bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purification and some properties of endoglucanase from Glyptotermes xiamenensis
Authors: Shi Y. , Tao Y.‐M. , Ma S.‐J. , An G. , Long M.‐N. , Chen Q.‐X. 
Published: November 2009

AbstractAn endoglucanase (EGase) from Glyptotermes xiamenensis was purified by extraction with phosphate buffer solution and ammonium sulfate fractionation, and then chromatographed on DEAE Sepharose Fast Flow followed by Sephadex G‐100 columns. The purified enzyme was determined to be homogeneous by polyacrylamide gel electrophoresis (PAGE). Enzyme molecular weight was determined to be 44.8 kDa and the enzyme was a monomeric protein. The specific activity was determined to be 458.7 U/mg. The optimum pH and optimum temperature of the enzyme for the hydrolysis of carboxymethycellulose sodium (CMC‐Na) were investigated to be at pH 5.0 and at 40°C, respectively. The enzyme was stable over the pH range from 4.0 to 9.0 and at the temperature below 45°C. Kinetic behaviour of the enzyme in the hydrolysis of CMC‐Na followed Michaelis–Menten kinetics with constant (Km) of 7.2 mg/ml at pH 5.0 and 40°C. The activation energy was determined to be 49.3 KJ/mol. Chemical modification indicated that the residues of histidine, tryptophan and carboxylate were essential to the enzyme activity.
Structure characteristics and expression profiles of Bombyx mori α1 (IV) collagen gene, a temperature‐sensitive lethality‐related gene
Authors: Ji M.‐M. , Lu Y.‐J. , Gan L.‐P. , Niu Y.‐S. , Sima Y.‐H. , Xu S.‐Q. 
Published: November 2009

AbstractThe type IV collagen is a heterotrimer of two α1 (IV) and one α2 (IV) chains, which are encoded by emb‐9 and let‐2 genes in Caenorhabditis elegans, respectively, and the amino acid mutations in Gly‐X‐Y repeat region can cause temperature‐sensitive lethality during late embryogenesis. Here, we introduced a way to quickly and effectively do research on Bmlet‐2 (BmColIVα1) gene from Bombyx mori, a central model for Lepidoptera. BmColIVα1 gene is 6.583 kbp in full length, containing four exons, and its cDNA is 3.847 kbp, which contains an ORF for a protein of 819 amino acids with a molecular weight of 82.1 kDa and an isoelectric point of 6.43. The predicted protein sequence has closer relationship with α1 (IV) collagen chain of other species, and contains two conserved regions of collagen and nine PFAM domains of collagen triple helix repeat regions. Moreover, transmembrane region analysis and subcellular localization analysis reveal that this protein belongs to extracellular secreted protein. The experimental expression profile demonstrated that the expression level of BmColIVα1 was obviously higher in head and fat body on day 3 of the fifth instar. The mutations of BmColIVα1 gene located in exon 2 and exon 3 were identified in temperature‐sensitive lethal strain sch and wild stain Dazao. Seven mutations – namely, 242(T/A), 279(T/A), 556(T/C), 675(C/T), 1343(T/C), 1463(A/G), and 1574(T/C) – were novel, and five of them would modify the encoded amino acids, namely, 81(L/Q), 186(S/P), 448(L/S), 488(Q/R), and 525(V/A). The results of molecular modelling showed that the five amino acids mutations were located in four regions of 3‐helixs repetitive element sequence of ColIVα1 protein. BmColIVα1 protein is a member of the collagen family, and its gene might be a temperature‐sensitive lethality‐related gene.
Host suitability of UV‐irradiated eggs of three Lepidoptera species for rearing Trichogrammatoidea lutea Girault (Hymenoptera: Trichogrammatidae)
Authors: Mawela K. V. , Kfir R. , Krüger K. 
Published: November 2009

AbstractTo develop a rearing programme for the egg parasitoid Trichogrammatoidea lutea for augmentative biological control, the effects of ultraviolet (UV) irradiated host eggs were evaluated on the number of eggs parasitized, development time, number of progeny and sex ratio of T. lutea, using eggs of the lepidopteran species Helicoverpa armigera, Chilo partellus and Cadra cautella as hosts. UV‐irradiation of 13 min was sufficient to kill embryos of all three hosts. The highest mean percentage parasitism on UV‐irradiated and un‐irradiated eggs occurred on those of H. armigera (47.8% and 33.3%) and C. cautella (33.2% and 55.5%), followed by C. partellus (6.6% for both). The mean number of individuals emerged per single parasitized host of UV‐irradiated and un‐irradiated eggs was highest for H. armigera (2.5 and 2.1) and lower for C. partellus (1.3 and 1.4) and C. cautella (0.9 and 0.8). The sex ratio of T. lutea was female‐biased on UV‐irradiated eggs of H. armigera, on UV‐irradiated and un‐irradiated eggs of C. cautella, and male‐biased for C. partellus eggs and un‐irradiated eggs of H. armigera. The developmental time of T. lutea from egg to adult male and female differed slightly between UV‐irradiated and un‐irradiated eggs. Overall, UV‐irradiation of host eggs had negligible effects on percent parasitism, number of progeny per parasitized egg and sex ratio of T. lutea. Of the three lepidopteran species evaluated, H. armigera appears to be the most suitable host for mass‐rearing of T. lutea. The results indicate that UV‐irradiation of Lepidoptera eggs is suitable for mass rearing of T. lutea.
Life‐cycle variation, including female production by virgin females inFrankliniella occidentalis(Thysanoptera: Thripidae)
Authors: Kumm S. , Moritz G. 
Published: November 2009

AbstractThe influence of three different temperatures on developmental time and sex ratio was investigated in the bisexual Thysanoptera speciesFrankliniella occidentalis. Increasing temperatures decreased developmental time and induced a more female biased sex ratio. Remarkably, there are second instars with a prolonged developmental time requiring the same number of hours as the shortest developmental time from egg to adult. Arrhenotokous reproduction in this species is based on haplodiploidy, with virgin females producing male offspring exclusively. However, at all three temperatures tested, about 0.5% of offspring from unfertilized eggs were females. The presence ofWolbachiacould not be detected in Western flower thrips and can be excluded as influencing reproduction in this species.
Performance of Trichogrammatoidea sp. nr lutea Girault (Hymenoptera: Trichogrammatidae) collected from Mussidia spp. in Kenya on eggs of six lepidopteran hosts
Authors: Muli B. K. , Schulthess F. , Van Den Berg J. 
Published: November 2009

Abstract Mussidia nigrivenella Ragonot (Lepidoptera: Pyralidae), an important pest of maize ears in West Africa, has never been reported to attack crops in East and southern Africa (ESA), though it was found on various wild host plants in these regions. It was suggested that in ESA M. nigrivenella might be under natural control. In Kenya, exploration for natural enemies associated with Mussidia spp. yielded several parasitoids including a trichogrammatid egg parasitoid, Trichogrammatoidea sp. nr lutea Girault. The ability of T. sp. nr lutea to attack the eggs of several lepidopteran species found in Kenya was studied. The lepidopterans included the noctuids Busseola fusca (Fuller) and Sesamia calamistis (Hampson), the pyralids Eldana saccharina Walker, Mussidia fiorii Cecconi and de Joannis and Mussidia‘madagascariensis’, and the crambid Chilo partellus (Swinhoe). The former three species also infest cereals in West Africa. Trichogrammatoidea sp. nr lutea successfully attacked and developed in eggs of all six species indicating its potential to exploit other lepidopteran pests of maize in West Africa. Busseola fusca and S. calamistis were the most suitable hosts and had the largest number of eggs parasitized and progeny per female wasp where E. saccharina and C. partellus were the poorest hosts. The host species used to rear the parasitoid and the age of egg also significantly affected the total number of host eggs parasitized by the parasitoid. It was concluded that the ability of T. sp. nr lutea to exploit lepidopterans that are also pests of maize in West Africa may enhance biological control of M. nigrivenella and it should be considered for translocation to that area from Kenya.
Subjective mental time: the functional architecture of projecting the self to past and future
Authors: Arzy Shahar , Collette Sven , Ionta Silvio , Fornari Eleonora , Blanke Olaf 
Published: November 2009

AbstractHuman experience takes place in the line of mental time (MT) created through ‘self‐projection’ of oneself to different time‐points in the past or future. Here we manipulated self‐projection in MT not only with respect to one’s life events but also with respect to one’s faces from different past and future time‐points. Behavioural and event‐related functional magnetic resonance imaging activity showed three independent effects characterized by (i) similarity between past recollection and future imagination, (ii) facilitation of judgements related to the future as compared with the past, and (iii) facilitation of judgements related to time‐points distant from the present. These effects were found with respect to faces and events, and also suggest that brain mechanisms of MT are independent of whether actual life episodes have to be re‐experienced or pre‐experienced, recruiting a common cerebral network including the anteromedial temporal, posterior parietal, inferior frontal, temporo‐parietal and insular cortices. These behavioural and neural data suggest that self‐projection in time is a fundamental aspect of MT, relying on neural structures encoding memory, mental imagery and self.
Experience‐dependent increase in spine calcium evoked by backpropagating action potentials in layer 2/3 pyramidal neurons in rat somatosensory cortex
Authors: Krieger Patrik 
Published: November 2009

AbstractIn spines on basal dendrites of layer 2/3 pyramidal neurons in somatosensory barrel cortex, calcium transients evoked by back‐propagating action potentials (bAPs) were investigated (i) along the length of the basal dendrite, (ii) with postnatal development and (iii) with sensory deprivation during postnatal development. Layer 2/3 pyramidal neurons were investigated at three different ages. At all ages [postnatal day (P)8, P14, P21] the bAP‐evoked calcium transient amplitude increased with distance from the soma with a peak at around 50 μm, followed by a gradual decline in amplitude. The effect of sensory deprivation on the bAP‐evoked calcium was investigated using two different protocols. When all whiskers on one side of the rat snout were trimmed daily from P8 to P20‐24 there was no difference in the bAP‐evoked calcium transient between cells in the contralateral hemisphere, lacking sensory input from the whisker, and cells in the ipsilateral barrel cortex, with intact whisker activation. When, however, only the D‐row whiskers on one side were trimmed the distribution of bAP‐evoked calcium transients in spines was shifted towards larger amplitudes in cells located in the deprived D‐column. In conclusion, (i) the bAP‐evoked calcium transient gradient along the dendrite length is established at P8, (ii) the calcium transient increases in amplitude with age and (iii) this increase is enhanced in layer 2/3 pyramidal neurons located in a sensory‐deprived barrel column that is bordered by non‐deprived barrel columns.
Context‐specific modulation of cocaine‐induced locomotor sensitization and ERK and CREB phosphorylation in the rat nucleus accumbens
Authors: Marin Marcelo T. , Berkow Alexander , Golden Sam A. , Koya Eisuke , Planeta Cleopatra S. , Hope Bruce T. 
Published: November 2009

AbstractLearned associations are hypothesized to develop between drug effects and contextual stimuli during repeated drug administration to produce context‐specific sensitization that is expressed only in the drug‐associated environment and not in a non‐drug‐paired environment. The neuroadaptations that mediate such context‐specific behavior are largely unknown. We investigated context‐specific modulation of cAMP‐response element‐binding protein (CREB) phosphorylation and that of four upstream kinases in the nucleus accumbens that phosphorylate CREB, including extracellular signal‐regulated kinase (ERK), cAMP‐dependent protein kinase, calcium/calmodulin‐dependent kinase (CaMK) II and CaMKIV. Rats received seven once‐daily injections of cocaine or saline in one of two distinct environments outside their home cages. Seven days later, test injections of cocaine or saline were administered in either the paired or the non‐paired environment. CREB and ERK phosphorylation were assessed with immunohistochemistry, and phosphorylation of the remaining kinases, as well as of CREB and ERK, was assessed by western blotting. Repeated cocaine administration produced context‐specific sensitized locomotor responses accompanied by context‐specific enhancement of the number of cocaine‐induced phosphoCREB‐immunoreactive and phosphoERK‐immunoreactive nuclei in a minority of neurons. In contrast, CREB and CaMKIV phosphorylation in nucleus accumbens homogenates were decreased by cocaine test injections. We have recently shown that a small number of cocaine‐activated accumbens neurons mediate the learned association between cocaine effects and the drug administration environment to produce context‐specific sensitization. Context‐specific phosphorylation of ERK and CREB in the present study suggests that this signal transduction pathway is selectively activated in the same set of cocaine‐activated accumbens neurons that mediate this learned association.
Cerebellar involvement in timing accuracy of rhythmic finger movements in essential tremor
Authors: Avanzino Laura , Bove Marco , Tacchino Andrea , Ruggeri Piero , Giannini Alessandro , Trompetto Carlo , Abbruzzese Giovanni 
Published: November 2009

AbstractThe cerebellum is involved in the generation of essential tremor (ET) and cerebellar timing function is altered in patients with ET showing an increased variability of rhythmic hand movements. Using a sensor‐engineered glove, we evaluated motor behaviour during repetitive finger tapping movements in 15 patients with ET and in 11 age‐ and gender‐matched normal subjects. In addition, we investigated whether, in patients with ET, an inhibitory repetitive transcranial magnetic stimulation (1 Hz‐rTMS) over lateral cerebellum was able to change timing properties and motor behaviour. Patients with ET showed a longer touch duration (TD) and a lower inter tapping interval (ITI) than normal subjects. The temporal variability of the movement (coefficient of variation of ITI) was increased in patients with ET. Neither clinical rating scale or tremor measurements correlated with any parameter of motor performance in the ET group. 1 Hz‐rTMS over ipsilateral lateral cerebellum transiently affected the performance of patients with ET, by reducing TD values and normalizing ITI values. After 1 Hz‐rTMS, the coefficient of variation of ITI was restored to values similar to those of normal subjects. We postulate that the strategy to increase TD, probably adopted to allow a better perception of movement, can affect ITI and its variability. The results support the idea that the cerebellum plays a central role in the selection of motor strategy of rhythmic finger movements, particularly in terms of temporal organization of movement.
Acute action of rotenone on nigral dopaminergic neurons – involvement of reactive oxygen species and disruption of Ca2+ homeostasis
Authors: Freestone Peter S. , Chung Kenny K. H. , Guatteo Ezia , Mercuri Nicola B. , Nicholson Louise F.B. , Lipski Janusz 
Published: November 2009

AbstractRotenone is a toxin used to generate animal models of Parkinson’s disease; however, the mechanisms of toxicity in substantia nigra pars compacta (SNc) neurons have not been well characterized. We have investigated rotenone (0.05–1 μm) effects on SNc neurons in acute rat midbrain slices, using whole‐cell patch‐clamp recording combined with microfluorometry. Rotenone evoked a tolbutamide‐sensitive outward current (94 ± 15 pA) associated with increases in intracellular [Ca2+] ([Ca2+]i) (73.8 ± 7.7 nm) and intracellular [Na+] (3.1 ± 0.6 mm) (all with 1 μm). The outward current was not affected by a high ATP level (10 mm) in the patch pipette but was decreased by Trolox. The [Ca2+]i rise was abolished by removing extracellular Ca2+, and attenuated by Trolox and a transient receptor potential M2 (TRPM2) channel blocker, N‐(p‐amylcinnamoyl) anthranilic acid. Other effects included mitochondrial depolarization (rhodamine‐123) and increased mitochondrial reactive oxygen species (ROS) production (MitoSox), which was also abolished by Trolox. A low concentration of rotenone (5 nm) that, by itself, did not evoke a [Ca2+]i rise resulted in a large (46.6 ± 25.3 nm) Ca2+ response when baseline [Ca2+]i was increased by a ‘priming’ protocol that activated voltage‐gated Ca2+ channels. There was also a positive correlation between ‘naturally’ occurring variations in baseline [Ca2+]i and the rotenone‐induced [Ca2+]i rise. This correlation was not seen in non‐dopaminergic neurons of the substantia nigra pars reticulata (SNr). Our results show that mitochondrial ROS production is a key element in the effect of rotenone on ATP‐gated K+ channels and TRPM2‐like channels in SNc neurons, and demonstrate, in these neurons (but not in the SNr), a large potentiation of rotenone‐induced [Ca2+]i rise by a small increase in baseline [Ca2+]i.
Repetitive transcranial magnetic stimulation over the right dorsolateral prefrontal cortex decreases valuations during food choices
Authors: Camus Mickael , Halelamien Neil , Plassmann Hilke , Shimojo Shinsuke , O’Doherty John , Camerer Colin , Rangel Antonio 
Published: November 2009

AbstractSeveral studies have found decision‐making‐related value signals in the dorsolateral prefrontal cortex (DLPFC). However, it is unknown whether the DLPFC plays a causal role in decision‐making, or whether it implements computations that are correlated with valuations, but that do not participate in the valuation process itself. We addressed this question by using repetitive transcranial magnetic stimulation (rTMS) while subjects were involved in an economic valuation task involving the consumption of real foods. We found that, as compared with a control condition, application of rTMS to the right DLPFC caused a decrease in the values assigned to the stimuli. The results are consistent with the possibility that the DLPFC plays a causal role in the computation of values at the time of choice.
Orbitofrontal inactivation impairs reversal of Pavlovian learning by interfering with ‘disinhibition’ of responding for previously unrewarded cues
Authors: Burke Kathryn A. , Takahashi Yuji K. , Correll Jessica , Leon Brown P. , Schoenbaum Geoffrey 
Published: November 2009

AbstractOrbitofrontal cortex (OFC) is critical for reversal learning. Reversal deficits are typically demonstrated in complex settings that combine Pavlovian and instrumental learning. Yet recent work has implicated the OFC specifically in behaviors guided by cues and the features of the specific outcomes they predict. To test whether the OFC is important for reversing such Pavlovian associations in the absence of confounding instrumental requirements, we trained rats on a simple Pavlovian task in which two auditory cues were presented, one paired with a food pellet reward and the other presented without reward. After learning, we reversed the cue–outcome associations. For half the rats, OFC was inactivated prior to each reversal session. Inactivation of OFC impaired the ability of the rats to reverse conditioned responding. This deficit reflected the inability of inactivated rats to develop normal responding for the previously unrewarded cue; inactivation of OFC had no impact on the ability of the rats to inhibit responding to the previously rewarded cue. These data show that OFC is critical to reversal of Pavlovian responding, and that the role of OFC in this behavior cannot be explained as a simple deficit in response inhibition. Furthermore, the contrast between the normal inhibition of responding, reported here, and impaired inhibition of responding during Pavlovian over‐expectation, reported previously, suggests the novel hypothesis that OFC may be particularly critical for learning (or behavior) when it requires the subject to generate predictions about outcomes by bringing together or integrating disparate pieces of associative information.
Disruptions to human speed perception induced by motion adaptation and transcranial magnetic stimulation
Authors: Burton M. P. , McKeefry D. J. , Barrett B. T. , Vakrou C. , Morland A. B. 
Published: November 2009

AbstractTo investigate the underlying nature of the effects of transcranial magnetic stimulation (TMS) on speed perception, we applied repetitive TMS (rTMS) to human V5/MT+ following adaptation to either fast‐ (20 deg/s) or slow (4 deg/s)‐moving grating stimuli. The adapting stimuli induced changes in the perceived speed of a standard reference stimulus moving at 10 deg/s. In the absence of rTMS, adaptation to the slower stimulus led to an increase in perceived speed of the reference, whilst adaptation to the faster stimulus produced a reduction in perceived speed. These induced changes in speed perception can be modelled by a ratio‐taking operation of the outputs of two temporally tuned mechanisms that decay exponentially over time. When rTMS was applied to V5/MT+ following adaptation, the perceived speed of the reference stimulus was reduced, irrespective of whether adaptation had been to the faster‐ or slower‐moving stimulus. The fact that rTMS after adaptation always reduces perceived speed, independent of which temporal mechanism has undergone adaptation, suggests that rTMS does not selectively facilitate activity of adapted neurons but instead leads to suppression of neural function. The results highlight the fact that potentially different effects are generated by TMS on adapted neuronal populations depending upon whether or not they are responding to visual stimuli.
The development of automated access to symbolic and non‐symbolic number knowledge in children: an ERP study
Authors: Gebuis Titia , Herfs Inkeri K. , Kenemans J. Leon , De Haan Edward H. F. , Van der Smagt Maarten J. 
Published: November 2009

AbstractInfants can visually detect changes in numerosity, which suggests that a (non‐symbolic) numerosity system is already present early in life. This non‐symbolic system is hypothesized to serve as the basis for the later acquired symbolic system. Little is known about the processes underlying the transition from the non‐symbolic to symbolic code. In the current study we investigated the development of automatization of symbolic number processing in children from second (6.0 years) and fourth grade (8.0 years) and adults using a symbolic and non‐symbolic size congruency task and event‐related potentials (ERPs) as a measure. The comparison between symbolic and non‐symbolic size congruency effects (SCEs) allowed us to disentangle processes necessary to perform the task from processes specific to numerosity notation. In contrast to previous studies, second graders already revealed a behavioral symbolic SCE similar to that of adults. In addition, the behavioral SCE increased for symbolic and decreased for non‐symbolic notation with increasing age. For all age groups, the ERP data showed that the two magnitudes interfered at a level before selective activation of the response system, for both notations. However, only for the second graders distinct processes were recruited to perform the symbolic size comparison task. This shift in recruited processes for the symbolic task only might reflect the functional specialization of the parietal cortex.