bluuebunny/crossref_metadata_2025 huggingface dataset:
A randomized controlled trial of isotonic versus hypotonic maintenance intravenous fluids in hospitalized children
Authors: Saba Thomas G , Fairbairn James , Houghton Fiona , Laforte Diane , Foster Bethany J
Published: September 2011

Background

Isotonic saline has been proposed as a safer alternative to traditional hypotonic solutions for intravenous (IV) maintenance fluids to prevent hyponatremia. However, the optimal tonicity of maintenance intravenous fluids in hospitalized children has not been determined. The objective of this study was to estimate and compare the rates of change in serum sodium ([Na]) for patients administered either hypotonic or isotonic IV fluids for maintenance needs.

Methods

This was a masked controlled trial. Randomization was stratified by admission type: medical patients and post-operative surgical patients, aged 3 months to 18 years, who required IV fluids for at least 8 hours. Patients were randomized to receive either 0.45% or 0.9% saline in 5.0% dextrose. Treating physicians used the study fluid for maintenance; infusion rate and the use of additional fluids were left to their discretion.

Results

Sixteen children were randomized to 0.9% saline and 21 to 0.45% saline. Baseline characteristics, duration (average of 12 hours) and rate of study fluid infusion, and the volume of additional isotonic fluids given were similar for the two groups. [Na] increased significantly in the 0.9% group (+0.20 mmol/L/h [IQR +0.03, +0.4]; P = 0.02) and increased, but not significantly, in the 0.45% group (+0.08 mmol/L/h [IQR -0.15, +0.16]; P = 0.07). The rate of change and absolute change in serum [Na] did not differ significantly between groups.

Conclusions

When administered at the appropriate maintenance rate and accompanied by adequate volume expansion with isotonic fluids, 0.45% saline did not result in a drop in serum sodium during the first 12 hours of fluid therapy in children without severe baseline hyponatremia. Confirmation in a larger study is strongly recommended.

Clinical Trial Registration Number

NCT00457873(http://www.clinicaltrials.gov/)
Real-time feature extraction of P300 component using adaptive nonlinear principal component analysis
Authors: Turnip Arjon , Hong Keum-Shik , Jeong Myung-Yung
Published: September 2011

Background

The electroencephalography (EEG) signals are known to involve the firings of neurons in the brain. The P300 wave is a high potential caused by an event-related stimulus. The detection of P300s included in the measured EEG signals is widely investigated. The difficulties in detecting them are that they are mixed with other signals generated over a large brain area and their amplitudes are very small due to the distance and resistivity differences in their transmittance.

Methods

A novel real-time feature extraction method for detecting P300 waves by combining an adaptive nonlinear principal component analysis (ANPCA) and a multilayer neural network is proposed. The measured EEG signals are first filtered using a sixth-order band-pass filter with cut-off frequencies of 1 Hz and 12 Hz. The proposed ANPCA scheme consists of four steps: pre-separation, whitening, separation, and estimation. In the experiment, four different inter-stimulus intervals (ISIs) are utilized: 325 ms, 350 ms, 375 ms, and 400 ms.

Results

The developed multi-stage principal component analysis method applied at the pre-separation step has reduced the external noises and artifacts significantly. The introduced adaptive law in the whitening step has made the subsequent algorithm in the separation step to converge fast. The separation performance index has varied from -20 dB to -33 dB due to randomness of source signals. The robustness of the ANPCA against background noises has been evaluated by comparing the separation performance indices of the ANPCA with four algorithms (NPCA, NSS-JD, JADE, and SOBI), in which the ANPCA algorithm demonstrated the shortest iteration time with performance index about 0.03. Upon this, it is asserted that the ANPCA algorithm successfully separates mixed source signals.

Conclusions

The independent components produced from the observed data using the proposed method illustrated that the extracted signals were clearly the P300 components elicited by task-related stimuli. The experiment using 350 ms ISI showed the best performance. Since the proposed method does not use down-sampling and averaging, it can be used as a viable tool for real-time clinical applications.
Reduced cytotoxicity of insulin-immobilized CdS quantum dots using PEG as a spacer
Authors: Selim KM Kamruzzaman , Xing Zhi-Cai , Choi Moon-Jeong , Chang Yongmin , Guo Haiqing , Kang Inn-Kyu
Published: September 2011

Cytotoxicity is a severe problem for cadmium sulfide nanoparticles (CSNPs) in biological systems. In this study, mercaptoacetic acid-coated CSNPs, typical semiconductor Q-dots, were synthesized in aqueous medium by the arrested precipitation method. Then, amino-terminated polyethylene glycol (PEG) was conjugated to the surface of CSNPs (PCSNPs) in order to introduce amino groups to the surface. Finally, insulin was immobilized on the surface of PCSNPs (ICSNPs) to reduce cytotoxicity as well as to enhance cell compatibility. The presence of insulin on the surface of ICSNPs was confirmed by observing infrared absorptions of amide I and II. The mean diameter of ICSNPs as determined by dynamic light scattering was about 38 nm. Human fibroblasts were cultured in the absence and presence of cadmium sulfide nanoparticles to evaluate cytotoxicity and cell compatibility. The results showed that the cytotoxicity of insulin-immobilized cadmium sulfide nanoparticles was significantly suppressed by usage of PEG as a spacer. In addition, cell proliferation was highly facilitated by the addition of ICSNPs. The ICSNPs used in this study will be potentials to be used in bio-imaging applications.
Shuttle-like supramolecular nanostructures formed by self-assembly of a porphyrin via an oil/water system
Authors: Guo Peipei , Chen Penglei , Liu Minghua
Published: September 2011

In this paper, in terms of the concentration of an aqueous solution of a surfactant, we investigate the self-assembly behavior of a porphyrin, 5, 10, 15, 20-tetra(4-pyridyl)-21H, 23H-porphine [H2TPyP], by using an oil/water system as the medium. We find that when a chloroform solution of H2TPyP is dropwise added into an aqueous solution of cetyltrimethylammonium bromide [CTAB] with a lower concentration, a large amount of irregular nanoarchitectures, together with a small amount of well-defined shuttle-like nanostructures, hollow nanospheres, and nanotubes, could be produced. While a moderate amount of shuttle-like nanostructures accompanied by a few irregular nanoarchitectures, solid nanospheres, and nanorods are produced when a CTAB aqueous solution in moderate concentration is employed, in contrast, a great quantity of shuttle-like nanostructures together with a negligible amount of solid nanospheres, nanofibers, and irregular nanostructures are manufactured when a high-concentration CTAB aqueous solution is involved. An explanation on the basis of the molecular geometry of H2TPyP and in terms of the intermolecular π-π interactions between H2TPyP units, and hydrophobic interactions between CTAB and H2TPyP has been proposed. The investigation gives deep insights into the self-assembly behavior of porphyrins in an oil/water system and provides important clues concerning the design of appropriate porphyrins when related subjects are addressed. Our investigation suggests that an oil/aqueous system might be an efficient medium for producing unique organic-based nanostructures.
KKM and KY fan theorems in modular function spaces
Authors: Khamsi Mohamed Amine , Latif Abdul , Al-Sulami Hamid
Published: September 2011

In modular function spaces, we introduce Knaster-Kuratowski-Mazurkiewicz mappings (in short KKM-mappings) and prove an analogue to Ky Fan s fixed point theorem.

2010 Mathematics Subject Classification: Primary 46B20, 47H09; Secondary 47H10.
Activation of retinal microglia rather than microglial cell density correlates with retinal neovascularization in the mouse model of oxygen-induced retinopathy
Authors: Fischer Franziska , Martin Gottfried , Agostini Hansjürgen T
Published: September 2011

Background

Retinal neovascularization has been intensively investigated in the mouse model of oxygen-induced retinopathy (OIR). Here, we studied the contribution of microglial cells to vascular regression during the hyperoxic phase and to retinal neovascularization during the hypoxic phase.

Methods

Mice expressing green fluorescent protein (GFP) under the Cx3cr1 promoter labeling microglial cells were kept in 75% oxygen from postnatal day 7 (P7) to P12. Microglial cell density was quantified at different time points and at different retinal positions in retinal flat mounts. Microglial activation was determined by the switch from ramified to amoeboid cell morphology which correlated with the switch from lectin negative to lectin positive staining of GFP positive cells.

Results

Microglial cell density was constant in the peripheral region of the retina. In the deep vascular layer of the central region, however, it declined 14 fold from P12 to P14 and recovered afterwards. Activated microglial cells were found in the superficial layer of the central avascular zone from P8 to P12 and from P16 to P18. In addition, hyalocytes were found in the vitreal layer in the central region and their cell density decreased over time.

Conclusion

Density of microglial cells does not correlate with vascular obliteration or revascularization. But the time course of the activation of microglia indicates that they may be involved in retinal neovascularization during the hypoxic phase.
Folk medicine in the northern coast of Colombia: an overview
Authors: Gómez-Estrada Harold , Díaz-Castillo Fredyc , Franco-Ospina Luís , Mercado-Camargo Jairo , Guzmán-Ledezma Jaime , Medina José Domingo , Gaitán-Ibarra Ricardo
Published: September 2011

Background

Traditional remedies are an integral part of Colombian culture. Here we present the results of a three-year study of ethnopharmacology and folk-medicine use among the population of the Atlantic Coast of Colombia, specifically in department of Bolívar. We collected information related to different herbal medicinal uses of the local flora in the treatment of the most common human diseases and health disorders in the area, and determined the relative importance of the species surveyed.

Methods

Data on the use of medicinal plants were collected using structured interviews and through observations and conversations with local communities. A total of 1225 participants were interviewed.

Results

Approximately 30 uses were reported for plants in traditional medicine. The plant species with the highest fidelity level (Fl) were Crescentia cujete L. (flu), Eucalyptus globulus Labill. (flu and cough), Euphorbia tithymaloides L. (inflammation), Gliricidia_sepium_(Jacq.) Kunth (pruritic ailments), Heliotropium indicum L. (intestinal parasites) Malachra alceifolia Jacq. (inflammation), Matricaria chamomilla L. (colic) Mentha sativa L. (nervousness), Momordica charantia L. (intestinal parasites), Origanum vulgare L. (earache), Plantago major L. (inflammation) and Terminalia catappa L. (inflammation). The most frequent ailments reported were skin affections, inflammation of the respiratory tract, and gastro-intestinal disorders. The majority of the remedies were prepared from freshly collected plant material from the wild and from a single species only. The preparation of remedies included boiling infusions, extraction of fresh or dry whole plants, leaves, flowers, roots, fruits, and seeds. The parts of the plants most frequently used were the leaves. In this study were identified 39 plant species, which belong to 26 families. There was a high degree of consensus from informants on the medical indications of the different species.

Conclusions

This study presents new research efforts and perspectives on the search for new drugs based on local uses of medicinal plants. It also sheds light on the dependence of rural communities in Colombia on medicinal plants.
The dual origin of the peripheral olfactory system: placode and neural crest
Authors: Katoh Hiroyuki , Shibata Shinsuke , Fukuda Kimiko , Sato Momoka , Satoh Etsuko , Nagoshi Narihito , Minematsu Takeo , Matsuzaki Yumi , Akazawa Chihiro , Toyama Yoshiaki , Nakamura Masaya , Okano Hideyuki
Published: September 2011

Background

The olfactory epithelium (OE) has a unique capacity for continuous neurogenesis, extending axons to the olfactory bulb with the assistance of olfactory ensheathing cells (OECs). The OE and OECs have been believed to develop solely from the olfactory placode, while the neural crest (NC) cells have been believed to contribute only the underlying structural elements of the olfactory system. In order to further elucidate the role of NC cells in olfactory development, we examined the olfactory system in the transgenic mice Wnt1-Cre/Floxed-EGFP and P0-Cre/Floxed-EGFP, in which migrating NC cells and its descendents permanently express GFP, and conducted transposon-mediated cell lineage tracing studies in chick embryos.

Results

Examination of these transgenic mice revealed GFP-positive cells in the OE, demonstrating that NC-derived cells give rise to OE cells with morphologic and antigenic properties identical to placode-derived cells. OECs were also positive for GFP, confirming their NC origin. Cell lineage tracing studies performed in chick embryos confirmed the migration of NC cells into the OE. Furthermore, spheres cultured from the dissociated cells of the olfactory mucosa demonstrated self-renewal and trilineage differentiation capacities (neurons, glial cells, and myofibroblasts), demonstrating the presence of NC progenitors in the olfactory mucosa.

Conclusion

Our data demonstrates that the NC plays a larger role in the development of the olfactory system than previously believed, and suggests that NC-derived cells may in part be responsible for the remarkable capacity of the OE for neurogenesis and regeneration.
The association of near-infrared spectroscopy-derived tissue oxygenation measurements with sepsis syndromes, organ dysfunction and mortality in emergency department patients with sepsis
Authors: Shapiro Nathan I , Arnold Ryan , Sherwin Robert , O'Connor Jennifer , Najarro Gabriel , Singh Sam , Lundy David , Nelson Teresa , Trzeciak Stephen W , Jones Alan E ,   the Emergency Medicine Shock Research Network (EMShockNet)
Published: September 2011

Introduction

Near-infrared spectroscopy (NIRS) noninvasively measures peripheral tissue oxygen saturation (StO2). NIRS may be utilized along with a vascular occlusion test, in which limb blood flow is temporarily occluded and released, to quantify a tissue bed's rate of oxygen exchange during ischemia and recovery. The objective of this study was to test the hypothesis that NIRS-derived StO2 measures (StO2 initial, StO2 occlusion and StO2 recovery) identify patients who are in shock and at increased risk of organ dysfunction (Sequential Organ Failure Assessment (SOFA) score ≥ 2 at 24 hours) and dying in the hospital.

Methods

This prospective, observational study comprised a convenience sample of three cohorts of adult patients (age > 17 years) at three urban university emergency departments: (1) a septic shock cohort (systolic blood pressure < 90 after fluid challenge; the "SHOCK" cohort, n = 58), (2) a sepsis without shock cohort (the "SEPSIS" cohort, n = 60) and emergency department patients without infection (n = 50). We measured the StO2 initial, StO2 occlusion and StO2 recovery slopes for all patients. Outcomes were sepsis syndrome severity, organ dysfunction (SOFA score at 24 hours) and in-hospital mortality.

Results

Among the 168 patients enrolled, mean initial StO2 was lower in the SHOCK cohort than in the SEPSIS cohort (76% vs 81%), with an impaired occlusion slope (-10.2 and 5.2%/minute vs -13.1 and 4.4%/minute) and an impaired recovery slope (2.4 and 1.6%/second vs 3.9 and 1.7%/second) (P < 0.001 for all). The recovery slope was well-correlated with SOFA score at 24 hours (-0.35; P < 0.001), with a promising area under the curve (AUC) for mortality of 0.81. The occlusion slope correlation with SOFA score at 24 hours was 0.21 (P < 0.02), with a fair mortality AUC of 0.70. The initial StO2 was significantly but less strongly correlated with SOFA score at 24 hours (-0.18; P < 0.04), with a poor mortality AUC of 0.56.

Conclusions

NIRS measurements for the StO2 initial, StO2 occlusion and StO2 recovery slope were abnormal in patients with septic shock compared to sepsis patients. The recovery slope was most strongly associated with organ dysfunction and mortality. Further validation is warranted.

Trial registration

NCT01062685
Restrictive strategy of intraoperative fluid maintenance during optimization of oxygen delivery decreases major complications after high-risk surgery
Authors: Lobo Suzana M , Ronchi Luis S , Oliveira Neymar E , Brandão Paulo G , Froes Adriano , Cunrath Geni S , Nishiyama Kátia G , Netinho João G , Lobo Francisco R
Published: September 2011

Introduction

Optimal fluid management is crucial for patients who undergo major and prolonged surgery. Persistent hypovolemia is associated with complications, but fluid overload is also harmful. We evaluated the effects of a restrictive versus conventional strategy of crystalloid administration during goal-directed therapy in high-risk surgical patients.

Methods

We conducted a prospective, randomized, controlled study of high-risk patients undergoing major surgery. For fluid maintenance during surgery, the restrictive group received 4 ml/kg/hour and the conventional group received 12 ml/kg/hour of Ringer's lactate solution. A minimally invasive technique (the LiDCO monitoring system) was used to continuously monitor stroke volume and oxygen delivery index (DO2I) in both groups. Dobutamine was administered as necessary, and fluid challenges were used to test fluid responsiveness to achieve the best possible DO2I during surgery and for 8 hours postoperatively.

Results

Eighty-eight patients were included. The patients' median age was 69 years. The conventional treatment group received a significantly greater amount of lactated Ringer's solution (mean ± standard deviation (SD): 4, 335 ± 1, 546 ml) than the restrictive group (mean ± SD: 2, 301 ± 1, 064 ml) (P < 0.001). Temporal patterns of DO2I were similar between the two groups. The restrictive group had a 52% lower rate of major postoperative complications than the conventional group (20.0% vs 41.9%, relative risk = 0.48, 95% confidence interval = 0.24 to 0.94; P = 0.046).

Conclusions

A restrictive strategy of fluid maintenance during optimization of oxygen delivery reduces major complications in older patients with coexistent pathologies who undergo major surgery.

Trial registration

ISRCTN: ISRCTN94984995
Regenerated Luminal Epithelial Cells Are Derived from Preexisting Luminal Epithelial Cells in Adult Mouse Prostate
Authors: Liu June , Pascal Laura E. , Isharwal Sudhir , Metzger Daniel , Ramos Garcia Raquel , Pilch Jan , Kasper Susan , Williams Karin , Basse Per H. , Nelson Joel B. , Chambon Pierre , Wang Zhou
Published: September 2011

Determining the source of regenerated luminal epithelial cells in the adult prostate during androgen deprivation and replacement will provide insights into the origin of prostate cancer cells and their fate during androgen deprivation therapy. Prostate stem cells in the epithelial layer have been suggested to give rise to luminal epithelium. However, the extent of stem cell participation to prostate regrowth is not clear. In this report, using prostate-specific antigen-CreERT2-based genetic lineage marking/tracing in mice, preexisting luminal epithelial cells were shown to be a source of regenerated luminal epithelial cells in the adult prostate. Prostatic luminal epithelial cells could survive androgen deprivation and were capable of proliferating upon androgen replacement. Prostate cancer cells, typically exhibiting a luminal epithelial phenotype, may retain this intrinsic capability to survive and regenerate in response to changes in androgen signaling, providing part of the mechanism for the ultimate failure of androgen deprivation therapy in prostate cancer.
Foreknowledge and Freedom
Authors: Merricks Trenton
Published: September 2011

The bulk of the essay “Truth and Freedom” (Philosophical Review 118 [2009]: 29–57) opposes fatalism, which is the claim that if there is a true proposition to the effect that an action A will occur, then A will not be free. But that essay also offers a new way to reconcile divine foreknowledge and human freedom. In “The Truth about Freedom: A Reply to Merricks” (Philosophical Review 120 [2011]: 97–115), John Martin Fischer and Patrick Todd raise a number of objections to “Truth and Freedom,” most of which are objections to its treatment of foreknowledge. Their central complaint seems to be that that treatment is, despite its claims to the contrary, merely a form of Ockhamism—and a poorly developed form of Ockhamism at that. This essay replies to Fischer and Todd's specific objections. But, more importantly, it further clarifies the fundamental differences between the way it reconciles divine foreknowledge and human freedom and the Ockhamist's way. In particular, this essay further demonstrates that when it comes to divine foreknowledge's compatibility with human freedom, the fundamental question is not the Ockhamist's question of whether God's beliefs about what an agent will do in the future are “hard facts.” Rather, the fundamental question is whether God's beliefs about what an agent will do in the future depend on what that agent will do in the future.
The two-type continuum Richardson model: nondependence of the survival of both types on the initial configuration
Authors: Carstens Sebastian , Richthammer Thomas
Published: September 2011

We consider the model of Deijfen, Häggström and Bagley (2004) for competing growth of two infection types in Rd, based on the Richardson model on Zd. Stochastic ball-shaped infection outbursts transmit the infection type of the center to all points of the ball that are not yet infected. Relevant parameters of the model are the initial infection configuration, the (type-dependent) growth rates, and the radius distribution of the infection outbursts. The main question is that of coexistence: Which values of the parameters allow the unbounded growth of both types with positive probability? Deijfen, Häggström and Bagley (2004) conjectured that the initial configuration is basically irrelevant for this question, and gave a proof for this under strong assumptions on the radius distribution, which, e.g. do not include the case of a deterministic radius. Here we give a proof that does not rely on these assumptions. One of the tools to be used is a slight generalization of the model with immune regions and delayed initial infection configurations.
Asymptotic normality of the maximum likelihood estimator for cooperative sequential adsorption
Authors: Penrose Mathew D. , Shcherbakov Vadim
Published: September 2011

We consider statistical inference for a parametric cooperative sequential adsorption model for spatial time series data, based on maximum likelihood. We establish asymptotic normality of the maximum likelihood estimator in the thermodynamic limit. We also perform and discuss some numerical simulations of the model, which illustrate the procedure for creating confidence intervals for large samples.
Stability of the exit time for Lévy processes
Authors: Griffin Philip S. , Maller Ross A.
Published: September 2011

This paper is concerned with the behaviour of a Lévy process when it crosses over a positive level, u, starting from 0, both as u becomes large and as u becomes small. Our main focus is on the time, τu, it takes the process to transit above the level, and in particular, on the stability of this passage time; thus, essentially, whether or not τu behaves linearly as u ↓ 0 or u → ∞. We also consider the conditional stability of τu when the process drifts to -∞ almost surely. This provides information relevant to quantities associated with the ruin of an insurance risk process, which we analyse under a Cramér condition.
A dynamic contagion process
Authors: Dassios Angelos , Zhao Hongbiao
Published: September 2011

We introduce a new point process, the dynamic contagion process, by generalising the Hawkes process and the Cox process with shot noise intensity. Our process includes both self-excited and externally excited jumps, which could be used to model the dynamic contagion impact from endogenous and exogenous factors of the underlying system. We have systematically analysed the theoretical distributional properties of this new process, based on the piecewise-deterministic Markov process theory developed in Davis (1984), and the extension of the martingale methodology used in Dassios and Jang (2003). The analytic expressions of the Laplace transform of the intensity process and the probability generating function of the point process have been derived. An explicit example of specified jumps with exponential distributions is also given. The object of this study is to produce a general mathematical framework for modelling the dependence structure of arriving events with dynamic contagion, which has the potential to be applicable to a variety of problems in economics, finance, and insurance. We provide an application of this process to credit risk, and a simulation algorithm for further industrial implementation and statistical analysis.
On the Growth of the One-Dimensional Reverse Immunization Contact Processes
Authors: Tzioufas A.
Published: September 2011

We are concerned with the variation of the supercritical nearest-neighbours contact process such that first infection occurs at a lower rate; it is known that the process survives with positive probability. Regarding the rightmost infected of the process started from one site infected and conditioned to survive, we specify a sequence of space-time points at which its behaviour regenerates and, thus, obtain the corresponding strong law and central limit theorem. We also extend complete convergence in this case.
Some Results for Vacation Systems with Sojourn Time Limits
Authors: Katayama Tsuyoshi
Published: September 2011

In this paper we deal with an M/G/1 vacation system with the sojourn time (wait plus service) limit and two typical vacation rules, i.e. multiple and single vacation rules. Using the level crossing approach, explicit expressions for the steady-state distributions of the virtual waiting times are obtained in vacation systems with exponential and constant service times, a general vacation time, and two vacation rules.
Efficient Estimation of One-Dimensional Diffusion First Passage Time Densities via Monte Carlo Simulation
Authors: Ichiba Tomoyuki , Kardaras Constantinos
Published: September 2011

We propose a method for estimating first passage time densities of one-dimensional diffusions via Monte Carlo simulation. Our approach involves a representation of the first passage time density as the expectation of a functional of the three-dimensional Brownian bridge. As the latter process can be simulated exactly, our method leads to almost unbiased estimators. Furthermore, since the density is estimated directly, a convergence of order 1 / √N, where N is the sample size, is achieved, which is in sharp contrast to the slower nonparametric rates achieved by kernel smoothing of cumulative distribution functions.
First Passage Times of (Reflected) Ornstein-Uhlenbeck Processes Over Random Jump Boundaries
Authors: Bo Lijun , Wang Yongjin , Yang Xuewei
Published: September 2011

In this paper we study first passage times of (reflected) Ornstein-Uhlenbeck processes over compound Poisson-type boundaries. In fact, we extend the results of first rendezvous times of (reflected) Brownian motion and compound Poisson-type processes in Perry, Stadje and Zacks (2004) to the (reflected) Ornstein-Uhlenbeck case.
A Two-Dimensional Risk Model with Proportional Reinsurance
Authors: Badescu Andrei L. , Cheung Eric C. K. , Rabehasaina Landy
Published: September 2011

In this paper we consider an extension of the two-dimensional risk model introduced in Avram, Palmowski and Pistorius (2008a). To this end, we assume that there are two insurers. The first insurer is subject to claims arising from two independent compound Poisson processes. The second insurer, which can be viewed as a different line of business of the same insurer or as a reinsurer, covers a proportion of the claims arising from one of these two compound Poisson processes. We derive the Laplace transform of the time until ruin of at least one insurer when the claim sizes follow a general distribution. The surplus level of the first insurer when the second insurer is ruined first is discussed at the end in connection with some open problems.
Realization of an Ergodic Markov Chain as a Random Walk Subject to a Synchronizing Road Coloring
Authors: Yano Kouji , Yasutomi Kenji
Published: September 2011

An ergodic Markov chain is proved to be the realization of a random walk in a directed graph subject to a synchronizing road coloring. The result ensures the existence of appropriate random mappings in Propp-Wilson's coupling from the past. The proof is based on the road coloring theorem. A necessary and sufficient condition for approximate preservation of entropies is also given.
A Geometric Drift Inequality for a Reflected Fractional Brownian Motion Process on the Positive Orthant
Authors: Lee Chihoon
Published: September 2011

We study a d-dimensional reflected fractional Brownian motion (RFBM) process on the positive orthant S = ℝ+d, with drift r0 ∈ ℝd and Hurst parameter H ∈ (½, 1). Under a natural stability condition on the drift vector r0 and reflection directions, we establish a geometric drift towards a compact set for the 1-skeleton chain Ž̆ of the RFBM process Z; that is, there exist β, b ∈ (0, ∞) and a compact set C ⊂ S such that ΔV(x):= Ex[V(Ž̆(1))] − V(x) ≤ −βV(x) + b1C(x), x ∈ S, for an exponentially growing Lyapunov function V : S → [1, ∞). For a wide class of Markov processes, such a drift inequality is known as a necessary and sufficient condition for exponential ergodicity. Indeed, similar drift inequalities have been established for reflected processes driven by standard Brownian motions, and our result can be viewed as their fractional Brownian motion counterpart. We also establish that the return times to the set C itself are geometrically bounded. Motivation for this study is that RFBM appears as a limiting workload process for fluid queueing network models fed by a large number of heavy-tailed ON/OFF sources in heavy traffic.
The Hartman-Watson Distribution Revisited: Asymptotics for Pricing Asian Options
Authors: Gerhold Stefan
Published: September 2011

Barrieu, Rouault and Yor (2004) determined asymptotics for the logarithm of the distribution function of the Hartman-Watson distribution. We determine the asymptotics of the density. This refinement can be applied to the pricing of Asian options in the Black-Scholes model.
Direct Synthesis of Highly Substituted Furans from Acyloins and Active Methylene Compounds Catalyzed by Bismuth Triflate
Authors: Komeyama Kimihiro , Ohama Yuuki , Takaki Ken
Published: September 2011

Bi(OTf)3 was found to be an effective catalyst for a tandem condensation/cyclization of acyloins and β-diketones or β-keto esters to afford highly substituted furans in good yields.
Melting and Crystallization Behaviors of Alkali Metal (Fluorosulfonyl)(trifluoromethylsulfonyl)amides
Authors: Kubota Keigo , Matsumoto Hajime
Published: September 2011

Asymmetric perfluoroamides with Li+ and Rb+ exhibited unusual phase transition behaviors such as very slow crystallization and a large shift in melting point of the melt-crystallized salts, which have not been reported in alkali metal salts so far. Considering that corresponding symmetric amides do not exhibit such unique phenomena, the structural asymmetry in anions serves an important role in these phase-transition behaviors.
Synthesis of Carbon Nanotubes from Polypropylene in the Presence of Ni/Mo/MgO Catalysts via Combustion
Authors: Song Rongjun , Ji Qing
Published: September 2011

We demonstrated an efficient improvement of activity of Ni catalysts by combining with Mo and Mg elements, by which massive growth of multiwalled carbon nanotubes (MWNTs) with straight and double helical structures have been achieved from polypropylene (PP) by means of a one-step combustion method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) are applied to characterize the morphology and the purity of products.
Nickel-catalyzed Cycloaddition of Aromatic (O-Benzyl)ketoximes with Alkynes to Produce Isoquinoline and Isoquinoline N-Oxide Derivatives
Authors: Yoshida Yuji , Kurahashi Takuya , Matsubara Seijiro
Published: September 2011

A nickel-catalyzed cycloaddition of aromatic (O-benzyl)ketoximes with alkynes to afford 3,4-disubstituted isoquinoline derivatives has been developed. The reaction involves oxidative addition of N–O bond of O-benzylketoxime to Ni(0) and subsequent intermolecular C–H bond activation via elimination of benzyl alcohol. It was also found that ketoximes participate in the nickel-catalyzed reaction with alkynes to furnish isoquinoline N-oxide derivatives.
Cyclo(l-aspartyl-l-phenylalanyl)-containing Poly(dimethylsiloxane)-based Thixotropic Organogels
Authors: Hoshizawa Hiroko , Suzuki Masahiro , Hanabusa Kenji
Published: September 2011

Cyclo(l-aspartyl-l-phenylalanyl)-containing poly(dimethylsiloxane) was synthesized through a simple procedure. This compound had a good organogelation or thickener ability in many organic solvents. X-ray diffraction showed that the gelator forms amorphous structure due to the presence of poly(dimethylsiloxane). Furthermore, some organogels were thixotropic in that reversible gel-to-sol transition was induced by mechanical stress.
Obtaining models suitable for Rietveld refinement: the EXPO2011 techniques
Authors: Altomare Angela , Cuocci Corrado , Giacovazzo Carmelo , Moliterni Anna Grazia Giuseppina , Rizzi Rosanna
Published: September 2011

Rietveld refinement succeeds if the model is sufficiently close to the target structure. Severe distortions in the structural parameters or relatively high percentage of missed atoms do not allow the refinement to converge. Ab initio techniques like Direct or Patterson methods may rely only on the reflection intensities provided by full pattern decomposition algorithms. Owing to the relevant errors in the intensity estimates, the structural models provided by such phasing techniques are poor and require supplementary improvements before being submitted to Rietveld refinement. The situation is more favorable for non-ab initio techniques, when they can exploit the prior information on the full molecular geometry: their models can be easily submitted to Rietveld refinement, but often the accuracy of the refined model relies on the geometrical information rather than on the experiment. In this paper ab initio and non-ab initio phasing tools of EXPO2011, the updated and more powerful version of EXPO2009 [1], are described together with ancillary techniques for improving and completing the structural models.
Yield of HO2 Radicals in the OH-Initiated Oxidation of SO2
Authors: Jain Chaithanya , Schoemaecker Coralie , Fittschen Christa
Published: September 2011

The HO2 radical yield in the OH initiated oxidation of SO2 has been determined by direct observation of HO2 concentration time profiles following the 248 nm photolysis of H2O2/SO2/O2 mixtures. Initial OH radical concentrations have been deduced from a fit of the absolute HO2 concentration time profiles after 248 nm photolysis of H2O2 in the absence of SO2, an increase in the HO2 concentration upon addition of SO2 to this reaction mixture is observed and can be explained by a decrease of HO
x
-radical losses due to a faster decay of OH radicals in the presence of SO2. Simulations of theses profiles using recommended rate constants in a simple model are in agreement with an HO2-yield of 1.0 ± 0.1 from the OH initiated oxidation of SO2.
Integrating Active Learning & Quantitative Skills into Undergraduate Introductory Biology Curricula
Authors: Goldstein Jessica , Flynn Dan F. B.
Published: September 2011

Analytical and quantitative thinking skills are core components of science but can be challenging to teach in introductory biology courses. To address this issue, modest curriculum modifications, including methods of hypothesis testing, data collection, and statistical analysis, were introduced into existing exercises in an introductory biology laboratory course. After completing the updated course, students demonstrated improved ability to understand and interpret statistical analyses. Furthermore, students were more likely to understand that hypothesis development and quantitative data analysis are important parts of biology. This study indicates that small changes to laboratory curricula can effect important changes in student learning and attitudes.
Juvenile Detention Reform in New York City: Measuring Risk Through Research
Authors: Fratello Jennifer , Salsich Annie , Mogulescu Sara
Published: September 2011

This article is excerpted from Jennifer Fratello, Annie Salsich, & Sara Mogulescu's longer article of the same name published by the Vera Institute of Justice in April 2011. In 2006, faced with the challenges of a juvenile justice system nearing crisis, New York City officials concluded that they had to rethink the city's juvenile detention policies and practices. The development and implementation of the risk-assessment instrument (RAI) and community-based alternatives to detention (ATD) programs represent an important shift in New York City's juvenile detention policy. The RAI provides reliable guidance on risks of failure to appear or rearrest. The ATDs provide effective program alternatives to detention for moderate-risk youth. Given early outcomes, it appears that New York City's reform effort could serve as a model for other jurisdictions seeking to improve outcomes for youth while preserving public safety.
Experiments in the Criminal Justice System
Authors: Sturz Herbert
Published: September 2011

This article originally appeared in the Legal Aid Briefcase, February 1967, and was based on Herbert Sturz's testimony before the Senate Subcommittee on Executive Reorganization, December 13, 1966. The primary focus of the Vera Institute of Justice has been on the relationship of poverty to the administration of criminal justice. Well over 50 percent of individuals appearing in the criminal courts of America are indigent, and more are dangerously close. As a neutral private agency, the Vera Institute of Justice has brought together various public agencies in joint programs and experiments to address this issue with action-oriented interventions. This pilot project technique provides great flexibility, allowing planners to adopt successful programs or change the approach on short notice, as needed.
San Francisco's Family-Focused Probation: A Conversation with Chief Adult Probation Officer Wendy Still
Authors: Dizerega Margaret
Published: September 2011

The strengths of family and the impact of incarceration on family members are often ignored in the sentencing decision. Similarly, despite decades of research demonstrating that families play an important role in the successful reentry of individuals, they are often overlooked as a reentry resource. A family-focused approach to sentencing and supervision would ensure that family involvement is considered at each decision point in the criminal justice system. Believed to be the only U.S. jurisdiction that is using family impact statements at sentencing, the Adult Probation Department in San Francisco is committed to a family-focused approach. To discuss the department's innovative practices, the author interviewed Wendy Still, the chief adult probation officer of the city and county of San Francisco.
The Hsp70 and Hsp40 Chaperones Influence Microtubule Stability inChlamydomonas
Authors: Silflow Carolyn D , Sun Xiaoqing , Haas Nancy A , Foley Joseph W , Lefebvre Paul A
Published: September 2011

Mutations at the APM1 and APM2 loci in the green alga Chlamydomonas reinhardtii confer resistance to phosphorothioamidate and dinitroaniline herbicides. Genetic interactions between apm1 and apm2 mutations suggest an interaction between the gene products. We identified the APM1 and APM2 genes using a map-based cloning strategy. Genomic DNA fragments containing only the DNJ1 gene encoding a type I Hsp40 protein rescue apm1 mutant phenotypes, conferring sensitivity to the herbicides and rescuing a temperature-sensitive growth defect. Lesions at five apm1 alleles include missense mutations and nucleotide insertions and deletions that result in altered proteins or very low levels of gene expression. The HSP70A gene, encoding a cytosolic Hsp70 protein known to interact with Hsp40 proteins, maps near the APM2 locus. Missense mutations found in three apm2 alleles predict altered Hsp70 proteins. Genomic fragments containing the HSP70A gene rescue apm2 mutant phenotypes. The results suggest that a client of the Hsp70–Hsp40 chaperone complex may function to increase microtubule dynamics in Chlamydomonas cells. Failure of the chaperone system to recognize or fold the client protein(s) results in increased microtubule stability and resistance to the microtubule-destabilizing effect of the herbicides. The lack of redundancy of genes encoding cytosolic Hsp70 and Hsp40 type I proteins in Chlamydomonas makes it a uniquely valuable system for genetic analysis of the function of the Hsp70 chaperone complex.
Malaysian composers, geopolitical spaces and cultural difference
Authors: Baes Jonas
Published: September 2011

The case of Malaysian ‘new music’ composers resonates the political aspects in the production of cultural difference within a modernizing post-colonial nation-state in Southeast Asia. Caught in the discord of a state-induced cultural agenda that highly favored ‘syncretic’ and locally stylized popular idioms, Malaysian new music composers continuously struggle for aesthetic integrity within the backdrop of their country’s consistent growth en route to becoming a world economic power. Believing with Bunnell (2006), however, that a utopic kind of modernity in Malaysia is alluded to in its spatial dimensions, and in the ‘govern(nance) of the landscape’ (2006: 15–31), I therefore argue that the creative responses of those composers, to apparently marginalizing conditions of the present, may just as well involve spatial realms—be they ‘physical’ or otherwise.
Mineral powder concrete – effects of powder content on concrete properties
Authors: Tikkanen Johanna , Penttala Vesa , Cwirzen Andrzej
Published: September 2011

The effects of partial replacement of Portland cement with non-pozzolanic mineral powders on normal-strength concretes were studied. The observed concrete properties were workability, pumpability, compressive strength and microstructure. Superplasticisers were used in every test concrete. With the addition of mineral powders, the water requirement of the concrete mixes decreased and the compressive strength of the mineral powder concretes was kept at the same level as in a reference mix by using on average a 75 kg/m3 lower cement amount. Studies of the microstructure of the concretes were made using resin-impregnated and polished specimens that were prepared from three concretes, each containing a different mineral powder. In the environmental scanning electron microscopy study, the specimens showed densification of the interfacial transition zone when mineral powders were used. The effects of the mineral powders on the workability, water requirement and compressive strength values of the concretes were evaluated in relation to grading curves.
The conservation status of Callicebus caquetensis (Pitheciidae): a new species in southern Caquetá Department, Colombia
Authors: García Javier , Defler Thomas R. , Bueno Marta L.
Published: September 2011

Moynihan (1976) mentioned an undescribed species of Callicebus between the ríos Caquetá and Orteguaza, Caquetá Department, Colombia. In August 2008, we confirmed the new species, which is phylogenetically related to C. ornatus and C. discolor to the north and south of the type locality respectively. We described this species as Callicebus caquetensis Defler et al., 2010 establishing its distribution through direct observations and information from local communities. Eighty-two animals were seen, including the holotype and paratype, which were collected. A review of historical archives of aerial photographs and satellite maps was carried out to assess the loss of the original vegetation of the area, and we found the habitat in an advanced state of fragmentation caused by extensive ranching and illegal crop cultivation. Existing coverage is now limited to small fragments of the original primary forest and secondary vegetation. We analyzed a Google Earth image of 75 km2 of this primate´s habitat and found only 32% of forest and secondary forest vegetation remaining in 2002, the year the image was captured. We propose this Colombian endemic species should be considered as Critically Endangered (CR), (based upon the criteria A3c,d,e, C2 of the IUCN). We suggest that the Colombian and Caquetá governments and private individuals give special attention to this endemic primate, most importantly in the creation of reserves and in environmental education initiatives. This is probably the most endangered of Colombia’s primates.
A morphological analysis of some species of Callicebus, Thomas, 1903 (Pitheciidae - Callicebinae)
Authors: Auricchio Paulo
Published: September 2011

A chromogenetic field analysis was performed with 25 of 29 of the known species of the genus Callicebus. Some species presented polymorphism, such as C. moloch, C. hoffmansii and C. cupreus. C. bernhardi presents the same distribution of color in chromogenetic fields as C. moloch, differing only in pigment amount, mainly in ventral surfaces, suggesting C. bernhardi is a junior synonym of C. moloch. C. hoffmansii presents two distinct phenotypes, but without a geographic barrier between them. Callicebus cupreus, C. dubius and C. caligatus are distinct species.
Noteworthy record of a black howler monkey (Alouatta caraya) from the central dry Chaco of Paraguay
Authors: Giordano Anthony J. , Ballard Warren B.
Published: September 2011

No abstract
Preliminary observations of napo tamarins (Saguinus graellsi) and notes on primates of Wildsumaco Wildlife Sanctuary
Authors: Vanderhoff E. Natasha , Nillson Jonas
Published: September 2011

No abstract
Strategies for Securing Funding for Abortion Under the Hyde Amendment: A Multistate Study of Abortion Providers’ Experiences Managing Medicaid
Authors: Dennis Amanda , Blanchard Kelly , Córdova Denisse
Published: September 2011

Objectives. We investigated systematic barriers, identified by previous research, that prevent women from obtaining Medicaid coverage for an abortion even when it should legally be available: when the pregnancy resulted from rape or incest or threatens the mother's life. We also aimed to document strategies to improve access to federal Medicaid funding in qualifying cases.

Methods. We conducted in-depth interviews from 2007 to 2009 with representatives of 49 facilities that provided abortions in 11 states. Interviews focused on participants’ experiences and strategies in seeking federal Medicaid funding for abortions. We coded data both inductively and deductively and analyzed them thematically.

Results. Common strategies described by the few participants who secured Medicaid funding for abortions in cases of rape, incest, and life endangerment were facility-level interventions, such as developing relationships with Medicaid staff, building savvy billing departments, and encouraging clients to advocate for themselves, as well as broader legal and collaborative strategies.

Conclusions. Multipronged state-level interventions that combine advocacy, legal, and on-the-ground resources show the most promise of increasing access to federal Medicaid funding for abortion care.