterites lived in Russia, the twinning rate was higher (1.5%), and it decreased during the migration period in the second half of the 19th century (0.7%). After the group had settled in the USA and Canada, the population maintained a twinning rate of 1.0% until 1965. After 1965 the rate decreased to 0.7%, partly due to a decline in fertility among women aged 30 years and over. There was a significant seasonal variation: the twinning rate decreased to 0.5% in May–July compared to 1.2% for the other three seasons during the years up to 1965 (P<0.01), while more recent mothers did not show such a seasonal variation. The incidence of twin births in this population seems to have been influenced by environmental factors, which would change their effect seasonally and secularly.     

A Historical Perspective on Pitch Pine–Scrub Oak Communities in the Connecticut Valley of Massachusetts

We present a regional–historical approach to the interpretation, conservation, and management of pitch pine–scrub oak (PPSO) communities in the Connecticut Valley of Massachusetts. Historical studies, aerial photographs, GIS analyses, and extensive field sampling are used to (a) document changes in the historical distribution, composition, and dynamics of these communities, and (b) evaluate the importance of regional–historical approaches to understanding, conserving, and managing uncommon communities. At the time of European settlement, pine plains dominated by both pitch and white pine were widespread, occurring on 9000 ha or more of the extensive (approximately 32,000 ha) xeric outwash deposits in the Connecticut Valley. Pine plains were harvested for diverse forest products from the 17th to the early 19th centuries. After 1830, most sites were cleared and plowed for agriculture and then abandoned in the late 19th and early 20th centuries, resulting in widespread natural reforestation. Modern PPSO communities differ from historical communities with respect to landscape distribution, composition, and structure. Nearly all modern pitch pine stands in the Connecticut Valley became established on former agricultural fields. Current vegetation on these former fields differs substantially from those few sites that were never plowed. In particular, several species (for example, Gaultheria procumbens, Gaylussacia baccata, Quercus ilicifolia, and Q. prinoides) that are characteristic of unplowed sites have not successfully colonized former fields in the 50 to more than 100 years since agricultural abandonment. Urban, commercial, and residential development have been widespread in the 20th century. By 1985, only 38.6% of the outwash deposits remained forested, and only 1094 ha of pitch pine stands and 74 ha of scrub oak stands occurred, primarily in numerous small patches. Several stands have been destroyed since 1985, and development threatens all remaining sites. The trend towards rapid urban development in the 20th century makes it increasingly urgent that the few, relatively large, undeveloped sites be protected. Our results suggest that (a) land protection efforts should prioritize large, undeveloped sand plains, areas that were not plowed historically, and reestablishment of contiguity between isolated sites to facilitate colonization of former agricultural lands by sand plain species; (b) management of PPSO communities should not be restricted to maintenance of open barrens; “old-growth” pitch and white pine stands occurred historically, and some PPSO communities should be allowed to mature without frequent disturbance; (c) the exclusive use of prescribed fires during the spring months is unlikely to maintain communities similar to modern ones or to restore communities similar to historical ones. Establishment or maintenance of open barrens species and communities may require more varied disturbance regimes, perhaps including mechanical treatment in combination with prescribed fire to simulate severe summer fires; (d) regional–historical perspectives are critical for understanding modern community dynamics and for evaluating conservation objectives and management strategies for uncommon plant communities.     

The resting eggs of the Ctenopoda (Crustacea: Branchiopoda): a review

The resting eggs of the Ctenopoda have been studied since the second half of the 19th century. By now they are known in 21 species of the group but only in 4 species (Sida crystallina, Diaphanosoma brachyurum, Penilia avistoris and Holopedium gibberum) have they been investigated thoroughly. Gross and internal structure of eggs are characterized by considerable diversity. In general their structure has much in common with resting eggs of the Anostraca, Notostraca, Conchostraca and Onychopoda as well as with that of some other remotely related groups of freshwater invertebrates (Rotifera, Hydra). The taxonomic value of resting eggs is discussed. Probably they play a significant role in determining geographical distribution. Waterfowl are the main agent of their dispersal.     

Is sexual size dimorphism variable? Data on species of the genus <Emphasis Type="Italic">Martes</Emphasis> in the Urals

Sexual dimorphism in cranial measurements was studied in Ural populations of two species of the genus Martes, M. martes and M. zibellina. The index of sexual dimorphism averaged 8.39% in the former and 9.03% in the latter, being subject to geographic variation. For the first time, temporal variability of sexual dimorphism in dimensional characters was revealed in mammals by analyzing M. zibellina samples collected in different decades of the second half of the 20th century. The majority of corresponding microtrends had reciprocating dynamics.     

High throughput, multiplexed pathogen detection authenticates plague waves in medieval Venice, Italy

Background

Historical records suggest that multiple burial sites from the 14th–16^th centuries in Venice, Italy, were used during the Black Death and subsequent plague epidemics.

Methodology/Principal Findings

High throughput, multiplexed real-time PCR detected DNA of seven highly transmissible pathogens in 173 dental pulp specimens collected from 46 graves. Bartonella quintana DNA was identified in five (2.9%) samples, including three from the 16th century and two from the 15th century, and Yersinia pestis DNA was detected in three (1.7%) samples, including two from the 14th century and one from the 16th century. Partial glpD gene sequencing indicated that the detected Y. pestis was the Orientalis biotype.

Conclusions

These data document for the first time successive plague epidemics in the medieval European city where quarantine was first instituted in the 14th century.     

Structures of the plant trophic tract: Plastid stromules and cell-wall plasmodesmata

Plastid stromules and cell-wall plasmodesmata are special plant-cell stsructures. They were discovered a century and a half apart: stromules at the beginning of the 21st century and plasmodesmata the end of the 19th. The former and latter are intra- and intercellular fragments, respectively, of endoplasmic reticulum, which is a network for photosynthesis distribution in the plant body. Methods and history of discovery, structural similarities and differences, and series of functional interpretations are discussed. The origins of both structures are connected with photosynthesis and photosynthate export. Their tubular structure and transport function are similar. The mobility of both is under control of the actomyosin cytoskeleton. The temperature regimes of formation and functioning also are the same. Photosynthesis is possible at 0°C and even lower. The structures of the exporting network—stromules and plasmodesmata—do not form below 10°C, and after 20°C the numbers of the former and latter significantly increase in relation to growth of cytoskeleton plasticity. The structural and functional continuity of stromules and plasmodesmata are postulated as the mobile trophic tract of vascular plants.     

Introduction to fish imagery in art

Synopsis Fish have been the subject of works of art for at least 14000 years and appeared in primitive art from many cultures. In ancient civilizations of the West, fishes were a constant, if infrequent, motif. Fish designs in ancient Egypt were common and showed little change for 1500 years. Decorative fish designs of the Greeks and Romans (often with mythological significance) were adopted by early Christians as religious symbols. With the development of printing, the non-religious depiction of fish became more widespread and realistic paintings of fish, especially still lifes, appeared during the Renaissance. This still life tradition reached a peak in 17th century Netherlands. After 1750, fish images appeared in many different contexts. Realistic painters showed the agony of newly-caught fish, dramatic marine scenes with fish, and occasionally freshwater fishes in their habitats. In the twentieth century, fish were painted by many modern artists, including Matisse, Picasso, Klee, Masson, Beckman, Soutine, Magritte, and Thiebaud. Some of these artists' fish images are pleasing, others are violent or ambiguously symbolic. In contrast, contemporary nature artists tend to paint live fish in idealized settings, a style with roots in 17th century still lifes and oriental brush paintings. In Japan and China, fish have been an important theme in art and their use has been highly symbolic. A survey of fish images in art shows that artists, like scientists, create mainly in the context of historical precedents.     

The nature and status of Lysimachia x producta (Primulaceae)

Lysimachia Xproducta has been the subject of changing classifications for more than a century. Data from distribution, frequency, phenology, and habitat support the hypothesis of hybrid origin of the taxon. In status it is near the borderline between interspecific hybrid and species; this study supports its classification as the former.     

LONG-TERM TRENDS IN ABUNDANCE AND DISTRIBUTION OF MANATEES (TRICHECHUS MANATUS) IN THE NORTHERN BANANA RIVER, BREVARD COUNTY, FLORIDA

Four aerial survey projects were conducted between 1977 and 1986 to determine the abundance, density and distribution of West Indian manatees (Trichechus manatus), in the northern Banana River, Kennedy Space Center, Florida. Manatee density and distribution within selected portions of the 78.5 km² study area were determined. Peak numbers of manatees occurred in spring of each year. The maximum counts increased from 56 in 1978 to 297 in 1986. Manatee abundance was lowest in the winter of each year. Mean density per flight increased from 0.52 manatees/km2 in 1977–78 to 2.73/km² in 1984–86. This increase may reflect increases in the east coast population or shifts in the population distribution. Distributional changes were observed in the study area through time, with a lower percentage of manatees occurring in industrial areas and a correspondingly higher percentage of manatees in nonindustrial areas by 1985.     

Some data on the distribution,occurrence, and biology of rockfish of the genus <Emphasis Type="Italic">Sebastes</Emphasis> (Sebastidae) off the western coast of Sakhalin

Results of trawl surveys performed by SakhNIRO in Tatar Strait in the end of the 1970s and 1990s, as well as in the beginning of the current century, made it possible to clarify former concepts of rockfish species of the genus Sebastes dwelling off the western coast of Sakhalin, specific features of their distribution, and some aspects of biology. According to specified data, the number of rockfish species in the area of western Sakhalin attains ten.     

Frontiers in ATP synthase research: Understanding the relationship between subunit movements and ATP Synthesis

How biological systems make ATP has intrigued many scientists for well over half the 20th century, and because of the importance and complexity of the problem it seems likely to continue to be a source of fascination to both senior and younger investigators well into the 21st century. Scientific battles fought to unravel the vast secrets by which ATP synthases work have been fierce, and great victories have been short-lived, tempered with the realization that more structures are needed, additional subunits remain to be conquered, and that during ATP synthesis, not one, but several subunits may undergo either significant conformational changes, repositioning, or perhaps even physical rotation similar to bacterial flagella^(1,2). In this introductory article, the author briefly summarizes our current knowledge about the complex substructure of ATP synthases, what we have learned from X-ray crystallography of the F₁ unit, and current evidence for subunit movements.     

Extinction of Snub-Nosed Monkeys in China During the Past 400 Years

We describe the historical change in distribution of snub-nosed monkeys (Rhinopithecus), a genus which includes 3 of the 4 endemic primate species in China, from the Qing Dynasty (1616) to 2001. The monkeys were once widely distributed in south, southwest and central China, and in two provinces in northwest China (Gansu and Shaanxi). Unfortunately, most of their populations in the plains and in some mountainous regions have vanished. Today, extant groups occur only in isolated mountainous regions with an altitude 4,500 m above sea level. The dramatic diminution is closely related to social and natural events, which occurred in China during the last 400 years. 1) the rapidly increasing density of human beings, especially during the twentieth century; 2) wars, especially in the first half of the 20th century; 3) deteriorating environments and accelerated deforestation and 4) hunting monkeys for food, medicinal and economic purposes.     

Recent environmental change in North African wetland lakes: diatom and other stratigraphic evidence from nine sites in the CASSARINA Project

All nine wetland lakes in the CASSARINA North African suite of sample sites have been disturbed strongly by human activity during the 20th century. Dated lake sediment core were used to provide evidence of the extent of recent environmental change at each site. Sedimentary diatoms at seven sites were useful for inferring salinity change trends during the last century. At two sites preservation problems severely degraded the sedimentary diatom record. Sediment core integrity was otherwise established.Lithostratigraphic measurements indicated some site specific changes in soil erosion and sediment composition but, for the Egyptian Delta lakes, no physical signal synchronous with Aswan High Dam construction was found. Sedimentary diatom assemblages were generally site characteristic and halophilous taxa were common. At two sites planktonic diatoms indicated some recent eutrophication but generally the assemblages were more indicative of salinity changes. Diatom-inferred salinity trends for the seven sites typically indicated that reductions in water salinity occurred sometime during the early or mid 20th century.Rather than climate, hydrological modification of water resources is implicated as the primary driver of salinity changes during most of the 20th century. In the western North African region these modifications were mainly local land drainage and water diversion programmes to alleviate winter flooding and/or promote summer water availability. In the Delta region, the Nile has been intensively exploited since antiquity and intensively so from the late 19th century to release more fresh water for agriculture. Here, diatom records indicate that freshening began well before the Aswan High Dam but salinity fluctuations have tended to diminish during the latter part of the 20th century. A small reversal in the water freshening trend in the 1980/90s was possibly a response to land subsidence/sea-level change or to reduced freshwater supply.Freshwater supply to the sites is generally diminishing as former freshwater surpluses switch to deficit. One site (Merja Bokka, Morocco) became completely dry in 1998 as agriculture encroached and Megene Chitane, the only acid lake in Tunisia, is currently affected by excessive inflow abstraction. At the beginning of the 21st century, eight of the nine CASSARINA sites persist as viable but modified aquatic ecosystems. They nevertheless continue to support valuable aquatic biodiversity, especially in the Delta sites and in Chitane. The modern diatom communities are clearly tolerant of considerable environmental change but the remaining sites are increasingly threatened by major hydrological disturbance. Base-line floristic data for the late 20th century are given but continuous biomonitoring combined with effective management is needed urgently to help conserve North Africa's diminishing natural wetland lake resources.     

HYDROSTASIS IN THE SIRENIA: QUANTITATIVE DATA and FUNCTIONAL INTERPRETATIONS

It has long been assumed that the heavy bones and horizontal lungs of sirenians are adaptations for maintaining neutral buoyancy and horizontal trim. These assumptions are examined in the light of detailed measurements of skeletal weight distribution in the Florida manatee ( Trichechus manatus latirostris ), measurements of the positions of body and skeletal centers of gravity in the Amazonian manatee (T. inunguis ), and available data on lung morphology in sirenians. The detailed arrangement of bones, muscle masses, and viscera in a sirenian ( T. inunguis ) is illustrated in cross sections for the first time. The hypotheses that skeletal weight is appropriately distributed to serve as hydrostatic ballast, and that the lungs are properly designed to help maintain horizontal trim, are confirmed. We suggest that selection for maintenance of trim and maximization of turning moments of the flippers may help account, respectively, for hindlimb loss and shortening of the neck in both sirenians and cetaceans. We recommend that the term "pachyostosis" be used to refer only to thickening of bones regardless of their density; that "osteosclerosis" be used for the replacement of cancellous with compact bone; and that "pachyosteosclerosis" be used for the joint occurrence of these conditions. Pachyosteosclerosis in sirenians, which may be brought about during ontogeny by mechanisms involving thyroid and parathyroid hormones, is fully normal and adaptive in this order and in no sense "pathological."