The epiphytic diatom flora of mosses from Strømness Bay area, South Georgia

A total of 104 taxa, belonging to 27 genera, were recorded from 36 moss samples collected in the Strømness Bay area. Cluster analysis revealed two groups of samples. Group 1 consisted of the Achnanthes incognita–Fragilaria germainii assemblage and the Eunotia paludosa var. paludosa assemblage. Group 2 included the Pinnularia borealis assemblage. The major ecological factor dividing the two groups appears to be the moisture content of the samples. Group 1 represents wetter conditions, and the second group is found on very dry mosses. The assemblages of group 1 were separated from each other by pH. The Achnanthes incognita–Fragilaria germainii assemblage occurs in wet mosses with a circumneutral pH. The Eunotia paludosa var. paludosa assemblage prefers bryophyte habitats with low pH values. The size of Pinnularia borealis drops significantly according to the dryness of the moss habitat.     

The genius of E. E. metchnikoff— Discoveries over the centuries

On the 15 of May we celebrated the 150th anniversary of the outstanding Russian biologist Elias E. Metchnikoff (1845–1916)—Nobel Prize winner (1908), full and honorary member of many scientific academies of the world. His main works were applied to the zoology of invertebtates, evolution, embryology, immunology, microbiology, infectious pathology, gerontology, etc. Elias Metchnikoff published essays on anthropology, theory of orthobiosis, role of social and social-hygienic factors in solving the problems of old age and life elongation. On 30 May-2 June 1995 an International Symposium dedicated to Metchnikoff's 150th anniversary was held in Moscow. This is a text of the lecture given by us at the opening ceremony.     

Adventive flora of Israel — Phytogeographical,ecological and agricultural aspects

73 adventive wild species occur in the flora of Israel: 39 are of tropical origin, 20 are North American. The geographical distribution pattern suggests that about two thirds of the species reached Israel through neighbouring countries, while only one third arrived directly from their countries of origin. — Three patterns of population dynamics can be recognized: accidental species (7), colonizing species (30), and species penetrating into natural habitats (3). There is insufficient information about the remaining species. — About 20 species are widespread noxious weeds which now have economic significance in Israel, 20 others are known to have similar ecological tendencies in other countries. These species soon may become aggressive weeds in Israel.     

Cytological observations on some south Indian mosses — IV

Cytological studies are made in seven south Indian moss taxa. The chromosome numbers of Atrichum longifolium Card. et Dix. (n = 7), Enthostodon pilifer Mitt. (n = 26) and Pohlia camptotrachela (Ren. et Card.) Broth. (n = 11) are reported for the first time. An anaphasic bridge is observed in Atrichum pallidum Ren. et Card. Telophasic laggards are observed in Atrichum pallidum, Enthostodon pilifer and Pohlia camptotrachela.     

Bryophyte flora of the Sierras de Filabres,Cabrera, Alhamilla and Cabo de Gata (Almería,S.E. Spain)

Abstract

The bryophyte flora of the Sierras de Filabres, Cabrera, Alhamilla and Cabo de Gata of Almería province (S.E. Spain) includes 280 taxa (236 mosses and 44 liverworts) of which 74 are new to the province of Almería, 31 to the southeastern part of the Iberian Peninsula and 4 to the Iberian Peninsula. Data about their biogeography and ecology are given.     

Chronorhythms of the Circulating Erythrocytes and Leukocytes—Correlation with the E.S.R. Cycles

2750 healthy and fasting subjects, 20-30 years old, were studied over a half-year period in 1980. Considering the mean day value as a basic piece of information for statistics, the Erythrocyte Sedimentation Rate (E.S.R.) and the blood counts (erythrocytes, leukocytes, polymorphonuclears, lymphocytes, monocytes and eosinophils) were compared.

The timeless relation between E.S.R. and each cell type number or percentage is rectilinear. The stronger slope and relation apply to the polymorphonuclears (PMN) or to the overall leukocytes.

The chronological normalized variations of the E.S.R. and of the PMN or leukocyte number or percentage are highly correlated. E.S.R. is less correlated with monocytes, eosinophils and Lymphocytes. Contrary to what could have been expected, the erythrocyte situation is but an intermediate one.

The spectra derived from the time variations show that all the cell types, whatever they are, are to be taken into account to explain the E.S.R. value and variation with time, even if, for a given cell type, the correlation and timeless relation were but faint ones.

Each cell type has a specific spectrum. Erythrocytes are subject to low frequency variations (316-158 days). PMNs oscillate with time within the medium frequency range (90 days). Lymphocytes, monocytes and eosinophils fluctuate more quickly (53 days).     

Mutation analysis of the receptor for colicins E1–E7. A pilot study

Thirty eight mutant clones of the colicin indicator strainEscherichia coli K 12 ROW, selected by their insensitivity to any of the colicins El–E7, were isolated. Comparison of their sensitivity-resistance patterns to colicins El–E7 enabled us to draw a rough preliminary map of the receptor for E colicins. In this receptor, the highly specific binding site for colicin El partially overlaps with the domain shared by all colicins E2 through E7. A specific binding site of this domain appears to be common for colicins E3 and E6; a part of the E3 and E6 binding site is also common for colicins E4 and E5 and a small, least specific, part also for colicins E2 and E7. Using colicin assay experiments, the binding capacity of coliein E receptor mutants could be estimated. A decreased, but not completely lost ability of certain mutants to bind colicins E, correlated to their lowered sensitivity to them, was found. Thus the phenomenon of partial colicin resistance was established, showing that colicin sensitivity—resistance is not a qualitative but a quantitative marker.     

In search of a functional flora—towards a greater integration of ecology and taxonomy

Large-scale biodiversity informatics projects will not properly address the needs of one important potential user group. Ecologists do not have ready access to datasets which allow them to assign plant species to functional types. We believe that information technology has developed sufficiently to allow taxonomists and ecologists to work together to address this need and develop specimen databases to combine taxonomic data with ecological and ecophysiological information so that this information will be assigned to the correct taxon in the future. Digital images provide a rapid and economical method of vouchering specimen data, reducing the need to store physical vouchers in herbaria.     

Annotated List of Ichthyofauna of Inland and Coastal Waters of Sakhalin Island. 1. Families Petromyzontidae—Salmonidae

Journal of Ichthyology - A complete annotated list of marine, brackish-water, and freshwater ichthyofauna of Sakhalin Island and the adjacent southern part of the Sea of ​​Okhotsk is...     

Micropropagation of Calluna vulgaris cv. ‘H.E. Beale’

Axillary shoot producing cultures were obtained from microcuttings and shoot tips of Calluna vulgaris cv. H.E. Beale. For cultures derived from microcuttings the highest multiplication rate of 38 shoots (5 mm or longer) was obtained on a reduced salt medium with the addition of 0.5 mgl^-1 2-isopentenyladenine (2iP) during an 8 week subculture. For shoot tip derived cultures 0.2 mgl^-1 6-benzyladenine (BA) was the best cytokinin and led to a multiplication rate of 26 for a 6 week subculture. The addition of 1 g/l casein hydrolysate to a multiplication medium enhanced shoot proliferation in presence of 0.5 mgl^-1 BA.Despite various auxin treatments shoots formed no roots in vitro but rooted readily if transferred to a peat substrate ex vitro. A high rooting percentage (80%) was also obtained with shoots taken from the end of a multiplication phase and rooted directly. An additional subculture on low auxin containing media before transfer to peat substrate is recommended because the shoot condition can be improved in this way. A high number of rooted plantlets was produced, so the methods described will allow mass propagation.     

Karyological knowledge of the Italian vascular flora as inferred by the analysis of “Chrobase.it”

Abstract

Chromosome number knowledge of the Italian vascular flora is stored in the online database Chrobase.it, which includes 6723 records, referable to 3428 taxa, 2799 accepted species and subspecies (about 35% of the national flora), and 3410 different chromosome countings (cytotypes). Appropriate queries to Chrobase.it allowed us to calculate mean, modal and median chromosome numbers for the Italian vascular flora, for geographical subgroups (islands, south, centre, north) and for selected orders, families and genera. Chromosome number data were available for 41 out of 55 orders (74%) and 107 out of 428 families (67%), represented by 664 out of 1297 genera (51%). The most studied administrative regions are Sicily (844 taxa), Tuscany (592 taxa), and Sardinia (390 taxa), while the most studied families are Asteraceae (465 taxa), Fabaceae (266 taxa), Brassicaceae (158 taxa), and Poaceae (144 taxa). Chromosome numbers range from 2n = 6, occurring in several species of Hypochaeris (Asteraceae), to 2n = 240, occurring in Ophioglossum (Ophioglossaceae), Dryopteris (Dryopteridaceae) and Arenaria (Caryophyllaceae) (mode is 2n = 18, and median is 2n = 24). Chromosome number variability was analyzed by frequencies (linear plots) and ANOVA, resulting in significant differences among geographical groups (mean chromosome number increasing from islands-south to centre-north) and selected taxa. B-chromosomes occur in 5.3% of data (148 taxa) and their number is not significantly different among geographical areas, while they occur only in 14 orders, 17 families, and 56 genera. The number of B-chromosomes ranges from 1 to 13 (mode = 1, median = 2).     

The production of “bacteria-free” mice. Relationship between fecal flora and bacterial population of the skin

In mice, after a few days of oral treatment with antibiotics which are minimally absorbed, the bacterial fecal flora is eliminated. In the course of such treatment, the bacterial population of the skin becomes drastically reduced. After 9 weeks, cultures from the skin of the back are negative. Following 12 weeks of treatment, about 50% of the mice are shown to be persistently free of microbes that are detectable by conventional methods of culturing.Disinfection of the skin (chlorhexidine) on the fourth day of treatment had no effect on the time required to obtain negative whole-body cultures in these animals.We are indebted to Mrs. J. E. C. Lekkerkerk for skilful aid in the bacteriological evaluation of the samples and to Mr. W. Aarssen for assistance in the maintenance of the mice.     

Microbial transformation of steroids XVIII. Dehydrogenation of cortisone in position 1—2

У 248 ш0442;аммов различн044B;х родов (Fusarium, Actinomyces, Proactinomyces, Nocardia, Mycobacterium) автор044B; иисслeдо вали способность дeгидрировать кортизон в 043F;оложeнии 1–2 стeроидного скe043B;eта. у штаммов, у которых была доказана эта способность к дeгидрированию, He было найдeно различий в качeствe возника ющих мeтаболитов, однако скорость прeв ращeния у отдeльных штаммов He была одинаковой. Самоe быстроe тeчeниe прeвращeния наблюдалось у штамма Mycobacterium flavum № 390. У этого штамма мы исслeдовали поэтому влияниe на процeсс прeвv0440;ащeния — воз раста, нарастания культуры, рН срeды и тeмпeратуры фeрмeнтации. На качe ство возникающих мeтаболитов Нe удалось воздeй ствовать ни одним из этих факторов. При прeвращeнии кортизона при помощи указанного штамма в качeствe пeрвого продукта возникаeт прeднизон, который однко далee восстанавливаeтся в по043B;ожeнии 20 в соотвeтствующee 20 β-оксиосоизводноe. рАзвитиE БАктЕрио цидного дЕйствия нΑ грΑм-отрицΑтΕльныΕ оргΑнизмы Β сыΒороткΑх молодых животных Я. Шmе? я. коска Α. Лан Исследовали бакт ериоцидную актикн ость сыBороток, получен ных от поросят, вскормленных в ссерильных условиях, без материнского молозива. Сыворотки зтих поросят содержат комплемент, но не содержат ни малейших следов антител и не обладают бакт ериоцидным действиен по отношению к микробам Εсе са со и eаmо еа, находящимся в e-фазеΒ сыворотках стер ильных молодых Животных, искус ственно заселенных определенным типом микроба Ε. со, бактериоцидная активность была обнаружена уже на 4-7-й день после введения микробов. Зта бактериоцидная активность 0ка зывается спепифич еской только по отношению к штамму, которым поросята были заселены.