A new species of Epichloë symbiotic with Chinese grasses

Epichlo? species are fungal symbionts (endophytes) of grasses, six European and four North American biological species in genus Epichlo? have been described in previous researches. In this study we describe a new Epichlo? species, Epichlo? yangzii Li et Wang, found in natural symbioses with Roegneria kamoji native to China. We investigated the host specificity, morphology, interfertility tests and molecular phylogenetic evidences of this new species. The results indicated that E. yangzii is host specific and seedborne. Most morphological characteristics of this new species are typical in the genus. However differences are evident in several features including size of perithecia, asci and ascospores. In mating tests E. yangzii was not interfertile with E. elymi isolates from related hosts in genera Elymus. Phylogenetic relationships based on sequences of beta-tubulin gene (tub2) introns and translation elongation factor 1-alpha gene (tef1) introns showed that members of the new species grouped into exclusive clades with high bootstrap value.     

New Archaeozoological Data from the Fayum “Neolithic” with a Critical Assessment of the Evidence for Early Stock Keeping in Egypt

Faunal evidence from the Fayum Neolithic is often cited in the framework of early stock keeping in Egypt. However, the data suffer from a number of problems. In the present paper, large faunal datasets from new excavations at Kom K and Kom W (4850–4250 BC) are presented. They clearly show that, despite the presence of domesticates, fish predominate in the animal bone assemblages. In this sense, there is continuity with the earlier Holocene occupation from the Fayum, starting ca. 7350 BC. Domesticated plants and animals appear first from approximately 5400 BC. The earliest possible evidence for domesticates in Egypt are the very controversial domesticated cattle from the 9^th/8^th millennium BC in the Nabta Playa-Bir Kiseiba area. The earliest domesticates found elsewhere in Egypt date to the 6^th millennium BC. The numbers of bones are generally extremely low at this point in time and only caprines are present. From the 5^th millennium BC, the numbers of sites with domesticates dramatically increase, more species are also involved and they are usually represented by significant quantities of bones. The data from the Fayum reflect this two phase development, with very limited evidence for domesticates in the 6^th millennium BC and more abundant and clearer indications in the 5^th millennium BC. Any modelling of early food production in Egypt suffers from poor amounts of data, bias due to differential preservation and visibility of sites and archaeological remains, and a lack of direct dates for domesticates. In general, however, the evidence for early stock keeping and accompanying archaeological features shows large regional variation and seems to be mainly dependent on local environmental conditions. The large numbers of fish at Kom K and Kom W reflect the proximity of Lake Qarun.     

Ecophenotypic plasticity leads to extraordinary gastropod shells found on the “Roof of the World”

The often extraordinary shell forms and shapes of gastropods found in palaeolakes, such as the highly diverse Gyraulus fauna of the famous Steinheim Basin, have been puzzling evolutionary biologists for centuries, and there is an ongoing debate whether these aberrant shell forms are indicative of true species (or subspecies) or ecophenotypic morphs. Interestingly, one of the Steinheim Gyraulus morphs – a corkscrew-like open-coiled shell – has a recent analogue in the Lake Bangong drainage system on the western Tibetan Plateau. Therefore, a combination of morphological, molecular, palaeolimnological, and ecological analyses was used in this study to assess whether the extraordinary shell shape in Gyraulus sp. from this drainage system represents a (young) ecophenotypic phenomenon or if it has been genetically fixed over an extended period of time. Our morphological, ecological, and palaeolimnological data suggest that the corkscrew-like specimens remain restricted to a small pond near Lake Bangong with an elevated pH value and that the colonization may have occurred recently. The phylogenetic reconstruction based on two gene fragments shows that these nonplanispiral specimens cluster within the previous described Tibetan Plateau Gyraulus clade N2. A network analysis indicates that some haplotypes are even shared by planispiral and nonplanispiral specimens. Given the ephemerality of the phenomenon, the compact network patterns inferred, the likely young phylogenetic age of the aberrant Gyraulus shells studied, and the ecological peculiarities of the study site, we suggest that the evolution of the aberrant shell forms on the Tibetan Plateau could likely be considered as a rapid ecophenotypic response, possibly induced by ecological stress. This finding may thus have implications for the ongoing debate about the processes that have caused the extraordinary shell diversity in palaeolakes such as the Steinheim Basin.     

Recent attestations of “new” glume wheat in Turkey: a reassessment of its role in the reconstruction of Neolithic agriculture

Vegetation History and Archaeobotany - Studies of the origins of agriculture in the Near East have revealed that the eight plant species known as “Founder Crops”, i.e. emmer, einkorn,...     

Emergence and Spread of Basal Lineages of Yersinia pestis during the Neolithic Decline

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Analysis of the Putative Remains of a European Patron Saint–St. Birgitta

Saint Birgitta (Saint Bridget of Sweden) lived between 1303 and 1373 and was designated one of Europe''s six patron saints by the Pope in 1999. According to legend, the skulls of St. Birgitta and her daughter Katarina are maintained in a relic shrine in Vadstena abbey, mid Sweden. The origin of the two skulls was assessed first by analysis of mitochondrial DNA (mtDNA) to confirm a maternal relationship. The results of this analysis displayed several differences between the two individuals, thus supporting an interpretation of the two skulls not being individuals that are maternally related. Because the efficiency of PCR amplification and quantity of DNA suggested a different amount of degradation and possibly a very different age for each of the skulls, an orthogonal procedure, radiocarbon dating, was performed. The radiocarbon dating results suggest an age difference of at least 200 years and neither of the dating results coincides with the period St. Birgitta or her daughter Katarina lived. The relic, thought to originate from St. Birgitta, has an age corresponding to the 13^th century (1215–1270 cal AD, 2σ confidence), which is older than expected. Thus, the two different analyses are consistent in questioning the authenticity of either of the human skulls maintained in the Vadstena relic shrine being that of St. Birgitta. Of course there are limitations when interpreting the data of any ancient biological materials and these must be considered for a final decision on the authenticity of the remains.     

How Much Remains Undetected? Probability of Molecular Detection of Human Plasmodia in the Field

Background

In malaria endemic areas, most people are simultaneously infected with different parasite clones. Detection of individual clones is hampered when their densities fluctuate around the detection limit and, in case of P. falciparum, by sequestration during part of their life cycle. This has important implications for measures of levels of infection or for the outcome of clinical trials. This study aimed at measuring the detectability of individual P. falciparum and P. vivax parasite clones in consecutive samples of the same patient and at investigating the impact of sampling strategies on basic epidemiological measures such as multiplicity of infection (MOI).

Methods

Samples were obtained in a repeated cross-sectional field survey in 1 to 4.5 years old children from Papua New Guinea, who were followed up in 2-monthly intervals over 16 months. At each follow-up visit, two consecutive blood samples were collected from each child at intervals of 24 hours. Samples were genotyped for the polymorphic markers msp2 for P. falciparum and msp1F3 and MS16 for P. vivax. Observed prevalence and mean MOI estimated from single samples per host were compared to combined data from sampling twice within 24 h.

Findings and Conclusion

Estimated detectability was high in our data set (0.79 [95% CI 0.76–0.82] for P. falciparum and, depending on the marker, 0.61 [0.58–0.63] or 0.73 [0.71–0.75] for P. vivax). When genotyping data from sequential samples, collected 24 hours apart, were combined, the increase in measured prevalence was moderate, 6 to 9% of all infections were missed on a single day. The effect on observed MOI was more pronounced, 18 to 31% of all individual clones were not detected in a single bleed. Repeated sampling revealed little difference between detectability of P. falciparum and P. vivax.     

Weed finds as indicators for the cultivation regime of the early Neolithic Bandkeramik culture?

Ethnographic data combined with the characteristics of the weed species from Bandkeramik settlement sites give hints for the reconstruction of Early Neolithic agricultural practises in Central Europe. In contrast to the Balkan situation with a high diversity in cultivated crops, Bandkeramik field management can be reconstructed as a simple agricultural system with emphasis on summer crop growing. Permanent fields were treated with hoes, digging sticks or similar tools, sown in spring and grazed in autumn and winter. The intensity of field management seems to increase through time as shown by diachrone comparison of archaeobotanical data from Neolithic, Iron Age and Roman times. The absence of winter-cereals such as naked wheat, grown in the Balkan Peninsula, gives a hint of a certain emphasis on stock breeding. Summer crop growing would have had the advantage that the Bandkeramik fields could be grazed after harvest until next spring and would therefore be manured at the same time.     

‘Far and wide’: Social networking in the Early Neolithic of the Levant

Networking during the early stages of the Levantine Neolithic appears to have been encouraged by increasing demands for exotics, i.e. non-local commodities. The actual exchange of merchandise stimulated also transmission of knowledge, i.e. innovations. Together these were instrumental in affecting the social fabric of society. It appears that specific geographic settings as well as large-scale communal edifices played a pivotal role in sustaining and promoting Neolithic networking.     

Does grazing reduce survival of indigenous perennial grasses of the semi-arid woodlands of western New South Wales?

Abstract Exclosures were used to examine the impact of grazing upon the mortality patterns of populations of six indigenous grass species. The experiment compared unfenced areas with areas from which either sheep only or sheep, rabbits and kangaroos were excluded. There were large interspecific differences in mortality patterns, with Stipa nitida and Aristida browniana having relatively high mortality rates and Eragrostis eriopoda having relatively low mortality rates. Grazing-induced mortality was observed in treatment areas that were grazed by sheep, rabbits and kangaroos and in areas grazed only by rabbits and kangaroos. The short-lived S. nitida appears less likely to suffer grazing-induced mortality than species of intermediate longevity such as Monachather paradoxa. These observations help explain the decline in endemic perennial grasses that has taken place in the vegetation of western New South Wales since European settlement. Management of these rangelands to encourage these grasses must consider total grazing pressure and not simply the impact of livestock.     

Molecular basis for subtypic differences of the “a” subunit of coagulation factor XIII with description of the genesis of the subtypes

The “a” subunit of human coagulation factor XIII (F13A) exhibits genetic polymorphism defined by four common alleles, F13A*1A, *1B, *2A, and *2B. We have previously suggested on the basis of the isoelectric focusing patterns of the four allele products that point mutations at two separate sites and one intragenic crossing over might be involved in the genes of F13A polymorphism. Here, we report nucleotide substitutions associated with F13A polymorphism. A C/T transition of the second nucelotide of codon 564 in exon 12 is responsible for the difference between F13A*1A and *1B and that between F13A*2A and *2B, and a set of two base changes in codons 650 and 651 in exon 14 leads to the differences between F13A*1A and *2A and those between F13A*1B and *2B. The four combinations of the point mutations at the two exons thus correspond to the four alleles, two of which were generated by the point mutations from ancestral monomorphic gene. The results suggest strongly that intragenic crossing over must be involved in the genesis of the fourth allele. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods discriminating these base changes in exons 12 and 14 are also presented.     

Structural evidence that the small subunit found associated with the TL antigen is β 2-microglobulin

Comparative tryptic peptide mapping and partial amino-terminal primary sequence analysis of the light chain component associated with the TL antigens showed that the small subunit of TL was identical to the ₂m light chain associated with the H-2K or D product of the same strain. Peptide comparison of the ₂m from the Tla products of an A strain X-ray induced leukemia RADA1 (Tla ^a) and of a C57BL/6 strain X-ray induced leukemia ERLD (Tla ^b) showed differences to the extent of 25–35% in their peptides. This is consistent with previous results showing ₂m allelic variations between these mouse strains. The data prove the structural identity of the ₂m molecules from TL and H-2K, D antigens as well as reveal the strain specific polymorphism of the ₂m associated with these products.     

The structure of the plankton community of the Öregrundsgrepen (southwest Bothnian Sea)

Taxonomic composition and variations in density and biomass of the plankton community in the Öregrundsgrepen, a shallow coastal area, were investigated from June 1972 to November 1973. The phytoplankton biomass was large in spring but small during the rest of the year. The spring bloom was dominated by diatoms and dinoflagellates, especially byThalassiosira spp. which were also important during other seasons. Small forms, such asCryptomonas spp.,Rhodomonas spp. and monads, dominated during summer. Blue-green algae were never of any major importance. During the summer, the trophogenic layer exceeded 10 m in thickness. The metazoan fauna was of lower diversity than the plankton flora. The dominating species, the copepodsAcartia bifilosa andEurytemora affinis, constituted on the average 83% of the standing crop. The low salinities, 5–6 S, were regarded as the principal pertinent limiting factor. The metazoan fauna reached large biomass values from July to October. The protozoan fauna (in the case of ciliates), obtained biomass maxima during the spring bloom. It is suggested that the Öregrundsgrepen represents an area of elevated productivity within a region of low overall production, presumably due to local upwelling. From June 1972 to May 1973, the average biomasses were: phytoplankton 0.464 g C m^–2, ciliates 0.040 g C m^–2, copepod nauplii 0.010 g C m^–2, micro-rotifers 0.004 g C m^–2, and mesozooplankton (larger than 0.2 mm) 0.312 g C m^–2. It is estimated that about than 60% of the phytoplankton production is consumed by the microzooplankton (<0.2 mm).     

Woodland management at the Swedish middle Neolithic site of Alvastra? A new perspective

It is often argued that the repetitive removal of branches to improve the quantity and the quality of wood, i.e. woodland management, has been practiced in Europe from the Mesolithic and/or Neolithic onwards. The Neolithic pile dwelling of Alvastra in Sweden has been mentioned in textbooks as a classical example of this practice. The conclusion about woodland management at Alvastra was primarily based on palynological data, which do not provide any direct evidence. Is it correct to conclude that woodland management was practiced at Alvastra? To investigate that, this paper reviews the previous arguments and interpretations, focusing on wood data, and by comparing archaeological data with modern wood data. First, the assemblage of vertical posts from the latest excavations at Alvastra include a wide range of taxa, showing opportunistic use of the woody vegetation. Second, while the dendrochronological analysis of Quercus and Ulmus carried out in the 80 s has clearly indicated that the trees used for the posts grew under highly similar conditions and that particularly many Quercus trees started to grow more or less at the same time, the reason for the partially simultaneous start of growth remains unknown, and the posts used for the construction of the site do not provide evidence of repetitive removal of trunks from stools. Finally, analysis of the age/diameter data of the Corylus wood indicates the use of branches from unmanaged vegetation, while age data of Salix do not support management either. In conclusion, the data do not support the hypothesis of woodland management at Neolithic Alvastra, and it is most likely that people did not practice woodland management. This outcome corresponds to the conclusions in some of the previous publications about the site.

     

Dynamics of a vortex with the U-shaped filament (ends “anchored”) in the heart of the ground squirrel

The dynamics of an electrical scroll wave with the U-shaped filament with both ends of the filament being “anchored” on the endocardial surface and the dependence of the structure of pseudoECG on the dynamics of the vortex during the development of polymorphic tachysystolia have been studied by applying premature stimuli to the “target phase” with subsequent registration of the spatial and temporal distribution of electrical potential throughout the surface (endocardial and epicardial) of a thin (≈1 mm) preparation. It was found that (1) the pseudoECG of the polymorphic form during the tachysystolia attack can be observed in the case that the position of the filament ends on the surfaces of the preparation does not practically change from turn to turn (filament ends are “anchored”); (2) the thread of a scroll wave during this attack can twist and untwin (twisted filament), just as it was the case for scroll waves with a straight filament; (3) in the case of pseudoECG of polymorphic form, the twisting and untwining of the filament were stronger (the angle of maximal twisting was 120 degrees and more), and the angle of twisting changed by a substantially greater value from turn to turn as compared with the pseudoECG of monomorphic form; (4) in the case of pseudoECG of polymorphic form, the time interval between the appearance of waves on the surfaces of the preparation (T _epi-endo) was substantially greater and changed to a greater extent from turn to turn of the vortex; and (5) simultaneously with the appearance of pseudoECG of polymorphic form and the onset of changes in the twisting of the scroll and the T _epi-endo interval indicated in (2–4), significant changes in the patterns of coverage of the surface by excitation occurred. Based on the results obtained, an explanation of the reasons for the appearance of excitation breakdown patterns on the surface of the myocardium was proposed, which differs from the traditional viewpoint. These patterns may be the result of reflection on myocardial surfaces of the activity of not different simultaneously occurring sources of initiation of excitation but of a single three-dimensional vortex whose filament twists when passing through the thickness of the myocardium and can closely approach one or the other surface.