bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Points in the Forelimb Fictive Locomotor Cycle and Motor Coordination: Evidence From the Effects of Tonic Proprioceptive Perturbations in the Cat
Authors: Saltiel Philippe , Rossignol Serge
Published: August 2004

During locomotion, the limbs of one girdle must remain coordinated in different conditions. To understand the neural mechanisms underlying such coordination, tonic protraction/ retraction of one shoulder or tonic flexion/extension of one elbow was applied during fictive locomotion in high decerebrate and paralyzed cats. We studied bilateral changes in the timing and amplitude characteristics of electroneurographic (ENG) muscle nerve bursts of cleidobrachialis (ClB, elbow flexor and shoulder protractor) and the two heads of triceps (long, TriLo, elbow extensor and shoulder retractor and lateral, TriLa, elbow extensor). Perturbations induced bilateral changes in amplitude and timing of ENG bursts that were anchored on certain critical points in the cycle. These critical points could correspond to morphological characteristics within the bursts or to bilateral onsets or offsets of ENG bursts. For instance, in response to shoulder and elbow perturbations, burst changes occur in relation to a fixed point, labeled point C, occurring at about mid-extensor burst and corresponding to a simultaneous abrupt increase in TriLa amplitude and a decrease in amplitude of contralateral ClB. At a point labeled B, corresponding to about mid-flexor burst, ClB amplitude increases above control with elbow extension or starts decreasing with shoulder protraction. Although cycle reorganization is specific for each type of tonic perturbation, a common feature is that the changes in burst duration are achieved through discrete shifts between consecutive critical points. It is postulated that coordination may be based on a discrete temporal cycle structure along which critical points delimiting burst components are shifted.
Movement-Related Discharge in the Cerebellar Nuclei Persists After Local Injections of GABAA Antagonists
Authors: Holdefer R. N. , Houk J. C. , Miller L. E.
Published: August 2004

Limb movement-related neurons in the cerebellar nuclei (CN) typically produce bursts of discharge in association with movement. Consequently, given the inhibitory nature of the Purkinje cell (PC) projection to CN, it is puzzling that only a minority of movement-related PCs pause; the majority burst. Some of the movement-related CN activity may be the result of excitation from collaterals of mossy and climbing fiber projections to the cerebellar cortex. The only other input to CN is diffuse and neuromodulatory, from locus ceruleus and raphe nuclei. To investigate the role of the excitatory mossy fiber input, single units in CN were recorded in macaque monkeys during the performance of reaching and manipulation tasks, before and after blocking the PC input with local microinjections of GABAA antagonists (bicuculline or SR95531). After these injections, the movement-related modulation of CN discharge was greater and began earlier, compared with the modulation in the preinjection group of neurons. These observations indicate that an important excitatory drive is provided by extracerebellar inputs to CN, most likely from collaterals of mossy fibers. PCs may serve primarily to regulate this activity, by either pausing or bursting as necessary.
Stereoscopic Processing of Absolute and Relative Disparity in Human Visual Cortex
Authors: Neri Peter , Bridge Holly , Heeger David J.
Published: August 2004

Stereoscopic vision relies mainly on relative depth differences between objects rather than on their absolute distance in depth from where the eyes fixate. However, relative disparities are computed from absolute disparities, and it is not known where these two stages are represented in the human brain. Using functional MRI (fMRI), we assessed absolute and relative disparity selectivity with stereoscopic stimuli consisting of pairs of transparent planes in depth in which the absolute and relative disparity signals could be independently manipulated (at a local spatial scale). In experiment 1, relative disparity was kept constant, while absolute disparity was varied in one-half the blocks of trials (“mixed” blocks) and kept constant in the remaining one-half (“same” blocks), alternating between blocks. Because neuronal responses undergo adaptation and reduce their firing rate following repeated presentation of an effective stimulus, the fMRI signal reflecting activity of units selective for absolute disparity is expected to be smaller during “same” blocks as compared with “mixed” ones. Experiment 2 similarly manipulated relative disparity rather than absolute disparity. The results from both experiments were consistent with adaptation with differential effects across visual areas such that 1) dorsal areas (V3A, MT+/V5, V7) showed more adaptation to absolute than to relative disparity; 2) ventral areas (hV4, V8/V4α) showed an equal adaptation to both; and 3) early visual areas (V1, V2, V3) showed a small effect in both experiments. These results indicate that processing in dorsal areas may rely mostly on information about absolute disparities, while ventral areas split neural resources between the two types of stereoscopic information so as to maintain an important representation of relative disparity.
Effect of Transcranial Magnetic Stimulation on Bimanual Movements
Authors: Chen Jen-Tse , Lin Yung-Yang , Shan Din-E , Wu Zin-An , Hallett Mark , Liao Kwong-Kum
Published: August 2004

Transcranial magnetic stimulation (TMS) of the motor cortex can interrupt voluntary contralateral rhythmic limb movements. Using the method of “resetting index” (RI), our study investigated the TMS effect on different types of bimanual movements. Six normal subjects participated. For unimanual movement, each subject tapped either the right or left index finger at a comfortable rate. For bimanual movement, index fingers of both hands tapped in the same (in-phase) direction or in the opposite (antiphase) direction. TMS was applied to each hemisphere separately at various intensities from 0.5 to 1.5 times motor threshold (MT). TMS interruption of rhythm was quantified by RI. For the unimanual movements, TMS disrupted both contralateral and ipsilateral rhythmic hand movements, although the effect was much less in the ipsilateral hand. For the bimanual in-phase task, TMS could simultaneously reset the rhythmic movements of both hands, but the effect on the contralateral hand was less and the effect on the ipsilateral hand was more compared with the unimanual tasks. Similar effects were seen from right and left hemisphere stimulation. TMS had little effect on the bimanual antiphase task. The equal effect of right and left hemisphere stimulation indicates that neither motor cortex is dominant for simple bimanual in-phase movement. The smaller influence of contralateral stimulation and the greater effect of ipsilateral stimulation during bimanual in-phase movement compared with unimanual movement suggest hemispheric coupling. The antiphase movements were resistant to TMS disruption, and this suggests that control of rhythm differs in the 2 tasks. TMS produced a transient asynchrony of movements on the 2 sides, indicating that both motor cortices might be downstream of the clocking command or that the clocking is a consequence of the 2 hemispheres communicating equally with each other.
Real-Coded Memetic Algorithms with Crossover Hill-Climbing
Authors: Lozano Manuel , Herrera Francisco , Krasnogor Natalio , Molina Daniel
Published: August 2004

This paper presents a real-coded memetic algorithm that applies a crossover hill-climbing to solutions produced by the genetic operators. On the one hand, the memetic algorithm provides global search (reliability) by means of the promotion of high levels of population diversity. On the other, the crossover hill-climbing exploits the self-adaptive capacity of real-parameter crossover operators with the aim of producing an effective local tuning on the solutions (accuracy). An important aspect of the memetic algorithm proposed is that it adaptively assigns different local search probabilities to individuals. It was observed that the algorithm adjusts the global/local search balance according to the particularities of each problem instance. Experimental results show that, for a wide range of problems, the method we propose here consistently outperforms other real-coded memetic algorithms which appeared in the literature.
Refinement of gene expression patterns in the earlyXenopusembryo
Authors: Wardle Fiona C. , Smith James C.
Published: August 2004

During blastula and gastrula stages of Xenopus development, cells become progressively and asynchronously committed to a particular germ layer. We have analysed the expression of genes normally expressed in ectoderm,mesoderm or endoderm in individual cells from early and late gastrula embryos,by both in situ hybridization and single-cell RT-PCR. We show that at early gastrula stages, individual cells in the same region may express markers of two or more germ layers, and `rogue' cells that express a marker outside its canonical domain are also observed at these stages. However, by the late gastrula stage, individual cells express markers that are more characteristic of their position in the embryo, and `rogue' cells are seen less frequently. These observations exemplify at the gene expression level the observation that cells of the early gastrula are less committed to one germ layer than are cells of the late gastrula embryo. Ectodermal cells induced to form mesendoderm by the addition of Activin respond by activating expression of different mesodermal and endodermal markers in the same cell, recapitulating the response of marginal zone cells in the embryo.
Essential role of Gata transcription factors in sympathetic neuron development
Authors: Tsarovina Konstantina , Pattyn Alexandre , Stubbusch Jutta , Müller Frank , van der Wees Jacqueline , Schneider Carolin , Brunet Jean-Francois , Rohrer Hermann
Published: August 2004

Sympathetic neurons are specified during their development from neural crest precursors by a network of crossregulatory transcription factors, which includes Mash1, Phox2b, Hand2 and Phox2a. Here, we have studied the function of Gata2 and Gata3 zinc-finger transcription factors in autonomic neuron development. In the chick, Gata2 but not Gata3 is expressed in developing sympathetic precursor cells. Gata2 expression starts after Mash1, Phox2b, Hand2 and Phox2a expression, but before the onset of the noradrenergic marker genes Th and Dbh, and is maintained throughout development. Gata2 expression is affected in the chick embryo by Bmp gain- and loss-of-function experiments, and by overexpression of Phox2b, Phox2a, Hand2 and Mash1. Together with the lack of Gata2/3 expression in Phox2b knockout mice,these results characterize Gata2 as member of the Bmp-induced cluster of transcription factors. Loss-of-function experiments resulted in a strong reduction in the size of the sympathetic chain and in decreased Th expression. Ectopic expression of Gata2 in chick neural crest precursors elicited the generation of neurons with a non-autonomic, Th-negative phenotype. This implies a function for Gata factors in autonomic neuron differentiation,which, however, depends on co-regulators present in the sympathetic lineage. The present data establish Gata2 and Gata3 in the chick and mouse,respectively, as essential members of the transcription factor network controlling sympathetic neuron development.
Differential large-scale chromatin compaction and intranuclear positioning of transcribed versus non-transcribed transgene arrays containing β-globin regulatory sequences
Authors: Dietzel Steffen , Zolghadr Kourosh , Hepperger Claudia , Belmont Andrew S.
Published: August 2004

Previous work has demonstrated a more decondensed large-scale chromatin structure and a more internal nuclear position for gene-rich versus gene-poor chromosome regions. Here, we show that large-scale chromatin opening and changes in intranuclear positioning of chromosome regions can be induced by normal levels of endogenous transcription factors acting on mammalian regulatory sequences. We transfected mouse erythroleukemia cells with a 15 kbp plasmid containing a lac operator repeat plus β-globin regulatory sequences driving a β-galactosidase reporter gene. After green-fluorescent-protein/lac-repressor fusion-protein binding or after fluorescence in situ hybridization, the volume and location of the transgene array signal were measured. With both detection methods, we found that the volume was severalfold larger when transcription was on. While silent transgene arrays were located close to the nuclear membrane, we observed a significantly more internal position for the transcriptionally active state. Our results indicate that both large-scale chromatin decondensation and changes in nuclear positioning as observed for large, complex gene-rich chromosome regions can be reproduced by endogenous regulatory sequences acting within simple repetitive transgene arrays.
Spatio-temporal activation of Smad1 and Smad5 in vivo: monitoring transcriptional activity of Smad proteins
Authors: Monteiro Rui M. , de Sousa Lopes Susana M. Chuva , Korchynskyi Olexander , Dijke Peter ten , Mummery Christine L.
Published: August 2004

Signaling by bone morphogenetic proteins is essential for a wide variety of developmental processes. Receptor-regulated Smad proteins, Smads 1 and 5, are intracellular mediators of bone morphogenetic protein signaling. Together with Smad4, these proteins translocate to the nucleus and modulate transcription by binding to specific sequences on the promoters of target genes. We sought to map transcriptional Smad1/5 activity in development by generating embryonic stem cell lines carrying a Smad1/5-specific response element derived from the Id1 promoter coupled to β-galactosidase or luciferase as reporters. Three independent lines (BRE-lac1, BRE-lac2 and BRE-luc) have shown the existence of an autocrine bone morphogenetic protein signaling pathway in mouse embryonic stem cells. Reporter activity was detected in chimeric embryos, suggesting sensitivity to physiological concentrations of bone morphogenetic protein. Reporter activity in embryos from transgenic mouse lines was detected in tissues where an essential role for active bone morphogenetic protein signaling via Smads 1 or 5 had been previously established. We have thus generated, for the first time, an in vivo readout for studying the role of Smad1/5-mediated transcriptional activity in development.
lis-1is required for dynein-dependent cell division processes inC. elegansembryos
Authors: Cockell Moira M. , Baumer Karine , Gönczy Pierre
Published: August 2004

We investigated the role of the evolutionarily conserved protein Lis1 in cell division processes of Caenorhabditis elegans embryos. We identified apparent null alleles of lis-1, which result in defects identical to those observed after inactivation of the dynein heavy chain dhc-1, including defects in centrosome separation and spindle assembly. We raised antibodies against LIS-1 and generated transgenic animals expressing functional GFP–LIS-1. Using indirect immunofluorescence and spinning-disk confocal microscopy, we found that LIS-1 is present throughout the cytoplasm and is enriched in discrete subcellular locations, including the cell cortex, the vicinity of microtubule asters, the nuclear periphery and kinetochores. We established that lis-1 contributes to, but is not essential for, DHC-1 enrichment at specific subcellular locations. Conversely, we found that dhc-1, as well as the dynactin components dnc-1 (p150Glued) and dnc-2 (p50/dynamitin), are essential for LIS-1 targeting to the nuclear periphery, but not to the cell cortex nor to kinetochores. These results suggest that dynein and Lis1, albeit functioning in identical processes, are targeted partially independently of one another.
Novel small GTPase subfamily capable of associating with tubulin is required for chromosome segregation
Authors: Okai Takuro , Araki Yasuhiro , Tada Minoru , Tateno Toshiyuki , Kontani Kenji , Katada Toshiaki
Published: August 2004

The small GTPase superfamily, which includes the Ras, Rho/Rac, Rab, Arf and Ran subfamilies, serves as a signal transducer to regulate cell proliferation and differentiation, actin cytoskeleton, membrane trafficking, and nuclear transport. Here, we identify novel GTPases (human Gie1 and Gie2) that form a distinct subfamily of the small GTPases in terms of their sequences and intracellular function. Gie stands for `novel GTPase indispensable for equal segregation of chromosomes', and this subfamily is conserved in multicellular organisms. Expression of dominant-negative Gie mutants in mammalian cells or knockdown of Gie transcripts using RNA interference in Drosophila S2 cells induced abnormal morphology in the chromosome segregation. Gie protein has ability to bind to tubulin and localizes with microtubules on the spindle mid-zone in late mitosis. Furthermore, overexpression of Gie mutants that lack putative effector domains but have tubulin-binding ability induced micronucleus formation. Thus, this is the first report showing that a small GTPase subfamily capable of associating with microtubules might be involved in chromosome segregation.
Nitric oxide negatively regulates proliferation and promotes neuronal differentiation through N-Myc downregulation
Authors: Ciani Elisabetta , Severi Sabina , Contestabile Andrea , Bartesaghi Renata , Contestabile Antonio
Published: August 2004

Nitric oxide (NO) has been found to act as an important negative regulator of cell proliferation in several systems. We report here that NO negatively regulates proliferation of neuronal cell precursors and promotes their differentiation by downregulating the oncogene N-Myc. We have studied this regulatory function of NO in neuroblastoma cell lines (SK-N-BE) and in primary cerebellar granule cell cultures. In a neuronal NO synthase (nNOS) overexpressing neuroblastoma cell line exposed to the differentiative action of retinoic acid, NO slowed down proliferation and accelerated differentiation towards a neuronal phenotype. This effect was accompanied by a parallel decrease of N-Myc expression. Similar results could be obtained in parental SK-N-BE cells by providing an exogenous source of NO. Pharmacological controls demonstrated that NO's regulatory actions on cell proliferation and N-Myc expression were mediated by cGMP as an intermediate messenger. Furthermore, NO was found to modulate the transcriptional activity of N-Myc gene promoter by acting on the E2F regulatory region, possibly through the control of Rb phosphorylation state, that we found to be negatively regulated by NO. In cerebellar granule cell cultures, NOS inhibition increased the division rate of neuronal precursors, in parallel with augmented N-Myc expression. Because a high N-Myc expression level is essential for neuroblastoma progression as well as for proliferation of neuronal precursors, its negative regulation by NO highlights a novel physiopathological function of this important messenger molecule.
The genetics of Pak
Authors: Hofmann Clemens , Shepelev Mikhail , Chernoff Jonathan
Published: August 2004

p21-activated kinases (Paks) are a highly conserved family of enzymes that bind to and are activated by small GTPases of the Cdc42 and Rac families. With the notable exception of plants, nearly all eukaryotes encode one or more Pak genes, indicating an ancient origin and important function for this family of enzymes. Genetic approaches in many different experimental systems, ranging from yeast to mice, are beginning to decipher the different functions of Paks. Although some of these functions are unique to a given organism, certain common themes have emerged, such as the activation of mitogen-activated protein kinase (MAPK) cascades and the regulation of cytoskeletal structure through effects on the actin and tubulin cytoskeletons.
Qualitätsmanagement in den medizinischen Laboratorien der Schweiz / Quality management in Swiss diagnostic laboratories
Authors: Hänseler E. , Siegrist H. P.
Published: August 2004

Since 1994, efforts to maintain quality assurance in
Swiss medical laboratories have had a legal basis in
Switzerland which allows the enforcement of measures
to improve efficiency in all types of laboratories. Proof of
an adequate quality assurance program is a prerequisite
for all laboratories which are reimbursed by the social
security system.
The first phase defined measures with regard to quality
assurance and quality control. In the second phase, a
continuous education program was established which
allowed people with different educational backgrounds
PhD, MD, pharmacist) to enter the program.
In Switzerland, half of the analytical volume of medical
diagnostics is carried out in the practitioners laboratory.
By establishing a continuous education program especially
designed for practitioners and by enlarging the
number of hours of training for the students in medical
school, the basis of laboratory medicine should become
familiar to care providers as well.
Using random spot checks, the laboratories are
checked annually to see if they comply with legal requirements.
Laboratories which do not meet the minimum requirements are subject to sanctions: these are primarily
of educational nature, but can result in the suspension
of remuneration by the social security system.
More than 100 laboratories from different disciplines of
laboratory medicine were accredited on a voluntary basis
by the end of 2003. The number of newly accredited laboratories
has been declining since 2001, since most of
the labs which initially wanted to implement a quality
management system are already accredited. As the next
step, the authorities intend to improve the quality management
of the pre-analytical phase.
Qualitätssichernde Maßnahmen im Rahmen des Point-of-Care-Testing (POCT) / Strategies for quality assurance in point-of-care testing
Authors: Tiran A. , Hubmann M. , Schweiger C.
Published: August 2004

The guideline “Measures of quality assurance for point-of-care testing (POCT)” was developed for a university
hospital. It covers the special requirements of POCT
together with the basic requirements of quality management
systems in the medical laboratory. As an example,
the guideline may help with the implementation of a
POCT quality assurance system in other hospitals.
Prognostic value of soluble interleukin-2 receptor plasma levels in non-responders with chronic hepatitis C treated with pegylated interferon alpha 2b and ribavirin / Der prognostische Wert von Plasmaspiegeln des löslichen Interleukin-2-Rezeptors in mit pegyliertem Interferon alpha 2b und Ribavirin behandelten Non-Respondern mit chronischer Hepatitis C
Authors: Griga T. , Schmiegel W. , Henke H.
Published: August 2004

In patients with chronic HCV infection, a significant elevation
in serum levels of soluble interleukin-2 receptor
has been shown. Different results have been found for
the efficacy of interferon therapy.

We studied the plasma levels of the soluble interleukin-2 receptor in primary non-responders who had undergone
a re-treatment with pegylated interferon alpha 2b
and ribavirin to evaluate the differences between
responders and non-responders to this therapy. The
study was performed on 15 patients with chronic HCV
infection who had shown no response to primary therapy
and on 15 healthy volunteers. The plasma levels of the
soluble interleukin-2 receptor were determined using
enzyme-linked immunosorbent assay. The patients
underwent a therapy with pegylated interferon alpha 2b
and ribavirin for 48 weeks. The plasma levels of the soluble
interleukin-2 receptor were determined during therapy,
and in the case of response, 24 weeks after therapy.
Four out of 15 patients showed a sustained virological
response after therapy. Before re-treatment, the soluble
interleukin-2 receptor plasma levels were significantly
higher in patients who showed no response to re-treatment
with pegylated interferon alpha 2b/ribavirin compared
with healthy controls (1552 [932−2225] pg/ml vs.
884 [489−1704] pg/ml, p = 0.003). There was no significant
difference in soluble interleukin-2 receptor plasma
levels before therapy between patients with sustained
virological response (932 [840−1339] pg/ml) and healthy
controls. Therapy had to be stopped in one patient due
to thrombocytopenia.

Plasma levels of the soluble interleukin-2 receptor
seem to be a prognostic marker of sustained virological
response in non-responders prior to a re-treatment with
pegylated interferon alpha 2b and ribavirin.
Field incidence of rice yellow mottle virus, genus sobemovirus on rice and a weed species in the field in Cote d'Ivoire
Authors: Abo M. E. , Alegbejo M. D. , Sy A. A. ,   et al.
Published: August 2004

Field surveys carried out between 1996 and 1997 in Cote d'Ivoire on weed hosts to detect the occurrence and subsistence of rice yellow mottle virus (RYMV) in nature show that rice and Echinochloa crus-pavonis (Link) harbour the virus. There was consistent detection of RYMV throughout the sampling period in rice samples mostly from the lowland varieties. It is thus evident that RYMV subsists more on rice in nature. This could serve as a source of inoculum for infection to newly transplanted rice in the field.
Plant height and height of the main ear in maize (Zea mays L.) at different locations and different plant densities
Authors: Gyenes-Hegyi Z. , Pók I. , Kizmus L. ,   et al.
Published: August 2004

The plant height and the height of the main ear were studied over two years in twelve single cross maize hybrids sown at three different plant densities (45, 65 and 85 thousand plants/ha) at five locations in Hungary (Keszthely, Gönc, Gyöngyös, Sopronhorpács, Martonvásár). The results revealed that plant height and the height of the main ear are important variety traits and are in close correlation with each other. It was found that the hybrids grew the tallest when the genetic distance between the parental components was greatest (Mv 4, Mv 5). The height of the main ear was also the greatest in these hybrids, and the degree of heterosis was highest (193% for plant height, 194% for the height of the main ear). The shortest hybrids were those developed between related lines (Mv 7, Mv 11). In this case the heterosis effect was the lowest for both plant height (128%) and the height of the main ear (144%). The ratio of the height of the main ear to the plant height was stable, showing little variation between the hybrids (37–44%). As maize is of tropical origin it grows best in a humid, warm, sunny climate. Among the locations tested, the Keszthely site gave the best approximation to these conditions, and it was here that the maize grew tallest. The dry, warm weather in Gyöngyös stunted the development of the plants, which were the shortest at this location. Plant density had an influence on the plant size. The plants were shortest when sown at a plant density of 45,000 plants/ha, and the main ears were situated the lowest in this case. At all the locations the plant and main ear height rose when the plant density was increased to 65,000 plants/ha. At two sites (Gönc and Sopronhorpács) the plants attained their maximum height at the greatest plant density (85,000 plants/ha). In Keszthely there was no significant difference between these two characters at plant densities of 65 and 85 thousand plants/ha, while in Gyöngyös and Martonvásár the greatest plant density led to a decrease in the plant and main ear height. The year had a considerable effect on the characters tested.
Modified joint scaling test for evaluating the effect of the level of heterozygosity of the female parent
Authors: Marton L. C. , Kuti C.
Published: August 2004

In earlier studies the inheritance of chilling tolerance in maize was investigated using the joint scaling test on six genotypes forming a systematic genetic series - P1, P2, F1, F2, B1, B2. The values of some genotypes (P1, P2, F1) were overestimated by the model, while those of the other genotypes (F2, B1, B2) were underestimated. It was thought that this could be due to the effect of the level of heterozygosity in the female parent. The level of heterozygosity of the female parent in the P1, P2, F1 genotypes is 0%, while in the F2, B1, B2 genotypes it is 100%. In addition to the m, [d] and [h] parameters, a new parameter, [fh] (female heterozygosity) was thus introduced. Analysis carried out with the new model confirmed a significant female heterozygosity effect.
Genotype × environment interaction of seed yield and seed index in bitter vetch
Authors: Turk M. A.
Published: August 2004

Nine bitter vetch selection lines were evaluated in three successive years to determine their yield and seed index (100-seed weight) stabilities, based on three parameters: phenotypic index (P), regression coefficient (bi), and least deviation from regression (S2 di). The line Sel. 2517 (L7) was identified as the most stable one for the growing seasons, while Sel. 2509 (L2) and Sel. 2511 (L4) were found to be stable for seed yield under favourable climatic conditions. For seed index Sel. 2515 (L6) was identified as the most stable line. Selection line 2513 (L5), which originated from Cyprus, had the highest degree of responsiveness to changing environments.
Lentil (Lens culinaris Medic.) productivity as influenced by rate and method of phosphate placement in a Mediterranean environment
Authors: Tawaha A. M. , Turk M. A.
Published: August 2004

The influence of rates and methods of phosphate placement on the productivity of lentil (Lens culinaris Medic.) was studied in a two-field experiment. Each experiment consisted of four levels of phosphorus (0, 17.5, 35.0 and 52.5 kg P ha-1) and two methods of placement (banding and broadcast). Lentils grown at Kufran had higher seed yield than those grown at Houfa. Seed yield, pods plant-1 and branches plant-1 increased significantly in both locations after phosphorus application compared with the control. Seed yield was significantly greater with band placement than with the broadcast method of phosphorus application at both locations.
Effects of salinity on water use efficiency and its components in chickpea (Cicer arietinum L.)
Authors: Gholipoor M. , Soltani A. , Shekari F. , Shekari Fb.
Published: August 2004

In order to investigate the effects of salinity on water use efficiency (WUE) and its components, i.e. transpiration efficiency (TE), uptake efficiency (UE) and harvest index (HI), in chickpea, four chickpea cultivars were grown in pots containing soils with 0.8 (C=control), 2 (S1) and 3.9 (S2) dSm-1 salinity. At S1, the WUE of all cultivars increased, but subsequently decreased with increasing salinity. The relative contribution of TE to the sum of squares of WUE was relatively higher than UE and HI. Therefore, the TE component had a more crucial improving effect on WUE than the other two WUE components. At the S2 level, UE and HI were lower than in the control. Path analysis revealed that the simultaneous selection of non-stressed cultivars for higher TE and HI, and of salt-stressed cultivars for better TE and UE should be practised to improve WUE under non-stressed and high stress conditions, respectively. With respect to ion contents, the screening of salt-subjected cultivars for higher K+ content in the roots might result in an increase in both the total dry matter (TDM) and WUE of chickpea under stress conditions. Additionally, the selection of non-stressed cultivars on the basis of higher shoot Ca2+ concentration might stimulate the TDM and WUE of chickpea under non-stressed conditions.
Effect of silicon at panicle initiation on the growth of rice (Var. ADT-36) plants at different growth stages
Authors: Arthanari P. M. , Gnanamoorthy P. , Ramasamy S.
Published: August 2004

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India during the Rabi (November 1997-March 1998) and Kharif (July 1998-November 1998) seasons to identify the effect of silicon at panicle initiation on the growth of rice plant (Variety ADT-36) at different growth stages. Furnace slag was applied as a silicon source at 2 t/ha at the panicle initiation stage along with other nutrients. The dry matter production was recorded at the active tillering, panicle initiation, booting, flowering, one week after flowering and maturity stages in both the seasons. The total dry matter production was greater in the Kharif season than in the Rabi season. The application of slag at the panicle initiation stage along with N and K at the flowering stage had a significant influence over the dry matter production. A similar trend was observed in both the seasons. The silicon uptake was recorded at the panicle initiation and maturity stages. About 30-40% of the silicon absorbed during the early stages and the maturity stage was present in the shoot, whereas 20-30 % of the silicon absorbed during the maturity stages was present in the leaf blades. Based on the results, it is concluded that the supply of silicon during the panicle initiation stage is most important for plant growth.
Integration of transformation technology and traditional breeding of cereals
Authors: Bedő Z.
Published: August 2004

The integration of conventional plant breeding and plant transformation is necessitated by the fact that, prior to the gene technological phase, traditional breeding methods have to be used to develop agronomically valuable homozygous genotypes which can then be modified for a gene or genome segment by means of gene manipulation techniques. Once the genotype selected by means of conventional breeding has been transformed, traditional methods are again used to examine the agronomic properties of the lines developed from the transgenic plant and the stability of the transgenic variety, following the DUS criteria elaborated by UPOV. The seed production of genetically modified plant varieties must be safe and economical and the cultivation of the variety should contribute to the sustainable development of up-to-date crop production.
Development of female and male gametophytes in cereal species
Authors: Timár I. , Pónya Z. , Szabó L ,   et al.
Published: August 2004

The first steps in studies on the female and male gametophytes of wheat involved the light microscope analysis of semi-thin sections of embryo sacs containing egg-cells developingin planta. The information thus obtained on the development of the egg-cell from its initial formation to maturity contributed to the successful isolation of egg-cells. The morphological and ultrastructural details of egg-cells isolated 3, 6, 9, 12, 15 and 18 days after emasculation were examined to determine the function of the female gametophyte and its suitability for micromanipulation. A sufficient number of gametoplasts in the right stage of development are required for the successful microinjection andin vitrofusion of egg-cells and male gametes. No data are yet available on the fusiogenicity of wheat egg-cells in various stages of development. Variousin vitrofertilisation and microinjection techniques could be of service in gamete fusion experiments aimed at the creation of interspecific and intergeneric hybrids which do not occur in nature due to sporophytic incompatibility. The results acquired in investigations on immature embryos can be used for the study of embryos developing from egg-cells fertilisedin vitro.
Zinc, lead, cadmium and copper concentrations of meadow plants along the M3 motorway
Authors: Naszradi T. , Németh N. , Köles P. ,   et al.
Published: August 2004

The toxic heavy metal concentrations were investigated in plants in a meadow located 51 kilometres from Budapest along the M3 motorway. The field is regularly harvested, and the hay is used as fodder. The area under investigation is situated directly alongside the protecting fence of the motorway. The soil of the area is classified as chernozem brown forest soil. In 2000 approximately 22,860 cars per month travelled on the motorway. The plant samples were taken at a distance of 5, 10, 25, 50 and 100 metres from the motorway. At each distance 10 samples were collected. After digestion with hydrogen peroxide and nitric acid the zinc, lead, cadmium and copper contents of the samples were analysed using an ICP spectrophotometer. After analysing the data it was established that for each of the heavy metals the concentration of metal in the plant samples decreased as the distance from the motorway grew. The measured zinc, cadmium and copper concentrations were similar to those reported by other authors (on average 44.9, 0.276 and 5.25 mg kg-1), while the values of the lead concentration were lower than those published previously (on average 2.93 mg kg-1). This may have been due to the widespread use of lead-free fuel.
Association between field and laboratory predictors of drought tolerance in wheat disomic addition lines
Authors: Farshadfar E. , Mohammadi R. , Sutka J.
Published: August 2004

In order to locate QTLs controlling field and laboratory indicators of drought tolerance, chromosome addition lines of Agropyron elongatum (donor) in the genetic background of Chinese Spring (recipient) were tested in the field and laboratory of the College of Agriculture, Razi university, Kermanshah, Iran. The plant genetic material was cultivated in the field and laboratory under two different water regimes (irrigated and non-irrigated). High significant differences were found for promptness index (PI), coleoptile length (CL) and root length (RL) under stress and non-stress conditions, indicating the presence of genetic variation and the possibility of selection for these traits. High correlation coefficients were found between PI, germination stress index (GSI) and stress tolerance index (STI), displaying a high association between the indices of field and laboratory predictors of drought tolerance. Field and laboratory predictors of drought tolerance showed that most of the QTLs controlling drought tolerance criteria in Agropyron are located on chromosomes 3E, 5E and 7E, which collectively constitute 84.3% of the additive genetic variance.
Use of perfect markers in wheat quality research and breeding
Authors: Morell M. K. , Gale K. R.
Published: August 2004

A primary objective of the wheat breeder is to develop populations with optimum combinations of genes controlling key traits. As more is known about the control of specific traits by specific genes, more emphasis can be placed on the use of markers for specific genes, or specific alleles of genes, in wheat breeding. Markers that define specific genes are known as “perfect” markers as they are 100% linked to a gene controlling some significant component of the variability in the trait of interest. Perfect markers are of interest not only because they provide the breeder with a direct means of selecting for a trait, but also because they are directly linked to the mechanism underpinning the trait and are therefore highly valuable from a research perspective. In this paper, we discuss the range of perfect markers available for use in breeding and research in wheat quality. The choice of genes selected, the types of polymorphisms in the genes being targeted, the marker systems used to reveal the polymorphism, and strategies for the implementation of the markers in breeding and research are discussed. In addition, we discuss the future potential for the development of perfect markers given the rapid developments in cereal science and genomics.
Molecular cytogenetic analysis of wheat-alien hybrids and derivatives
Authors: Molnár-Láng M. , Linc G , D. Nagy E. ,   et al.
Published: August 2004

New wheat × barley, wheat ×Aegilops biuncialisand wheat × rye hybrids were produced with the aim of alien gene transfer from these species into wheat. Amphiploids were produced with the help of colchicine treatment from the last two combinations. The new wheat × barley hybrids were multiplied in tissue culture because of the high degree of sterility and then pollinated with wheat to obtain backcross progenies. Wheat-barley chromosome pairing was detected using genomicin situhybridization (GISH) in two combinations (Mv9 kr1 × Igri, Asakazekomugi × Manas).In vitroconditions caused an increase in chromosome arm association frequency in both combinations and in fertility in some regenerants. Five wheat-barley translocations were produced in a wheat background and characterized through the combination of cytogenetic and molecular genetic approaches (GISH, FISH and SSR markers). The following translocations were identified: 2DS.2DL-1HS, 3HS.3BL, 6BS.6BL-4HL, 4D-5HS and 7DL.7DS-5HS. Physical mapping of the SSR markers on chromosomes 1H and 5H was carried out using the intragenomic and interspecific translocation breakpoints and the centromere as physical landmarks.  Disomic wheat-Aegilops biuncialisadditions were produced after backcrossing the wheat-Ae. biuncialisamphiploids. Fluorescencein situhybridization (FISH) was carried out using two repetitive DNA clones (pSc119.2 and pAs1) onAe. biuncialisand its two diploid progenitor species to detect chromosome polymorphism. The 7M and 3M disomic chromosome additions were selected and five more lines still need to be characterized.  The octoploid triticale (Mv9 kr1 × Lovászpatonai) produced in Martonvásár was crossed with a 1RS.1BL wheat cultivar Matador. GISH analysis detected pairing between the 1RS arm of the translocation chromosome and that of Lovászpatonai rye in 32 % of the pollen mother cells, making it possible to select recombinants from this combination. The new recombinants between the 1RS of Petkus and the 1RS of Lovászpatonai rye cultivars are being analysed with the help of microsatellite markers.
Seed production aspects of genetically modified crop varieties
Authors: Láng L.
Published: August 2004

The seed multiplication of genetically modified (GM) plants requires a modification of the multiplication process used for conventional seed. The difference compared to conventionally-bred varieties involves the detection of the modified character during variety maintenance, seed multiplication and processing, the need for separate storage, processing and transportation, the extra cleaning required for the transportation, storage and processing equipment, and the extra administration necessary for the documentation and labelling of GM seed lots. All in all this results in the lower exploitation of seed-producing capacity and in additional costs. The appearance of GM plants also has an effect on the breeders and seed multipliers of conventional varieties, however, since the possibility of contamination cannot be excluded. The producers of seed free of GMs (within the tolerance threshold) are forced to employ costly cultivation techniques (temporal and spatial isolation, removal of volunteer plants) and laboratory tests (for GM contamination) if their varieties are to stay on the market and if it is to remain possible to produce GM-free products in the future.
Photosynthetic productivity of six winter wheat genotypes (Triticum aestivum L.)
Authors: Sabo M.
Published: August 2004

Vezetéknév
Effect and residual effect of N fertilisation on the N uptake of winter wheat in a long-term field experiment
Authors: Berecz K. , Németh I.
Published: August 2004

In wheat production, N fertilisation is one of the most effective agro-technical devices to increase yield and N concentration. In Hungary, fertiliser use, particularly that of N, has dropped dramatically in the last decade. The aim of this experiment was to study the direct and residual effect of N fertilisation on the grain yield and N uptake of winter wheat after 30 years of intensive N fertilisation. A long-term fertilisation experiment was set up on brown forest soil (Eutric Cambisol) with medium N status at Keszthely (Hungary) in 1965. In 1995, the plots were halved. From that year on, half of the plots no longer received N fertiliser, while the other half of the plots was fertilised with increasing N doses. Two years after the treatment modification, no residual effect of long-term intensive N fertilisation (10.44 t N/30 years) could be detected. Under the investigated site conditions, the omission of yearly N fertilisation led to low wheat yields and low N concentrations both in the grains and in the vegetative organs above the uppermost internode.
Investigation on low doses of atrazine, metribuzin and pendimethalin on weeds and yield of wheat
Authors: Pandey J. , Gopinath K. A. , Verma A. K.
Published: August 2004

The results obtained showed that there was severe competition between wheat and the predominant weed species Phalaris minor, Avena ludoviciana and Melilotus indica. Competition by other weed species was normal. The maximum reduction in grain and straw yields due to weed competition was 34.8% and 43.7%, respectively. Weed control treatments lowered the weed population and weed biomass accumulation and boosted up the crop yield. A significant reduction in the weed population and weed dry weight was observed with increasing doses of both atrazine and metribuzin. Metribuzin at 200 g ha-1 killed all the plants of M. indica and gave excellent control of both P. minor (98%) and A. ludoviciana (89%). Atrazine at higher doses had an almost similar effect on P. minor, A. ludoviciana and M. indica with 83-87% control. Pendimethalin gave good control of P. minor and M. indica (75-83%) but poor control of A. ludoviciana (55%). The highest yield was recorded in hand weeding which was significantly superior to all other treatments. Metribuzin at 100 g ha-1 was the next best treatment, and this rate was superior to the higher doses. Pendimethalin and atrazine also brought about a marked increase in the crop yield. Higher doses of atrazine and metribuzin had a phytotoxic effect on the crop, reducing the number of productive tillers and finally lowering the crop yield, despite their excellent control of dominant weed species.
Process Research: State of the Art and Where to Go Next?
Authors: Tirkkonen-Condit Sonja
Published: August 2004

I will first briefly review the past developments in the research of translation processes and then focus on three items which seem particularly worthy of attention and research effort. First, among the multiplicity of aims and purposes, the search for the features of expertise emerges as a foundation on which the success of many other pursuits depends. Second, there is a need for a critical review, time and again, of established methodologies of empirical research, at the same time as new methodologies are being developed. Third, while methodologies mature and pave the way for replicable experiments, the time is ripe for the pooling of resources in joint projects as envisioned by the late Process Team in 1996.
Cognitive Models, Prototype Effects and 'Translation'
Authors: Sandra Halverson
Published: August 2004

In the paper, I argue that human cognition is vital for language, the creation of human understanding of the world, scientific or otherwise, and in the interaction between these two. I consider the link between the world, language and the mind as it is played out in the task of determining what constitutes the object of study for the field of translation studies. The basic argument is that determining what is to be included in the 'translation' category is like all other category judgements, a highly cognitive endeavour. As such, the structures and processes involved in human cognition are vital elements of the process of matching word to 'thing', and of grouping kinds. In the paper, I outline the basic philosophy/cognitive science framework in which my investigations are couched and present the results of two empirical studies. The data from the first study indicates a pattern of prototype effects for the 'translation' category, which is subsequently supplemented with etymological data in order to derive a cognitive model for 'translate'. In the final discussion, I demonstrate the power of this cognitive model in addressing resilient (meta)theoretical dilemmas in the field of translation studies, including the position of interlingual translation as compared to other types of translation, the question of disciplinary boundaries and relationships, and the current position and potential utility of the equivalence concept.