bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations in autologous neutralization and CD4 dependence of b12 resistant HIV-1 clade C envclones obtained at different time points from antiretroviral naïve Indian patients with recent infection
Authors: Ringe Rajesh , Thakar Madhuri , Bhattacharya Jayanta
Published: September 2010

Background

Limited information is available on HIV-1 Indian clade C sensitivities to autologous antibodies during the course of natural infection. In the present study, a total of 37 complete envelope clones (Env) were amplified at different time points predominantly from the plasma of five Indian patients with recent HIV-1 infection and envelope-pseudotyped viruses were examined for their magnitude of sensitivity to autologous plasma antibodies during natural course of infection.

Results

Variable low levels of neutralization were consistently detected with contemporaneous autologous plasma. In contrast to clade B and African clade C HIV-1 envelopes, Env clones obtained from four patients were found to be resistant to IgG1b12. The majority of the Env clones were resistant to 2G12 and 2F5 due to the absence of the minimal motifs required for antibody recognition, but were sensitive to 4E10. Nonetheless, Env clones from one patient were found to be sensitive to 2G12, atypical for clade C, and one Env clone exhibited unusual sensitivity to 17b, suggesting spontaneous exposure of CD4i epitopes. Phylogenetic analysis revealed that Env clones were closely clustered within patients. Variation in the potential N-linked glycosylation pattern also appeared to be different in patients over the course of infection. Interestingly, we found that the sensitivity of Envs to contemporaneous autologous NAbs correlated positively with increased sensitivity to soluble CD4 and inversely with anti-CD4 antibody and Envs with increased NAb sensitivity were able to efficiently infect HeLa cells expressing low CD4.

Conclusion

Our data showed considerable variations in autologous neutralization of these early HIV-1 clade C Envs in each of these patients and indicate greater exposure to CD4 of Envs that showed increased autologous neutralization. Interestingly, Env clones obtained from a single patient at different time points were found to retain sensitivity to b12 antibody that binds to CD4 binding site in Env in contrast to Envs obtained from other patients. However, we did not find any association between increased b12 sensitivity of Envs obtained from this particular patient with their degree of exposure to CD4.
Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections
Authors: Hua Rong-Hong , Chen Na-Sha , Qin Cheng-Feng , Deng Yong-Qiang , Ge Jin-Ying , Wang Xi-Jun , Qiao Zu-Jian , Chen Wei-Ye , Wen Zhi-Yuan , Liu Wen-Xin , Hu Sen , Bu Zhi-Gao
Published: September 2010

Background

Differential diagnose of Japanese encephalitis virus (JEV) infection from other flavivirus especially West Nile virus (WNV) and Dengue virus (DV) infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV.

Results

To map the epitopes on the PrM/M protein, we designed a set of 20 partially overlapping fragments spanning the whole PrM, fused them with GST, and expressed them in an expression vector. Linear epitope M14 (105VNKKEAWLDSTKATRY120) was detected by enzyme-linked immunosorbent assay (ELISA). By removing amino acid residues individually from the carboxy and amino terminal of peptide M14, we confirmed that the minimal unit of the linear epitope of PrM/M was M14-13 (108KEAWLDSTKAT118). This epitope was highly conserved across different JEV strains. Moreover, this epitope did not cross-react with WNV-positive and DENV-positive sera.

Conclusion

Epitope M14-13 was a JEV specific lineal B-cell epitpe. The results may provide a useful basis for the development of epitope-based virus specific diagnostic clinical techniques.
Alvimopan Use in Laparoscopic and Open Bowel Resections: Clinical Results in a Large Community Hospital System
Authors: Absher Randall K , Gerkin Todd M , Banares Linda W
Published: September 2010

Background:

Alvimopan has received Food and Drug Administration approval to accelerate the time to upper and lower gastrointestinal recovery following partial large or small bowel resection with primary anastomosis.

Objective:

To assess the efficacy, safety, and economic benefit of alvimopan in patients undergoing open or laparoscopic bowel resection in a community hospital system setting.

Methods:

This 6-month, open-label, multi-hospital, prospective study combined with a retrospective chart review compared postoperative length of stay and postoperative ileus-related morbidity (nasogastric tube insertion, hospital read-mission) for patients undergoing open or laparoscopic bowel resection who received alvimopan 12 mg (n = 108) versus historical control bowel resection patients (n = 91) who would have been eligible to receive alvimopan. Multivariate analysis assessed the effects of age and surgery type on postoperative length of stay. Additional-day hospital costs were estimated using ordinary least-squares regression to calculate costs based on length of stay in the control cohort.

Results:

Compared with historical controls, patients receiving alvimopan had a mean 1.8-day shorter postoperative length of stay (p = 0.01) and lower rates of nasogastric tube insertion (2% vs 15%, p < 0.001) Multivariate analysis revealed a statistically significant reduction in postoperative length of stay in the alvimopan group of approximately 1.2 days (p = 0.01), regardless of age or surgery type, with an even larger difference (3.2 days) observed in patients ≥70 years old. Mean cost savings associated with alvimopan use ranged from $531 (laparoscopic bowel resection) to $997 (open bowel resection) per patient.

Conclusions:

Consistent with clinical trial data, alvimopan use resulted in an approximately 1 day shorter postoperative length of stay and was associated with substantial cost savings.
Spike-Time Precision and Network Synchrony Are Controlled by the Homeostatic Regulation of the D-Type Potassium Current
Authors: Cudmore Robert H. , Fronzaroli-Molinieres Laure , Giraud Pierre , Debanne Dominique
Published: September 2010

Homeostatic plasticity of neuronal intrinsic excitability (HPIE) operates to maintain networks within physiological bounds in response to chronic changes in activity. Classically, this form of plasticity adjusts the output firing level of the neuron through the regulation of voltage-gated ion channels. Ion channels also determine spike timing in individual neurons by shaping subthreshold synaptic and intrinsic potentials. Thus, an intriguing hypothesis is that HPIE can also regulate network synchronization. We show here that the dendrotoxin-sensitive D-type K+current (ID) disrupts the precision of AP generation in CA3 pyramidal neurons and may, in turn, limit network synchronization. The reduced precision is mediated by the sequence of outwardIDfollowed by inward Na+current. The homeostatic downregulation ofIDincreases both spike-time precision and the propensity for synchronization in iteratively constructed networksin vitro. Thus, network synchronization is adjusted in area CA3 through activity-dependent remodeling ofID.
Neuroligin 1 Is Dynamically Exchanged at Postsynaptic Sites
Authors: Schapitz Inga U. , Behrend Bardo , Pechmann Yvonne , Lappe-Siefke Corinna , Kneussel Silas J. , Wallace Karen E. , Stempel A. Vanessa , Buck Fritz , Grant Seth G. N. , Schweizer Michaela , Schmitz Dietmar , Schwarz Jürgen R. , Holzbaur Erika L. F. , Kneussel Matthias
Published: September 2010

Neuroligins are postsynaptic cell adhesion molecules that associate with presynaptic neurexins. Both factors form a transsynaptic connection, mediate signaling across the synapse, specify synaptic functions, and play a role in synapse formation. Neuroligin dysfunction impairs synaptic transmission, disrupts neuronal networks, and is thought to participate in cognitive diseases.

Here we report that chemical treatment designed to induce long-term potentiation or long-term depression (LTD) induces neuroligin 1/3 turnover, leading to either increased or decreased surface membrane protein levels, respectively. Despite its structural role at a crucial transsynaptic position, GFP-neuroligin 1 leaves synapses in hippocampal neurons over time with chemical LTD-induced neuroligin internalization depending on an intact microtubule cytoskeleton. Accordingly, neuroligin 1 and its binding partner postsynaptic density protein-95 (PSD-95) associate with components of the dynein motor complex and undergo retrograde cotransport with a dynein subunit.

Transgenic depletion of dynein function in mice causes postsynaptic NLG1/3 and PSD-95 enrichment. In parallel, PSD lengths and spine head sizes are significantly increased, a phenotype similar to that observed upon transgenic overexpression of NLG1 (Dahlhaus et al., 2010). Moreover, application of a competitive PSD-95 peptide and neuroligin 1 C-terminal mutagenesis each specifically alter neuroligin 1 surface membrane expression and interfere with its internalization. Our data suggest the concept that synaptic plasticity regulates neuroligin turnover through active cytoskeleton transport.
Estradiol Rapidly Regulates Membrane Estrogen Receptor α Levels in Hypothalamic Neurons
Authors: Dominguez Reymundo , Micevych Paul
Published: September 2010

Estrogen receptors (ERs) and estrogen-binding proteins have been localized intracellularly and on the cell surface. The membrane-associated proteins initiate signaling that activates a myriad of cellular responses including the modulation of ion channels and ultimately transcription. Although many of the downstream actions of membrane ERs, including ERα and ERβ, have been characterized, the mechanisms regulating membrane ER levels have remained elusive in the nervous system. In the present study, we used surface biotinylation to identify and study the estradiol regulation of membrane ERα in mixed-sex, cultured hypothalamic neurons from rat. Following surface biotinylation, Western blot analysis revealed full-length 66 kDa ERα and several ERα splice variants, most notably a biotinylated 52 kDa ERα-immunoreactive protein. Treatment of the neurons with estradiol caused a rapid and transient increase of the biotinylated 52 kDa and 66 kDa ERα proteins in the plasma membrane. Exposure of the neurons to estradiol also significantly increased internalization of 52 kDa and 66 kDa ERα membrane proteins, a measure of receptor activation. In the hypothalamus, membrane ERα signaling depends on transactivation of metabotropic glutamate receptor-1a (mGluR1a). Estradiol treatment increased the internalization of mGluR1a in parallel with ERα, a finding consistent with the hypothesis of an ERα-mGluR1a signaling unit. These results demonstrate that estradiol regulates the amount of ERα in the membrane, suggesting estradiol can regulate its own membrane signaling.
Auditory–Visual Multisensory Interactions in Humans: Timing, Topography, Directionality, and Sources
Authors: Cappe Céline , Thut Gregor , Romei Vincenzo , Murray Micah M.
Published: September 2010

Current models of brain organization include multisensory interactions at early processing stages and within low-level, including primary, cortices. Embracing this model with regard to auditory–visual (AV) interactions in humans remains problematic. Controversy surrounds the application of an additive model to the analysis of event-related potentials (ERPs), and conventional ERP analysis methods have yielded discordant latencies of effects and permitted limited neurophysiologic interpretability. While hemodynamic imaging and transcranial magnetic stimulation studies provide general support for the above model, the precise timing, superadditive/subadditive directionality, topographic stability, and sources remain unresolved. We recorded ERPs in humans to attended, but task-irrelevant stimuli that did not require an overt motor response, thereby circumventing paradigmatic caveats. We applied novel ERP signal analysis methods to provide details concerning the likely bases of AV interactions. First, nonlinear interactions occur at 60–95 ms after stimulus and are the consequence of topographic, rather than pure strength, modulations in the ERP. AV stimuli engage distinct configurations of intracranial generators, rather than simply modulating the amplitude of unisensory responses. Second, source estimations (and statistical analyses thereof) identified primary visual, primary auditory, and posterior superior temporal regions as mediating these effects. Finally, scalar values of current densities in all of these regions exhibited functionally coupled, subadditive nonlinear effects, a pattern increasingly consistent with the mounting evidence in nonhuman primates. In these ways, we demonstrate how neurophysiologic bases of multisensory interactions can be noninvasively identified in humans, allowing for a synthesis across imaging methods on the one hand and species on the other.
Separable Codes for Attention and Luminance Contrast in the Primary Visual Cortex
Authors: Pooresmaeili Arezoo , Poort Jasper , Thiele Alexander , Roelfsema Pieter R.
Published: September 2010

The visual system encodes the features of visual stimuli as well as their behavioral relevance. Stimuli with a high luminance contrast evoke more activity in the visual cortex than stimuli with a low contrast. At the same time, attended stimuli evoke more activity than nonattended stimuli. There is a debate about how visual features and attention jointly determine neuronal activity in the visual cortex. Some studies suggested that attention increases apparent contrast (Reynolds et al., 2000), others that attention amplifies responses by a constant factor (Williford and Maunsell, 2006), and yet others that attention and contrast have largely additive effects (Buracas and Boynton, 2007; Thiele et al., 2009). The influence of attention on contrast sensitivity differs between neurons, raising the possibility that attention and contrast could be coded conjointly in a population of neurons. Here we investigate this possibility by recording neuronal activity at multiple sites in the primary visual cortex of macaque monkeys using multielectrode recording techniques and support vector machines to decode attended stimuli as well as stimulus contrast. We find that many, but not all, V1 neurons are influenced by attention and that the effects of attention and contrast are additive on average. Stimulus contrast can be decoded from neuronal responses not strongly modulated by attention, whereas the attended stimulus can be decoded as the difference in activity of cells that are influenced by attention and cells that are not. The success of the approach suggests that visual attention and stimulus contrast are represented by largely separable codes.
Visual Saliency Computations: Mechanisms, Constraints, and the Effect of Feedback
Authors: Soltani Alireza , Koch Christof
Published: September 2010

The primate visual system continuously selects spatial proscribed regions, features or objects for further processing. These selection mechanisms—collectively termed selective visual attention—are guided by intrinsic, bottom-up and by task-dependent, top-down signals. While much psychophysical research has shown that overt and covert attention is partially allocated based on saliency-driven exogenous signals, it is unclear how this is accomplished at the neuronal level. Recent electrophysiological experiments in monkeys point to the gradual emergence of saliency signals when ascending the dorsal visual stream and to the influence of top-down attention on these signals. To elucidate the neural mechanisms underlying these observations, we construct a biologically plausible network of spiking neurons to simulate the formation of saliency signals in different cortical areas. We find that saliency signals are rapidly generated through lateral excitation and inhibition in successive layers of neural populations selective to a single feature. These signals can be improved by feedback from a higher cortical area that represents a saliency map. In addition, we show how top-down attention can affect the saliency signals by disrupting this feedback through its action on the saliency map. While we find that saliency computations require dominant slow NMDA currents, the signal rapidly emerges from successive regions of the network. In conclusion, using a detailed spiking network model we find biophysical mechanisms and limitations of saliency computations which can be tested experimentally.
Orexin Directly Excites Orexin Neurons through Orexin 2 Receptor
Authors: Yamanaka Akihiro , Tabuchi Sawako , Tsunematsu Tomomi , Fukazawa Yugo , Tominaga Makoto
Published: September 2010

Orexin neurons (hypocretin neurons) have a critical role in the regulation of sleep/wakefulness, especially in the maintenance of arousal. Here, we revealed that orexin neurons are directly and indirectly activated by orexin via the orexin 2 receptor (OX2R). Orexin B (1 μm) induced depolarization in orexin neurons, which was still observed in the presence of TTX (1 μm), AP-5 (50 μm), and CNQX (20 μm). In addition, orexin B induced inward currents in the presence of TTX, suggesting a direct activation of orexin neurons. Although orexin B application induced depolarization in orexin neurons of OX1R knock-out mice at comparable levels to wild-type mice, the observation that orexin B failed to depolarize orexin neurons in the OX2R knock-out mice suggested that OX2R was a primary receptor for this response. Moreover, immunoelectron microscopic analyses revealed direct contacts among orexin neurons, which exhibited structural similarities to the glutamatergic synapses. Together, these results suggest that orexin neurons form a positive-feedback circuit through indirect and direct pathways, which results in the preservation of the orexin neuron network at a high activity level and/or for a longer period. Therefore, the activation of orexin neurons through OX2R might have an important role in the maintenance of arousal.
Corticocortical Connections Mediate Primary Visual Cortex Responses to Auditory Stimulation in the Blind
Authors: Klinge Corinna , Eippert Falk , Röder Brigitte , Büchel Christian
Published: September 2010

Blind individuals have to rely on nonvisual information to a greater extent than sighted to efficiently interact with the environment, and consequently exhibit superior skills in their spared modalities. These performance advantages are often paralleled by responses in the occipital cortex, which have been suggested to be essential for nonvisual processing in the blind. However, it is currently unclear through which pathways (i.e., thalamocortical or corticocortical connections) nonvisual information reaches the occipital cortex of the blind. Here, we used functional magnetic resonance imaging to study blind and matched sighted humans with an auditory discrimination paradigm and used dynamic causal modeling to investigate the effective connectivity underlying auditory activations in the primary visual cortex of blind volunteers. Model comparison revealed that a model connecting the medial geniculate nucleus (MGN), primary auditory cortex (A1), and primary visual cortex (V1) in a bidirectional manner outperformed all other models in both groups. Regarding inference on model parameters, we observed that basic auditory mechanisms (i.e., sensory input to MGN and connections from MGN to A1) did not differ significantly between the two groups. In contrast, we found clear evidence for stronger corticocortical connections from A1 to V1 in the blind, whereas results with regard to thalamocortical enhancement (from MGN to V1 and, in a control analysis, from the lateral geniculate nucleus to V1) were not consistent. These results suggest that plastic changes especially in corticocortical connectivity allow auditory information to evoke responses in the primary visual cortex of blind individuals.
A p38 Mitogen-Activated Protein Kinase-Dependent Mechanism of Disinhibition in Spinal Synaptic Transmission Induced by Tumor Necrosis Factor-α
Authors: Zhang Haijun , Nei Hui , Dougherty Patrick M.
Published: September 2010

Tumor necrosis factor-α (TNFα) is a proinflammatory cytokine that contributes to inflammatory and neuropathic pain. The mechanism by which TNFα modulates synaptic transmission in mouse substantia gelatinosa was studied using whole-cell patch clamp and immunohistochemistry. TNFα was confirmed to significantly increase the frequency of spontaneous EPSCs (sEPSCs) in spinal neurons and to also produce a robust decrease in the frequency of spontaneous IPSCs (sIPSCs). The enhancement of excitatory synaptic transmission by TNFα is in fact observed to be dependent on the suppression of sIPSCs, or disinhibition, in that blockade of inhibitory synaptic transmission prevents the effect of TNFα on sEPSCs but not vice versa. TNFα-induced inhibition of sIPSCs was blocked by neutralizing antibodies to TNF receptor 1 (TNFR1) but not to TNFR2 and was abolished by the p38 mitogen-activated protein kinase inhibitor SB202190 [4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole]. TNFα rapidly inhibited spontaneous action potentials in GABAergic neurons identified in transgenic mice expressing enhanced green fluorescent protein controlled by the GAD67 promoter. This inhibitory effect was also blocked by intracellular delivery of SB202190 to the targeted cells. The inhibition of spontaneous activity in GABAergic neurons by TNFα is shown as mediated by a reduction in the hyperpolarization-activated cation current (Ih). These results suggest a novel TNFα–TNFR1–p38 pathway in spinal GABAergic neurons that may contribute to the development of neuropathic and inflammatory pain by TNFα.
The α2δ Ligand Gabapentin Inhibits the Rab11-Dependent Recycling of the Calcium Channel Subunit α2δ-2
Authors: Tran-Van-Minh Alexandra , Dolphin Annette C.
Published: September 2010

The α2δ subunits of voltage-gated calcium channels are important modulatory subunits that enhance calcium currents and may also have other roles in synaptogenesis. The antiepileptic and antiallodynic drug gabapentin (GBP) binds to the α2δ-1 and α2δ-2 isoforms of this protein, and its binding may disrupt the binding of an endogenous ligand, required for their correct function. We have shown previously that GBP produces a chronic inhibitory effect on calcium currents by causing a reduction in the total number of α2δ and α1subunits at the cell surface. This action of GBP is likely to be attributable to a disruption of the trafficking of α2δ subunits, either to or from the plasma membrane. We studied the effect of GBP on the internalization of, and insertion into the plasma membrane of α2δ-2 using an α-bungarotoxin binding site-tagged α2δ-2 subunit, and a fluorescent derivative of α-bungarotoxin. We found that GBP specifically disrupts the insertion of α2δ-2 from post-Golgi compartments to the plasma membrane, and this effect was prevented by a mutation of α2δ-2 that abolishes its binding to GBP. The coexpression of the GDP-bound Rab11 S25N mutant prevented the GBP-induced decrease in α2δ-2 cell surface levels, both in cell lines and in primary neurons, and the GBP-induced reduction in calcium channel currents. In contrast, the internalization of α2δ-2 was unaffected by GBP. We conclude that GBP acts by preventing the recycling of α2δ-2 from Rab11-positive recycling endosomes to the plasma membrane.
Post-Error Behavioral Adjustments Are Facilitated by Activation and Suppression of Task-Relevant and Task-Irrelevant Information Processing
Authors: King Joseph A. , Korb Franziska M. , von Cramon D. Yves , Ullsperger Markus
Published: September 2010

Error monitoring by the posterior medial frontal cortex (pMFC) has been linked to post-error behavioral adaptation effects and cognitive control dynamics in lateral prefrontal cortex (LPFC). It remains unknown, however, whether control adjustments following errors produce post-error behavioral adjustments (PEBAs) by inhibiting inappropriate responses or facilitating goal-directed ones. Here we used functional magnetic resonance imaging to investigate the hemodynamic correlates of PEBAs in a stimulus–response compatibility task. Our task was designed to test whether PEBAs are implemented by suppressing motor responses primed by irrelevant stimulus features (face location), redirecting attention to relevant features (face gender), or both or neither of these possibilities. Independent of PEBAs, error-related pMFC activation was followed by post-error recruitment of prefrontal and parietal control regions and, crucially, both (1) suppressed response-related activity in sensorimotor cortex and (2) enhanced target processing in face-sensitive sensory cortex (“fusiform face area”). More importantly, by investigating the covariation between post-error hemodynamic activity and individual differences in PEBAs, we showed that modulation of task-related motor and sensory processing was dependent on whether participants produced generally slower responses (“post-error slowing”; PES) or selectively reduced interference effects (“post-error reduction of interference”; PERI), respectively. Each of these behaviorally dependent effects was mediated by distinct LPFC control mechanisms (PES: inferior frontal junction; PERI: superior frontal sulcus). While establishing relationships between PEBAs and cognitive control, our findings suggest that the neural architecture underlying sequential behavioral adaptation may be determined primarily by how control is executed by the individual when adjustments are needed.
Intermittent Hypoxia Promotes Hippocampal Neurogenesis and Produces Antidepressant-Like Effects in Adult Rats
Authors: Zhu Xin-Hong , Yan Hua-Cheng , Zhang Jie , Qu Hong-Da , Qiu Xing-Sheng , Chen Liang , Li Shu-Ji , Cao Xiong , Bean Jonathan C. , Chen Long-Hua , Qin Xi-He , Liu Ji-Hong , Bai Xiao-Chun , Mei Lin , Gao Tian-Ming
Published: September 2010

Increasing evidence indicates that stimulating hippocampal neurogenesis could provide novel avenues for the treatment of depression, and recent studies have shown thatin vitroneurogenesis is enhanced by hypoxia. The aim of this study was to investigate the potential regulatory capacity of an intermittent hypobaric hypoxia (IH) regimen on hippocampal neurogenesis and its possible antidepressant-like effect. Here, we show that IH promotes the proliferation of endogenous neuroprogenitors leading to more newborn neurons in hippocampus in adult rats. Importantly, IH produces antidepressant-like effects in multiple animal models screening for antidepressant activity, including the forced swimming test, chronic mild stress paradigm, and novelty-suppressed feeding test. Hippocampal x-ray irradiation blocked both the neurogenic and behavioral effects of IH, indicating that IH likely produces antidepressant-like effects via promoting neurogenesis in adult hippocampus. Furthermore, IH stably enhanced the expression of BDNF in hippocampus; both the antidepressant-like effect and the enhancement of cell proliferation induced by IH were totally blocked by pharmacological and biological inhibition of BDNF–TrkB (tyrosine receptor kinase B) signaling, suggesting that the neurogenic and antidepressant-like effects of IH may involve BDNF signaling. These observations might contribute to both a better understanding of physiological responses to IH and to developing IH as a novel therapeutic approach for depression.
When ‘towards’ means ‘away from’: the case of directional-ablative syncretism in the Ardeşen variety of Laz (South-Caucasian)
Authors: Kutscher Silvia
Published: September 2010

This paper deals with morphosyntactic and semantic characteristics of the spatial case called motative in the Ardeşen-variety of Laz. The motative can be used to mark the ground-nominal in allative as well as in ablative spatial expressions, while the ground-nominal in static spatial expressions is unmarked for case. Hence, the motative case shows a conflation of the allative with ablative spatial semantics, while at the same time excluding locative spatial meaning. Given that this kind of syncretism has been claimed to be non-existent, the findings for Ardeşen-Laz are of special relevance for the refinement of the typology on spatial case-systems.
Fluorescence Quenching of Phycoerythrin by Anthraquinone Dyes
Authors: Kathiravan A. , Renganathan R.
Published: September 2010

Fluorescence quenching of phycoerythrin (PE) by a series of anthraquinone dyes has been investigated using steady state fluorescence technique in water medium. The dyes used were Uniblue, Acid blue 129, Alizarin and Alizarin red S. The quenching of PE was found to obey the Stern-Volmer equation and the corresponding Stern-Volmer plots were linear indicating the dynamic quenching. The quenching rate constants (kq) were calculated by using fluorescence data. The mechanism of quenching is discussed on the basis of quenching rate constants as well as the reduction potential of dyes. The electron transfer mechanism has been proved by the calculation of free energy change (ΔGet) by applying Rehm-Weller equation.
Synthesis and Viscoelastic Behavior of an Anionic Gemini Surfactant in Aqueous Solution
Authors: Wu Huijue , Du Xigang , Lu Yao , Zhang Xin , Yang Zhengyu
Published: September 2010

A novel anionic Gemini surfactant, sodium dialkylbenzene disulfonate with spacer of -C3H6-, was synthesized and confirmed by 1HNMR, MS and IR. Such Gemini surfactant in dilute aqueous solution without additives was researched by rotational rheometer and exhibited special viscoelastic behaviors and shear-thinning properties like entangled polymer solution. The influence of concentration and shear rate on viscosity and shear modulus has been studied and the reason of enhancing viscosity has also been discussed.
Comparative Study of the Absolute Values of Enthalpy and Gibbs Free Energy of Solvation of Proton from Cluster-ion Solvation data and Direct Determination of the Thermodynamic Parameters of Proton in Aqueous and Non-aqueous Solvents
Authors: Bhattacharyya Ranjana , Lahiri Sujit Chandra
Published: September 2010

Absolute values of enthalpy and Gibbs free energy of hydration (h) or solvation (s) of H+ ion, ΔH0(H+)h or s and ΔG0(H+)h or s in aqueous and non-aqueous solvents (methanol, ethanol, n-propanol, iso-propanol, n-butanol, t-butanol, ethylene glycol, propylene carbonate, n-methyl formamide, acetone, tetrahydro furan, 1,4-dioxan, acetonitrile) were determined directly using a single standard state [i.e.H2(g) at 1bar and 298.15K]. A comparative study of the methods of Tissandier et al. and the present one has been made. The values −1299.4 kJ mol−1(−1303.9 kJ mol−1) and −1284.5 kJ mol−1(−1288.9 kJ mol−1) for the absolute enthalpy [∆H0
h(H+)] and Gibbs free energy [∆G0
h(H+)] of hydration determined in the present work have been found to be much lower than the corresponding values −1150.1±0.9 kJ mol−1 and −1104.5±0.3 kJmol−1 determined by Tissandier et al. using cluster-ion solvation data. The values of Tissandier et al. have been acclaimed to be the most accurate values of these quantities by most of the workers. However, the method is based on approximations and assumptions and uses a number of conventional standard states. The calculations use the principle of ionic additivity and Klot’s equation which are open to question. The equations, based on the difference between several sets of energy values of different ion-pairs of similar magnitude, have been used. Thus, the method is insensitive and many of the important energy terms characterizing the ions and the structure of the solvents are eliminated. Thus the accuracy of the energy values are not without question.Our method, on the other hand, is a direct one using a single standard state. The most important contributory factor for the determination of ΔG0
h(H+) is the Gibbs free energy of charging and the value is accurately known. Thus, the values for ΔH0
h(H+) and ΔG0
h(H+) determined by us though much lower than those of Tissandier et al. can be regarded to be reasonable.
Synthesis, Characterization and CMC Determination of some Double-Chain Surfactant-Cobalt(III) Complexes
Authors: Sasikala K. , Senthil Kumar R. , Arunachalam S.
Published: September 2010

Some new surfactant-cobalt(III) complex ions of the type, cis-[Co(X)2(C14H29NH2)2]3+ (where X = ethylenediamine or 2,2’ bipyridyl or 1,10-phenanthroline) and cis-α-[Co(trien)(C14H29NH2)2]3+ were synthesized and characterized by IR, NMR, UV-Visible electronic absorption spectra, elemental analysis and metal analysis. The critical micelle concentration (CMC) values of these surfactant-cobalt(III) complexes in aqueous solution were obtained from conductance measurements. Specific conductivity data (at 298, 308 and 318 K) served for the evaluation of temperature-dependent CMC and the thermodynamics of micellization (ΔG0
m, ΔH0
m, ΔS0
m).
GH and IGF1 levels are positively associated with musculotendinous collagen expression: experiments in acromegalic and GH deficiency patients
Authors: Doessing Simon , Holm Lars , Heinemeier Katja M , Feldt-Rasmussen Ulla , Schjerling Peter , Qvortrup Klaus , Larsen Jytte O , Nielsen Rie H , Flyvbjerg Allan , Kjaer Michael
Published: September 2010

Objective

Disproportionate growth of musculoskeletal tissue is a major cause of morbidity in both acromegalic (ACRO) and GH-deficient (GHD) patients. GH/IGF1 is likely to play an important role in the regulation of tendon and muscle collagen. We hypothesized that the local production of collagen is associated with the level of GH/IGF1.

Design and methods

As primary outcomes, collagen mRNA expression and collagen protein fractional synthesis rate (FSR) were determined locally in skeletal muscle and tendon in nine ACRO and nine GHD patients. Moreover, muscle myofibrillar protein synthesis and tendon collagen morphology were determined.

Results and conclusions

Muscle collagen I and III mRNA expression was higher in ACRO patients versus GHD patients (P<0.05), whereas collagen protein FSR did not differ significantly between ACRO and GHD patients in muscle (P=0.21) and tendon (P=0.15).IGF1EaandIGF1EcmRNA expression in muscle was higher in ACRO patients versus GHD patients (P<0.01). MuscleIGF1EamRNA expression correlated positively with collagen I mRNA expression (P<0.01). Tendon collagen fibrillar area tended to be higher in GHD patients relative to ACRO patients (P=0.07). Thus, we observed a higher expression for collagen andIGF1mRNA in local musculotendinous tissue in ACRO patients relative to GHD patients. Moreover, there was a tendency towards a higher collagen protein FSR and a smaller collagen fibril diameter in ACRO patients relative to GHD patients. The results indicate a collagen-stimulating role of local IGF1 in human connective tissue and add to the understanding of musculoskeletal pathology in patients with either high or low GH/IGF1 axis activity.
Epistemologia e metodologia para as pesquisas críticas em administração: leituras aproximadas de Horkheimer e Adorno
Authors: Batista-dos-Santos Ana Cristina , Alloufa Jomária Mata de Lima , Nepomuceno Luciana Holanda
Published: September 2010

Baseado em leituras de Horkheimer e Adorno, autores da chamada primeira geração da Escola de Frankfurt, o texto socializa compreensões sobre ontologia, epistemologia e metodologia crítica visando a contribuir com a prática de pesquisas críticas, de tradição frankfurtiana, no campo da Administração. Parte da discussão ontológica para fundamentar a perspectiva epistemológica frankfurtiana. Apresenta, então, dimensões epistemológicas críticas e propõe três pares categóricos dialéticos para a compreensão da realidade: naturalização versus história, sistema versus práxis social, alienação/dominação versus emancipação. O texto discute aspectos metodológicos e finaliza socializando um exemplo de pesquisa crítica, de tradição frankfurtiana, na Administração.
Avaliação de parâmetros da biodigestão anaeróbia de dejetos de suínos alimentados com dietas à base de milho e sorgo
Authors: Orrico Júnior Marco A. P. , Orrico Ana C. A. , Lucas Júnior Jorge De
Published: September 2010

O objetivo deste trabalho foi avaliar a interferência da dieta à base de sorgo em substituição à de milho na composição e no tratamento dos dejetos. Foram utilizados 24 biodigestores batelada de bancada, dos quais 12 foram abastecidos com dejetos de suínos alimentados com dieta á base de milho, e o restante, com dieta á base de sorgo. A cada 30 dias foram esvaziados três biodigestores dentro de cada dieta, em um total de quatro tempos de retenção hidráulica (TRH) 30; 60; 90 e 120 dias. Para avaliar a eficiência do processo de biodigestão anaeróbia, foram avaliadas as reduções de sólidos totais, sólidos voláteis totais, demanda química de oxigênio, demanda bioquímica de oxigênio, número mais provável (NMP) de coliformes totais e termotolerantes, além dos potenciais de produção do biogás e metano. Os resultados mostraram que os dejetos dos suínos alimentados com dietas à base de sorgo apresentaram menor eficiência no processo, principalmente nos potenciais de produção de biogás e metano. Em média, os potenciais foram 8,6% menor (P<0,01) que os potenciais obtidos em biodigestores abastecidos com dejetos de suínos alimentados com dieta à base de milho. Com relação ao NMP de coliformes totais e termotolerantes, apenas foram observadas reduções significativas conforme aumentou TRH.
Desempenho de válvulas antigotas e microaspersores
Authors: Sandri Delvio , Bessa Kady S. E. , Mesquita Márcio , Prado Lazaro C. R. A.
Published: September 2010

Nos últimos anos, foram introduzidos novos modelos de dispositivos para cultivo em ambiente protegido, como as válvulas antigotas e microaspersores, necessitando-se avaliar o desempenho dos mesmos. Assim, o objetivo deste trabalho foi avaliar o desempenho hidráulico de válvulas antigotas novas e usadas, sob baixa e alta pressão, em microaspersores do grupo modular e modelo Hadar. O CVf e CVq do conjunto microaspersor e válvula antigotas de baixa pressão e somente o microaspersor modular foram classificados como ruins ou inaceitáveis e a válvula anti-gotas modular de alta pressão nova como inaceitável. A válvula Hadar apresentou o melhor desempenho para todas as pressões de serviço. As válvulas avaliadas abriram em pressões inferiores às indicadas pelos seus fabricantes. O tempo de uso interferiu no desempenho das válvulas antigotas modular de baixa pressão, sendo o modelo novo o que apresentou menor índice de CVf para a pressão de abertura e fechamento.
Eficiência de um hidrociclone de geometria "rietema" para pré-filtragem de água para irrigação
Authors: Cruz Othon C. Da , Zanini José R.
Published: September 2010

O hidrociclone é um equipamento amplamente utilizado pela indústria em processos envolvendo separação sólido-líquido, porém ainda pouco utilizado na agricultura irrigada no Brasil. Neste trabalho, avaliou-se o desempenho deste equipamento como pré-filtrante de partículas sólidas, oriundas dos processos erosivos e do assoreamento dos recursos hídricos. Os testes foram realizados com um hidrociclone de geometria "Rietema", possuindo diâmetro de 19,2 cm na parte cilíndrica, operando com vazões variando entre 10 m³ h-1 e 27 m³ h-1. Os materiais particulados usados em suspensão foram: solo franco-argiloso e areia de rio. Os resultados mostraram que a perda de carga máxima média foi de 52 kPa e 47 kPa para as suspensões aquosas de areia e solo, respectivamente. Seu melhor desempenho ocorreu operando com suspensão aquosa de areia, apresentando eficiência total de 92,3% para a vazão de 26,9 m³ h-1. Concluiu-se que o equipamento avaliado é mais eficiente para remoção de partículas de areia, podendo ser utilizado como pré-filtro em sistemas de irrigação.
Proposta de um sistema de medição de desempenho aplicado à mecanização agrícola
Authors: Peloia Paulo R. , Milan Marcos
Published: September 2010

As organizações líderes dos mais diferentes setores têm como característica medir o próprio desempenho de modo sistêmico, porém nas empresas agrícolas ainda não é comum o emprego desse conceito, incluindo o setor de mecanização. A mecanização tem um forte impacto na composição dos custos de produção, e conhecer o seu desempenho é primordial para o sucesso de empresa agrícola. A importância que as medidas de desempenho têm no auxílio à gestão e o que a mecanização representa para os custos de produção justificaram o desenvolvimento deste trabalho, que tem como objetivo propor um sistema de medição de desempenho integrado para dar suporte à gestão da mecanização agrícola. A metodologia foi dividida em duas etapas: adaptação de um modelo conceitual sistêmico, com base no Balanced Scorecard - BSC; aplicação do modelo a um estudo de caso na agroindústria canavieira. A adaptação e a aplicação do modelo conceitual permitiu obter indicadores de desempenho de modo sistêmico e associados a: custo e prazo (tradicionalmente utilizados); controle e melhoria na qualidade de operações e processos de apoio; preservação ambiental; segurança, saúde, satisfação, motivação e capacitação de colaboradores; desenvolvimento de sistemas de informação. Conclui-se que o modelo auxiliou na elaboração do sistema de medição de desempenho para a gestão de sistemas mecanizados e que os indicadores permitem uma visão integrada da empresa e associada aos objetivos estratégicos.
"Quo vadis", Europa? Uma pergunta que não quer calar
Authors: Camargo Sonia de
Published: September 2010

Dois temas básicos são discutidos e examinados neste trabalho: a incorporação de dez novos membros aos quadros da União Européia e a constitucionalização de sua estrutura jurídico-institucional. Para tanto, proponho-me, de um lado, a reconstituir os passos político-institucionais que cobrem o período que vai de uma Europa do pós-guerra, fragmentada e enfraquecida, a uma Europa pós-Guerra Fria, pronta para se estender a todo o continente, processo que se abre em maio de 2004 com a incorporação de dez Estados vindos do Leste Europeu; de outro, a reproduzir o debate institucional entre uma Europa federal e uma Europa de Estados, o qual levou a que, em junho de 2003, fosse apresentado ao Conselho Europeu reunido em Salônica o projeto do novo Tratado da União e, em dezembro de 2003, fosse discutido, na Cúpula de Chefes de Estado da UE, reunida em Bruxelas, o texto da primeira Constituição para a Europa.
The effect of anti-hypertensive drugs on the obstructive pancreatitis in rats
Authors: Silva Roberto de Barros , Ramalho Fernando Silva , Ramalho Leandra Z. Naira
Published: September 2010

PURPOSE: To investigate the effect of ACE inhibitor, lisinopril and AT1 blocker, losartan, on the obstructive pancreatitis in rat. METHODS: Acute pancreatitis in rats (n=21) was induced for a common hepatic duct were ligated proximal to its entry into the pancreas and the common bile - pancreatic duct were also ligated near its junction with the duodenum, under ether anesthesia, after which the abdomen were closed. The animals was divided in tree groups, being two treated and control group. The animals was treated with Losartan and Lisinopril at the dose of 10µg/Kg body weight per day, i.p., in a proportional volume, for five days, before and after treatement. RESULTS: The inflammation, collagen deposition in the pancreas of treated animals were smaller, suggesting that the use of antihypertensive agents interfered positively in the depletion of the injury of the pancreas. Scythe showed a correlation between activity of pancreatic stellate cells (PSCs) lower in treated animals when compared to control. CONCLUSION: The pancreatic stellate cells strength are involved in collagen production during acute pancreatitis and why antihypertensive drugs such as lisinopril and losartan may possibly have beneficial effects in reducing pancreatic fibrosis in models of experimental obstructive pancreatitis.
Effect of sirolimus on renal injury induced by bile duct ligation in rats
Authors: Ozturk Hulya , Terzi Akan , Ozturk Hayrettin , Kukner Aysel
Published: September 2010

PURPOSE: To evaluate the effects of sirolimus (SRL) on renal injury in rats with bile duct ligation. METHODS: A total of 21 male Sprague-Dawley rats weighing 220-260g were used. Group 1 (Sham-control, n=7) rats were undergone laparotomy alone and bile duct was just dissected from the surrounding tissue. Group 2 rats (BDL/Untreated, n=7) were subjected to bile duct ligation and no drug was applied. Group 3 rats (BDL/SRL, n =7) received a daily dose of sirolimus (0.5 mg·day-1xkg-1 dissolved 1 ml in saline) by orogastric tube for 14 days after BDL. At the end of the two-week period, biochemical and histological evaluation were processed. RESULTS: AST, ALT, AP and TB levels values were decreased in group 3 when compared to group 2. There was no significant difference in serum levels of BUN and creatinine among all the experimental groups. Histological evaluation of the liver of BDL/Untreated group rats demonstrated marked portal fibrosis and signs of major bile duct obstruction with prominent portal and lobular inflammation. In BDL/SRL group, moderate damage was seen. Tubular injury scores were higher in the BDL subgroups; however, group 3 rats showed considerably fewer lesions in the tubules and interstitium compared to the group 2 rats. In group 2 animals, in the epithelial cells of proximal tubules presented vacuoles and hydropic changes, atrophy and inflammatory cell infiltrate in the medullar interstitium. CONCLUSIONS: Sirolimus decreased tubulointerstitial lesions in kidney induced by bile duct ligation in rats. The improve effects of sirolimus on renal morphology can be due to improved liver function or due to direct action on the kidney.
Pulmonary function and quality of life in patients with morbid obesity six months after bariatric surgery
Authors: Xavier Márcia Arruda Fajardo , Ceneviva Reginaldo , Terra Filho João , Sankarankutty Ajith Kumar
Published: September 2010

PURPOSE: To investigate the body weight, pulmonary function and quality of life of twenty patients with morbid obesity six months after the Fobi-Capella operation. METHODS: Patients were evaluated before and six months after surgery. The patients were mainly female (75%), the average age was 40.5 ± 10.27 years; average weight 110.11 kg ± 21.77 and average body mass index (BMI) 39.93 ± 7.13 kg/m² in the postoperative evaluation. Pulmonary function was assessed by spirometry using a Pulmonet/Godart NV Bilt Vetr Hotland spirometer and quality of life was assessed by applying the Moorehead-Ardelt questionnaire. The pre- and postoperative spirometry values were compared by the paired Student t test and the correlation between weight loss and pulmonary function was determined by linear regression, with the level of significance set at p < 0.05. RESULTS: The spirometry variables Respiratory Frequency (RF), Expiratory Reserve Volume (ERV) and Functional Residual Capacity (FRC) differed significantly between the pre- and postoperative periods, whereas Residual Volume (RV), Vital Capacity (VC), Total Lung Capacity (TLC), FEF25-75 (Forced Expiratory Flow between 25 and 75% FVC) and FEV1/FVC% (Forced Expiratory Volume in the 1st second/ Forced Vital Capacity ratio) did not differ between periods. Only one patient reported worsening of quality of life. There was a positive correlation between weight loss and ERV (p=0.0117, r=0.5514), but no correlations were observed for the other variables. CONCLUSIONS: There was a significant weight loss and an improvement of pulmonary function as seen by respiratory frequency, reduction and increased expiratory reserve volume and functional residual capacity. The quality of life of the patients also improved after the Fobi-Capella operation.