bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genomewide Transcriptional Analysis of the Cold Shock Response in
Bacillus subtilis
Authors: Beckering Carsten L. , Steil Leif , Weber Michael H. W. , Völker Uwe , Marahiel Mohamed A. 
Published: October 2002

ABSTRACT

Previous studies with two-dimensional gel electrophoresis techniques revealed that the cold shock response in
Bacillus subtilis
is characterized by rapid induction and accumulation of two classes of specific proteins, which have been termed cold-induced proteins (CIPs) and cold acclimatization proteins (CAPs), respectively. Only recently, the
B. subtilis
two-component system encoded by the
desKR
operon has been demonstrated to be essential for the cold-induced expression of the lipid-modifying desaturase Des, which is required for efficient cold adaptation of the membrane in the absence of isoleucine. At present, one of the most intriguing questions in this research field is whether DesKR plays a global role in cold signal perception and transduction in
B. subtilis
. In this report, we present the first genomewide transcriptional analysis of a cold-exposed bacterium and demonstrate that the
B. subtilis
two-component system DesKR exclusively controls the desaturase gene
des
and is not the cold-triggered regulatory system of global relevance. In addition to this, we identified a set of genes that might participate as novel players in the cold shock adaptation of
B. subtilis
. Two cold-induced genes, the elongation factor homolog
ylaG
and the σ
L
-dependent transcriptional activator homolog
yplP
, have been examined by construction and analysis of deletion mutants.
Laminar hydromagnetic natural convection flow along a heated vertical surface in a stratified environment with internal heat absorption
Authors: Chamkha A J 
Published: October 2002

The problem of steady, laminar, natural convection flow along a vertical permeable surface immersed in a thermally stratified environment in the presence of magnetic-field and heat-absorption effects is studied numerically. Conditions for similarity solutions are determined for arbitrary stable and unstable thermal environment stratification. Numerical solution of the similarity equations is performed using an implicit, iterative, tri-diagonal finite-difference method. Comparison with previously published work is performed and the results are found to be in excellent agreement. The effects of Hartmann number, heat-absorption coefficient, and the wall mass-transfer parameter on the velocity and temperature profiles as well as the skin-friction coefficient and Nusselt number are presented graphically and discussed. It is found that both the magnetic-field and heat-absorption effects eliminate the occurrence of the fluid backflow and temperature deficit in the outer part of the boundary layer predicted for the nonmagnetic case. PACS Nos.: 44.20, 44.25, 47.65
State space formulation for boundary-layer magneto-hydrodynamic free convection flow with one relaxation time
Authors: Ezzat M A , Samaan A A , Bary A Abd-El 
Published: October 2002

We introduce a magnetohydrodynamic model of a boundary-layer equation for a conducting viscous fluid. The state space approach is adopted for one-dimensional problems including heat sources with one relaxation time. The resulting formulation is applied to a problem for the whole space with a plane distribution of heat sources. The reflection method together with the solution obtained for the whole space is applied to a semi-space problem with a plane distribution of heat sources located inside the fluid. Numerical results for the velocity, temperature, and induced-magnetic- and induced-electric-field distributions are given and illustrated graphically for both problems. PACS No.: 47.65+a
Transfer of the self energy into field energy of density E2/8π during assembly of a localized charge distribution from infinity
Authors: Favreau R F 
Published: October 2002

Purcell proposes that the potential energy U of a localized distribution of electrostatic charge has physical significance only as the total energy of the whole configuration. Feynman, on the other hand, favors the idea that U be localized as field energy of density E2/8π however, he points out that the demonstration of E2/8π as localized energy remains ambiguous. The article shows that by calculating the work done by the Maxwell stresses during assembly from infinity of a charge distribution of density q(r), it may be demonstrated unambiguously how the Maxwell stresses create a flow of work that distributes U into localized field energy of density E2/8π. This result supports the Feynman point of view. PACS No.: 03.50De
Spectroscopic theory for organic and organometallic conductors
Authors: Oza A T 
Published: October 2002

Here the Gaussian distributions obtained in the UVvisible and infrared spectra of inclusion compounds and charge-transfer complexes are derived theoretically. In some organometallic conductors, log α (where α is the absorption coefficient) is normally distributed. This result and the Gaussian centre-split in a compound are explained theoretically. PACS No.: 72.80Le
Eddy currents in the SternGerlach experiment
Authors: Sulcs S , Gilbert B C 
Published: October 2002

We calculate the effects of Larmor precession in the two-state SternGerlach experiment performed with silver atoms. We compare the time constants and Q factors for an oscillating magnetic-dipole moment in free space and in close proximity to an iron magnet. Numerical modelling suggests that the original SternGerlach experiment was too dissipative to have eliminated classical explanations. A recent experiment, also admitting a classical interpretation, is discussed briefly. A new experiment is proposed that should be able to confirm quantum mechanics unequivocally. PACS Nos.: 03.65Bz, 41.20Gz, 32.10Dk
L′interprétation matricielle de la théorie de Markoff classique
Authors: Perrine Serge 
Published: October 2002

On explicite l′approche de Cohn (1955) de la théorie de
Markoff. On montre en particulier comment l′arbre complet des
solutions de l′équation diophantienne associée
apparasît comme quotient du groupe GL (2, ℤ)
des
matrices 2 × 2
à coefficients entiers et de
déterminant ±1
par un sous‐groupe diédral D6
à 12 éléments. Différents développements
intermédiaires sont faits autour du groupe Aut (F 2)des automorphismes du groupe libre engendré par deux
éléments F 2.We detail the approach followed by Cohn for the Markoff theory.
We show particularly how appears the whole tree of solutions for
the associated Diophantine equation as a quotient of the group GL (2, ℤ) of matrices 2 × 2 with integer coefficients and determinant ±1 by its dihedral subgroup D6 with 12 elements. Some developments are made with the
group Aut (F 2) of automorphisms of the free group F 2 generated by two elements.
Mitochondrial DNA differences distinguishing Meloidogyne mayaguensis from the major species of tropical root-knot nematodes
Authors: Blok Vivian , Fargette Mireille , Wishart Jane , Phillips Mark , Berthier Karine 
Published: October 2002

Abstract- The mitochondrial DNA region between the COII and lRNA genes and the 63 base pair tandem repeat region have been used to differentiate and characterise Meloidogyne spp. In this study these regions have been amplified from M. mayaguensis, M. javanica, M. arenaria, M. incognita and M. hapla. Meloidogyne mayaguensis produces a unique product of 705 bp from the COII and lRNA region. Also, a product of 322 bp was produced from the 63 bp repeat region of M. mayaguensis unlike M. javanica, M. arenaria, and M. incognita that exhibit hypervariability in this region. Meloidogyne mayaguensis is a widely distributed root-knot nematode with the potential to cause great economic damage. These molecular diagnostics can be used for accurate identification of M. mayaguensis and can be used to monitor the occurrence and spread of this species, and to provide quarantine services tools to limit its dispersal.
Heterodera glycines Ichinohe, 1952 (Nematoda: Tylenchida) from Argentina. 4. Morphological and morphometrical characterisation of cysts
Authors: Doucet Marcelo , Lax Paola 
Published: October 2002

AbstractCysts of Heterodera glycines races 1 and 3, collected in two localities in Argentina, were morphologically and morphometrically characterised. Although the morphological characters showed considerable variability, they were not useful in differentiating the populations. Most of the morphometrical characters showed a certain degree of variability and presented differences from values of other known populations of the species. No significant differences were observed between the mean values of the two populations, except for the characters' body length and body diameter.
Description of Bursaphelenchus aberrans n. sp. (Nematoda: Parasitaphelenchidae) isolated from pine wood in Guangdong Province, China
Authors: Kan Zhuo , Yusheng Fang , Jun Zhao 
Published: October 2002

AbstractBursaphelenchus aberrans n. sp. is described and figured. The nematode was found in dead wood of Pinus massoniana Lamb. from one locality in Fengkai county, Guangdong Province, China. Both sexes are of moderate length ranging from 459-562 μm in the female and 390-556 μm in the male with a slender body (a = 35-42 in female and 31-48 in male) and a medium length tail (c = 13-17 in female and 14-19 in male). The stylet measures 12-14 μm long and the spicule 16-20 μm. The female vulva is located at 71-78% and has the anterior vulval lip posteriorly directed to form a small flap. The conoid tail of both sexes is ventrally curved, tapering gradually to the terminus. The male has a short, terminal, caudal ala. The spicule form is unusual for the genus in that the rostrum and condylus are fused and cap-like. A cucullus is lacking. B. aberrans n. sp. is similar to B. idius Rühm, 1956 in spicule shape, from which it differs in longer spicule length (16-20 vs 14-15 μm) and proportionately longer tail (c = 13-19 vs 23-33). It is also similar to B. bestiolus Massey, 1964 in all essential measurements, but the two species are easily differentiated by spicule shape as well as by the greater number of lateral incisures in B. aberrans n. sp. (4 vs 0).
Mycetophagy in Filenchus misellus (Andrássy, 1958) Lownsbery & Lownsbery, 1985 (Nematoda: Tylenchidae), with notes on its morphology
Authors: Kadota Ikuo , Tsukiboshi Takao , Okada Hiroaki 
Published: October 2002

AbstractPopulation growth rates on fungal colonies and morphological characteristics were investigated in a member of the genus Filenchus (Tylenchidae) collected from decomposing rice straw in Fukushima-city, northern Japan. The nematode was identified as F. misellus on the basis of the great similarity in morphological measurements to the known populations of the species. Population growth rates were measured 40 days after inoculating nematodes on to seven fungal species cultured in Petri dishes at 25oC. Growth rates were high on Chaetomium globosum and Coprinus cinereus, intermediate on Pleurotus ostreatus and Rhizoctonia solani and low on Agaricus bisporus, Fusarium oxysporum and Pythium ultimum. The ability of the nematode to feed on fungi in decomposing organic matter suggests the possibility for alternative life history strategies and greater ecological amplitude for members of Filenchus and other genera of Tylenchidae.
The African Rhigonematoidea (Nematoda: Rhigonematida). 2. Six new species of Rhigonema Cobb, 1898 (Rhigonematidae)
Authors: Hunt David 
Published: October 2002

AbstractSix new species of Rhigonema are described from the gut of various African diplopods. Rhigonema fecundum sp. n., from South Africa, is characterised by medium to fairly long body length, finely pilose anterior region, posterior margin of cephalic collar smoothly fused to body contour, Type 2 genital tract with a long ovejector, presence of a long, closely adpressed, vulval flap, tail shape in both sexes, broad spicules of medium length and complement of 23 copulatory papillae of which three pairs are subdorsal or sublateral in position. Rhigonema oxydesmi sp. n., from Oxydesmus platycercus concolor, Zaire, is characterised by medium body length, slightly projecting cephalic collar, finely pilose anterior region, Type 2 female genital tract with a long ovejector, presence of a short, adpressed, vulval flap, tail shape in both sexes, medium length spicules with a hamate capitulum and complement of 23 copulatory papillae, three pairs of which are subdorsal or sublateral in position. Rhigonema peziphorum sp. n., from Sphaerotherium selindum, Zimbabwe, is characterised by medium body length, prominently projecting cephalic collar, finely pilose anterior region, Type 1 female genital tract with a medium length ovejector, rather large eggs, absence of a prominent vulval flap, presence of a spermatophore, tail shape in both sexes, unusually short spicules with a weakly hamate capitulum and complement of 23 copulatory papillae. It is the only known Rhigonema species to form a spermatophore. Rhigonema rostrellum sp. n., from Ivory Coast, is characterised by medium body length, finely pilose anterior region, Type 2 genital tract with a very long ovejector, presence of a closely adpressed vulval flap, tail shape in both sexes, broad spicules of medium length and complement of 23 copulatory papillae of which three pairs are subdorsal or sublateral in position. Rhigonema spicatum sp. n., from Congoromus flabellatus, Zaire, is characterised by medium body length, slightly projecting cephalic collar, densely pilose anterior region, Type 2 female genital tract with a long ovejector, presence of an adpressed vulval flap, tail shape in both sexes, relatively short spicules with a hamate capitulum and complement of 23 copulatory papillae. Rhigonema xiphiurus sp. n., from Oxydesmus sicarius, Zaire, is characterised by medium body length, projecting cephalic collar, coarsely pilose anterior region with bristly microtrichs, microtrichs extending down body to beyond vulval level in female and a similar relative position in the male, Type 2 female genital tract with a long ovejector, elongate female tail, convex conoid male tail with an exceptionally well developed subulate projection, very short spicules and disposition of the 23 copulatory papillae, three pairs of which are dorsal or sublateral in position. A synopsis of the other eight nominal species of African Rhigonema is appended.
Bizarre Ichthyocephalidae (Nematoda: Rhigonematida) from Vietnam with description of Ichthyocephaloides comatu sp. n., Xystrognathus priscus gen. n., sp. n. and X. phrissus gen. n., sp. n.
Authors: Spiridonov Sergei , Van Luc Pham , Hunt David 
Published: October 2002

AbstractA bizarre new genus and three new species of parasitic Ichthyocephalidae are described and illustrated from the gut of Vietnamese diplopods. Ichthyocephaloides comatus sp. n., an atypical member of a predominantly Australasian genus, is characterised by the very posterior vulva (V = 92), single genital tract lacking a vaginal diverticulum, dorsal microtrichs long and curled but ventral microtrichs short and bristle-like, basal bulb barely wider than isthmus, short, conoid tail in both sexes, complement of 20 copulatory papillae, five pairs being precloacal and five pairs postcloacal, and spicule form and relative size. The extremely posterior vulva, lack of vaginal diverticulum, short, conoid tail in both sexes and presence of only 20 copulatory papillae immediately distinguish this species from I. dasyacanthus Hunt & Sutherland, 1984, I. xesmostoma Hunt, 1994, I. eurystoma Hunt, 1999 and I. longisaccus Hunt, 1999, all of which have a more anterior vulva, genital tract with a well developed vaginal diverticulum, a longer, subulate tail in both sexes and more numerous copulatory papillae. Xystrognathus gen. n., a highly unusual genus of ichthyocephalid, has an apparently primitive suite of characters and probably represents the oldest lineage of the family yet discovered. It is characterised within the Ichthyocephalidae by having 23 copulatory papillae, three of the postcloacal pairs being subdorsal or sublateral in position plus a single midventral papilla (well developed in the type, less so in the other species) on the anterior cloacal lip, a very posteriorly located vulva, digonant female genital system lacking a vaginal diverticulum, isomorphic and more or less isometric spicules and isthmus ca the same length or shorter than the height of the basal bulb. Xystrognathus gen. n. is the only genus known within the Ichthyocephalidae where the copulatory papillae are arranged in a pattern typical of the Afro-Asian Rhigonematoidea. It may represent the ancestral lineage of the family. Xystroganthus priscus gen. n., sp. n. and X. phrissus gen. n., sp. n. are described and differentiated from each other on the basis of female tail length and shape, development of the midventral papilla and form of the anterior vulval lip (deeply bilobed in the latter species).
A software tool as an aid to the identification of species of Longidorus Micoletzky, 1922 (Nematoda: Dorylaimoidea)
Authors: Tiefenbrunner Wolfgang , Tiefenbrunner Astrid , Tiefenbrunner Martin , Wahra Andreas 
Published: October 2002

AbstractThe genus Longidorus includes plant-parasitic and virus vector species and is therefore of great practical importance. This paper describes a computer identification tool that uses only morphometrical data. The data used are the same as those of the polytomous keys of Chen et al. (1997) or Arias and Bravo (1997). For each specimen examined, the software computes the similarity to all 116 species of the genus accepted by Chen et al. (1997) and Loof and Chen (1999). In addition, a graphical multivariate presentation procedure, based on a distance matrix, is described to rapidly compare analysed specimens with reference data from the literature. A later version of the programme has been adapted for analysis of the genus Xiphinema.
First record of the genus Bursaphelenchus Fuchs, 1937 in Thailand and description of B. thailandae sp. n. (Nematoda: Parasitaphelenchidae)
Authors: Braasch Helen , Braasch-Bidasak Rainulf 
Published: October 2002

AbstractWood samples were taken from pine trees in the mountainous region between Pai and Maehongson in northern Thailand. Four species of Bursaphelenchus were recovered from the samples: Bursaphelenchus hylobianum, B. mucronatus, B. aberrans and B. thailandae sp. n. Bursaphelenchus thailandae sp. n. is most similar to B. sychnus but also shows similarities with B. ruehmi, B. hunanensis and B. steineri. It has a relatively small stylet lacking distinct basal knobs and a lateral field with four lines. The female has more or less protruding vulval lips and a slim, conoid, tail. The relatively small and delicate spicules show a distinctive darker sector and lack a cucullus. The male tail has a very small terminal 'bursa'. Bursaphelenchus thailandae sp. n. is tentatively included in the B. fungivorus -group of the genus Bursaphelenchus. Brief notes and morphometric data are given for the other species found. The record of B. mucronatus indicates that conditions for the establishment of the closely related B. xylophilus (the cause of pine wilt disease) may be suitable in Thailand and strict phytosanitary measures are therefore advisable.
Nothacrobeles borregi n. sp. (Nematoda: Cephalobidae) from Anza Borrego, California and N. laticollaris (De Ley & Vandebroek, 1992) n. comb.
Authors: Baldwin James , Poiras Larisa , Bumbarger Daniel , Mundo-Ocampo Manuel 
Published: October 2002

AbstractNothacrobeles borregi n. sp. is described from blow-sand in the vicinity of the roots of creosote bush (Larrea tridentata) from Anza Borrego State Park, San Diego, California. The new species is distinctive from all others of the genus by the specific morphology of the labial probolae and lips, as viewed with both interference light and scanning electron microscopy. The probolae include a basal ridge unique by its large size, smooth rim (lacking tines), and unusual large triangular platelet projections on each side; the probolae are also distinctive in having a knob-like ledge separate and posterior to the basal ridge. Nothacrobeles borregi n. sp. provides a new insight into homology of characters important for addressing problems with generic level classification in Cephalobinae. These hypotheses of homology suggest a basis for transferring N. laticollaris n. comb. (syn. Cervidellus laticollaris). Characteristics of Nothacrobeles in relation to Cervidellus and Stegelletina are discussed.
Notes on the genus Cactodera Krall & Krall, 1978 and proposal of Betulodera betulae gen. nov., comb. nov. (Nematoda: Heteroderidae)
Authors: Sturhan Dieter 
Published: October 2002

AbstractBased mainly on an analysis of the host ranges of the species presently placed in Cactodera, sensu lato, and of selected morphological characteristics, an attempt is made to improve the definition of the genus which, after exclusion of C. betulae and C. johanseni, is considered to be monophyletic. The host range of Cactodera, sensu stricto, appears to be restricted to the subclass Caryophyllidae with the ten known species showing an adaptive radiation on host genera in five families of the orders Caryophyllales and Polygonales. This may be a result of co-evolution. Cactodera betulae cannot be assigned to any of the presently recognised genera of cyst-forming nematodes and therefore Betulodera gen. nov. is proposed with B. betulae comb. nov. as the type and only species. The relationship of Betulodera gen. nov. to other genera of Heteroderidae and to some undescribed heteroderid species has still to be evaluated. The new genus is characterised by circumfenestrate cysts with only a slightly protruding vulval cone, three incisures in the lateral field of the second-stage juveniles and presence of phasmids in the males. The hosts are in unrelated plant orders and subclasses. Cactodera aquatica, a species inquirenda, is returned to the genus Heterodera and Heterodera johanseni (Sharma et al. , 2001) comb. nov. is proposed for C. johanseni.