Statistical Analysis of Environmental Space-Time Processes edited by N. D. Le and J. V. Zidek

Statistical Analysis of Environmental Space‐Time Processes (N. D. Le and J. V. Zidek) Jon Wakefield Computer‐Intensive Methods of Data Analysis in Biology (D. A. Roff) A. W. Kemp Randomization, Bootstrap, and Monte Carlo Methods in Biology (3rd Edition) (B. F. J. Manly) A. W. Kemp Applied Mixed Models in Medicine, 2nd edition (H. Brown and R. Prescott) Matthew J. Gurka Stochastic Modeling for Systems Biology (D. J. Wilkinson) Olaf Wolkenhauer Knowledge Discovery in Proteomics (I. Jurisica and D. Wigle) Zhen Zhang Computational Genome Analysis: An Introduction (R. C. Deonier, S. Tavaré, and M. S. Waterman) Marc Suling Stochastic Orders (M. Shaked and J. G. Shantikumar) Subhash Kochar Brief Reports by the Editor Measurement Error in Nonlinear Models: A Modern Perspective, 2nd edition (R. J. Carroll, D. Ruppert, L. A. Stefansky, and C. M. Crainiceanu) Basic Statistics and Pharmaceutical Statistical Applications, 2nd edition (J. E. De Muth) A Handbook of Statistical Analyses Using Stata, 4th edition (S. Rabe‐Hesketh and B. S. Everitt) Introduction to Randomized Controlled Clinical Trials, 2nd edition (J. N. S. Matthews) Survival and Event History Analysis (P. K. Andersen and N. Keiding, editors) A Pocket Guide to Epidemiology (D. G. Kleinbaum, K. M. Sullivan, and N. D. Barker)     

Vergleichende cytotaxonomische Untersuchungen anRanunculus seguieri und der Artengruppe desR. alpestris (Ranunculaceae)

Morphological and cytological investigations as well as crossing experiments were carried out withRanunculus seguieri Vill. and 4 species of theRanunculus alpestris L. group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. & Kit.). ForR. seguieri andR. alpestris, localities and distribution are given in addition to extensive diagnoses. A key to the species includes morphological characteristics and distribution data forR. traunfellneri, R. bilobus, andR. crenatus. New diagnostic characters are described. Crossing experiments betweenR. seguieri and the species of theR. alpestris group were unsuccessful. All 5 species have a chromosome number of 2n = 16, the record forR. bilobus is new. There is no statistically significant difference between the karyotypes ofR. seguieri andR. alpestris s. str. Nevertheless, according to morphological evidence and crossing experiments,R. seguieri is not closely related to theR. alpestris group.

     

Effects of variation in individual growth on plant species coexistence

Abstract. Both size structure and variability (spatial heterogeneity, disturbance, stochasticity, variation in species attributes, etc.) are regarded as regulatory mechanisms of species coexistence. However, none of the models so far proposed consider both size structure and variability simultaneously. A size-structured variation model for plant-community dynamics is proposed, which is based on the diffusion model for growth dynamics of plant populations. This model has four functions: (1) mean growth rate of individuals of size x at time t, G(t, x) (species-specific mean traits, e.g. competitive ability); (2) variance in growth rate of individuals of size x at time t, D(t, x) (stochastic factors due to genetic variation, environmental heterogeneity, spatial variation of individuals, etc.); (3) mortality rate of individuals of size x at time t, M(t, x); and (4) recruitment rate at time t, R(t), as a boundary condition. The interference function for individuals of size x at time t, C(t, x), is introduced, which expresses the degree of interactions between individuals and hence averaged effects of local neighbourhood competition; the G(t, x), D(t, x), M(t, x) and R(t) functions are given in terms of C(t, x). These four functions describe the growth dynamics of individuals of each species in the plant community. Effects of the G(t, x), D(t, x), M(t, x) and R(t) functions on species coexistence in plant communities were evaluated by simulation and the relative importance of the D(t, x) function as well as size structure was shown for species coexistence especially in plant communities where competition among species is non-transitive or niche limitation does not work.     

The chromosomes of two Drosophila races: D. nasuta nasuta and D. n. albomicana

Heterochromatin distribution and differentiation in metaphase chromosomes of two morphologically identical Drosophila races, D. nasuta nasuta and D. n. albomicana, have been studied by C- and N-banding methods. — The total heterochromatin values differ only slightly between these races. However, homologous chromosomes of the two Drosophila forms show striking differences in the size of heterochromatin regions and there is an alternating pattern in D. n. nasuta and D. n. albomicana of chromosomes which contain more, or respectively less heterochromatin than their counterparts in the other race. — Three different N-banding patterns could be obtained depending on the conditions of the method employed: One banding pattern occurs which corresponds to the C-banding pattern. Another pattern is the reverse of the C-band pattern; the euchromatic chromosome regions and the centromeres are stained whereas the pericentric heterochromatin regions remain unstained. In the Y chromosomes of both races and in chromosome 4 of D. n. albomicana, however, the heterochromatin is further differentiated. In the third N-banding pattern only the centromeres are deeply stained. Furthermore, between the races, subtle staining differences in the pericentric heterochromatin regions can be observed as verified in F₁ hybrids. On the basis of C- and N-banding results specific aspects of chromosomal differences between D. n. nasuta and D. n. albomicana are discussed.Dedicated to Prof. W. Beermann on the occasion of his 60th birthday     

Diospyros foliosa: the correct name for D. elliptica, and new combinations in Fijian and Samoan Diospyros (Ebenaceae)

The correct name in Diospyros L. (Ebenaceae) for a species from Tonga first described as Maba elliptica J. R. Forst. & G. Forst. and incorrectly known as D. elliptica (J. R. Forst. & G. Forst.) P. S. Green is D. foliosa (A. Gray) Bakh. In addition to the nominate variety, six additional varieties are recognised from Fiji and Samoa. As these varieties lack names under D. foliosa, the following new combinations are proposed: D. foliosa var. elliptica (J. R. Forst. & G. Forst.) Dorr, D. foliosa var. fijiensis (Bakh.) Dorr, D. foliosa var. fructuosa (A. C. Sm.) Dorr, D. foliosa var. iridea (Fosberg) Dorr, D. foliosa var. opaca (A. C. Sm.) Dorr, and D. foliosa var. savaiiensis (Christoph.) Dorr.     

Site-directed mutagenesis of the succinate dehydrogenase subunits B and D from Corynespora cassiicola reveals different fitness costs and sensitivities to succinate dehydrogenase inhibitors

Carboxamide fungicides target succinate dehydrogenase (SDH). Recently published monitoring studies have shown that Corynespora cassiicola isolates are resistant to one or several SDH inhibitors (SDHIs) with amino acid substitutions in the SDH B and D subunits. We confirmed, by site-directed mutagenesis of the sdhB and sdhD genes, that each of the mutations identified in the field strains of C. cassiicola conferred resistance to boscalid and, in some cases, cross-resistance to other SDHIs (fluopyram, carboxin and penthiopyrad). Analyses of the enzyme activity and sdhB and sdhD gene expression show that modifications (SdhB_H278Y and SdhD_H105R) that result in a decline in SDH enzyme activity may be complemented by gene overexpression. The SdhB_H278Y, SdhB_I280V and SdhD_H105R mutants suffered large fitness penalties based on their biological properties, including conidia production and germination, mycelial growth, pathogenicity or survival abilities under environment stress. However, fitness cost was not found in the SdhB_H278R, SdhD_D95E and SdhD_G109V mutants. In the evaluation of resistance to boscalid in 2018 and 2019, the frequency of the SdhD_D95E and SdhD_G109V genotypes in the Liaoning and Shandong provinces changed dramatically compared with 2005–2017, from low resistance frequency (0.53% for D95E and 2.53% for G109V) to dominant resistance frequency (17.28% for D95E and 15.38% for G109V). Considering both the fitness and increased frequency of these genotypes, we may infer that the SdhD_D95E and SdhD_G109V mutants will be the dominant resistance mutants in field.     

Multivariable Model-building: A Pragmatic Approach to Regression Analysis Based on Fractional Polynomials for Modelling Continuous Variables by ROYSTON, P. and SAUERBREI, W.

Multivariable Model‐building: A Pragmatic Approach to Regression Analysis Based on Fractional Polynomials for Modelling Continuous Variables (P. Royston and W. Sauerbrei) David W. Hosmer Modern Multivariate Statistical Techniques: Regression, Classification, and Manifold Learning (A. J. Izenman) Debashis Ghosh A Primer on Linear Models (J. F. Monahan) Muni S. Srivastava Mixed Effects Models and Extensions in Ecology with R (A. F. Zuur, E. N. Ieno, N. J. Walker, A. A. Saveliev, and G. M. Smith) Carl James Schwarz Random Effect and Latent Variable Model Selection (D. B. Dunson, Editor) Kenneth Rice Missing Data in Clinical Studies (G. Molenberghs and M. G. Kenward) Suzanne R. Dubnicka Functional and Operatorial Statistics (S. Dabo‐Niang and F. Ferraty, Editors) Jason D. Nielsen Statistical Analysis and Modelling of Spatial Point Patterns (J. Illian, A. Penttinen, H. Stoyan, and D. Stoyan) Jesper Møller Solved Problem in Geostatistics (O. Leuangthong, K. D. Khan, and C. V. Deutsch) Ole F. Christensen Statistical Methods for Environmental Epidemiology with R : A Case Study in Air Pollution and Health (R. D. Peng and F. Dominici) David Buckeridge Correspondence Analysis in Practice, Second Edition (M. Greenacre) Willem Heiser Introduction to Statistical Mediation Analysis (D. P. MacKinnon) Tyler J. VanderWeele Brief Reports by the Editor The EM Algorithm and Extensions, 2nd edition (G. J. McLachlan and T. Krishnan) Probability Models for DNA Sequence Evolution, 2nd edition (R. Durrett) Bayesian Methods for Data Analysis, 3rd edition (B. P. Carlin and T. A. Louis) Nonlinear Regression with R (C. Ritz and J. C. Streibig) Cancer Mortality and Morbidity Patterns in the U.S. Population: An Interdisciplinary Approach (K. G. Manton, I. Akushevich, and J. Kravchenko)     

Five new nomenclatural combinations in Dasymaschalon and Goniothalamus (Annonaceae)

Three new nomenclatural combinations are validated in Dasymaschalon (Annonaceae), with the elevation of varietal names to the specific rank: D. longiusculum (Bân) Jing Wang & R. M. K. Saunders, D. megalanthum (Merr.) Jing Wang & R. M. K. Saunders, and D. minutiflorum (Nurmawati) Jing Wang & R. M. K. Saunders. New nomenclatural combinations are furthermore validated in Goniothalamus (Annonaceae), following the successful conservation of the generic name over Richella. Two species names in Richella are here transferred to Goniothalamus as G. monospermus (A. Gray) R. M. K. Saunders and G. obtusatus (Baill.) R. M. K. Saunders.     

The genus Gottschelia Grolle (Jungermanniopsida,Lophoziaceae) in China,with a description of G. grollei,sp. nov.

Abstract

The genus Gottschelia Grolle is reported as new to mainland China, from Yunnan Province. Previously G. schizopleura (Spruce) Grolle was the only known Chinese species, reported from Taiwan. However, two further species have recently been found in the Gaoligong Shan range, Yunnan Province, G. patoniae Grolle, Schill & D.G. Long, previously known from the East Himalaya of Nepal and India (Sikkim) and G. grollei D.G. Long & Váňa, described here as a new species endemic to China, the fourth known species in the genus. The differences between the three Chinese species are enumerated with notes on distribution and ecology.     

E75、R78和D82是影响大肠埃希氏菌FtsZ自身组装及其与MreB相互作用的重要氨基酸

【目的】探索大肠埃希氏菌Escherichia coli FtsZ突变体FtsZ~(E75A)、FtsZ~(R78G)和FtsZ~(D82A)对FtsZ自身组装和FtsZ-MreB相互作用的影响。【方法】利用常规分子克隆和定点突变技术,构建FtsZ及其突变体表达载体,亲和纯化得到相应的目标蛋白;通过同源重组构建QN6(ftsZ::yfp-cat)、QN7(ftsZ~(E75A)::yfp-cat)、QN8(ftsZ~(R78G)::yfp-cat)和QN9(ftsZ~(D82A)::yfp-cat)菌株;利用活细胞成像技术观察FtsZ及其突变体的胞内定位模式;免疫沉淀和细菌双杂交实验检测FtsZ/FtsZ*-FtsZ*或FtsZ/FtsZ*-MreB间的相互作用;光扫描检测定点突变对FtsZ组装特性的影响。【结果】FtsZ~(E75A)、FtsZ~(R78G)和FtsZ~(D82A)突变体的功能活性降低、各突变体在E.coli内不能正确的定位和形成功能性Z环;FtsZ/FtsZ*-FtsZ*单体间的相互作用减弱或消失,FtsZ*-MreB相互作用破坏;FtsZ突变体体外聚合效率降低。【结论】FtsZ E75、R78和D82是影响FtsZ正确组装和功能及FtsZ-MreB相互作用的重要氨基酸。     

Regulation of Nadp-Malic Enzyme in the Eye-Antennal Disc of D. melanogaster/D. simulans Hybrids: Evidence for cis- and trans-Regulation

Pattern regulation of malic enzyme (ME) distribution in D. melanogaster/D. simulans (mel/sim) hybrid eye-antennal discs was investigated. Both cis- and trans-regulation of the spatial distribution pattern was observed within the eye portion of the disc complex. D. simulans possesses gene(s) that operate in trans in the hybrids to suppress ME staining along the morphogenetic furrow, a region that always stains in D. melanogaster. ME structural genes of both species were expressed in cis within the ommatidial preclusters and clusters of the hybrids. Malic enzyme was not expressed elsewhere in the eye disc of either species. Restoration of the D. melanogaster furrow pattern element occurred in partial hybrids that were homozygous for the D. melanogaster 3R where the structural gene resides. Therefore, a dominant gene(s) in the D. simulans 3R suppresses the D. melanogaster furrow pattern, while a recessive gene(s) in the D. melanogaster 3R restores the pattern when the trans-suppressor is removed. These conclusions agree with those found for regulation of aldehyde oxidase distribution in D. melanogaster/D. simulans hybrid wing discs.     

Role of rye chromosome 2R from wheat-rye substitution line 2R(2D)1 ( Triticum aestivum L. cv. Saratovskaya 29- Secale cereale L. cv. Onokhoiskaya) in genetic regulation of meiotic restitution in wheat-rye polyhaploids

A study was made of the role of rye chromosome 2R from the wheat-rye substitution line 2R(2D)₁ (Triticum aestivum L. cv. Saratovskaya 29-Secale cereale L. cv. Onokhoiskaya) in genetic regulation of meiotic restitution in wheat-rye polyhaploids 2R(2D)₁ × S. cereale L. cv. Onokhoiskaya. Rye chromosome 2R proved to affect the completeness of the meiotic program, suppressing the formation of restitution gametes. This was evident from the reductional division of univalent chromosomes in AI and the occurrence of the second meiotic division. The interrelationships between the type of chromosome division in AI and the two-step character of meiosis are discussed. The structural and functional organization of the centromeric regions of chromosomes undergoing reductional division is assumed to determine the two-step character of division. Original Russian Text ? O.G. Silkova, A.I. Shchapova, V.K. Shumny, 2007, published in Genetika, 2007, Vol. 43, No. 7, pp. 971–981.     

Das Phloem der Haustorien vonCuscuta

Summary Haustoria ofCuscuta odorata R. & P. andC. grandiflora H.B.K. show continuous traces of sieve elements, connecting the phloem of the host with that of theCuscuta shoot. The continuity of this haustorial phloem is discernible by callose fluorescence after staining with aniline blue. The fine structural criteria for sieve tubes are analyzed electronmicroscopically, with special respect to sieve pores, P-protein, and a distinct wall-standing smooth surfaced ER. Within the central part of the haustorium sieve tubes are elongated, while the elements abutting the phloem of theCuscuta shoot are nearly isodiametric in shape. Both elements are associated with rather large companion cells, derived from an unequal division.

     

Isozyme variability in species of the genus Drosophila. III. Qualitative comparison of the esterases of D. aldrichi and D. mulleri

Two closely related species, Drosophila aldrichi and D. mulleri, are compared on the basis of their esterase isozyme patterns after starch gel electrophoresis. Comparable esterases between the two species are identified by substrate specificity, inhibition, and enhancement of esterase activity by various agents. The extensive electrophoretic variability of most of the esterases in nature is described and data relating to the inheritance of the various enzyme forms are presented.This work was supported (in part) by a U.S. Public Health Service research grant (GM 11609 to W. S. Stone and M. R. Wheeler) and a training grant (2 T1-GM 337-07 to R. P. Wagner et al.) from the National Institutes of Health.     

Applied Spatial Data Analysis with R. by BIVAND, R. S., PEBESMA, E. J., and GOMEZ-RUBIO, V.

Applied Spatial Data Analysis with R (R. S. Bivand, E. J. Pebesma, and V. Gomez‐Rubio) Jay M. Ver Hoef Bayesian Disease Mapping: Hierarchical Modeling in Spatial Epidemiology (A. B. Lawson) J. Law Disease Surveillance: A Public Health Informatics Approach (J. S. Lombardo and D. L. Buckeridge, editors) Iris Pigeot Survival Analysis for Epidemiologic and Medical Research (S. Selvin) M. G. Valsecchi Survival and Event History Analysis: A Process Point of View (O. O. Aalen, O. Borgan, and H. K. Gjessing) Patricia Grambsch Nonlinear Dimensionality Reduction (J. A. Lee and M. Verleysen) Haonan Wang Model Selection and Model Averaging (G. Claeskens and N. L. Hjort) Thomas M. Loughin Meta‐Analysis of Binary Data Using Profile Likelihood (D. Böhning, R. Kuhnert, and S. Rattanasiri) Eloise Kaizar Wavelet Methods in Statistics with R (G. P. Nason) Jeffrey S. Morris Adaptive Design Theory and Implementation Using SAS and R (M. Chang) Feifang Hu Ecological Models and Data in R (B. M. Bolker) Rachel M. Fewster Applied Multiway Data Analysis (P. M. Kroonenberg) Renato Coppi Brief Reports by the Editor Sampling of Populations: Methods and Applications, 4th edition (P. S. Levy and S. Lemeshow) Applied Survival Analysis: Regression Modeling of Time‐to‐Event Data, 2nd edition (D. W. Hosmer, S. Lemeshow, and S. May) SAS for Data Analysis: Intermediate Statistical Methods (M. G. Marasinghe and W. J. Kennedy) Advances in Mathematical and Statistical Modeling (B. C. Arnold, N. Balakrishnan, J. M. Sarabia, and R. Mínguez, editors) An Introduction to Generalized Linear Models, 3rd edition (A. J. Dobson and A. G. Barnett) Design and Analysis of Bioavailability and Bioequivalence Studies, 3rd edition (S.‐C. Chow and J.‐P. Liu)     

Age‐dependent dystonia in striatal Gγ7 deficient mice is reversed by the dopamine D2 receptor agonist pramipexole

Gγ7 is enriched in striatum and forms a heterotrimeric complex with Gα_olf/Gβ, which is coupled to D1 receptor (D1R). Here, we attempted to characterize the pathophysiological, neurochemical, and pharmacological features of mice deficient of Gγ7 gene. Gγ7 knockout mice exhibited age‐dependent deficiency in rotarod behavior and increased dystonia‐like clasping reflex without loss of striatal neurons. The neurochemical basis for the motor manifestations using immunoblot analysis revealed increased levels of D1R, ChAT and NMDA receptor subunits (NR1 and NR2B) concurrent with decreased levels of D2R and Gα_olf, possibly because of the secondary changes of decreased Gα_olf/Gγ7‐mediated D1R transmission. These behavioral and neurochemical changes are closely related to those observed in Huntington's disease (HD) human subjects and HD model mice. Taking advantage of the finding of D2R down‐regulation in Gγ7 knockout mice and the dopamine‐mediated synergistic relationship in the control of locomotion between D2R‐striatopallidal and D1R‐stritonigral neurons, we hypothesized that D2‐agonist pramipexole would reverse behavioral dyskinesia caused by defective D1R/Gα_olf signaling. Indeed, the rotarod deficiency and clasping reflex were reversed by pramipexole treatment under chronic administration. These findings suggest that Gγ7 knockout mice could be a new type of movement disorders, including HD and useful for the evaluation of therapeutic candidates.     

Contributions to the cytotaxonomy of the Commelinaceae*

Further material of Gibasis geniculata (Jacq.) Rohw. (syn. Tradescantia geniculata Jacq.) and other Gibasis species collected in the field has been studied. The existence of several species in our earlier experimental material is confirmed. These include G. geniculata itself (2n= 32 or 48 small chromosomes), G. oaxacana D. R. Hunt (2n= 16 small chromosomes) and G. schiedeana (Kunth) D. R. Hunt, which has two chromosome forms, 2n= 10 and 2n= 16, both with large chromosomes. These forms are diploid and tetraploid based on x= 5 and x= 4 respectively and show a Robertsonian relationship with each other. The cytology of tetraploid (2n= 20) G. karwinskyana is confirmed and that of a diploid form (2n=10) described. The recently described G. consobrina D. R. Hunt (2n= 20) is shown to be cytologically comparable with G. karwinskyana, but to differ in significant details. Next, the cytology of G. pulchella (Kunth) Rafin., the type species of Gibasis, is described and also that of the allied G. matudae D. R. Hunt. Both G. pulchella (2n= 10, 15) and G. matudae (2n= 10) show interchange heterozygosity, with complete rings of ten chromosomes at meiosis in some plants of G. pulchella. Preliminary comments are made on the cytology of G. aguensis (Standl. & Steyerm.) Rohw. (2n= 10), another ally of G. pulchella, and on the G. linearis group, where the basic number appears to be x= 6 but two karyotype patterns have been found. A discussion of chromosome architecture in Gibasis in relation to the taxonomy of the genus concludes the paper.     

Strahlenbiologische Untersuchungen an Gammariden (Crustacea,Amphipoda)

Zusammenfassung 1. Der Einfluß einmaliger Röntgenbestrahlungen auf die Überlebenszeiten der euryhalinen AmphipodenGammarus duebeni Lilljeborg,Gammarus salinus Spooner undGammarus zaddachi Sexton wurde bei einer konstanten Temperatur von 15⁰ C und einem Salzgehalt von 10 untersucht.2. Bestrahlungen mit Dosen von 625 und 1250 R führen beiG. duebeni zum vorzeitigen Tod von nur einigen Versuchstieren, Bestrahlungen mit 2500 R und höheren Dosen zum vorzeitigen Tod aller Versuchstiere.3. BeiG. duebeni sind die strahlenempfindlicher als die , die Jungtiere strahlenempfindlicher als adulte Individuen.4.G. salinus undG. zaddachi sind strahlenempfindlicher alsG. duebeni.5. Die LD₅₀-Kurven lassen drei Bereiche erkennen. Bei mittleren Dosen ändert sich die Zeitspanne, in der 50% der Versuchstiere sterben, nur wenig oder gar nicht mit der Dosis. Bei hohen und niedrigen Dosen ist die Überlebenszeit dosisabhängig.6. Die Strahlenempfindlichkeit vonG. duebeni war im ersten Quartal des Jahres 1967, in dem die Temperaturen über den langfristigen Monatsmitteln lagen, geringer als bei Flohkrebsen, die zu einem späteren Zeitpunkt gefangen wurden oder aus Laboratoriumszuchten stammten.7. Die Häutungsvorgänge, deren Beeinflussung nur beiG. duebeni untersucht wurde, werden durch Bestrahlungen mit 1250 R oder geringeren Dosen nicht beeinflußt.8. Nach einer Bestrahlung mit 20 000 R sind 2 Tage nach der Bestrahlung nur wenige oder gar keine Häutungen möglich. Nach Bestrahlungen mit 10 000 und 5000 R erfolgen die Häutungen verspätet.9. Als Folge von Bestrahlungen mit letalen Dosen nimmt die Zahl der Häutungen um den 30. Tag nach der Bestrahlung ab.10. Die Häutungsvorgänge waren bei Tieren, die im ersten Quartal 1967 gefangen und bestrahlt wurden, weniger beeinflußbar als bei Tieren, die aus Laboratoriumszuchten stammten oder zu einem späteren Zeitpunkt gefangen wurden.11. Nach Bestrahlungen mit letalen Dosen treten zwei kritische Phasen auf. Ein Teil der mit mittleren und der größte Teil der mit hohen Dosen bestrahlten Tiere stirbt bereits in der ersten kritischen Phase. Die zweite kritische Phase wird von allen mit niedrigen Dosen bestrahlten Tieren erreicht. Tiere, die sich in der ersten kritischen Phase häuten, haben eine geringe Lebenserwartung.12. Die Überlebenszeit des einzelnen Individuums hängt außer von der Bestrahlungsdosis von dem Zeitpunkt ab, zu dem es sich innerhalb der Versuchszeit häutet.

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Radiobiological investigations on gammarids (Crustacea, Amphipoda)

Effects of single exposures of X-radiation on survival were studied inGammarus duebeni, G. salinus andG. zaddachi under constant conditions of temperature (15⁰ C) and salinity (10 ). Effects on moulting were investigated inG. duebeni. The amphipods were irradiated with doses between 625 and 20,000 R.G. salinus andG. zaddachi are equally radioresistant (LD_50/30 : 1,700 R) but less resistant thanG. duebeni (LD_50/30(males) : 3,900 R; LD_{50/30(females)} : 3,500 R). At high doses, half of the test individuals die within a few days; at medium doses survival time is dose-independent; at lower doses survival time again increases with decreasing doses up to dose-ranges (below 1,250 R forG. duebeni, 1,000 R forG. salinus andG. zaddachi), at which only a few individuals die before their natural death. Subadult gammarids are less resistant;G. duebeni of 4 to 7 mm body length have a LD_50/30 of 2,200 R. Death distribution after medium doses indicates that at least two mechanisms are involved in acute mortality. A first mortality maximum occurs shortly after irradiation; subsequently, mortality decreases for a few days, and is followed by another maximum. At lower doses no individual dies during the first critical period. Shortening of survival time at higher doses results from survival of fewer individuals to the second critical period. Few or no moults occur inG. duebeni irradiated with 20,000 R following the second day after irradiation and after the 30th day in those individuals irradiated with 2,500 to 10,000 R; moulting is delayed after exposure to 5,000 to 10,000 R. Individuals ofG. duebeni taken from the field during the mild winter 1966/67 were more resistant to radiation, and moulting was less affected, than in laboratory-reared amphipods, or in those collected in the field during other seasons. Besides on irradiation dose, survival time of an individual depends on the time of its moulting in the course of an experiment.

     

Is there a role for mannan-binding lectin in the diagnosis of inflammatory bowel disease?

Mannan-binding lectin (MBL) activates the lectin-complement pathway as part of the innate immune defence by binding to the surface of microorganisms. Therefore, MBL2 presents an interesting candidate gene for the inflammatory bowel diseases, ulcerative colitis (UC) and Crohn's disease (CD). In our study, we evaluated the MBL serum concentrations and genotypes for diagnostic and classification purposes of patients with CD and UC. The MBL serum concentration was analysed in 98 CD patients and in 83 UC patients. In total, 82 patients with inflammatory rheumatic disorders and 189 healthy individuals served as controls. All study subjects were genotyped for the MBL2 polymorphisms G54D, G57E and R52C and the NOD2 (CARD15) mutations R702W, G908R and L1007fsinsC. Neither the median MBL serum concentration nor the MBL2 genotype distribution differed significantly between cohorts. Measurement of MBL serum concentrations offers no benefit for the diagnosis of CD or UC.