bluuebunny/crossref_metadata_2025 huggingface dataset:
An implicit enumeration method for an exact test of weighted kappa
Authors: Brusco Michael J. , Stahl Stephanie , Steinley Douglas
Published: July 2007

The kappa coefficient is one of the most widely used measures for evaluating the agreement between two raters asked to assign N objects to one of K nominal categories. Weighted versions of kappa enable partial credit to be awarded for near agreement, most notably in the case of ordinal categories. An exact significance test for weighted kappa can be conducted by enumerating all rater agreement tables with the same fixed marginal frequencies as the observed table, and accumulating the probabilities for all tables that produce a weighted kappa index that is greater than or equal to the observed measure. Unfortunately, complete enumeration of all tables is computationally unwieldy for modest values of N and K. We present an implicit enumeration algorithm for conducting an exact test of weighted kappa, which can be applied to tables of non‐trivial size. The algorithm is particularly efficient for ‘good’ to ‘excellent’ values of weighted kappa that typically have very small p‐values. Therefore, our method is beneficial for situations where resampling tests are of limited value because the number of trials needed to estimate the p‐value tends to be large.
Controlling item exposure and test overlap on the fly in computerized adaptive testing
Authors: Chen Shu‐Ying , Lei Pui‐Wa , Liao Wen‐Han
Published: July 2007

This paper proposes an on‐line version of the Sympson and Hetter procedure with test overlap control (SHT) that can provide item exposure control at both the item and test levels on the fly without iterative simulations. The on‐line procedure is similar to the SHT procedure in that exposure parameters are used for simultaneous control of item exposure rates and test overlap rate. The exposure parameters for the on‐line procedure, however, are updated sequentially on the fly, rather than through iterative simulations conducted prior to operational computerized adaptive tests (CATs). Unlike the SHT procedure, the on‐line version can control item exposure rate and test overlap rate without time‐consuming iterative simulations even when item pools or examinee populations have been changed. Moreover, the on‐line procedure was found to perform better than the SHT procedure in controlling item exposure and test overlap for examinees who take tests earlier. Compared with two other on‐line alternatives, this proposed on‐line method provided the best all‐around test security control. Thus, it would be an efficient procedure for controlling item exposure and test overlap in CATs.
Use of mental simulations to change theory of planned behaviour variables
Authors: Armitage Christopher J. , Reidy John G.
Published: July 2007

Objectives The predictive validity of the theory of planned behaviour is well established, but much less is known about: (a) whether there are causal relationships between key components of the model and (b) how to go about changing the theory of planned behaviour variables. This study tested the ability of outcome and process simulations to change variables specified in the theory of planned behaviour in relation to blood donation.

Design Participants (N = 146) were randomized to one of four conditions: outcome simulation only, process simulation only, process‐plus‐outcome simulation and a distractor control condition. The dependent variables were state anxiety, and intention attitude, subjective norm and perceived control from the theory of planned behaviour.

Methods Participants were asked to empty their mind and visualize themselves: (a) after donating blood (outcome manipulation), (b) preparing to donate blood (process manipulation), (c) both preparing to donate blood and after having donated blood (process‐plus‐outcome manipulation) or (d) both preparing to get a high mark and after having got a high mark on their course (control condition). Following mental rehearsal, participants completed the dependent variables.

Results There were no main effects of outcome simulation, but process simulation successfully increased intention, subjective norm and perceived control. There was also a significant outcome simulation × process simulation interaction for attitude. The effect of the process manipulation on intention was mediated by subjective norm and perceived control.

Conclusions The findings show promise for the use of mental simulations in changing cognitions and further research is required to extend the present findings to other health behaviours.
Multiple Correlative Immunolabeling for Light and Electron Microscopy Using Fluorophores and Colloidal Metal Particles
Authors: Kandela Irawati K. , Bleher Reiner , Albrecht Ralph M.
Published: July 2007

Multiple correlative immunolabeling permits colocalization of molecular species for sequential observation of the same sample in light microscoopy (LM) and electron microscopy (EM). This technique allows rapid evaluation of labeling via LM, prior to subsequent time-consuming preparation and observation with transmission electric miscroscopy (TEM). The procedure also yields two different complementary data sets. In LM, different fluorophores are distinguished by their respective excitation and emission wavelengths. In EM, colloidal metal nanoparticles of different elemental composition can be differentiated and mapped by energy-filtering transmission electron microscopy with electron spectroscopic imaging. For the highest level of spatial resolution in TEM, colloidal metal particles were conjugated directly to primary antibodies. For LM, fluorophores were conjugated to secondary antibodies, which did not affect the spatial resolution attainable by fluorescence microscopy but placed the fluorophore at a sufficient distance from the metal particle to limit quenching of the fluorescence signal. It also effectively kept the fluorophore at a sufficient distance from the colloidal metal particles, which resulted in limiting quenching of the fluorescent signal. Two well-defined model systems consisting of myosin and α-actinin bands of skeletal muscle tissue and also actin and α-actinin of human platelets in ultrathin Epon sections were labeled using both fluorophores (Cy2 and Cy3) as markers for LM and equally sized colloidal gold (cAu) and colloidal palladium (cPd) particles as reporters for TEM. Each sample was labeled by a mixture of conjugates or labels and observed by LM, then further processed for TEM. (J Histochem Cytochem 55: 983–990, 2007)
Diabetes and Arterial Extracellular Matrix Changes in a Porcine Model of Atherosclerosis
Authors: McDonald Thomas O. , Gerrity Ross G. , Jen Christy , Chen Hao-Ji , Wark Kathleen , Wight Thomas N. , Chait Alan , O'Brien Kevin D.
Published: July 2007

Patients with diabetes are at substantially increased risk for atherosclerosis and clinical cardiovascular events. Because arterial extracellular matrix contains several molecules, including biglycan, versican, hyaluronan, and elastin, that may affect plaque lipid retention and stability, we determined whether diabetes affects plaque content of these molecules in a porcine model of hyperlipidemia and diabetes. Coronary artery sections were studied from non-diabetic normolipidemic ( n=11, N-NL), diabetic normolipidemic ( n=10, DM-NL), non-diabetic hyperlipidemic ( n=16, N-HL), and diabetic hyperlipidemic ( n=15, DM-HL) animals. Hyaluronan, biglycan, versican, and apolipoprotein B (apoB) were detected with mono-specific peptides or antisera, and elastin with Movat's pentachrome stain, and contents of each were quantified by computer-assisted morphometry. In the hyperlipidemic groups, diabetes was associated with a 4-fold increase in intimal area, with strong correlations between intimal area and immunostained areas for hyaluronan ( R2 = 0.83, p<0.0001), biglycan ( R2 = 0.72, p<0.0001), and apoB ( R2 = 0.23, p=0.0069). In contrast, median (interquartile range) intimal elastin content was significantly lower with diabetes [N-HL: 5.2% (2.4–8.2%) vs DM-HL: 1.5% (0.5–4.2%), p=0.01], and there was a strong negative correlation between intimal total and elastin areas (Spearman r = −0.62, p=0.001). In this porcine model, diabetes was associated with multiple extracellular matrix changes that have been associated with increased lesion instability, greater atherogenic lipoprotein retention, and accelerated atherogenesis.
Demyelination, Astrogliosis, and Accumulation of Ubiquitinated Proteins, Hallmarks of CNS Disease inhsf1-Deficient Mice
Authors: Homma Sachiko , Jin Xiongjie , Wang Guanghu , Tu Naxin , Min Jinna , Yanasak Nathan , Mivechi Nahid F.
Published: July 2007

The heat shock transcription factors (Hsfs) are responsible for the heat shock response, an evolutionarily conserved process for clearance of damaged and aggregated proteins. In organisms such asCaenorhabditis elegans, which contain a single Hsf, reduction in the level of Hsf is associated with the appearance of age-related phenotypes and increased accumulation of protein aggregates. Mammalian cells express threehsfs(hsf1,hsf2,hsf4) and their role in CNS homeostasis remains unclear. In this study, we examined the effects of deletion of single or multiplehsfgenes in the CNS using mutant mice. Our results show thathsf1−/−mice display progressive myelin loss that accompanies severe astrogliosis and this is exacerbated in the absence of either thehsf2orhsf4gene. Magnetic resonance imaging and behavioral studies indicate reduction in the white matter tracts of the corpus callosum, and deficiencies in motor activity, respectively, in agedhsf1−/−mice. Concomitantly,hsf1−/−aged CNS exhibit increased activated microglia and apoptotic cells that are mainly positive for GFAP, an astrocyte-specific marker. Studies based on the expression of short-lived ubiquitinated green fluorescent protein (GFPu) in livinghsf1−/−cells indicate that they exhibit reduced ability to degrade ubiquitinated proteins, accumulate short-lived GFPu, and accumulate aggregates of the Huntington's model of GFP containing trinucleotide repeats (Q103-GFP). Likewise,hsf1−/−brain and astrocytes exhibit higher than wild-type levels of ubiquitinated proteins, increased levels of protein oxidation, and increased sensitivity to oxidative stress. These studies indicate a critical role for mammalianhsfgenes, but specificallyhsf1, in the quality control mechanisms and maintenance of CNS homeostasis during the organism's lifetime.
Elevated [18F]Fluorodopamine Turnover in Brain of Patients with Schizophrenia: An [18F]Fluorodopa/Positron Emission Tomography Study
Authors: Kumakura Yoshitaka , Cumming Paul , Vernaleken Ingo , Buchholz Hans-Georg , Siessmeier Thomas , Heinz Andreas , Kienast Thorsten , Bartenstein Peter , Gründer Gerhard
Published: July 2007

Previous positron emission tomography (PET) studies with levodopa analogs have revealed a modestly increased capacity for dopamine synthesis in the striatum of patients with schizophrenia compared with healthy age-matched control subjects. We hypothesized that not just the synthesis but also the turnover of radiolabeled dopamine is elevated in patients. To test the hypothesis, we reanalyzed 2-h-long [18F]fluorodopa (FDOPA)/PET recordings from eight unmedicated patients with schizophrenia and 15 healthy age-matched control subjects, using new methods for the quantification of [18F]fluorodopamine steady-state kinetics. The fractional rate constant for the catabolism and elimination of [18F]fluorodopamine was elevated nearly twofold in striatum, the largest biochemical difference in brain of schizophrenics yet reported. The magnitude of the intrinsic blood–brain FDOPA clearance with correction for this loss of [18F]fluorodopamine metabolites was increased by 20% in caudate and putamen and by 50% in amygdala and midbrain of the patients. However, the magnitude of the steady-state storage of FDOPA and its decarboxylated metabolites (Vd) was reduced by one-third in the caudate nucleus and amygdala of the schizophrenic group. Thus, reduced steady-state storage of [18F]fluorodopamine occurs in the midst of accelerated synthesis in brain of untreated patients. Positive scores of the positive and negative syndrome scale correlated inversely with the magnitude ofVdin amygdala, suggesting an association between positive symptoms and impaired steady-state storage of FDOPA metabolites in that structure.
Benefits of Contrast Normalization Demonstrated in Neurons and Model Cells
Authors: Gaudry Kate S. , Reinagel Pamela
Published: July 2007

The large dynamic range of natural stimuli poses a challenge for neural coding: how is a neuron to encode large differences at high contrast while remaining sensitive to small differences at low contrast? Many sensory neurons exhibit contrast normalization: gain depends on the range of stimuli presented, such that firing-rate modulation is not proportional to contrast. However, coding depends strongly on the precision of spike timing and the reliability of spike number, neither of which can be predicted from neural gain. The presumption that contrast normalization is associated with maintained coding efficiency remained untested. We report that, as contrast decreases, responses are more variable and encode less information, as expected. Nevertheless, these changes can be small, and information transmission is even better preserved across contrasts than rate modulation. The extent of contrast normalization is correlated with the extent to which information transmission is preserved across contrasts. Specifically, normalization is associated with maintaining the bits of information per spike rather than bits per second. Finally, we show that a nonadapting model can exhibit both contrast normalization and the associated information preservation.
Primary Sensory Neuron Addition in the Adult Rat Trigeminal Ganglion: Evidence for Neural Crest Glio-Neuronal Precursor Maturation
Authors: Lagares Alfonso , Li Hong-Yun , Zhou Xin-Fu , Avendaño Carlos
Published: July 2007

It is debated whether primary sensory neurons of the dorsal root ganglia increase the number in adult animals and, if so, whether the increase is attributable to postnatal neurogenesis or maturation of dormant, postmitotic precursors. Similar studies are lacking in the trigeminal ganglion (TG). Here we demonstrate by stereological methods that the number of neurons in the TG of adult male rats nearly doubles between the third and eighth months of age. The increase is mainly attributable to the addition of small, B-type neurons, with a smaller contribution of large, A-neurons. We looked for possible proliferative or maturation mechanisms that could explain this dramatic postnatal expansion in neuron number, using bromodeoxyuridine (BrdU) labeling, immunocytochemistry for neural precursor cell antigens, retrograde tracing identification of peripherally projecting neurons, andin vitroisolation of precursor cells from adult TG explant cultures. Cell proliferation identified months after an extended BrdU administration was sparse and essentially corresponded to glial cells. No BrdU-labeled cell took up the peripherally injected tracer, and only a negligible number coexpressed BrdU and the pan-neuronal tracer neuron-specific enolase. In contrast, a population of cells not recognizable as mature neurons in the TG and neighboring nerve expressed neuronal precursor antigens, and neural crest glioneuronal precursor cells were successfully isolated from adult TG explants. Our data suggest that a protracted maturation process persists in the TG that can be responsible for the neuronal addition found in the adult rat.
Dopaminergic Signaling and Striatal Neurodegeneration in Huntington's Disease
Authors: Tang Tie-Shan , Chen Xi , Liu Jing , Bezprozvanny Ilya
Published: July 2007

Huntington's disease (HD) is a neurodegenerative disorder caused by polyglutamine (polyQ) expansion in Huntingtin protein (Htt). PolyQ expansion in Httexpcauses selective degeneration of striatal medium spiny neurons (MSNs) in HD patients. Striatal MSN neurons receive glutamatergic input from the cortex and dopaminergic input from the substantia nigra. In previous studies with the yeast artificial chromosome (YAC128) transgenic HD mouse model, we established a connection between glutamate receptor activation, disturbed calcium (Ca2+) signaling, and apoptosis of HD MSNs (Tang et al., 2005). Here, we used the same YAC128 mouse model to investigate the role of dopaminergic signaling in HD. We discovered that glutamate and dopamine signaling pathways act synergistically to induce elevated Ca2+signals and to cause apoptosis of YAC128 MSNsin vitro. We demonstrated that potentiating effects of dopamine are mediated by D1-class dopamine receptors (DARs) and not by D2-class DARs. Consistent within vitrofindings, in whole-animal experiments we found that persistent elevation of striatal dopamine levels exacerbated the behavioral motor deficits and MSN neurodegeneration in YAC128 mice. We further discovered that the clinically relevant dopamine pathway inhibitor tetrabenazine alleviated the motor deficits and reduced striatal cell loss in YAC128 mice. Our results suggest that dopamine signaling pathway plays an important role in HD pathogenesis and that antagonists of dopamine pathway such as tetrabenazine or dopamine receptor blockers may have a therapeutic potential for treatment of HD beyond well established “symptomatic” benefit.
A Cholinergic Gating Mechanism Controlled by Competitive Interactions in the Optic Tectum of the Pigeon
Authors: Marín Gonzalo , Salas Carlos , Sentis Elisa , Rojas Ximena , Letelier Juan Carlos , Mpodozis Jorge
Published: July 2007

We describe the operation of a midbrain neural circuit in pigeons that may participate in selecting and attending to one visual stimulus from the myriad displayed in their visual environment. This mechanism is based on a topographically organized cholinergic signal reentering the optic tectum (TeO). We have shown previously that, whenever a visual stimulus activates neurons in a given tectal location, this location receives a strong bursting feedback from cholinergic neurons of the nucleus isthmi pars parvocellularis (Ipc), situated underneath the tectum. Here we show that, if a second visual stimulus is presented, even far from the first, the feedback signal to the first tectal location is diminished or suppressed, and feedback to the second tectal location is initiated. We found that this long-range suppressive interaction is mostly mediated by the nucleus isthmi pars magnocellularis, which sends a wide-field GABAergic projection to Ipc and TeO. In addition, two sets of findings indicate that the feedback from the Ipc modulates the ascending output from the TeO. First, visually evoked extracellular responses recorded in the dorsal anterior subdivision of the thalamic nucleus rotundus (RtDa), receiving the ascending tectal output, are closely synchronized to this feedback signal. Second, local inactivation of the Ipc prevents visual responses in RtDa to visual targets moving in the corresponding region of visual space. These results suggest that the ascending transmission of visual activity through the tectofugal pathway is gated by this cholinergic re-entrant signal, whose location within the tectal visual map is dynamically defined by competitive interactions.
Mutant Cu/Zn-Superoxide Dismutase Associated with Amyotrophic Lateral Sclerosis Destabilizes Vascular Endothelial Growth Factor mRNA and Downregulates Its Expression
Authors: Lu Liang , Zheng Lei , Viera Liliana , Suswam Esther , Li Yanyan , Li Xuelin , Estévez Alvaro G. , King Peter H.
Published: July 2007

Vascular endothelial growth factor (VEGF) plays a neuroprotective role in mice harboring mutations of copper–zinc superoxide dismutase 1 (SOD1) in familial amyotrophic lateral sclerosis (ALS). Conversely, the loss of VEGF expression through genetic depletion can give rise to a phenotype resembling ALS independent of SOD1 mutations. Here, we observe a profound downregulation of VEGF mRNA expression in spinal cords of G93A SOD1 mice that occurred early in the course of the disease. Using anin vitroculture model of glial cells expressing mutant SOD1, we demonstrate destabilization and downregulation of VEGF RNA with concomitant loss of protein expression that correlates with level of transgene expression. Using a luciferase reporter assay, we show that this molecular effect is mediated through a portion of the VEGF 3′-untranslated region (UTR) that harbors a class II adenylate/uridylate-rich element. Other mutant forms of SOD1 produced a similar negative effect on luciferase RNA and protein expression. Mobility shift assay with a VEGF 3′-UTR probe reveals an aberrantly migrating complex that contains mutant SOD1. We further show that the RNA stabilizing protein, HuR (human antigen R), is translocated from nucleus to cytoplasm in mutant SOD1 cellsin vitroand mouse motor neuronsin vivo. In summary, our data suggest that mutant SOD1 gains a novel function, possibly by altering the ribonucleoprotein complex with the VEGF 3′-UTR. We postulate that the resultant dysregulation of VEGF posttranscriptional processing critically reduces the level of this neuroprotective growth factor and accelerates the neurodegenerative process in ALS.
Hippocampal GABAergic Synapses Possess the Molecular Machinery for Retrograde Nitric Oxide Signaling
Authors: Szabadits Eszter , Cserép Csaba , Ludányi Anikó , Katona István , Gracia-Llanes Javier , Freund Tamás F. , Nyíri Gábor
Published: July 2007

Nitric oxide (NO) plays an important role in synaptic plasticity as a retrograde messenger at glutamatergic synapses. Here we describe that, in hippocampal pyramidal cells, neuronal nitric oxide synthase (nNOS) is also associated with the postsynaptic active zones of GABAergic symmetrical synapses terminating on their somata, dendrites, and axon initial segments in both mice and rats. The NO receptor nitric oxide-sensitive guanylyl cyclase (NOsGC) is present in the brain in two functional subunit compositions: α1β1and α2β1. The β1subunit is expressed in both pyramidal cells and interneurons in the hippocampus. Using immunohistochemistry andin situhybridization methods, we describe that the α1subunit is detectable only in interneurons, which are always positive for β1subunit as well; however, pyramidal cells are labeled only for β1and α2subunits. With double-immunofluorescent staining, we also found that most cholecystokinin- and parvalbumin-positive and smaller proportion of the somatostatin- and nNOS-positive interneurons are α1subunit positive. We also found that the α1subunit is present in parvalbumin- and cholecystokinin-positive interneuron terminals that establish synapses on somata, dendrites, or axon initial segments. Our results demonstrate that NOsGC, composed of α1β1subunits, is selectively expressed in different types of interneurons and is present in their presynaptic GABAergic terminals, in which it may serve as a receptor for NO produced postsynaptically by nNOS in the very same synapse.
Serotonin Neuron Transplants Exacerbate l-DOPA- Induced Dyskinesias in a Rat Model of Parkinson's Disease
Authors: Carlsson Thomas , Carta Manolo , Winkler Christian , Björklund Anders , Kirik Deniz
Published: July 2007

Clinical trials in patients with Parkinson's disease have shown that transplants of fetal mesencephalic dopamine neurons can form a new functional innervation of the host striatum, but the clinical benefits have been highly variable: some patients have shown substantial recovery in motor function, whereas others have shown no improvement and even a worsening in the 3,4-dihydroxyphenyl-l-alanine (l-DOPA)-induced dyskinetic side effects. Differences in the composition of the grafted cell preparation may contribute to these discrepancies. In particular, the number of serotonin neurons contained in the graft can vary greatly depending on the dissection of the fetal tissue. Importantly, serotonin neurons have the ability to store and release dopamine, formed from exogenously administeredl-DOPA. Here, we have evaluated the effect of transplants containing serotonin neurons, or a mixture of dopamine and serotonin neurons, onl-DOPA-induced dyskinesias in 6-hydroxydopamine-lesioned animals. As expected, dopamine neuron-rich grafts induced functional recovery, accompanied by a 60% reduction inl-DOPA-induced dyskinesia that developed gradually over the first 10 weeks. Rats with serotonin-rich grafts with few dopamine neurons, in contrast, showed a progressive worsening of theirl-DOPA-induced dyskinesias over time, and no functional improvement. The antidyskinetic effect of dopamine-rich grafts was independent of the number of serotonin neurons present. We conclude that serotonin neurons in the grafts are likely to have a detrimental effect onl-DOPA-induced dyskinesias in cases in which the grafts contain no or few dopamine neurons.
Neural Systems in the Visual Control of Steering
Authors: Field David T. , Wilkie Richard M. , Wann John P.
Published: July 2007

Visual control of locomotion is essential for most mammals and requires coordination between perceptual processes and action systems. Previous research on the neural systems engaged by self-motion has focused on heading perception, which is only one perceptual subcomponent. For effective steering, it is necessary to perceive an appropriate future path and then bring about the required change to heading. Using function magnetic resonance imaging in humans, we reveal a role for the parietal eye fields (PEFs) in directing spatially selective processes relating to future path information. A parietal area close to PEFs appears to be specialized for processing the future path information itself. Furthermore, a separate parietal area responds to visual position error signals, which occur when steering adjustments are imprecise. A network of three areas, the cerebellum, the supplementary eye fields, and dorsal premotor cortex, was found to be involved in generating appropriate motor responses for steering adjustments. This may reflect the demands of integrating visual inputs with the output response for the control device.
Approximating the Variance of the Conditional Probability of the State of a Hidden Markov Model
Authors: Siegmund David O , Yakir Benjamin
Published: July 2007

In a hidden Markov model, one "estimates" the state of the hidden Markov chain at t by computing via the forwards-backwards algorithm the conditional distribution of the state vector given the observed data. The covariance matrix of this conditional distribution measures the information lost by failure to observe directly the state of the hidden process. In the case where changes of state occur slowly relative to the speed at which information about the underlying state accumulates in the observed data, we compute approximately these covariances in terms of functionals of Brownian motion that arise in change-point analysis. Applications in gene mapping, where these covariances play a role in standardizing the score statistic and in evaluating the loss of noncentrality due to incomplete information, are discussed. Numerical examples illustrate the range of validity and limitations of our results.
Climate Change: The Uncertainties, the Certainties and What They Imply About Action
Authors: Schelling Thomas C.
Published: July 2007

Thomas Schelling argues although the uncertainties regarding climate change are many, the certainties create certain urgencies and inaction is an extreme position; he emphasizes technological advance and governmental sponsorship.
Optimization of an Enzyme Assisted Process for Juice Extraction and Clarification from Litchis (Litchi Chinensis Sonn.)
Authors: Shah Narendra
Published: July 2007

Litchi pulp was treated with various concentration levels of hydrolytic enzymes viz. pectinase (0-0.133%w/w), cellulase (0-0.266%w/w) and hemicellulase (0-0.20%w/w) for different durations (30-150 min) at 45°C. The effect of enzyme treatment conditions was studied on yield, clarity, apparent viscosity and total soluble solids (TSS) of juice obtained from the pulp. The optimum process conditions were determined by employing a second order central composite rotatable design in combination with response surface methodology. Yield, clarity and TSS of juice were found to increase and apparent viscosity was found to decrease significantly by enzymatic treatment. The optimum conditions for enzymatic treatment of pulp obtained after a 2 sided desirability function with the responses juice yield, clarity and TSS to be maximized and viscosity to be minimized were 0.076% (w/w) pectinase, 0.138% (w/w) cellulase, 0.107% (w/w) hemicellulase and incubation time of 106.5 min. The predicted values for juice yield, clarity, viscosity and TSS under optimized conditions were 77.19 %, 93.53%, 1.359mPa s and 19.68°brix which showed a good agreement with the experimental values under the same set of conditions.
Effect of Storage Time on the Physicochemical and Sensory Properties of Man-tou (Chinese Steamed Bread)
Authors: Sha Kun , Qian Ping , Wang Li-Jun , Lu Zhan-hui , Li Li-Te
Published: July 2007

In this study, quality of Man-tou, the Chinese traditional steamed bread during storage was studied. Values for water retention capacity, total water solubles, soluble starch, and soluble amylose and amylopectin of Man-tou decreased with storage time. Results showed that hardness, chewiness and gumminess of Man-tou increased, while, springiness cohesiveness and resilience decreased along with prolonged storage time (p<0.05). Sensory evaluation results showed that all sensory rating of Man-tou, including softness, stickiness, cohesiveness, elasticity, taste and total score, dropped drastically within 24 h of storage time (p<0.05). Differential Scanning Calorimeter (DSC) was used to determine crystalline structure of amylopectin in Man-tou, and the value for enthalpy of crystallization was found increased with storage time. Amylopectin crystallization was significantly associated to Man-tou firming (p<0.01).
Risky Sexual Behavior, Testing, and HIV Treatments
Authors: Mechoulan Stéphane
Published: July 2007

This paper studies the impact of antiretroviral therapies (ARVs) on HIV testing and risky sexual behavior. I use data collected in San Francisco among a high-risk population from 1994 to 2002. The evidence supports the hypothesis of a causal link between the introduction of ARVs in late 1996 and the sharp increase in risky sexual behavior that ensued. Further, following ARVs, testers take more risks while non-testers take fewer risks. The proportion of testers remains stable, which was ambiguous a priori. To the extent that ARVs may induce changes in the composition of the testing and non-testing groups, such effects do not seem to affect the results.
Animal House: Economics of Pets and the Household
Authors: Schwarz Peter M , Troyer Jennifer L , Walker Jennifer Beck
Published: July 2007

We develop a model of the household that includes pets. We use over twenty years of data from the Consumer Expenditure Survey to consider pet ownership and expenditures for single and married households. Households with very young children are less likely to own pets and have lower pet expenditures, showing a substitute relationship. Households with older children are more likely to own pets, suggesting a complementary relationship. However, households with more children show reduced pet spending, evidence of a substitute relationship. Surprisingly, when the effect of income on pet ownership and pet spending are jointly considered in computing the income elasticities, women in married households have smaller income elasticities for pet expenditures than do men. This finding is the opposite of what has been found for women and men with regard to expenditures on children.
Tacit Collusion in Capacity Investment: The Role of Capacity Exchanges
Authors: Hogendorn Christian
Published: July 2007

In many capacity-intensive industries (e.g. electricity, bandwidth), exchanges allow firms, including competitors, to buy and sell wholesale capacity before selling on the retail market. Capacity exchanges allow firms to smooth demand shocks, but do they also facilitate tacit collusion to limit capacity investment? This paper models investment and exchange in a one-shot game and in a repeated game with tacit collusion. It finds that the presence of the exchange does not reduce total capacity investment, and thus does not raise consumer prices. In fact, the exchange may make it more difficult to sustain tacit collusion.
Tax Differentials and the Segmentation of Networks of Cooperation in Oligopoly
Authors: Benchekroun Hassan , Claude Denis
Published: July 2007

This paper studies the effects of uncoordinated environmental tax policies on firms' incentives to form bilateral R&D collaborations. It is shown that the complete network is pair-wise stable for small differences in the taxation of environmental emissions. Larger tax differentials may induce firms to abandon all their international collaborations.
Regularization Parameter Selection in Discrete Ill-Posed Problems — The Use of the U-Curve
Authors: Krawczyk-Stańdo Dorota , Rudnicki Marek
Published: July 2007

Regularization Parameter Selection in Discrete Ill-Posed Problems — The Use of the U-Curve

To obtain smooth solutions to ill-posed problems, the standard Tikhonov regularization method is most often used. For the practical choice of the regularization parameter α we can then employ the well-known L-curve criterion, based on the L-curve which is a plot of the norm of the regularized solution versus the norm of the corresponding residual for all valid regularization parameters. This paper proposes a new criterion for choosing the regularization parameter α, based on the so-called U-curve. A comparison of the two methods made on numerical examples is additionally included.
Iterative Estimators of Parameters in Linear Models with Partially Variant Coefficients
Authors: Hu Shaolin , Meinke Karl , Chen Rushan , Huajiang Ouyang
Published: July 2007

Iterative Estimators of Parameters in Linear Models with Partially Variant Coefficients

A new kind of linear model with partially variant coefficients is proposed and a series of iterative algorithms are introduced and verified. The new generalized linear model includes the ordinary linear regression model as a special case. The iterative algorithms efficiently overcome some difficulties in computation with multidimensional inputs and incessantly appending parameters. An important application is described at the end of this article, which shows that this new model is reasonable and applicable in practical fields.
Selected Multicriteria Shortest Path Problems: An Analysis of Complexity, Models and Adaptation of Standard Algorithms
Authors: Tarapata Zbigniew
Published: July 2007

Selected Multicriteria Shortest Path Problems: An Analysis of Complexity, Models and Adaptation of Standard Algorithms

The paper presents selected multicriteria (multiobjective) approaches to shortest path problems. A classification of multi-objective shortest path (MOSP) problems is given. Different models of MOSP problems are discussed in detail. Methods of solving the formulated optimization problems are presented. An analysis of the complexity of the presented methods and ways of adapting of classical algorithms for solving multiobjective shortest path problems are described. A comparison of the effectiveness of solving selected MOSP problems defined as mathematical programming problems (using the CPLEX 7.0 solver) and multi-weighted graph problems (using modified Dijkstra's algorithm) is given. Experimental results of using the presented methods for multicriteria path selection in a terrain-based grid network are given.
Breathe Right Nasal Strips and the Respiratory Disturbance Index in Sleep Related Breathing Disorders
Authors: Gosepath Jan , Amedee Ronald G. , Romantschuck Stephanie , Mann Wolf J.
Published: July 2007

This investigation assesses the effects of Breathe Right nasal strips on the respiratory disturbance index (RDI) measured by polysomnography in patients suffering from obstructive sleep apnea and snoring. The positive effect of these strips on nasal ventilation was shown in earlier studies. Twenty-six patients with an RDI higher than 10 in an initial measurement underwent a second preoperative polysomnography with Breathe Right nasal strips in place. Nineteen of these 26 patients showed reduction of RDI during the second night of polysomnography using the nasal strips, indicating that nasal obstruction seems to be a predominant factor in the etiology of snoring and apnea in these individuals. Demographic data, medical history, rhinoscopy, clinical assessment of pharyngeal obstruction (Mueller's maneuver), as well as anterior rhinomanometry and acoustic rhinometry were used to identify typical findings correlating with a positive effect of the Breathe Right nasal strips on the RDI: 1. Hyperplasia or hypertrophy of the lower turbinates, septal deviation, and/or allergic rhinitis. 2. None or only minor pharyngeal obstruction. 3. Age less than 55 years. If a positive effect is seen during polysomnography with the strips in place, patients will most likely profit from an improvement of nasal ventilation. This may help to target more effectively septal or turbinate surgery if applicable. In other cases, if a significant RDI reduction is obtained by the use of the nasal strips, they could also offer a noninvasive modality of treatment, especially since the high degree of co-morbidity in this group of patients can sometimes make a surgical approach less favorable.
Long-Term Efficacy of our Surgical Approach to Turbinate Hypertrophy
Authors: Schmelzer B. , Katz S. , Vidts G.
Published: July 2007

In our department, chronically enlarged inferior turbinates (not responding to adequate medical therapy) are treated with the CO2-laser or by partial inferior turbinoplasty. In this work, the latter technique is described and the short- and long-term results (up to 9 years of follow-up) are evaluated. Relief of nasal obstruction was reported by 93.5% of the patients. There was a good correlation between this success rate and the objective measurements of the nasal resistance by active anterior rhinomanometry. Rhinorrhea or postnasal drip was still present in 32.5%. Atrophic changes of the nasal mucosa were not observed in any of the patients. Early postoperative epistaxis was found in 6.5% of the patients. Late postoperative epistaxis did not occur.
Correlation of Allergy and Severity of Sinus Disease
Authors: Ramadan Hassan H. , Fornelli Rick , Ortiz A. Orlando , Rodman Susan
Published: July 2007

Allergy is an important consideration in the evaluation of patients with rhinosinusitis. Several studies have addressed staging systems for rhinosinusitis based on the extent of disease present on computed tomography (CT) scanning. The severity and extent of sinus disease present on CT imaging helps guide decisions regarding medical and surgical treatment options. This study evaluates the severity of sinus disease in allergic and nonallergic patients. A total of 42 patients at our institution underwent both modified RAST and coronal sinus CT scan in the evaluation of their rhinosinusitis symptoms. A single, blinded staff neuroradiologist staged all 42 CT scans using the Lund-Mackay staging system. None of the patients had undergone sinus surgery. Age, sex, co-morbidities, asthma, smoking, RAST score, total IgE, and CT staging score were analyzed. Allergic patients were found to have a higher CT scan score (mean score = 12) when compared to nonallergic patients (mean score = 6), indicating more extensive sinus disease (p = 0.03). We conclude that allergy is a significant factor in the development of rhinosinusitis, and allergic patients are more likely to demonstrate advanced disease on CT scan when compared to nonallergic patients.
Acoustic Rhinometry of the Oriental Nose
Authors: Burres Steven A.
Published: July 2007

Most studies have established normal values for acoustic rhinometric (AR) analysis of the nasal passage based on a primarily Caucasian or mixed population. Because consistent anatomic differences do occur in anthropomorphic measurements of the nose of different races, AR analysis was performed on an Asian population to determine whether differences occurred in the minimum cross-sectional area (MCA). AR with expanded testing was performed on a non-Asian control group and an Asian study population containing 28 subjects, with 56 half-cavities (F:20; M:8; age range 21–58), including 16 Vietnamese, 8 Korean, 4 Thai, all of whom had physically typical mesorrhine noses. In the Asian population, the mean MCA of each half-cavity was 0.56 ± 0.16 cm2, and 39.3% of subjects had significant asymmetry between their two half-cavities. The mean MCA increased to 0.67 ± 0.12 cm2 after the placement of a Breathe Right Strip Dilator (BRSD) over the nasal bridge, which was a significant increase in 32% of subjects, and to 0.68 ± 0.14 cm2 after the application of 1% Neosinephrine, a significant increase in 34% of those tested compared to the resting state. The combination of BRSD and Neosinephrine produced an MCA of 0.72 ± 0.11 cm2, which was a statistically significant increase in 24 half-cavities (43%). Compared to our non-Asian population, the Asian group had fewer subjects with significant asymmetry (39% versus 59%) before expanded testing and fewer responders to BRSD (48% versus 79%).
Increased Expression of IL-4, IL-5, IFN-γ, IL-6, IL-8, and TGF-β mRNAs in Maxillary Mucosa of Patients with Chronic Sinusitis
Authors: Min Yang-Gi , Lee Chul Hee , Rhee Chae-Seo , Hong Soon Kwan , Kwon Sam Hyun
Published: July 2007

This study aimed to investigate expression of various cytokine mRNAs, including IL-6, IL-8, TGF-β, IL-4, IL-5, and IFN-γ in maxillary sinus mucosa of patients with chronic sinusitis. Maxillary sinus mucosae of six patients with chronic sinusitis and turbinate mucosae of six healthy subjects were obtained. We performed RT-PCR and Southern blot to examine gene expression of the cytokines IL-6, IL-8, TGF-β, IL-4, IL-5, and IFN-γ in maxillary sinus mucosa and compared the results with cytokine gene expressions in normal turbinate mucosa. IL-6, IL-8, TGF-β, IL-4, IL-5, and IFN-γ mRNAs were expressed more frequently in maxillary sinus mucosa from patients with chronic sinusitis than in normal turbinate mucosa. All the maxillary sinus mucosa specimens revealed relatively higher mean density ratio for each cytokine investigated than did normal turbinate mucosa. IL-6, IL-8, TGF-β, IL-4, IL-5, and IFN-γ mRNAs were expressed simultaneously in maxillary sinus mucosa of chronic sinusitis. These cytokines may be responsible for recruitment of inflammatory cells and for mucosal thickening in chronic sinusitis, and thus chronicity of the disease.
Cover Picture: Preparation of Highly Luminescent Nanocrystals and Their Application to Light‐Emitting Diodes (Adv. Mater. 15/2007)
Authors: Lim J. , Jun S. , Jang E. , Baik H. , Kim H. , Cho J.
Published: July 2007

A detailed synthetic procedure for the preparation of highly luminescent nanocrystals in multigram amounts is described by Eunjoo Jang and co‐workers on p. 1927. In addition, application of the nanocrystals in an UV light‐emitting diode (LED) is reported. Efficiency and spectral measurements reveal that the nanocrystal‐LEDs have excellent performance characteristics. Thus, the scalable one‐pot synthesis enables the production of highly luminescent and photostable quantum dots, which have high potential as light converting materials in LED applications.
Integrals of relay feedback responses for extracting process information
Authors: Lee Jietae , Sung Su Whan , Edgar Thomas F.
Published: July 2007

Relay feedback methods have been widely used in tuning proportional‐integral‐derivative controllers automatically. Previous approaches usually use specific point data such as the oscillation amplitude and period of the relay response. In this article, we propose new identification methods, which use integrals of the relay response instead of the point data. The proposed methods guarantee better accuracy and advantages in obtaining the ultimate information of process as well as parametric models compared with previous approaches, because effects of the high order harmonic terms are suppressed significantly using the integrals of the relay responses. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Modeling solubilities of sugars in alcohols based on original experimental data
Authors: Montañés Fernando , Olano Agustín , Ibáñez Elena , Fornari Tiziana
Published: July 2007

Solubility of six different carbohydrates in methanol, ethanol, 1‐propanol, and 2‐propanol were measured at 22, 30, and 40°C. Ketose sugars (fructose, tagatose, and lactulose) show higher solubilities than aldoses (glucose, galactose, and lactose). The binary solid–liquid equilibrium data obtained was satisfactory represented by using the A‐UNIFAC model. Additionally, the capability of the model to predict the carbohydrate solubility in alcohol–alcohol and alcohol–water mixed solvents was explored. © 2007 American Institute of Chemical Engineers AIChE J, 2007
A comparative volumetric analysis of the amygdaloid complex and basolateral division in the human and ape brain
Authors: Barger Nicole , Stefanacci Lisa , Semendeferi Katerina
Published: July 2007

The amygdaloid complex functions to facilitate effective appraisal of the social environment and is an essential component of the neural systems subserving social behavior. Despite its critical role in mediating social interaction, the amygdaloid complex has not attracted the same attention as the isocortex in most evolutionary analyses. We performed a comparative analysis of the amygdaloid complex in the hominoids to address the lack of comparative information available for this structure in the hominoid brain. We demarcated the amygdaloid complex and the three nuclei constituting its basolateral division, the lateral, basal, and accessory basal nuclei, in 12 histological series representing all six hominoid species. The volumes obtained for these areas were subjected to allometric analyses to determine whether any species deviated from expected values based on the other hominoids. Differences between groups were addressed using nonparametric comparisons of means. The human lateral nucleus was larger than predicted for an ape of human brain size and occupied the majority of the basolateral division, whereas the basal nucleus was the largest of the basolateral nuclei in all ape species. In orangutans the amygdala and basolateral division were smaller than in the African apes. While the gorilla had a smaller than predicted lateral nucleus, its basal and accessory basal nuclei were larger than predicted. These differences may reflect volumetric changes occurring in interconnected cortical areas, specifically the temporal lobe and orbitofrontal cortex, which also subserve social behavior and cognition, suggesting that this system may be acted upon in hominoid and hominid evolution. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.