bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sleep architecture of the melanin‐concentrating hormone receptor 1‐knockout mice
Authors: Adamantidis Antoine , Salvert Denise , Goutagny Romain , Lakaye Bernard , Gervasoni Damien , Grisar Thierry , Luppi Pierre‐Hervé , Fort Patrice 
Published: March 2008

AbstractGrowing amounts of data indicate involvement of the posterior hypothalamus in the regulation of sleep, especially paradoxical sleep (PS). Accordingly, we previously showed that the melanin‐concentrating hormone (MCH)‐producing neurons of the rat hypothalamus are selectively activated during a PS rebound. In addition, intracerebroventricular infusion of MCH increases total sleep duration, suggesting a new role for MCH in sleep regulation. To determine whether activation of the MCH system promotes sleep, we studied spontaneous sleep and its homeostatic regulation in mice with deletion of the MCH‐receptor 1 gene (MCH‐R1–/– vs. MCH‐R1+/+) and their behavioural response to modafinil, a powerful antinarcoleptic drug. Here, we show that the lack of functional MCH‐R1 results in a hypersomniac‐like phenotype, both in basal conditions and after total sleep deprivation, compared to wild‐type mice. Further, we found that modafinil was less potent at inducing wakefulness in MCH‐R1–/– than in MCH‐R1+/+ mice. We report for the first time that animals with genetically inactivated MCH signaling exhibit altered vigilance state architecture and sleep homeostasis. This study also suggests that the MCH system may modulate central pathways involved in the wake‐promoting effect of modafinil.
Generation recruitment and death of brain cells throughout the life cycle ofSorexshrews (Lipotyphla)
Authors: Bartkowska Katarzyna , Djavadian Rouzanna L. , Taylor Jan R. E. , Turlejski Kris 
Published: March 2008

AbstractYoung shrews of the genusSorexthat are born in early summer reduce their body size before wintering, including a reduction of brain weight of 10–30%. In the spring they mature sexually, double their body weight and regain about half of the loss in brain weight. To investigate the mechanisms of brain weight oscillations we studied the rate of cell death and generation in the brain during the whole life cycle of the common shrew (Sorex araneus) and pygmy shrew (S. minutus). After weaning, shrews generate new brain cells in only two mammalian neurogenic zones and approximately 80% of these develop into neurones. The increase of the shrew brain weight in the spring did not depend on recruitment of new cells. Moreover, adultSorexshrews did not generate new cells in the dentate gyri. Injections of 5‐HT1A receptor agonists in the adult shrews induced neurogenesis in their dentate gyri, showing the presence of dormant progenitor cells. Generation of new neurones in the subventricular zone of the lateral ventricles and their recruitment to olfactory bulbs continued throughout life. TUNEL labelling showed that the rate of cell death in all brain structures, including the proliferation zones and olfactory bulb, was very low throughout life. We conclude that neither cell death nor recruitment significantly contributes to seasonal oscillations and the net loss of brain weight in theSorexshrews. With the exception of dentate gyrus and olfactory bulb, cellular populations of brain structures are stable throughout the life cycle of these shrews.
Endothelial cell‐derived bone morphogenetic proteins regulate glial differentiation of cortical progenitors
Authors: Imura Tetsuya , Tane Kotoha , Toyoda Nana , Fushiki Shinji 
Published: March 2008

AbstractGliogenesis is an important component of cortical development during the postnatal period. Two macroglial cells are generated in a particular order, i.e. astrocytes first and oligodendrocytes later. The mechanisms underlying this sequence of glial differentiation are unknown but interactions with blood vessels are postulated to play a role. We show, using a mouse in‐vitro coculture system, that endothelial cells promote astrocyte differentiation but inhibit oligodendrocyte differentiation of postnatal cortical progenitors. Endothelial cells produce bone morphogenetic proteins (BMPs) to activate Sma‐ and Mad‐related protein (Smad) signalling in progenitors and the effects of endothelial cells on glial differentiation are blocked by the BMP antagonist Noggin. Differentiation of progenitors into astrocytes results in the inhibition of endothelial cell growth, accompanied by changes in gene expression of angiogenic factors, indicating bidirectional interactions between progenitors and endothelial cells. In vivo, Smad signalling is activated in various types of cortical cells including progenitors in association with astrogenesis but is inactivated before the peak of oligodendrogenesis. Capillary vessels isolated from the developing cortex express high levels of BMPs. Together, these results demonstrate that endothelial cells regulate glial differentiation by secreting BMPs in vitro and suggest a similar role in cortical gliogenesis in vivo.
ALG‐2 interacting protein AIP1: a novel link between D1 and D3 signalling
Authors: Zhan Lingping , Liu Bigang , Jose‐Lafuente Maria , Chibalina Margarita V. , Grierson Andrew , Maclean Alan , Nasir Jamal 
Published: March 2008

AbstractDopamine signalling is a critically important process in the human brain that controls mood, cognition and motor activity. In order to gain detailed insight into this signalling pathway at the molecular level, we carried out yeast two‐hybrid screens with D1‐like (D1, D5) and D2‐like (D2, D3, D4) dopamine receptors and identified 11 dopamine receptor interacting proteins (DRIPs). Using the C‐terminal domain of D1 receptor as bait, we identified AIP1 (ALG‐2 interacting protein 1), a known modulator of caspase‐dependent and caspase‐independent cell death, including neuronal cell death, that is also part of the endosomal transport system. In a separate yeast two‐hybrid screen, using the third intracellular cytoplasmic loop of D3 as bait, we again identified AIP1. The interaction of AIP1 with both D1 and D3 was confirmed in vitro and in vivo using a variety of methods, including glutathione S‐transferase (GST) pull‐down, blot overlay and coimmunoprecipitation from mouse brain lysates. We have also observed colocalization of D1 and D3 with AIP1 in mouse brain tissue. In addition, coexpression of AIP1 with D1 resulted in > 50% reduction in binding capacity of D1 to its antagonist. Finally, AIP1 up‐regulates D1 and D3 expression and appears to be important for their stability and trafficking.
Differential synaptic plasticity of the corticostriatal and thalamostriatal systems in an MPTP‐treated monkey model of parkinsonism
Authors: Raju Dinesh V. , Ahern Todd H. , Shah Deep J. , Wright Terrence M. , Standaert David G. , Hall Randy A. , Smith Yoland 
Published: March 2008

AbstractTwo cardinal features of Parkinson's disease (PD) pathophysiology are a loss of glutamatergic synapses paradoxically accompanied by an increased glutamatergic transmission to the striatum. The exact substrate of this increased glutamatergic drive remains unclear. The striatum receives glutamatergic inputs from the thalamus and the cerebral cortex. Using vesicular glutamate transporters (vGluTs) 1 and 2 as markers of the corticostriatal and thalamostriatal afferents, respectively, we examined changes in the synaptology and relative prevalence of striatal glutamatergic inputs in methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐treated monkeys using electron microscopic immunoperoxidase and confocal immunofluorescence methods. Our findings demonstrate that the prevalence of vGluT1‐containing terminals is significantly increased in the striatum of MPTP‐treated monkeys (51.9 ± 3.5% to 66.5 ± 3.4% total glutamatergic boutons), without any significant change in the pattern of synaptic connectivity; more than 95% of vGluT1‐immunolabeled terminals formed axo‐spinous synapses in both conditions. In contrast, the prevalence of vGluT2‐immunoreactive terminals did not change after MPTP treatment (21.7 ± 1.3% vs. 21.6 ± 1.2% total glutamatergic boutons). However, a substantial increase in the ratio of axo‐spinous to axo‐dendritic synapses formed by vGluT2‐immunoreactive terminals was found in the pre‐caudate and post‐putamen striatal regions of MPTP‐treated monkeys, suggesting a certain degree of synaptic reorganization of the thalamostriatal system in parkinsonism. About 20% of putative glutamatergic terminals did not show immunoreactivity in striatal tissue immunostained for both vGluT1 and vGluT2, suggesting the expression of another vGluT in these boutons. These findings provide striking evidence that suggests a differential degree of plasticity of the corticostriatal and thalamostriatal system in PD.
Learning‐related changes in reward expectancy are reflected in the feedback‐related negativity
Authors: Bellebaum Christian , Daum Irene 
Published: March 2008

AbstractThe feedback‐related negativity (FRN) has been hypothesized to be linked to reward‐based learning. While many studies have shown that the FRN only occurs in response to unexpected negative outcomes, the relationship between the magnitude of negative prediction errors and FRN amplitude remains a matter of debate. The present study aimed to elucidate this relationship with a new behavioural procedure that allowed subjects to predict precise reward probabilities by learning an explicit rule. Insight into the rule did not only influence subjects' choice behaviour, but also outcome‐related event‐related potentials. After subjects had learned the rule, the FRN amplitude difference between non‐reward and reward mirrored the magnitude of the negative prediction error, i.e. it was larger for less likely negative outcomes. Source analysis linked this effect to the anterior cingulate cortex. P300 amplitude was also modulated by outcome valence and expectancy. It was larger for positive and unexpected outcomes. It remains to be clarified, however, whether the P300 reflects a positive prediction error.
Tau expression levels from various adeno‐associated virus vector serotypes produce graded neurodegenerative disease states
Authors: Klein Ronald L. , Dayton Robert D. , Tatom Jason B. , Diaczynsky Cynthia G. , Salvatore Michael F. 
Published: March 2008

AbstractNeurodegenerative diseases involving neurofibrillary tangle pathology are pernicious. By expressing the microtubule‐associated protein tau, a major component of tangles, with a viral vector, we induce neuropathological sequelae in rats that are similar to those seen in human tauopathies. We tested several variants of the adeno‐associated virus (AAV) vector for tau expression in the nigrostriatal system in order to develop models with graded onset and completeness. Whereas previous studies with AAV2 tau vectors produced partial lesions of the nigrostriatal system, AAV9 or AAV10 tau vectors were more robust. These vectors had formidable efficacy relative to 6‐hydroxydopamine for dopamine loss in the striatum. Time‐courses for tau transgene expression, dopamine loss and rotational behavior tracked the disease progression with the AAV9 tau vector. There was a nearly complete lesion over a delayed time‐course relative to 6‐hydroxydopamine, with a sequence of tau expression by 1 week, dopamine loss by 2 weeks and then behavior effect by 3–4 weeks. Relative to AAV2 or AAV8, tau expression from AAV9 or AAV10 peaked earlier and caused more dopamine loss. Varying vector efficiencies produced graded states of disease up to nearly complete. The disease models stemming from the AAV variants AAV9 or AAV10 may be useful for rapid drug screening, particularly for tau diseases that affect the nigrostriatal system, such as progressive supranuclear palsy.
Imbrication of the external anal sphincter may yield similar functional results as overlapping repair in selected patients
Authors: Oberwalder M. , Dinnewitzer A. , Nogueras J. J. , Weiss E. G. , Wexner S. D. 
Published: March 2008

AbstractObjective  Overlapping external anal sphincter repair is the preferred procedure for incontinent patients with functional yet anatomically disrupted anterior external anal sphincter. When incomplete disruption, thinning or technically difficult mobilization of the external anal sphincter occurs, imbrication without division may be the more feasible surgical option. The aim of the study was to assess retrospectively the indications for external anal sphincter imbrication in patients who underwent either overlapping external anal sphincter repair or external anal sphincter imbrication, and to compare the success rates.Method  Patients who had external anal sphincter repair and follow up of at least 3 months were studied. Fecal incontinence was measured using the validated Wexner fecal Incontinence Scoring system (0 = perfect continence, 20 = complete incontinence); postoperative scores 0–10 were interpreted as successful, and scores of 11–20 as failures.Results  A total of 131 females who had anal sphincter repair between 1988 and 2000 were analysed. One hundred and twenty‐one patients had overlapping external anal sphincter repair (group I), and 10 had external anal sphincter imbrication (group II). Indications for external anal sphincter imbrication were attenuation of the external anal sphincter without overt defect (n = 5), partial disruption of external anal sphincter with muscle fibres bridging the scar (n = 2), thick bulk of scar between the muscle edges (n = 2), and wide lateral retraction of the muscle edges (n = 1). There were no statistically significant differences between the groups relative to preoperative incontinence score (16.5 vs 16.5, P = 0.99), pudendal nerve terminal motor latency assessment (left 9.6%vs 0.0%, P = 0.19; right 13.4%vs 11.1%, P = 0.84), and extent of electromyography pathology (61%vs 47%, P = 0.30). The patients in group I were younger than those in group II (mean age 50.8 years vs. 61.7 years, respectively; P = 0.052) and the length of follow‐up was significantly longer (32.3 months vs 14.3 months, respectively; P < 0.0001). Both procedures had similar success rates (59.5%vs 60%; P = 0.98).Conclusion  Imbrication of the external anal sphincter may yield similar results as overlapping external anal sphincter repair in patients with incomplete external anal sphincter disruptions, external anal sphincter attenuation, and in patients presenting with wide lateral retraction of the muscle edges.
Awareness of risk factors amongst first degree relative patients with colorectal cancer
Authors: Akhtar S. , Sinha S. , McKenzie S. , Sagar P. M. , Finan P. J. , Burke D. 
Published: March 2008

AbstractBackground  The association between family history of colorectal cancer (CRC) in first degree relatives (FDRs) and the risk of developing the disease has been well established. However, little is known about the degree of awareness of CRC risk factors amongst FDRs. This study examined awareness of familial, dietary and lifestyle risk amongst FDRs.Method  Consent to approach relatives was obtained from CRC patients who attended outpatients following surgery for CRC. A study specific questionnaire was sent by post to their FDRs. The dietary and lifestyle risk factors tested in the questionnaire were those promoted in CRC educational material.Results  One hundred and four questionnaires were returned out of 137 sent (76%). Fifty‐nine per cent (n = 61) of FDRs were aware of their increased risk. Fifty‐five per cent (n = 57) were aware of the link between CRC and smoking; however, knowledge of association of CRC with excessive alcohol consumption (32%) and lack of exercise (40%) was less well appreciated. Higher awareness scores were obtained by those with a university education (P < 0.001). Ninety four per cent believed that relatives of CRC patients were not provided with enough information as to their being at risk and risk factors.Conclusions  This study provides an initial assessment of the awareness of CRC risk factors in a population at increased risk. It demonstrates a poor level of knowledge. Improved education strategies allowing FDRs to make dietary and lifestyle modifications that could reduce their lifetime risk of developing CRC are necessary.
A novel exocrine gland in the trochanter of ant legs
Authors: Billen Johan 
Published: March 2008

AbstractWe found a hitherto unknown gland in the trochanter of several ant species. The gland occurs at the proximal ventral part of the trochanter in all legs. It consists of a thickening of the tegumental epithelium, the lining cuticle of which is characterized by narrow vertical pores that lead the secretion to the outside. Its function is probably that of producing lubricant substances to allow optimal manoeuvrability of the articulation between the trochanter and the coxa.
Is the End of the MFA a Threat?
Authors: Marouani Mohamed Ali 
Published: March 2008

AbstractThe end of the Multifiber Agreement in January, 2005 had a negative impact on the apparel industry of regional exporters, but the effects were weaker than expected. Using a dynamic general equilibrium model, the article provides a prospective assessment of the impact on Tunisia of the phase out of the MFA, and of the agreement which manages the rate of growth of Chinese clothing exports to Europe, until the end of 2007. The main findings are an increase in unemployment and wage inequality but no significant effects on the main macroeconomic variables, if the exchange rate management takes into account this shock.
Globalization and Taste Convergence: the Cases of Wine and Beer
Authors: Aizenman Joshua , Brooks Eileen 
Published: March 2008

AbstractThis paper investigates changes in cultural consumption patterns for a low‐concentration industry: wine and beer. Using data on 38 countries from 1963–2000, there is clear convergence in the consumption of wine relative to beer between 1963 and 2000. Convergence occurs even more quickly within groups of countries that have a higher degree of integration. A key prediction of international trade is confirmed in the data: greater trade integration weakens the association between production and consumption patterns—although the relative consumption of wine can be explained well in 1963 by grape production and latitude, these variables are much less significant in 2000. Despite these “scientific” explanations, there is also a cultural angle to wine consumption. While the relative wine consumption of France and Germany is converging, several Latin American countries fail to converge. The patterns of convergence are consistent with dynamics of adjustment in overlapping generation habit formation models.
NUTRITIONAL REQUIREMENTS OF HAEMATOCOCCUS PLUVZALIS AND RELATED SPECIES1
Authors: Pringsheim Ernest G. 
Published: March 2008

SUMMARY All the described species and varieties of the genus Haematococcus were available. After isolation in pure culture they were used studying their nutritional requirements.H. buetschlii and H. droebakensis had already been shown by Droop to need vitamin B12. H. capensis typ., H. capensis var. borealis, and H. zimbabwiensis were found to do so also. The 7 strains of H. pluvi‐alis from various localities investigated showed slight physiological deviations, although morphologically they were so similar that they should not be described as varieties. A dilute inorganic nutrient solution with trace elements and iron kept in solution by EDTA was suitable either as such or supplemented with growth‐promoting compounds. The growth was speeded by low concentrations of acetate and by enhancing photosynthesis. No strain of H. pluvialis absolutely required cobalamin, although it stimulated. Thiamine had a much more pronounced effect; for some strains it was indispensable. Although the response varies slightly from strain to strain, a luxuriant growth for all was obtained only with acetate and B1, and usually enhanced by B12. A peculiar feature of H. pluvialis is the catching up of cultures initially retarded by thiamine deficiency (probably due to slow Bl synthesis). When H. pluvialis multiplied fast its appearance differed from that considered typical: no red pigment and the cell wall not inflated. In nature it evidently lives under conditions unfavorable for good growth although suitable for survival in competition with other organisms.
PHOTOINDUCTION AND PHOTOREVERSAL OF THE NOSTOCACEAN DEVELOPMENTAL CYCLE1
Authors: Lazaroff Norman 
Published: March 2008

SUMMARY The developmental cycle of Nostoc muscorum, a nitrogen‐fixing blue‐green alga, is controlled by the spectral quality of illumination. Red light with peak activity at 650 mμ induces development of filaments from a nonfilamentous (aseriate) stage of the life cycle. Red‐light photoinduction is reversed by simultaneous or subsequent exposure to light from a broad band in the green region of the spectrum. Photoreversibility of the red‐light induction, by green light, decays very slowly, remaining at an appreciable level for over 24 hr after the primary stimulus. Allophycocyanin is indicated to be the photoreceptor for red‐light induction. One or more phycoeythrins may operate as photoreceptors for reversal of induction. The dosage response and wavelength dependence of developmental photocontrol in Nostoc muscorum A indicate that a nonphotosynthetic mechanism is involved in both developmental photoinduction and its photoreversal.
EFFECTS OF TEMPERATURE AND ILLUMINANCE ON CELL DIVISION RATES OF THREE SPECIES OF TROPICAL OCEANIC PHYTOPLANKTON1
Authors: Thomas William H. 
Published: March 2008

SUMMARY Three species of tropical oceanic phytoplankton were isolated from two locations in the eastern Pacific Ocean. Unialgal cultures were maintained in an enriched seawater medium. The effects of temperature, and, in separate experiments, illuminance, on the exponential cell division rates of those algae were investigated. For 2 isolates of Gymnodinium sp. (probably G. simplex), maximum growth rates were 1.25 and 1.7 divisions/24 hr, the optimum temperature range was 23–29 C, the compensation illuminance was 35 ft‐c, and the saturation illuminance was 750 ft‐c and above. For a small species of Chaetoceros, the maximum growth rate was 6.0 divisions/24 hr, the optimum temperature range was 23–37 C, the compensation illuminance was 10 ft‐c, and the saturation illuminance was 600 ft‐c. For a small Nannochloris species, the maximum growth rate was 4.5 divisions/ 24 hr, the optimum temperature range was 27–37 C, and the saturation illuminance was 800 ft‐c. Nannochloris grew heterotrophically by apparently utilizing organic matter supplied by soil extract.
HETEROTROPHY OF FOUR MARINE PHYTOPLANKTERS AT LOW SUBSTRATE CONCENTRATIONS1
Authors: Sloan P. R. , Strickland J. D. H. 
Published: March 2008

SUMMARY Three pelagic marine phytoplankters, Coccolithus huxleyi, Skeletonema costatum, and Thalassiosira rotula, and a facultative heterotroph, Cyclotella cryptica, have been exposed to three organic substrates, viz, glucose, acetate, and glutamate, at low concentrations (organic carbon 0.25 mg/liter). Experiments were performed in the dark and light and the net assimilation of substrate was measured by using radiocarbon. The dark uptake of carbon dioxide was also determined, together with photosynthesis at near optimum light intensity. The expected heterotrophy was detected with Cyclotella cryptica. Thalassiosira rotula was found to assimilate glutamate at an appreciable rate. In all cases, however, the short‐term uptake of carbon dioxide in the dark was the greatest assimilation rate measured. Values are discussed in relation to their ecological significance and it is concluded that heterotrophic survival of these and probably most other algae in the open ocean would be impossible unless they were in contact with a high concentration of substrate in the form of particulate matter.