bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal Alteration and Mineralization of Middle Jurassic Dexing Porphyry Cu‐Mo Deposit, Southeast China
Authors: Li Xiaofeng , Sasaki Munetake
Published: November 2007

The Dexing deposit is located in a NE‐trending magmatic belt along the southeastern margin of the Yangtze Craton. It is the largest porphyry copper deposit in China, consisting of three porphyry copper orebodies of Zhushahong, Tongchang and Fujiawu from northwest to southeast. It contains 1168 Mt of ores with 0.5% Cu and 0.01% Mo. The Dexing deposit is hosted by Middle Jurassic granodiorite porphyries and pelitic schist of Proterozoic age. The Tongchang granodiorite porphyry has a medium K cal‐alkaline series, with medium K2O content (1.94–2.07 wt%), and low K2O/(Na2O + K2O) (0.33–0.84) ratios. They have high large‐ion lithophile elements, high light rare‐earth elements, and low high‐field‐strength elements. The hydrothermal alteration at Tongchang is divided into four alteration mineral assemblages and related vein systems. They are early K‐feldspar alteration and A vein; transitional (chlorite + illite) alteration and B vein; late phyllic (quartz + muscovite) alteration and D vein; and latest carbonate, sulfate and oxide alteration and hematite veins. Primary fluid inclusions in quartz from phyllic alteration assemblage include liquid‐rich (type 1), vapor‐rich (type 2) and halite‐bearing ones (type 3). These provide trapping pressures of 20–400 ´ 105 Pa of fluids responsible for the formation of D veins. Igneous biotite from least altered granochiorite porphyry and hydrothermal muscovite in mineralized granodiorite porphyry possess δ18O and δD values of 4.6‰ and −87‰ for biotite and 7.1–8.9‰, −71 to −73‰ for muscovite. Stable isotopic composition of the hydrothermal water suggests a magmatic origin. The carbon and oxygen isotope for hydrothermal calcite are −4.8 to −6.2‰ and 6.8–18.8‰, respectively. The δ34S of pyrite in quartz vein ranges from −0.1 to 3‰, whereas δ34S for chalcopyrite in calcite veins ranges from 4 to 5‰. These are similar to the results of previous studies, and suggest a magmatic origin for sulfur. Results from alteration assemblages and vein system observation, as well as geochemical, fluid inclusion, stable isotope studies indicate that the involvement of hydrothermal fluids exsolved from a crystallizing melt are responsible for the formation of Tongchang porphyry Cu‐Mo orebodies in Dexing porphyry deposit.
Racial/Ethnic Disparities in Self‐Reported Pediatric Orthodontic Visits in the United States
Authors: Okunseri Christopher , Pajewski Nicholas M. , McGinley Emily L. , Hoffmann Raymond G.
Published: November 2007

Objective: Studies in orthodontics have focused primarily on clinical care and techniques. Little, however, has been reported from epidemiological studies using national data on orthodontic dental visits as a measure of orthodontic service utilization and access to care in minority populations. We examined the effect of race/ethnicity and socioeconomic factors on pediatric orthodontic visits in the United States.

Methods: We analyzed data from the Medical Expenditure Panel Survey, 1996‐2004. Descriptive and multiple regression analyses were performed, with self‐reported orthodontic visits in a given year as the main outcome variable.

Results: The prevalence of an orthodontic visit among children ages 9 to 18 years remained relatively constant (ranged between 14.3 percent and 16.8 percent) from 1996 to 2004. Multiple regression analyses revealed significantly lower odds of an orthodontic visit for Black and Hispanic children in comparison with White children. Males, children from low‐income families, children eligible for Medicaid, and children with other public or no insurance were generally less likely to have made an orthodontic visit.

Conclusion: Substantial racial/ethnic disparities in self‐reported orthodontic visits exist for Black and Hispanic children even after adjusting for possible covariates. Children from lower‐income families and those without private health insurance were less likely to report an orthodontic visit in the United States.
Risk Indicators for Missing Teeth in Working‐Age Pomeranians – An Evaluation of High‐Risk Populations
Authors: Mundt Torsten , Schwahn Christian , Mack Florian , Polzer Ines , Samietz Stefanie , Kocher Thomas , Biffar Reiner
Published: November 2007

Objective:The goal of this study was to examine whether psychosocial conditions for general health described in the public health literature are also reflected in tooth loss.

Methods:The relation of psychosocial factors to missing teeth was evaluated among 2,501 individuals aged 25 to 59 years from the population‐based cross‐sectional Study of Health in Pomerania using logistic regression analyses. The case group included 15 percent of participants of each 5‐year age group with the highest number of missing teeth.

Results:Unemployment, dose‐dependent current and former smoking, a poor general health status, and a longer time since the last dental appointment were significant risk indicators for missing teeth. Alcohol consumption, use of interdental cleaning products, and checkup as the reason for the last dental visit were protective. Women with low education and low income were identified as a high‐risk group for missing teeth by the three‐way interaction between gender, school education, and household income. The effect of marital status was modified by gender: being single was a risk indicator for men but it was protective for women.

Conclusions:The study supports the hypothesis that psychosocial conditions that affect health status as described in the general public health literature also have an effect on tooth loss. Strategies to prevent tooth loss may be expeditiously implemented in combination with approaches to prevent other health‐related problems.
Energy input and zooplankton species richness
Authors: Hessen Dag O. , Bakkestuen Vegar , Walseng Bjørn
Published: November 2007

What are the relative contribution of temperature and solar irradiance as types of energy deliveries for species richness at the ecosystem level? In order to reveal this question in lake ecosystems, we assessed zooplankton species richness in 1891 Norwegian lakes covering a wide range in latitude, altitude, and lake area. Geographical variables could largely be replaced by temperature‐related variables, e.g. annual monthly maximum temperature or growth season. Multivariate analysis (PCA) revealed that not only maximum monthly temperature, but also energy input in terms of solar radiation were closely associated with species richness. This was confirmed by stepwise, linear regression analysis in which lake area was also found to be significant. We tested the predictive power of the “metabolic scaling laws” for species richness by regressing Ln of species richness over the inverse of the air temperature (in Kelvin), corrected for the activation energy (eV) as predicted by the Boltzmann constant. A significant, negative slope of 0.78 for ln richness over temperature, given as 1/kT, was found, thus slightly higher than the range of slopes predicted from the scaling law (0.60–0.70).

Temperature basically constrained the upper bound of species number, but it was only a modest predictor of actual richness. Both PCA‐analysis and linear regression models left a large unexplained variance probably due to lake‐specific properties such as catchment influence, lake productivity, food‐web structure, immigration constraints or more stochastic effects.
CHAOTIC PHASE SYNCHRONIZATION AND ITS BREAKDOWN - MAPPING MODEL AND CRITICAL DYNAMICS
Authors: FUJISAKA HIROKAZU , TSUKAMOTO NAOFUMI , UCHIYAMA SATOKI
Published: November 2007

In the present paper, we briefly discuss the construction of mapping model of coupled oscillator systems for limit-cycle oscillators and chaotic oscillators. A comparison of the proposed mapping model and other models, i.e., the Ikeda map and the phase map model is made. Furthermore, the critical dynamics associated with the breakdown of chaotic phase synchronization based on the present mapping model is discussed.
FLOCKING STATES OF SELF-PROPELLING PARTICLES IN FREE SPACE
Authors: LEUNG KWAN-TAI , CHEN HSUAN-YI
Published: November 2007

We present particle-based simulations for the flocking behavior of self-propelling particles. Built upon previous models, our models include realistic but simple rules for the self-propelling, drag, and inter-particle interactions. Depending on both the strength and range of the interactions, a host of stationary phases appear, including independent wandering, formation flight, swarm, and rotating vortex. Of particular interest, we determine that the rotating flock can only arise in the absence of long-range alignment. We also construct a phenomenological continuum model and obtain steady-state solutions for the rotating state.
STATISTICAL PHYSICS APPROACH TO POLITICAL DISTRICTING PROBLEM
Authors: CHOU CHUNG-I , LI SAI-PING
Published: November 2007

The Political Districting Problem is to partition a zone into several electoral districts subject to some constraints such as contiguity, population equality, etc. In this paper, we apply statistical physics methods to Political Districting Problem. This political problem is mapped to a q-state Potts model system, and the political constraints are written in the form of an energy function with the interactions between sites or external fields acting on the system. Districting into q voter districts is equivalent to finding the ground state of this q-state Potts model. We illustrate this problem by districting Taipei city and compare it to a computer-generated artificial system.
A RELATION ON ROUND-OFF ERROR, ATTRACTOR SIZE AND ITS DYNAMICS
Authors: SHI PENGLIANG
Published: November 2007

A system of logistic map coupled with slowly driven items or another map is investigated in this paper. Several artificial behaviors emerge if the relation is not kept: α β < γ. Here α is number of computational precision digit, for instance, for double precision which has a unit round-off of 2 × 10−16. And β is parameter characterized of maximum of local dynamical expansion ability β or contraction ability 1/β. γ is attractor size of the system. β can be extracted from concept of the Lyapunov number, which is closely related to the well-known Lyapunov exponent.
MULTIFRACTALS ON SMALL-WORLD NETWORKS
Authors: KIM KYUNGSIK , CHANG K. H. , HA DEOCK-HO
Published: November 2007

We investigate the multifractals of the first passage time on a one-dimensional small-world network with reflecting and absorbing barriers. We analyze numerically the distribution of the first passage time at which the random walker arrives for the first time at an absorbing barrier after starting from an arbitrary initial site. Our simulation is found to estimate the fractal dimension D0 = 0.920 ∼ 0.930 for the different network sizes and random rewiring fractions. In particular, our simulation results are compared with the numerical computations for regular networks.
EFFICIENT ROUTING ON SCALE-FREE NETWORKS
Authors: ZHOU TAO
Published: November 2007

The nodes with the largest degree are very susceptible to traffic congestion, thus an effective way to improve traffic and control congestion can be redistributing traffic load in hub nodes to others. We proposed an efficient routing strategy, which can remarkably enhance the network throughput. In addition, by using detrended fluctuation analysis, we found that the traffic rate fluctuation near the critical point exhibits the 1/f scaling in the power spectrum, which is in accordance with the empirical data.
PULSES AND CHAOS: DYNAMICAL RESPONSE IN A SIMPLE GENETIC OSCILLATOR
Authors: FONSLET JESPER , RUD-PETERSEN KRISTIAN , KRISHNA SANDEEP , JENSEN MOGENS H.
Published: November 2007

We investigate the dynamical behaviour of the genetic feedback loop present in the signalling network of the transcription factor NF -κ B . This transcription factor is one of the most important regulators in mammalian cells, involved in a large number of cellular responses. We find that when the external stimulus is constant, the concentration of NF -κ B inside the cell nucleus is either stationary or shows spiky oscillations. If the external stimulus is time dependent, the response can be more intricate. Here, we consider the response to pulsed and periodic stimuli. In the latter case the response can be chaotic with the NF -κ B concentration converging to a strange attractor. The corresponding bifurcation diagram is also presented.
BIPOLARON DYNAMICS IN NON-DEGENERATE POLYMERS
Authors: YAN YONG-HONG , WU CHANG-QIN , LI BAO-WEN
Published: November 2007

Bipolaron dynamics in non-degenerate polymers are discussed using the nonadiabatic dynamic method. First, charge injection process from metal electrode to a nondegenerate polymer in a metal/polymer/metal structure has been investigated. We demonstrate that the dynamical formation of a bipolaron sensitively depends on the work function of metal electrode. We also study the bipolaron dissociation process. It is found that the electric field that can dissociate the bipolaron is up to 106 V/cm, which is consistent with experiments.
A CONCISE APPROACH FOR ONE-DIMENSIONAL HOLSTEIN MODEL
Authors: REN QING-BAO , CHEN QING-HU
Published: November 2007

A concise variational approach is to propose to calculate the ground-state properties of none-dimensional Holstein model. The results in the weak and strong coupling limit can be easily recovered analytically. It is shown that, in the nontrivial intermediate electron-phonon coupling regime, the present results are in good agreement with those by density-matrix renormalization group and numerical exact diagonalizations. The present approach is more concise than any other analytical ones in this field, and can be easily generalized to Holstein models in higher dimensions and with more electrons.
AMPLITUDE DEPENDENCE OF THE SHAPIRO STEPS
Authors: TEKIĆ JASMINA
Published: November 2007

The existence and stability of the Shapiro steps in the ac driven dissipative Frenkel-Kontorova model are studied. The particular attention has been focused on, the variations of the step width and critical depinning force with the ac amplitude. The amplitude dependence is strongly influenced by the frequency of ac force where at the higher frequencies, the oscillations have the Bessel like form.
STABILITY OF QUANTUM MOTION: A SEMICLASSICAL APPROACH
Authors: WANG WEN-GE , LI BAOWEN
Published: November 2007

A semiclassical theory is used for the study of fidelity. For systems with weak chaos in the classical limit, we show that the fidelity has a non-Fermi-Golden-Rule decay, which can be explained by the closeness of the distribution of action difference in the semiclassical theory to the Levy distribution. For systems with strong chaos in the classical limit, we present a semiclassical expression for fidelity decay in the Lyapunov regime, which is more general than the previously predicted Lyapunov decay and λ1 decay of fidelity. For systems with regular motion in the classical limit, we derive the fidelity decay for initial narrow Gaussian wavepackets, which displays a quite complex behaviour, from Gaussian to power law decay t−α with 1 ≤ α ≤ 2.
The Ultrafast Dynamics of Photodetachment
Authors: Chen Xiyi , Bradforth Stephen E.
Published: November 2007

Photodetachment is a general property of condensed-phase anions exposed to visible or ultraviolet light, but its mechanism has not been fully explored until recently. The combination of femtosecond pump-probe experiments in both bulk liquids and solvated clusters and quantum mechanical descriptions of the relevant excited states has provided new insight into the spectroscopy, energetics, and dynamics of the detachment process. We review detachment phenomena for the prototypical atomic systems, iodide in water and sodide in tetrahydrofuran, and these systems provide the relevant framework for molecular systems. The iodide system has been studied in gas-phase clusters as well as bulk solution. This article also contrasts mechanisms as a function of energy from purely charge-transfer-to-solvent detachment to regimes in which there is direct and indirect participation of the bulk conduction band.
Extraordinary Transmission of Metal Films with Arrays of Subwavelength Holes
Authors: Coe James V. , Heer Joseph M. , Teeters-Kennedy Shannon , Tian Hong , Rodriguez Kenneth R.
Published: November 2007

Metal films with patterns of subwavelength holes (grids or meshes) have interesting optical properties including the extraordinary transmission effect. These optically thick metal films transmit more radiation than that incident on the holes owing to the excitation of surface plasmons (SPs). Meshes present a new and simple way to excite SPs at perpendicular incidence (i.e., without the need to vary the angle of the incident beam). This represents a new opportunity to integrate SPs with experiments and devices—a new instrument in the toolbox of SP techniques that may broaden the range of SP applications. This review discusses the discovery, basic optical physics, the role of SPs, and applications of the extraordinary transmission of subwavelength hole arrays.
Quasicrystal Surfaces
Authors: Thiel Patricia A.
Published: November 2007

Studies of ordered, yet nonperiodic, metallic alloys known as quasicrystals have generated exciting questions and fundamental insights about the relationship between surface atomic structure and surface properties. In this review, I give examples from oxidation, friction, heterogeneous catalysis, and solid film growth, in which the Al-rich quasicrystals exhibit unusual properties, relative to crystalline materials of similar composition.
Two-Dimensional Infrared Spectroscopy of Photoswitchable Peptides
Authors: Hamm Peter , Helbing Jan , Bredenbeck Jens
Published: November 2007

We present a detailed discussion of the complimentary fields of the application of two-dimensional infrared (2D-IR) spectroscopy in comparison with two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy. Transient 2D-IR (T2D-IR) spectroscopy of nonequilibrium ensembles is probably one of the most promising strengths of 2D-IR spectroscopy, as the possibilities of 2D-NMR spectroscopy are limited in this regime. T2D-IR spectroscopy uniquely combines ultrafast time resolution with microscopic structural resolution. In this article we summarize our recent efforts to investigate the ultrafast structural dynamics of small peptides, such as the unfolding of peptide secondary structure motifs. The work requires two ingredients: 2D-IR spectroscopy and the possibility of triggering a structural transition of a peptide on an ultrafast timescale using embedded or intrinsic photoswitches. Several photoswitches have been tested, and we discuss our progress in merging these two pathways of research.
Insulin-Like Signaling, Nutrient Homeostasis, and Life Span
Authors: Taguchi Akiko , White Morris F.
Published: November 2007

Insulin-like signaling is critical for nutrient homeostasis, growth and survival. However, work with lower metazoans—Caenorhabditis elegans and Drosophila—shows that reduced insulin-like signaling extends life span. In addition, reduced insulin signaling in higher animals—rodents and humans—causes glucose intolerance and hyperinsulinemia that progresses to diabetes and shortens the life span of affected individuals. Hyperinsulinemia usually develops to maintain glucose homeostasis and prevent the progression toward life-threatening type 2 diabetes; however, increased circulating insulin may have negative effects on the brain that promote age-related disease. We discuss the possibility that the brain is the site where reduced insulin-like signaling can consistently extend mammalian life span—just as reduced insulin-like signaling extends the life span of lower metazoans.
Physiological Regulation of Prostaglandins in the Kidney
Authors: Hao Chuan-Ming , Breyer Matthew D.
Published: November 2007

Cyclooxygenase-derived prostanoids exert complex and diverse functions within the kidney. The biological effect of each prostanoid is controlled at multiple levels, including (a) enzymatic reactions catalyzed sequentially by cyclooxygenase and prostanoid synthase for the synthesis of bioactive prostanoid and (b) the interaction with its receptors that mediate its functions. Cyclooxygenase-derived prostanoids act in an autocrine or a paracrine fashion and can serve as physiological buffers, protecting the kidney from excessive functional changes during physiological stress. Through these actions, prostanoids play important roles in maintaining renal function, body fluid homeostasis, and blood pressure. Renal cortical COX2-derived prostanoids, particularly PGI2and PGE2, play critical roles in maintaining blood pressure and renal function in volume-contracted states. Renal medullary COX2-derived prostanoids appear to have an antihypertensive effect in individuals challenged with a high-salt diet. Loss of EP2 or IP receptor is associated with salt-sensitive hypertension. COX2 also plays a role in maintaining renal medullary interstitial cell viability in the hypertonic environment of the medulla. Cyclooxygenase-derived prostanoids also are involved in certain pathological processes. The cortical COX2-derived PGI2participates in the pathogenesis of renal vascular hypertension through stimulating renal renin synthesis and release. COX-derived prostanoids also appear to be involved in the pathogenesis of diabetic nephropathy. COXs, prostanoid synthases, and prostanoid receptors should provide fruitful targets for intervention in the pharmacological treatment of renal disease.
Regulated Airway Goblet Cell Mucin Secretion
Authors: Davis C. William , Dickey Burton F.
Published: November 2007

Major advances in understanding regulated mucin secretion from airway goblet cells have been made in the past decade in the areas of pharmacology and basic cell biology. For instance, it is now appreciated that nucleotide agonists acting locally through P2Y purinoceptors on apical membranes of surface goblet cells provide the major regulatory system for mucin secretion. Similarly, Clara cells, the primary secretory cell in the mouse airways (and human small airways), are now recognized as major mucin-secreting cells. In Clara cells, the relative lack of staining for mucosubstances reflects essentially equal baseline rates of mucin synthesis and secretion, with little to no accumulation of mucin granules in storage pools. During mucous metaplasia induced under inflammatory conditions, mucin synthesis is massively upregulated in Clara cells, and stored mucin granules come to dominate the secretory cell phenotype. More importantly, we have seen a transition in the past few years from a pharmacological focus on regulated mucin secretion to a more molecular mechanistic focus that has great promise going forward. In part, these advances are occurring through the use of well-differentiated primary human bronchial epithelial cell cultures, but recent work in mouse models perhaps has had the most important impact. Emerging data from Munc13-2- and synaptotagmin 2–deficient mouse models represent the first direct, molecular-level manipulations of proteins involved in regulated secretory cell mucin secretion. These new data indicate that Munc13-2 is responsible for regulating a baseline mucin secretory pathway in the airways and is not essential for purinergic agonist–induced mucin secretion. In contrast, synaptotagmin 2, a fast Ca2+sensor for the SNARE complex, is essential for regulated secretion. Interestingly, these early results suggest that there are two pathways for excocytic mucin release from goblet cells.
State Failure
Authors: Bates Robert H.
Published: November 2007

State failure is characterized by government predation and the militarization of civic society. Drawing on data from the study of civil war, state failure, and violence, this article explores the roles of per capita income, ethnicity, and democratization. It argues that public revenues are more relevant to state failure than are private incomes; that several configurations of ethnic groups can lead to violence; and that state failure is far more likely in intermediate democracies than in full democracies or aristocracies.
Three weeks of early-onset exercise prolongs obesity resistance in DIO rats after exercise cessation
Authors: Patterson Christa M. , Dunn-Meynell Ambrose A. , Levin Barry E.
Published: November 2007

We assessed the effect of early-onset exercise as a means of preventing childhood obesity using juvenile male rats selectively bred to develop diet-induced obesity (DIO) or to be diet resistant (DR) when fed a 31% fat high-energy diet. Voluntary wheel running begun at 36 days of age selectively reduced adiposity in DIO vs. DR rats. Other 4-wk-old DIO rats fed a high-energy diet and exercised (Ex) for 13 wk increased their core temperature, gained 22% less body weight, and had 39% lighter fat pads compared with sedentary (Sed) rats. When wheels were removed after 6 wk (6 wk Ex/7 wk Sed), rats gained less body weight over the next 7 wk than Sed rats and still had comparable adipose pad weights to 13-wk-exercised rats. In fact, only 3 wk of exercise sufficed to prevent obesity for 10 wk after wheel removal. Terminally, the 6-wk-Ex/7-wk-Sed rats had a 55% increase in arcuate nucleus proopiomelanocortin mRNA expression vs. Sed rats, suggesting that this contributed to their sustained obesity resistance. Finally, when Sed rats were calorically restricted for 6 wk to weight match them to Ex rats (6 wk Rstr/7 wk Al), they increased their intake and body weight when fed ad libitum and, after 7 wk more, had higher leptin levels and adiposity than Sed rats. Thus, early-onset exercise may favorably alter, while early caloric restriction may unfavorably influence, the development of the hypothalamic pathways controlling energy homeostasis during brain development.
Target Selection for Visually Guided Reaching in Macaque
Authors: Song Joo-Hyun , Takahashi Naomi , McPeek Robert M.
Published: November 2007

We examined target selection for visually guided reaching in monkeys using a visual search task in which an odd-colored target was presented with distractors. The colors of the target and distractors were randomly switched in each trial between red and green, and the number of distractors was varied. Previous studies of saccades and attention have shown that target selection in this task is easier when a greater number of homogenous distractors is present. We found that monkeys made fewer reaches to distractors and that reaches to the target were completed more quickly when a greater number of homogenous distractors was present. When the target was presented in a sparse array of distractors, reaches had longer movement durations and greater trajectory curvature. Reaching errors were directed more often to a distractor adjacent to the target, suggesting a spatially coarse-to-fine progression during target selection. Reaches were also influenced by the properties of trials in the recent past. When the colors of the target and distractors remained the same from trial to trial rather than switching, reaches were completed more quickly and accurately, indicating that color priming across trials facilitates target selection. Moreover, when difficult search trials were randomly intermixed with easier trials without distractors, reach latencies were influenced by the difficulty of previous trials, indicating that motor initiation strategies are gradually adjusted based on accumulated experience. Overall, these results are consistent with reaching results in humans, indicating that the monkey provides a sound model for understanding the neural underpinnings of reach target selection.
Spinal Peritoneal Shunts for Conditions Other than Hydrocephalus and Pseudotumor Cerebri: A Clinical Report
Authors: James Hector E. , Postlethwait Richard
Published: November 2007

Background: To treat with minimally invasive surgery, recurrent spinal arachnoid cysts, progressive syringomyelia, cranial and spinal cerebrospinal fluid fistulas. Patients andMethods: This is a clinical report that describes the management of recurrent spinal arachnoid cysts (2 patients), progressive syringomyelia (11 patients), postoperative spinal cerebrospinal fluid fistulas (15 patients) and postoperative cranial cerebrospinal fluid fistulas (2 patients) that were treated with spinal peritoneal shunts. The spinal arachnoid cyst and syringomyelia patients promptly resolved the signs and symptoms. The cranial and spinal cerebrospinal fluid fistula patients had a resolution of the fistulas. The shunts placed for spinal arachnoid cysts and syringomyelia required permanent implantation. The shunts placed for cerebrospinal fluid fistulas were temporary. All were removed, except for 2 patients whose parents did not want further operative interventions. Conclusion: Spinal peritoneal shunts have a variety of clinical applications and should be considered by neurological surgeons for disease processes other than communicating hydrocephalus and pseudotumor cerebri.
Is Intracranial Pressure Waveform Analysis Useful in the Management of Pediatric Neurosurgical Patients?
Authors: Eide P.K. , Egge A. , Due-Tønnessen B.J. , Helseth E.
Published: November 2007

Background: We have reported casuistic observations that intracranial pressure (ICP) waveform analysis may be useful in the management of pediatric patients. Method: We here report our whole patient material of 65 children undergoing ICP monitoring with storage of their ICP raw data files during the years 2002–2005. We retrospectively explored the clinical symptoms/findings and radiological cerebral ventricular size before ICP monitoring. Mean ICP was the actively treated ICP parameter. Using an algorithm for identification of cardiac-beat-induced pressure waves we retrospectively determined the mean ICP wave amplitude and latency, in addition to mean ICP. Outcome with regard to change in symptoms/findings during a 1-year period was determined in 55 children. Results: The material includes children with hydrocephalus, craniosynostosis, shunt failure, benign intracranial hypertension and others. The ICP recordings gave wrong diagnostic information due to bad signal quality in 5 of 65 patients (7.7%). The mean ICP wave amplitude was increased in those with papilledema, lethargy and nausea. The main observations were that the mean ICP wave amplitude (not mean ICP) was increased in those that improved from clinical symptoms/findings after treatment and in those that were unchanged/worse after not being treated. Conclusions: Waveform analysis with computation of the mean ICP wave amplitude was more useful by providing information about the quality of the ICP recording, by comparing better with the symptoms/findings at the time of ICP monitoring and by best predicting outcome. Most significantly, 14 of 55 patients (25%) with high amplitudes and left untreated did not recover spontaneously.
Spontaneous Subdural Fluid Collections following Transection of a Fatty Filum Terminale: Case Report and Review of the Literature
Authors: Abel Taylor J. , Chowdhary Abhineet , Gabikian Patrik , Ojemann Jeff G. , Ellenbogen Richard G. , Avellino Anthony M.
Published: November 2007

We present the case of a 6-year-old girl who developed bilateral subdural fluid collections following transection of her fatty filum terminale. The patient presented to our emergency department 3 weeks subsequent to surgery, reporting symptoms of headache, nausea, and vomiting. The presence of bilateral subdural fluid collections was confirmed by head computerized tomography. Subdural fluid collections and hematomas have been associated with intracranial hypotension and excessive cerebrospinal fluid leakage; however, there are relatively few cases of subdural fluid collections/hematomas following spine surgery reported in the literature. To our knowledge, this is a unique description of development and resolution of subdural fluid collections following surgical transection of a fatty filum terminale.
Three Sisters with Chiari I Malformation with and without Associated Syringomyelia
Authors: Weisfeld-Adams James D. , Carter Michael R. , Likeman Marcus J. , Rankin Julia
Published: November 2007

Two daughters of non-consanguineous Ashkenazi Jewish parentage presented with occipital headaches in the second decade of life. Each had a symptomatic Chiari I malformation (CMI) and a large cervicothoracic syrinx. A third sister was diagnosed as having CMI without syrinx after MR screening of first-degree relatives. A fourth (the eldest) sister was asymptomatic and did not have CMI or syrinx. The girls’ mother had platybasia on screening MR and a history of cough headaches. All four sisters also had demonstrable platybasic features on MR. The girls’ father was asymptomatic and radiologically normal. This family represents the first reported case of three siblings in one family with confirmed CMI with or without syrinx. We discuss the possible genetic and mechanical mechanisms for the development of these abnormalities in this family.
Cerebral Differences in Explicit and Implicit Emotional Processing – An fMRI Study
Authors: Scheuerecker J. , Frodl T. , Koutsouleris N. , Zetzsche T. , Wiesmann M. , Kleemann A.M. , Brückmann H. , Schmitt G. , Möller H.-J. , Meisenzahl E.M.
Published: November 2007

The processing of emotional facial expression is a major part of social communication and understanding. In addition to explicit processing, facial expressions are also processed rapidly and automatically in the absence of explicit awareness. We investigated 12 healthy subjects by presenting them with an implicit and explicit emotional paradigm. The subjects reacted significantly faster in implicit than in explicit trials but did not differ in their error ratio. For the implicit condition increased signals were observed in particular in the thalami, the hippocampi, the frontal inferior gyri and the right middle temporal region. The analysis of the explicit condition showed increased blood-oxygen-level-dependent signals especially in the caudate nucleus, the cingulum and the right prefrontal cortex. The direct comparison of these 2 different processes revealed increased activity for explicit trials in the inferior, superior and middle frontal gyri, the middle cingulum and left parietal regions. Additional signal increases were detected in occipital regions, the cerebellum, and the right angular and lingual gyrus. Our data partially confirm the hypothesis of different neural substrates for the processing of implicit and explicit emotional stimuli.
Ability of Cyclohexenonic Long-Chain Fatty Alcohol to Ameliorate Diabetes-Induced Cystopathy in the Rat
Authors: Kazuyama Emi , Saito Motoaki , Okada Shinichi , Satoh Keisuke
Published: November 2007

We investigated the pharmacological effects of N-hexacosanol on diabetic rat detrusor. Eight-week-old male Sprague-Dawley rats were randomly divided into 4 groups: diabetic rats induced by 50 mg/kg intraperitoneally of streptozotocin treated with N-hexacosanol (0, 2 or 8 mg/kg, subcutaneously every day) and control rats. Bladder function was estimated by functional studies using carbachol and KCl. Contractile response curves to increasing concentrations of carbachol were constructed in the absence and presence of various concentrations of subtype-selective muscarinic antagonists, that is, atropine, pirenzepine, methoctramine and 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP). The participation levels of muscarinic M2 and M3 receptor mRNAs in detrusor were investigated by real-time polymerase chain reaction. Treatment with N-hexacosanol did not alter diabetic status of the rats, but significantly improved the diabetes-induced hypercontractility of the rat bladder. Estimations of the pA2 values for atropine, pirenzepine, methoctramine and 4-DAMP indicate that the carbachol-induced contractile response is mediated through the M3 receptor subtype in all groups. Furthermore, N-hexacosanol ameliorated the diabetes-induced upregulation of muscarinic M2 receptor mRNAs in streptozotocin-diabetic rat detrusor. Our data indicate that N-hexacosanol has therapeutic effects on hypercontractility in the diabetic bladder by ameliorating overexpression of muscarinic M2 and M3 receptor mRNAs without significant alternations of pharmacological profiles.
Application of a Robotic Telemanipulation System in Stereotactic Surgery
Authors: Tian Zengmin , Lu Wangsheng , Wang Tianmiao , Ma Belin , Zhao Quanjun , Zhang Guolai
Published: November 2007

To assess the clinical usefulness, accuracy, and safety of telemanipulation for frameless stereotactic surgery using the CAS-BH5 robot system, we prospectively evaluated 10 patients (age: 5–79 years; mean: 44 years) who underwent telemanipulation frameless stereotactic operations from September to December 2005. The CAS-BH5 robot system consists of three main parts: a planning subsystem, a surgical localization subsystem, and a telemanipulation subsystem. Specifically, CAS-BH5 is capable of network communication, video transmission, graphic simulation and human-machine interaction, and thus facilitates remote planning and transmission of neuronavigation data, monitoring and manipulating. Telemanipulation was performed via a digital data network with a speed of 2,000 kilobytes per second by a neurosurgeon in Beijing while the patients were located in Yan’an, 1,300 km away. Remote fiducial registration was performed with a mean accuracy of 1.05 mm and the standard difference between the planned and actual trajectory was 0.13 mm. The mean time from fiducial registration to closure was 30.2 ± 1.66 min. At 12-month follow-up, 90% of patients had improved neurologically. There were no complications. This preliminary data indicates that telemanipulation in frameless stereotactic surgeries is feasible, reliable and safe. In the future, we believe that telemanipulation will facilitate collaboration between surgeons, enhance training, allow for sharing of resources, and have wide applications in the field of neurosurgery.
Unstable Politics
Authors: Nooruddin Irfan , Chhibber Pradeep
Published: November 2007

What explains variations in electoral volatility? The authors argue that fiscal space—availability of financial resources to enact policy initiatives and provide public programs—possessed by governments can explain the level of electoral volatility. Where governments have fiscal space, citizens reward incumbent parties with their continued support. But when fiscal space is constrained, the incumbent government's ability to provide state resources is drastically reduced. Citizens are therefore less likely to reward the party at the polls and are available to opposition politicians and alternative appeals. Vote-switching ensues, and the incumbent government is voted out of the office. The authors test this argument and others in the existing literature on electoral returns from state assembly elections across 15 major Indian states from 1967 to 2004. The results support the argument that fiscal space influences electoral volatility.
Who Gives, Who Receives, and Who Wins?
Authors: Brown David S. , Brown J. Christopher , Desposato Scott W.
Published: November 2007

How does international support for nongovernmental organizations (NGOs) lead to political change in the developing world? Massive amounts of domestic government spending and international aid are now distributed through NGOs instead of state bureaucracies. Recent scholarship suggests that this decentralization of developmental aid to NGOs has unintended political effects on recipient communities, but the mechanisms driving political effects are unclear. In this article, the authors test whether NGO type affects the results of NGO aid, comparing the political impact of politicized and nonpoliticized NGOs. They do not find any difference between politicized and nonpoliticized NGOs. The results imply that to create political change, ideological predispositions held by individual NGOs are less important than is their ability to raise the level of social capital and civil society. Simply providing the infrastructure necessary to develop social capital and civil society can have a measurable political impact.
Cyber kiosks and dilemmas of social inclusion in rural India
Authors: Sreekumar T.T.
Published: November 2007

Enhanced deployment of information and communication technologies (ICTs) is considered as a major factor in eliminating vestiges of feudal social organization and hierarchies in rural Asia, and a techno-development paradigm of social change inherited from the industrial era is envisioned. South Asia has particularly witnessed massive proliferation of civil-society-based development initiatives to demonstrate ICTs’ potential to provide unprecedented social and economic opportunities for vulnerable groups such as women and marginalized communities. Social exclusion is often understood as a matter of lack of awareness and inappropriate project design, and incorporation of gender concerns ‘from the very beginning of the project design’ is suggested as a more or less universal solution for enhancing participation. This article challenges this conventional wisdom and argues that civil society’s engagement with ICTs has not been successful in bridging the social divides it attempted to address. The patterns of ICTs’ deployment and control in the rural setting tend to reinforce existing social divides and, in certain cases, create new divides. The participation of women and the underprivileged in these projects is abysmally low and this is in striking contrast to the projected image of these initiatives as being overtly sensitive to issues of gender and social divisions. The article argues that the question of inclusion is better understood when addressed as a matter of structure rather choice.
Complexifying media power: a study of the interplay between media and audience discourses on politics
Authors: Schrøder Kim Christian , Phillips Louise
Published: November 2007

The article reports from a research project about how the media function as a democratic resource for citizens in Denmark. It brings together discourse- and audienceanalysis perspectives into one research design, questioning the often simplified notions of media power found in media/politics research. Our three-tiered study explores the media/citizen nexus, in a social context where politics spans the continuum from traditional parliamentary politics, through grassroots organizations (‘subpolitics’) and everyday politics (‘life-politics’). First, we explore the citizens’ daily life with the media in the perspective of democratic citizenship, as people report this to us in group conversations. Second, we analyse the media’s discursive constructions of ‘politics’, focusing on the political issues around traffic and transport policy, but including all political coverage of a variety of media during one selected week. Third, we explore the citizens’ construction of ‘politics’ through focus group discussions. We see these studies as interrelated, but abstain from making causal generalizations about agenda setting and definitional power, preferring to map them as three interrelated discursive territories of contemporary politics, and to discuss possible linkages between media discourses and citizens’ discourses. We thus end up by ‘complexifying’ the media/citizen connection beyond simplistic notions of media power.
Playing on the digital commons: collectivities, capital and contestation in videogame culture
Authors: Coleman Sarah , Dyer-Witheford Nick
Published: November 2007

This article examines the complex relation of commodity and commons regimes in video and computer game culture. Digital play is today both a multibillion business and the site of numerous ‘do it yourself’ practices of production and reproduction, ranging from warez networks and abandonware archives through ‘modding’ (game modification) and machinima-making to the player-created content of massively multiplayer online games. Such practices are variously symbiotic with and antagonistic to commercial gaming. They are the occasion of extraordinary cooperative arrangements between game developers and players, and of fierce disputes over intellectual property. In both cases, video and computer games reveal the subversion of ‘unidimensional’ media institutions, positing sharp distinction between producers and consumers, by an emergent ‘multidimensionality’ of new media in which these roles are deeply confounded.
Japan's mobile technoculture: the production of a cellular playscape and its cultural implications
Authors: Daliot-Bul Michal
Published: November 2007

The reception of mobile communication and internet by Japan’s youth in the late 1990s has determined the shaping of the mobile communication market in this country. From a business-oriented device, mobile phones were transformed into an intensely personal part of the users’ lives, particularly notable for offering a spectacular interactive playscape that challenges the tyranny of everyday life. Rather than being a trivial mechanism of stress release or a means to make the in-between temporalities of everyday life more enjoyable, this playscape has come to be a cultural arena that both reflects as well as induces socio-cultural change. In reconstructing the cultural production of Japan’s cellular playscape, this article focuses on two sets of issues. The first is the contextualization of the mobile communication market in Japan within broader cultural processes in which youths have become the new cultural avant-garde of urban lifestyles. The second is an analysis of how the merging of play into everyday life through mobile communication technologies is creating new modes of relating to the social, technological and urban environments.
Activists as interpretive communities: rituals of consumption and interaction in an alternative media audience
Authors: Rauch Jennifer
Published: November 2007

This multiple-method study bridges what John D.H. Downing has called a ‘distinctly disturbing gulf’ between our knowledge of social actors and theories about alternative media by considering the symbolic uses of news in an activist audience and by extending theories of news reading as a ritual act through which social bonds are produced. Because people often read news in private or diffuse situations, reading must be represented to other community members through discourse in order to communicate those information sources – and hence social ideals – they have in common. In interviews, activists downplayed consumption of corporate media, but diaries confirmed that they used a wide range of both alternative and mainstream sources. I propose that this interpretive community achieved its identity in part by rejecting mainstream media, so that performing the role of ‘alternative reader’ served as a marker of individual taste and group belonging.
Values Management
Authors: Paarlberg Laurie E. , Perry James L.
Published: November 2007

This article explores the process by which formal management systems foster the creation of shared organization values, addressing the basic question: Can workplace values be “managed?” Drawing upon interviews conducted at a Department of Defense installation with civilian employees and managers over a 5-year period, we use comparative case analysis to explore differences in the relationships between installation practices and social values across high-performing and low-performing work units. Our findings suggest that strategic values are motivating to employees to the extent that they reflect employees' internal affective, normative, and task-oriented values, a zone of existing values. Although values management is a social process that results from routine interactions, formal management systems provide opportunities to enhance the social interactions that are motivating to employees. Middle managers play key roles in using formal management systems to integrate the organization's strategic practices with values that derive from employees' societal, cultural, and religious experiences.