bluuebunny/crossref_metadata_2025 huggingface dataset:
Information Disclosure and Unraveling in Matching Markets
Authors: Ostrovsky Michael , Schwarz Michael
Published: May 2010

This paper explores information disclosure in matching markets. A school may suppress some information about students in order to improve their average job placement. We consider a setting with many schools, students, and jobs, and show that if early contracting is impossible, the same, “balanced” amount of information is disclosed in essentially all equilibria. When early contracting is allowed and information arrives gradually, if schools disclose the balanced amount of information, students and employers will not find it profitable to contract early. If they disclose more, some students and employers will prefer to sign contracts before all information is revealed. (JEL C78, D82, D83)
Are Speculators Unwelcome in Multi-Object Auctions?
Authors: Pagnozzi Marco
Published: May 2010

I consider a uniform-price auction under complete information. The possibility of resale attracts speculators who have no use value for the objects on sale. A high-value bidder may strictly prefer to let a speculator win some of the objects and then buy in the resale market, in order to keep the auction price low. Although resale induces entry by speculators and therefore increases the number of competitors, high-value bidders' incentives to “reduce demand” are also affected. Allowing resale to attract speculators reduces the seller's revenue when bidders' valuations are dispersed. Speculators increase the seller's revenue only when they are outbid. (JEL D44, D83)
Are Tax Incentives for Charitable Giving Efficient? Evidence from France
Authors: Fack Gabrielle , Landais Camille
Published: May 2010

This paper estimates the effect of tax incentives for charitable contributions in France. We focus on two reforms that increased the nonrefundable tax credit rate for charitable contributions by 32 percent. We use a difference-in-difference identification, comparing the evolution of contributions for groups of households with similar income, but different taxable status due to differences in family size. We control for censoring issues and investigate distributional effects using a three-step censored quantile regression estimator. We find that the price elasticity of contributions is relatively small, but tends to increase with the level of gifts. (JEL D14, D64, H24)
A Greater Price for a Greater Good? Evidence that Consumers Pay More for Charity-Linked Products
Authors: Elfenbein Daniel W , McManus Brian
Published: May 2010

To study whether consumers will pay more for products that generate charitable donations, we analyze data from eBay on charity and noncharity auctions of otherwise identical products. Charity prices are 6 percent higher, on average, than noncharity prices. Bids below the closing price are also higher, as are bids by individuals bidding on identical charity and noncharity products. Bidders appear to value charity revenue at least partially as a public good, as they submit bids earlier in charity auctions, stimulating other bidders to bid more aggressively. Our results help explain why firms may pledge charitable donations, green production, or similar activities. (JEL D12, D44, D64, L81, M14, M31)
Guillain-Barré Syndrome Following H1N1 Immunization in a Pediatric Patient
Authors: Tremblay Marie-Eve , Closon Aurélie , D'Anjou Guy , Bussières Jean-François
Published: May 2010

Objective:

To report a case of Guillain-Barré syndrome (GBS) following a dose of influenza A (H1N1) vaccine (Arepanrix).

Case Summary:

An 11-year-old boy was admitted to the hospital after presenting with facial diplegia; abdominal, forehead, and thigh pain; and acute cervical pain. He had received the Arepanrix H1N1 subcutaneous vaccine 13 days before symptom onset. The neurologic examination also revealed a symmetric bilateral paralysis of the VIIth cranial nerve and intense pain, proximal weakness of the shoulder girdles and pelvis, and preserved deep tendon reflexes. Cerebrospinal fluid analysis revealed an albuminocytologic dissociation. Therefore, a diagnosis of atypical GBS following vaccination against H1N1 influenza was made.

Discussion:

Based on the clinical evaluation, laboratory test results, neurologic features, and the exclusion of alternative diagnoses, the Naranjo probability scale revealed a probable relationship between the clinical manifestations of GBS and the vaccine against influenza A (H1N1) received by the patient. This is the first published case for the 2009 influenza pandemic in children.

Conclusions:

While recent studies have found inconclusive results on the association between influenza vaccine and GBS, all suspected cases should be published for further evaluation.
Deletion of cathepsin H perturbs angiogenic switching, vascularization and growth of tumors in a mouse model of pancreatic islet cell cancer
Authors: Gocheva Vasilena , Chen Xiaoping , Peters Christoph , Reinheckel Thomas , Joyce Johanna A.
Published: May 2010

Proteases can regulate many aspects of tumor development as their actions, which include degradation of the extracellular matrix, proteolytic processing of chemokines and activation of other enzymes, influence several key tumorigenic processes. Members of one protease class, the cysteine cathepsins, have received increasing recognition for their involvement in cancer development, and numerous clinical studies have reported correlations between elevated cathepsin levels and malignant progression. This is also the case for cathepsin H, a member of the cysteine cathepsin family, and its utility as a prognostic marker has been analyzed extensively. However, there is limited information available on its specific functions in tumor development and progression. To gain further insight into the role of this protease in cancer, we crossed cathepsin H-deficient mice with the RIP1-Tag2 model of pancreatic islet carcinogenesis. Deletion of cathepsin H significantly impaired angiogenic switching of the pre-malignant hyperplastic islets and resulted in a reduction in the subsequent number of tumors that formed. Moreover, the tumor burden in cathepsin H null RT2 mice was significantly reduced, in association with defects in the blood vasculature and increased apoptosis. Thus, we demonstrate here for the first time important tumor-promoting roles for cathepsin H in vivo using a mouse model of human cancer.
Structure, mechanism and inhibition of γ-secretase and presenilin-like proteases
Authors: Wolfe Michael S.
Published: May 2010

Presenilin is the catalytic component of γ-secretase, a complex aspartyl protease and a founding member of intramembrane-cleaving proteases. γ-Secretase is involved in the pathogenesis of Alzheimer's disease and a top target for therapeutic intervention. However, the protease complex processes a variety of transmembrane substrates, including the Notch receptor, raising concerns about toxicity. Nevertheless, γ-secretase inhibitors and modulators have been identified that allow Notch processing and signaling to continue, and promising compounds are entering clinical trials. Molecular and biochemical studies offer a model for how this protease hydrolyzes transmembrane domains in the confines of the lipid bilayer. Progress has also been made toward structure elucidation of presenilin and the γ-secretase complex by electron microscopy as well as by studying cysteine-mutant presenilins. The signal peptide peptidase (SPP) family of proteases are distantly related to presenilins. However, the SPPs work as single polypeptides without the need for cofactors and otherwise appear to be simple model systems for presenilin in the γ-secretase complex. SPP biology, structure, and inhibition will also be discussed.
Is BACE1 a suitable therapeutic target for the treatment of Alzheimer's disease? Current strategies and future directions
Authors: Klaver David W. , Wilce Matthew C.J. , Cui Hao , Hung Amos C. , Gasperini Robert , Foa Lisa , Small David H.
Published: May 2010

Alzheimer's disease (AD) is characterized by the extracellular deposition of the β-amyloid protein (Aβ). Aβ is a fragment of a much larger precursor protein, the amyloid precursor protein (APP). Sequential proteolytic cleavage of APP by β-secretase and γ-secretase liberates Aβ from APP. The aspartyl protease BACE1 (β-siteAPP-cleavingenzyme 1) catalyses the rate-limiting step in the production of Aβ, and as such it is considered to be a major target for drug development in Alzheimer's disease. However, the development of a BACE1 inhibitor therapy is problematic for two reasons. First, BACE1 has been found to have important physiological roles. Therefore, inhibition of the enzyme could have toxic consequences. Second, the active site of BACE1 is relatively large, and many of the bulky compounds that are needed to inhibit BACE1 activity are unlikely to cross the blood-brain barrier. This review focuses on the structure BACE1, current therapeutic strategies based on developing active-site inhibitors, and new approaches to therapy involving targeting the expression or post-translational regulation of BACE1.
Molecular diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency: an update of new CYP21A2 mutations
Authors: Concolino Paola , Mello Enrica , Zuppi Cecilia , Capoluongo Ettore
Published: May 2010

Steroid 21-hydroxylase deficiency is present in more than 90% of patients with congenital adrenal hyperplasia, an inherited metabolic disorder of adrenal steroidogenesis. Impaired enzymatic activity leads to the accumulation of metabolic intermediates (progesterone and 17-hydroxyprogesterone), which results in excessive androgen production and varied signs of virilisation. CYP21A2 is an active gene and encodes for the steroid 21-hydroxylase enzyme, whereas CYP21A1P is an inactive pseudogene that contains a series of deleterious mutations. The major part of disease-causing mutations in CYP21A2 alleles are CYP21A1P-derived sequence transferred to the active gene by macro or microconversion events. Approximately 5% of all disease-causing CYP21A2 alleles harbour rare mutations that do not originate from the pseudogene. A list of all reported CYP21A2 mutations can be found in the CYP21A2 database created by the Human Cytochrome P450 (CYP) Allele Nomenclature Committee (http:www.imm.Ki.se/CYPalleles/cyp21.htm). Unfortunately, the last update of this database was in 2006. However, over the last 4 years many other novel CYP21A2 mutations have been reported in PubMed. The aim of this review is to provide a focus on the molecular and genetic aspects of the diagnosis of 21-hydroxylase deficiency. In addition, an updated list of the last new CYP21A2 mutations is included.

Clin Chem Lab Med 2010;48:1057–62.
Evaluation of the BacT/ALERT® 3D system for the implementation of in-house quality control sterility testing at Canadian Blood Services
Authors: Mastronardi Cherie , Perkins Heather , Derksen Paul , denAdmirant Michael , Ramírez-Arcos Sandra
Published: May 2010

Background: Until recently, Canadian Blood Services (CBS) was performing quality control sterility testing of blood components using three different processes. This study was conducted in order to standardize sterility testing at all CBS centers in a cost-effective manner using the BacT/ALERT® 3D system.

Methods: Blood components including fresh frozen plasma, platelet concentrates, and red blood cells were inoculated with eight bacterial species at target concentrations of 1 and 10 CFU/mL. Pre- and post-spiked samples were inoculated into BacT/ALERT® aerobic and anaerobic culture bottles and incubated for a maximum of 10 days. Specificity of the positive culture bottles was verified by Gram staining. Positive results obtained pre- and post-implementation of the in-house sterility testing program at CBS were collected and analyzed.

Results: The BacT/ALERT®3D system detected all bacteria in all blood components tested in this validation. Positive cultures were obtained within 28 h of incubation with the exception of Propionibacterium acnes which was detected within 134 h. The percentage of positive cultures ranged from 0.01% to 0.2%. All contaminants isolated were either normal skin flora or environmental microorganisms.

Conclusions: This study demonstrates the capability of the BacT/ALERT®3D system to detect aerobic and anaerobic bacterial contamination in all tested blood components, thereby supporting its use for quality control sterility testing and not only bacterial screening. A standardized process will allow CBS to evaluate and compare blood collection and manufacturing practices across the country.

Clin Chem Lab Med 2010;48:1179–87.
Roles of Semaphorin-6B and Plexin-A2 in Lamina-Restricted Projection of Hippocampal Mossy Fibers
Authors: Tawarayama Hiroshi , Yoshida Yutaka , Suto Fumikazu , Mitchell Kevin J. , Fujisawa Hajime
Published: May 2010

Hippocampal mossy fibers project preferentially to the proximal-most lamina of the suprapyramidal region of CA3, the stratum lucidum, and proximal-most parts of the infrapyrmidal region of CA3c. Molecular mechanisms that govern the lamina-restricted projection of mossy fibers, however, have not been fully understood. We previously studied functions of neural repellent Semaphorin-6A (Sema6A), a class 6 transmembrane semaphorin, and its receptors, plexin-A2 (PlxnA2) and PlxnA4, in mossy fiber projection and have proposed that PlxnA4-expressing mossy fibers are principally prevented from entering the Sema6A-expressing suprapyramidal and infrapyramidal regions of CA3 but are permitted to grow into proximal parts of the regions, where repulsive activity of Sema6A is competitively suppressed by PlxnA2 (Suto et al., 2007). In the present study we demonstrate that Sema6B, another class 6 transmembrane semaphorin, is expressed in CA3 and repels mossy fibers in a PlxnA4-dependent mannerin vitro. InSema6B-deficient mice several mossy fibers aberrantly project to the stratum radiatum and the stratum oriens. The number of aberrant mossy fibers is increased inSema6A;Sema6Bdouble knock-out mice, indicating that Sema6A and Sema6B function additively to regulate proper projection of mossy fibers. PlxnA2 does not suppress the Sema6B response, but itself promotes growth of mossy fibers. Based on these results, we propose that the balance between mossy fiber repulsion by Sema6A and Sema6B and attraction by PlxnA2 and unknown molecule(s) prescribes the areas permissive for mossy fibers to innervate.
Frequency-Dependent Attentional Modulation of Local Field Potential Signals in Macaque Area MT
Authors: Khayat Paul S. , Niebergall Robert , Martinez-Trujillo Julio C.
Published: May 2010

Visual attention modulates neuronal responses in primate motion processing area MT. However, whether it modulates the strength local field potentials (LFP-power) within this area remains unexplored, as well as how this modulation relates to the one of the neurons' response. We investigated these issues by simultaneously recording LFPs and neuronal responses evoked by moving random dot patterns of varying direction and contrast in area MT of two male monkeys (Macaca mulatta) during different behavioral conditions. We found that: (1) LFP-power in the γ (30–120 Hz), but not in the δ (2–4 Hz), θ (4–8 Hz), α (8–12 Hz), β1(12–20 Hz), and β2(20–30 Hz) frequency bands, was tuned for motion direction and contrast, similarly to the neurons' response, (2) shifting attention into a neuron's receptive field (RF) decreased LFP-power in the bands below 30 Hz (except the θ band), whereas shifting attention to a stimulus motion direction outside the RF had no effect in these bands, (3) LFP-power in the γ band, however, exhibited both spatial- and motion direction-dependent attentional modulation (increase or decrease), which was highly correlated with the modulation of the neurons' response. These results demonstrate that in area MT, shifting attention into the RFs of neurons in the vicinity of the recording electrode, or to the direction of a moving stimulus located far away from these RFs, distinctively modulates LFP-power in the various frequency bands. They further suggest differences in the neural mechanisms underlying these types of attentional modulation of visual processing.
Evidence for Specialized Rhythm-Generating Mechanisms in the Adult Mammalian Spinal Cord
Authors: Frigon Alain , Gossard Jean-Pierre
Published: May 2010

Locomotion and scratch are characterized by alternation of flexion and extension phases within one hindlimb, which are mediated by rhythm-generating circuitry within the spinal cord. By definition, the rhythm generator controls cycle period, phase durations, and phase transitions. The aim was to determine whether rhythm-generating mechanisms for locomotion and scratch are similar in adult decerebrate cats. The regulation of cycle period during fictive scratching was evaluated, as were the effects of specific sensory inputs on phase durations and transitions during spontaneous fictive locomotion and pinna-evoked fictive scratching. Results show that cycle period during fictive scratching varied predominantly with flexion phase duration, contrary to spontaneous fictive locomotion, where cycle period varied with extension phase duration. Ankle dorsiflexion greatly increased extension phase duration and cycle period during fictive locomotion but did not alter cycle period during scratching. Moreover, stimulating the plantaris (ankle extensor muscle) nerve during flexion reset the locomotor rhythm to extension but not the scratch rhythm. Stimulating the plantaris nerve during extension prolonged the extension phase and cycle period during fictive locomotion but not during fictive scratching. Stimulating the sartorius nerve (hip flexor muscle) during early flexion reduced the flexion phase and cycle period during fictive locomotion, but considerably prolonged the flexion phase and cycle period during fictive scratching. These data indicate that cycle period, phase durations, and phase transitions are not regulated similarly during fictive locomotion and scratching, with or without sensory inputs, providing evidence for specialized rhythm-generating mechanisms within the adult mammalian spinal cord.
Tyk2/STAT3 Signaling Mediates β-Amyloid-Induced Neuronal Cell Death: Implications in Alzheimer's Disease
Authors: Wan Jun , Fu Amy K. Y. , Ip Fanny C. F. , Ng Ho-Keung , Hugon Jacques , Page Guylène , Wang Jerry H. , Lai Kwok-On , Wu Zhenguo , Ip Nancy Y.
Published: May 2010

One of the pathological hallmarks of Alzheimer's disease (AD) is deposition of extracellular amyloid-β (Aβ) peptide, which is generated from the cleavage of amyloid precursor protein (APP). Accumulation of Aβ is thought to associate with the progressive neuronal death observed in AD. However, the precise signaling mechanisms underlying the action of Aβ in AD pathophysiology are not completely understood. Here, we report the involvement of the transcription factor signal transducer and activator of transcription 3 (STAT3) in mediating Aβ-induced neuronal death. We find that tyrosine phosphorylation of STAT3 is elevated in the cortex and hippocampus of APP/PS1 transgenic mice. Treatment of cultured rat neurons with Aβ or intrahippocampal injection of mice with Aβ both induces tyrosine phosphorylation of STAT3 in neurons. Importantly, reduction of either the expression or activation of STAT3 markedly attenuates Aβ-induced neuronal apoptosis, suggesting that STAT3 activation contributes to neuronal death after Aβ exposure. We further identify Tyk2 as the tyrosine kinase that acts upstream of STAT3, as Aβ-induced activation of STAT3 and caspase-3-dependent neuronal death can be inhibited in tyk2−/−neurons. Finally, increased tyrosine phosphorylation of STAT3 is also observed in postmortem brains of AD patients. Our observations collectively reveal a novel role of STAT3 in Aβ-induced neuronal death and suggest the potential involvement of Tyk2/STAT3 signaling in AD pathophysiology.
11β-Hydroxysteroid Dehydrogenase Type 1 Expression Is Increased in the Aged Mouse Hippocampus and Parietal Cortex and Causes Memory Impairments
Authors: Holmes Megan C. , Carter Roderick N. , Noble June , Chitnis Shruti , Dutia Amy , Paterson Janice M. , Mullins John J. , Seckl Jonathan R. , Yau Joyce L. W.
Published: May 2010

Increased neuronal glucocorticoid exposure may underlie interindividual variation in cognitive function with aging in rodents and humans. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes the regeneration of active glucocorticoids within cells (in brain and other tissues), thus amplifying steroid action. We examined whether 11β-HSD1 plays a role in the pathogenesis of cognitive deficits associated with aging in male C57BL/6J mice. We show that 11β-HSD1 levels increase with age in CA3 hippocampus and parietal cortex, correlating with impaired cognitive performance in the water maze. In contrast, neither circulating corticosterone levels nor tissue corticosteroid receptor expression correlates with cognition. 11β-HSD1 elevation appears causal, since aging (18 months) male transgenic mice with forebrain-specific 11β-HSD1 overexpression (∼50% in hippocampus) exhibit premature age-associated cognitive decline in the absence of altered circulating glucocorticoid levels or other behavioral (affective) deficits. Thus, excess 11β-HSD1 in forebrain is a cause of as well as a therapeutic target in memory impairments with aging.
The Neurotoxic Effects of Estrogen on Ischemic Stroke in Older Female Rats Is Associated with Age-Dependent Loss of Insulin-Like Growth Factor-1
Authors: Selvamani Amutha , Sohrabji Farida
Published: May 2010

Hormone therapy to postmenopausal females increases the risk and severity of ischemic stroke. Our previous work using an animal model of menopause (reproductive senescence) shows that middle cerebral artery occlusion (MCAo) causes a larger cortical–striatal infarct in this older acyclic group compared with younger females. Moreover, although estrogen treatment is neuroprotective in younger females, estrogen paradoxically increases infarct volume in acyclic females. We hypothesized that the neurotoxic effects of estrogen in older females occurs because of decreased availability of IGF-1, a neuroprotectant that decreases with advancing age and is downregulated by estrogen treatment. Our data show that plasma IGF-1 levels are significantly reduced in reproductive senescent females and further reduced by estrogen at all ages. The neuroprotective effect of estrogen on MCAo-induced cortical infarct volume in mature adult female is reversed by intracerebroventricular injections of IGF-1 receptor antagonist JB-1. Similarly, estrogens neurotoxic effects on cortical infarct volume in senescent females is attenuated by concurrent IGF-1 treatment, and reversed when IGF-1 is infused 4 h after the onset of ischemia (delayed IGF-1 treatment). Delayed IGF-1/estrogen treatment also suppressed ischemia-induced ERK1 phosphorylation, reduced protein oxidation, and stimulated an early increase in prostaglandin E2at the infarct site. IGF-1 treatment was only protective in senescent females that received estrogen, indicating that the neuroprotective actions of this peptide require interaction with the steroid hormone receptor. These data support the hypothesis that stroke severity in older females is associated with decreased IGF-1 and further indicate that short-term postischemic IGF-1 therapy may be beneficial for stroke.
Liver X Receptor Agonist Treatment Ameliorates Amyloid Pathology and Memory Deficits Caused by High-Fat Diet in APP23 Mice
Authors: Fitz Nicholas F. , Cronican Andrea , Pham Tam , Fogg Allison , Fauq Abdul H. , Chapman Robert , Lefterov Iliya , Koldamova Radosveta
Published: May 2010

High-fat diet and certain dietary patterns are associated with higher incidence of sporadic Alzheimer's disease (AD) and cognitive decline. However, no specific therapy has been suggested to ameliorate the negative effects of high fat/high cholesterol levels on cognition and amyloid pathology. Here we show that in 9-month-old APP23 mice, a high-fat/high-cholesterol (HF) diet provided for 4 months exacerbates the AD phenotype evaluated by behavioral, morphological, and biochemical assays. To examine the therapeutic potential of liver X receptor (LXR) ligands, APP23 mice were fed HF diet supplemented with synthetic LXR agonist T0901317 (T0). Our results demonstrate that LXR ligand treatment causes a significant reduction of memory deficits observed during both acquisition and retention phases of the Morris water maze. Moreover, the effects of T0 on cognition correlate with AD-like morphological and biochemical parameters. We found a significant decrease in amyloid plaque load, insoluble Aβ and soluble Aβ oligomers.In vitroexperiments with primary glia demonstrate that Abca1 is essential for the proper lipidation of ApoE and mediates the effects of T0 on Aβ degradation by microglia. Microdialysis experiments performed on awake freely moving mice showed that T0 decreased Aβ levels in the interstitial fluid of the hippocampus, supporting the conclusion that this treatment increases Aβ clearance. The data presented conclusively shows that LXR activation in the context of a metabolic challenge has critical effects on AD phenotype progression by attenuating Aβ deposition and facilitating its clearance.
Attention Alters Feature Space in Motion Processing
Authors: Zirnsak Marc , Hamker Fred H.
Published: May 2010

Attending to a particular feature modulates the activity of neurons throughout the visual field with the result that relevant features are enhanced while irrelevant features are suppressed. Do these modulatory influences merely lead to a gating of relevant features, or does attention have a direct impact on the representation of feature space, leading to a different percept depending on the content of attention? We observed that direction estimates of the static motion aftereffect drastically change when human observers attend to a stimulus whose motion direction differs from the one of the adaptor. This observation suggests that feature-based attention might operate by local magnifications of feature space between relevant and irrelevant features.
Connexin 43 Mediates the Tangential to Radial Migratory Switch in Ventrally Derived Cortical Interneurons
Authors: Elias Laura A. B. , Turmaine Mark , Parnavelas John G. , Kriegstein Arnold R.
Published: May 2010

The adult cerebral cortex is composed of excitatory and inhibitory neurons that arise from progenitor cells in disparate proliferative regions in the developing brain and follow different migratory paths. Excitatory pyramidal neurons originate near the ventricle and migrate radially to their position in the cortical plate along radial glial fibers. On the other hand, inhibitory interneurons arise in the ventral telencephalon and migrate tangentially to enter the developing cortex before migrating radially to reach their correct laminar position. Gap junction adhesion has been shown to play an important mechanistic role in the radial migration of excitatory neurons. We asked whether a similar mechanism governs the tangential or radial migration of inhibitory interneurons. Using short hairpin RNA knockdown of Connexin 43 (Cx43) and Cx26 together with rescue experiments, we found that gap junctions are dispensable for the tangential migration of interneurons, but that Cx43 plays a role in the switch from tangential to radial migration that allows interneurons to enter the cortical plate and find their correct laminar position. Moreover this action is dependent on the adhesive properties and the C terminus of Cx43 but not the Cx43 channel. Thus, the radial phase of interneuron migration resembles that of excitatory neuron migration in terms of dependence on Cx43 adhesion. Furthermore, gap junctions between migrating interneurons and radial processes were observed by electron microscopy. These findings provide mechanistic and structural support for a gap junction-mediated interaction between migrating interneurons and radial glia during the switch from tangential to radial migration.
Heterogeneity in Ventricular Zone Neural Precursors Contributes to Neuronal Fate Diversity in the Postnatal Neocortex
Authors: Stancik Elizabeth K. , Navarro-Quiroga Ivan , Sellke Robert , Haydar Tarik F.
Published: May 2010

The recent discovery of short neural precursors (SNPs) in the murine neocortical ventricular zone (VZ) challenges the widely held view that radial glial cells (RGCs) are the sole occupants of this germinal compartment and suggests that precursor variety is an important factor of brain development. Here, we usein uteroelectroporation and genetic fate mapping to show that SNPs and RGCs cohabit the VZ but display different cell cycle kinetics and generate phenotypically different progeny. In addition, we find that RGC progeny undergo additional rounds of cell division as intermediate progenitor cells (IPCs), whereas SNP progeny generally produce postmitotic neurons directly from the VZ. By clearly defining SNPs as bona fide VZ residents, separate from both RGCs and IPCs, and uncovering their unique proliferative and lineage properties, these results demonstrate how individual neural precursor groups in the embryonic rodent VZ create diversity in the overlying neocortex.
MAG and OMgp Synergize with Nogo-A to Restrict Axonal Growth and Neurological Recovery after Spinal Cord Trauma
Authors: Cafferty William B. J. , Duffy Philip , Huebner Eric , Strittmatter Stephen M.
Published: May 2010

Functional recovery after adult CNS damage is limited in part by myelin inhibitors of axonal regrowth. Three molecules, Nogo-A, MAG, and OMgp, are produced by oligodendrocytes and share neuronal receptor mechanisms through NgR1 and PirB. While each has an axon-inhibitory rolein vitro, theirin vivointeractions and relative potencies have not been defined. Here, we compared mice singly, doubly, or triply mutant for these three myelin inhibitor proteins. The myelin extracted from Nogo-A mutant mice is less inhibitory for axons than is that from wild-type mice, but myelin lacking MAG and OMgp is indistinguishable from control. However, myelin lacking all three inhibitors is less inhibitory than Nogo-A-deficient myelin, uncovering a redundant and synergistic role for all three proteins in axonal growth inhibition. Spinal cord injury studies revealed an identicalin vivohierarchy of these three myelin proteins. Loss of Nogo-A allows corticospinal and raphespinal axon growth above and below the injury, as well as greater behavioral recovery than in wild-type or heterozygous mutant mice. In contrast, deletion of MAG and OMgp stimulates neither axonal growth nor enhanced locomotion. The triple-mutant mice exhibit greater axonal growth and improved locomotion, consistent with a principal role for Nogo-A and synergistic actions for MAG and OMgp, presumably through shared receptors. These data support the hypothesis that targeting all three myelin ligands, as with NgR1 decoy receptor, provides the optimal chance for overcoming myelin inhibition and improving neurological function.
Acute effects of hydrocortisone on the metabolic response to a glucose load: increase in the first-phase insulin secretion
Authors: Vila Greisa , Krebs Michael , Riedl Michaela , Baumgartner-Parzer Sabina M , Clodi Martin , Maier Christina , Pacini Giovanni , Luger Anton
Published: May 2010

Background and aim

Several basic science studies support the existence of non-genomic glucocorticoid signaling in pancreas, liver, and adipocytes, but its clinical relevance has not yet been elucidated. This study aimed at investigating the rapid effects of hydrocortisone on the human metabolic response to glucose.

Subjects and methods

In a randomized placebo-controlled crossover study, ten healthy men received an i.v. bolus of 0.6 mg/kg hydrocortisone once and placebo once 4 min before the administration of 330 mg/kg glucose. Cortisol, glucose, insulin, C-peptide, ghrelin, and peptide YY (PYY) levels were measured during the following 3 h. Minimal model analysis was performed for evaluating the metabolic response.

Results

Hydrocortisone attenuated the rise in plasma glucose during the initial 15 min following glucose administration (P=0.039), and it led to lower glucose levels during the first 2 h (P=0.017). This was accompanied by enhanced circulating insulin (P=0.02) and C-peptide (P=0.03) levels during the initial 15 min, and a 35% increase in the first-phase β-cell function (P=0.003). Hydrocortisone decreased PYY concentrations during the initial 30 min (P=0.014), but it did not affect the ghrelin response to glucose.

Conclusion

One i.v. bolus of hydrocortisone induces rapid effects on carbohydrate metabolism increasing the first-phase β-cell function. The modulation of PYY plasma levels suggests the possible non-genomic effects of glucocorticoids on appetite-regulatory hormones.
Giant Steps, freedom won over / by constraint
Authors: Michel Philippe
Published: May 2010

If we listen to all of the choruses available today amongst those recorded by John Coltrane in 1959 for the different takes of ‘Giant Steps’, we are left with the same feeling of whirling, caused by the extreme motivic repetition. Among the commentators of this piece, many have underlined the reoccurrence in the saxophone choruses, of a certain number of melodic figures (amongst which the emblematic ‘1-2-3-5’ motive, a defective pentatonic figure which pre-announced the polymodal system to be developed in the historic Coltrane quartet). This suggests, at least from the part of the saxophonist, a radical approach (restrictive and strangely constraining) to the principle of formulaic improvisation initiated by Charlie Parker. The limitation of melodic material, which Coltrane is confronted with throughout his improvisations on ‘Giant Steps’, is reinforced in the very particular arrangement of the formulaic material (a melodic matrix), which he systematically uses throughout the solos of a single session (even more so, to a certain extent, from one session to another): a paradigmatic and reductionnist analysis of the choruses, indeed shows Coltrane’s recourse to combinatorial principles, allowing him to open up the field of repetitive temporal extension, thus guaranteeing this sensation of whirling which it was manifestly aimed at. Obviously, one cannot help but establish a parallel between this reductionnist/combinatorial principle and the rigorous (if not serial) principles (similar to Alexander Tcherepnin’s and Joseph Schillinger’s) which underlines the composition from the melodic/harmonic theme. Such a cross-cultural adaptation of compositional techniques to improvisationnal context shows us on Coltrane’s part, a desire to find a new ‘way’, an original sound in close relation to the originality of the melodic-harmonic theme (from which the saxophonist seems to adopt as his own, the principle of theme-solo unity, so dear to Thelonious Monk, whose partner he had been). Finally, far from confining the analysis to observation of structural principles separated from all potential esthetic function (that is, from any musical realization), we conclude by attempting to discern what John Coltrane may have wished to feel (or make others feel) by means of what could seem to be simply a challenge, unnecessarily constricting. Besides the idea of an opening onto a circular sound world made accessible by combinatorics (close to the concept of ‘open work’), we even envisage that of freedom won over / by constraint.
Coltrane and Beyond
Authors: Whyton Tony , Tackley Catherine , Cotro Vincent
Published: May 2010

Welcome to the second special issue of the Jazz Research Journal focusing on John Coltrane. As a complement to the previous collection of writings, this issue explores both the musical practices and interdisciplinary contexts for Coltrane research, with contributions examining the artist’s life and music from a variety of unique perspectives. As an iconic jazz musician, Coltrane’s influence on the worlds of music, art and poetry has been profound and ‘Coltrane studies’ can now be considered a truly interdisciplinary and established research field. This issue further demonstrates the breadth of perspectives and disciplinary reach of Coltrane scholarship, following the 2007 International Coltrane Colloquium at the University of Tours.
Intervallic Structuring in the Compositions of John Coltrane
Authors: Florin Ludovic
Published: May 2010

The improvisational side of John Coltrane somewhat overshadows the composer he was. Yet, some themes meant so much to him that he would just play them without following up with any improvisations. This presentation is an attempt to define Coltrane's compositional process. What started this reflection was an intuition, listening to his music, that intervals of seconds and thirds are to be frequently found in the shaping of his originals. It seemed interesting to question this aspect by systematically examining all the saxophonist's 'written' compositions in order to decide if that intuition turned out to be right or wrong. Understanding this initial move also allows us to further grasp the musician's aesthetics. Methodology: ? So far I have selected only the compositions from the albums published under Coltrane's name, between 1957 and 1967. As for the publishing of seminar proceedings, the results will be extended to all the registered Coltrane compositions. ? In order to determine the frequency of intervals in a batch of 99 compositions, the software 'Monika' was used. Designed by musicologist Nicolas Meeùs, this programme is for 'description and help for analysis'. Prior to this counting, we had to establish what does or doesn't constitute the theme which, more often than not, was not written on music paper, especially from 1964 onwards. ? Of course, improvised pieces with a title but no theme, such as Chasin' the Trane for instance, have been ignored. Results : ? The resulting figures are quite obvious: intervals of seconds and thirds are indeed the most numerous. In fact, this comes as no surprise. On the other hand, the surprising thing is the amount of wider intervals. ? As years went by, one can witness an evolution. ? Also, in keeping with Rudolph Réti's idea of 'thematic process', some compositional devices in Coltrane's originals come out as recurring elements. ? Thus analysed, one realizes that some motifs - often a single one - make up a matrix for Coltrane's themes. ? Investigating further, one realizes that, more often than not, Coltrane's harmonic movements are not dictated by the cycle of fifths but by movements in seconds or thirds.
Feijoeiro manteiga, planta-teste para os vírus de vira-cabeça e da necrose branca do fumo
Authors: Costa A. S.
Published: May 2010

Entre cêrca de 200 variedades de feijoeiro ensaiadas, a Manteiga foi mais sensitiva aos vírus de vira-cabeça e da necrose branca, formando, nas fôlhas primárias, lesões locais adequadas para contagens. Com o vírus de vira-cabeça as lesões locais apareceram de 3 -6 dias após as inoculações, sob a forma de manchas cloróticas, às vezes com anéis necróticos; com o vírus da necrose branca as lesões se manifestaram em 1 - 4 dias, sob a forma de pontuações necróticas, pequenos anéis necróticos ou, em casos de certas estirpes do vírus, como pintas cloróticas. Feijoeiros com as fôlhas primárias tendo 2/3 de sua expansão ou mais desenvolvidas deram melhores resultados para o vírus de vira-cabeça; para o vírus da necrose branca os melhores resultados foram obtidos com fôlhas que tinham 2/3 ou ligeiramente menos de sua expansão total. O vírus de vira-cabeça não se tornou sistêmico em plantas inoculadas mecanicamente. A maioria das estirpes do vírus da necrose branca também não se tornou sistêmica em feijoeiros inoculados mecanicamente. Uma estirpe amarela deste tem a capacidade de se tornar sistêmica em feijoeiros sob determinadas condições. O sulfito de sódio em solução 0,0125 M, usado na extração do inóculo, aumentou ligeiramente o número de lesões formadas nas fôlhas do feijoeiro Manteiga pelo vírus de vira-cabeça; aumento consideravelmente maior foi obtido com a extração em presença de búfer de fosfato 0,1 M com pH 7, sendo êsse efeito atribuído a um aumento da sensitividade da planta-teste. A mistura de ambos causou aumento igual ou ligeiramente menor que o búfer só. Para o vírus da necrose branca a presença de sulfito de sódio 0,0125 M durante a extração aumentou consideravelmente o número de lesões, sendo esse efeito atribuído à diminuição na perda de atividade do vírus, devida à oxidação; o búfer sozinho ocasionou pequeno aumento em comparação com a testemunha, mas a mistura de búfer e sulfito de sódio deu o maior aumento.
Adubação da cana de açúcar. I - Adubação fosfatada em solo massapê-salmourao
Authors: Alvarez R. , Segalla A. L. , Catani R. A. , Arruda H. V. de
Published: May 2010

Neste trabalho são apresentados os resultados preliminares obtidos em terra massapê-salmourão da Usina Itaiquara, município de Tapiratiba, em três ensaios com diferentes fertilizantes fosfatados. No ensaio instalado em 1950, em presença de nitrogênio e potássio foram estudados oito tipos de adubos fosfatados, na dose de 120 kg/ha de P2O5 verificando-se que, estatísticamente, deram os mesmos resultados: superfosfáto'simples, serranafosfato, farinha de ossos degelatinados, farinha de ossos autoclavados, hiper-fosfato, fosfato argeliano e fosfato do Morro do Serrote. A bauxita fosforosa mostrou-se inferior ao superfosfáto e às duas farinhas de ossos. Em outros dois experimentos, instalados em 1952, foram estudados cinco tipos de fertilizantes fosfatados, nos níveis de 0, 40, 80 e 120 kg/ha de P2O5. e os resultados mostraram que não houve diferença entre o superfosfato simples, farinha de ossos degelatinados, fosfato bicálcico (fertifós) e hiperfosfato; o fosfato do Morro do Serrote foi inferior a êsses fertilizantes.
Variedades de cavalos de videira e sua melhor época de enraizamento
Authors: Ribas Wilson Corrêa , Conagin Armando
Published: May 2010

A indicação prática de que as melhores épocas para plantio de formação de vinhedo no Estado de São Paulo eram os meses de junho, julho e agosto, se baseavam em observações locais. No entanto, o atual progresso da viticultura paulista estava exigindo que se comprovassem experimentalmente essas informações. Por este trabalho se verificou ser possível a plantação, para formação de vinhedos em São Paulo, desde meados de junho a meados de setembro. Verificou-se também que, desde que seja possível, será melhor plantar os bacelos em junho, julho e agosto. Conseguiu-se ainda estabelecer mais nitidamente a preferência das variedades de bacelos estudadas com referência às suas melhores épocas de plantação. Verificou-se, também, corresponder à plantação nesses meses a ocorrência de melhor pagamento e formação de vegetação mais sadia e vigorosa, o que, indubitavelmente, deverá influir na formação de vinhedos mais homogêneos e de maior produção.
Ensaios de variedades de amendoim. II - Oitava e nona séries de ensaios
Authors: Pilho Vicente Canecchio , Tella Romeu de , Abramides Eduardo
Published: May 2010

No presente trabalho são apresentados os resultados obtidos em duas séries de ensaios instalados com o objetivo de estudar o comportamento, em três diferentes regiões agrícolas do Estado, das variedades de amendoim que se revelaram mais promissoras em ensaios anteriores, cujos dados já foram publicados. De um modo geral, as duas séries compreenderam seis experiências plantadas em três Estações Experimentais do Instituto Agronômico. Pelos resultados obtidos destacaram-se, pela maior produtividade, as variedades Roxo 40 e 54 e a Tatuí 76. Os maiores rendimentos foram obtidos em solo terra-roxa-misturada da Estação Experimental Central em Campinas, em 1952-53, com uma produção mínima de 2.990 quilos por hectare e máxima de 5.170 quilos por hectare.
O farelo de torta de mamona na adubação da batatinha
Authors: Boock O. J.
Published: May 2010

Na composição de fórmulas de adubação para a cultura da batatinha com freqüência entrava o farelo de torta de algodão, com resultados satisfatórios (1). Em conseqüência da proibição do seu emprêgo como fertilizante, para ser usado exclusivamente na composição de rações para animais, procurou-se um outro farelo que pudesse substituí-lo e que não tivesse emprêgo "in natura", na alimentação animal. Dentre eles sobressaiu-se o farelo de torta de mamona, que possui um princípio tóxico, a ricinina. No presente trabalho são fornecidos os resultados da sua utilização na composição de fórmulas de adubação para batatinha. As conclusões a que se chegou vieram recomendar o seu uso em confronto com o farelo de torta de algodão e sulfato de amónio. Os resultados alcançados, em experiências levadas a efeito em seis localidades do Estado e em épocas diferentes, mostraram que a mistura dêsse fertilizante com o sulfato de potássio e superfosfato, ou outro adubo nitrogenado, em partes iguais, pode substituir o farelo de torta de algodão
Adubação do algodoeiro: III - Ensaios sôbre a aplicação de azôto em cobertura
Authors: Neves O. S. , Freire E. S.
Published: May 2010

Nêste trabalho são apresentados os resultados de três ensaios realizados entre 1937-38 e 1941-42 nas Estações Experimentais de Mococa (em solo massapê), Tietê (em solo argiloso) e Tatuí (em terra-roxa-misturada), nos quais canteiros adubados com fósforo e potássio foram comparados com outros que receberam esses nutrientes e mais azoto. O azôto, nas formas de salitre do Chile e de Calnitro IG (mistura de nitrato de amônio e carbonato de cálcio), foi aplicado pelo método usual - nos sulcos destinados às sementes, no momento do plantio - ou em cobertura, ao achar-se o algodoeiro em pleno desenvolvimento. O fósforo e o potássio foram sempre empregados nos sulcos de plantio. Em Mococa e Tietê os ensaios foram conduzidos, nos mesmos canteiros, por três anos; em Tatuí, por dois. Os dois adubos azotados deram o mesmo resultado. Em Mococa eles aumentaram apreciavelmente a produção, não se notando diferença entre os dois métodos de aplicação, mas em Tietê e Tatuí o azôto empregado nos sulcos de plantio em regra pouco aumentou ou mesmo deprimiu a produção, ao passo que a elevou consideravelmente quando aplicado em cobertura. • Em Mococa, tendo chovido nos dias imediatos ao plantio, os adubos azotados não prejudicaram o "stand"; por outro lado, as chuvas caídas não foram suficientes para lixiviar o azôto do massapê utilizado para o ensaio. Em Tietê o motivo principal da inferioridade da aplicação dos adubos azotados nos sulcos de plantio foi o prejuízo que eles causaram às sementes em germinação, devido à elevada concentração local de sais. Num dos dois anos de ensaio em Tatuí ficou patente que o azôto empregado nos sulcos foi arrastado antes de o algodoeiro o ter podido absorver, enquanto o aplicado em cobertura não sofreu esse inconveniente. O arrastamento do azôto, que se dá sobretudo quando êle é empregado por ocasião do plantio, não teve grande influência nos presentes ensaios, porque os solos usados para dois deles (Mococa e Tietê) eram argilosos e as chuvas caídas durante sua execução foram relativamente moderadas. Em terras leves, como são em grande parte as utilizadas para a cultura do algodoeiro, tanto esse fator como o excesso de concentração de sais teriam assumido muito maior importância, e, com isso, a superioridade da aplicação em cobertura se tornaria ainda mais pronunciada.
Fermentação alcoólica do caldo de cana-de-açúcar var. co. 290. IV - Efeito da adição de tiamina e manganês sôbre o rendimento alcoólico
Authors: Teixeira C. G. , Salati A.
Published: May 2010

Realizou-se uma experiência comparativa para verificar a influência da adição de tiamina e sulfato de manganês sôbre o rendimento alcoólico obtido pela fermentação do caldo de cana de açúcar da variedade Co. 290. Verificou-se que tanto a tiamina como o sulfato de manganês provocam um aumento no rendimento alcoólico. Pela adição das duas substâncias ao caldo de cana a ser fermentado, obtêm-se rendimentos alcoólicos superiores àquêles resultantes da adição de cada uma delas em separado. Rendimentos alcoólicos mais elevados foram ainda obtidos pela adição de farelo de arroz ao caldo de cana a ser fermentado. O farelo de arroz parece ser altamente benéfico na fermentação alcoólica em virtude do seu teor elevado em tiamina e, talvez, outras substâncias de importância para a nutrição e atividade do fermento alcoólico, tais como o ácido pantotênico e o manganês.