bluuebunny/crossref_metadata_2025 huggingface dataset:
Radially Branched Deployment for More Efficient Cell Transplantation at the Scale of the Human Brain
Authors: Silvestrini Matthew T. , Yin Dali , Coppes Valerie G. , Mann Preeti , Martin Alastair J. , Larson Paul S. , Starr Philip A. , Gupta Nalin , Panter S. Scott , Desai Tejal A. , Lim Daniel A.
Published: January 2013

Background: In preclinical studies, cell transplantation into the brain has shown great promise for the treatment of a wide range of neurological diseases. However, the use of a straight cannula and syringe for cell delivery to the human brain does not approximate cell distribution achieved in animal studies. This technical deficiency may limit the successful clinical translation of cell transplantation. Objective: To develop a stereotactic device that effectively distributes viable cells to the human brain. Our primary aims were to (1) minimize the number of transcortical penetrations required for transplantation, (2) reduce variability in cell dosing and (3) increase cell survival. Methods: We developed a modular cannula system capable of radially branched deployment (RBD) of a cell delivery catheter at variable angles from the longitudinal device axis. We also developed an integrated catheter-plunger system, eliminating the need for a separate syringe delivery mechanism. The RBD prototype was evaluated in vitro and in vivo with subcortical injections into the swine brain. Performance was compared to a 20G straight cannula with dual side ports, a device used in current clinical trials. Results: RBD enabled therapeutic delivery in a precise ‘tree-like’ pattern branched from a single initial trajectory, thereby facilitating delivery to a volumetrically large target region. RBD could transplant materials in a radial pattern up to 2.0 cm from the initial penetration tract. The novel integrated catheter-plunger system facilitated manual delivery of small and precise volumes of injection (1.36 ± 0.13 µl per cm of plunger travel). Both dilute and highly concentrated neural precursor cell populations tolerated transit through the device with high viability and unaffected developmental potential. While reflux of infusate along the penetration tract was problematic with the use of the 20G cannula, RBD was resistant to this source of cell dose variability in agarose. RBD enabled radial injections to the swine brain when used with a modern clinical stereotactic system. Conclusions: By increasing the total delivery volume through a single transcortical penetration in agarose models, RBD strategy may provide a new approach for cell transplantation to the human brain. Incorporation of RBD or selected aspects of its design into future clinical trials may increase the likelihood of successful translation of cell-based therapy to the human patient.
Ureteral Endometriosis: Proposal for a Diagnostic and Therapeutic Algorithm with a Review of the Literature
Authors: Maccagnano Carmen , Pellucchi Federico , Rocchini Lorenzo , Ghezzi Massimo , Scattoni Vincenzo , Montorsi Francesco , Rigatti Patrizio , Colombo Renzo
Published: January 2013

Introduction: The ureteral involvement in deep pelvic endometriosis in usually asymptomatic and might lead to a silent loss of renal function. As a matter of fact, the diagnosis and the treatment modalities are still a matter of debate. Materials and Methods: We performed a literature review by searching the MEDLINE database for articles published in English between 1996 and 2010, using the key words urinary tract endometriosis, ureteral endometriosis, diagnosis and treatment. We found more than 200 cases of ureteral endometriosis (UE). Results: The disease most commonly affects a single distal segment of the ureter, with a left predisposition in most of the patients. Two major pathological types of UE may be distinguished: intrinsic and extrinsic. The symptoms are usually nonspecific and owing to secondary obstruction. The diagnosis has to be considered as a step- by-step procedure, starting from physical examination to highly detailed imaging methods. Nowadays, the treatment is usually chosen according to the type of UE, the site lesion and the distance to the ureteral orifice, with the use of JJ stents remaining a matter of debate. Conclusions: A close collaboration between the gynecologist and the urologist is advisable, especially in referral centers. Surgical treatment can lead to good results in terms of both patient compliance and prognosis.
Vascular Calcifications, Arterial Aging and Arterial Remodeling in ESRD
Authors: London Gérard M. , Pannier Bruno , Marchais Sylvain J.
Published: January 2013

Background: Accelerated arterial aging and inadequate outward arterial remodeling are observed in end-stage renal disease (ESRD) patients. Whether these changes could be closely associated with arterial calcifications has never been investigated. Methods: 155 ESRD patients and 105 age-, sex-, and blood pressure-matched control subjects were included. Common carotid artery (CCA) pressure, diameter, intima-media thickness, elastic modulus, and presence of calcified plaques were measured ultrasonographically. Carotid artery stiffness was determined from simultaneously recorded CCA diameter and stroke changes in diameter and CCA pressure waveforms, obtained by applanation tonometry. Results: Compared with control subjects, ESRD patients had increased CCA systolic and pulse pressures (p < 0.001), larger CCA diameter (p < 0.001) and CCA intima-media thickness (p < 0.01) and similar CCA relative wall thickness. In ESRD patients the arterial remodeling was associated with increased CCA elastic modulus/stiffness (p < 0.001). In ESRD patients the association between CCA elastic modulus and age was characterized by a steeper slope (p = 0.03), but after separation of uremic patients according to the presence of calcifications, the accelerated aging was observed only in calcified subjects. Despite higher CCA systolic and pulse pressures, the CCA relative wall thickness was similar to controls indicating an inadequate pressure-associated remodeling. Moreover, the positive systolic pressure/relative thickness correlation observed in control subjects was lost with paradoxical negative correlation in calcified ESRD patients (p = 0.03). Conclusion: These results indicate that, in ESRD patients, accelerated arterial aging and inadequate arterial hypertrophy are closely associated with the calcifications of arterial walls. Inadequate hypertrophy is responsible for high circumferential stress applied on the vessels.
Emerging Clinical Evidence on Online Hemodiafiltration: Does Volume of Ultrafiltration Matter?
Authors: Canaud Bernard , Bowry Sudhir K.
Published: January 2013

Online hemodiafiltration (OL-HDF), first described in 1985, is today a widely prescribed treatment modality for end-stage chronic kidney disease (CKD) patients. Other than in the United States, prescription of the treatment modality is widespread with a steady increase since its inception. Indeed, in Western Europe, more CKD patients receive OL-HDF than peritoneal dialysis, hitherto the second most prescribed therapy after conventional hemodialysis. The rise and success of OL-HDF can be attributed to diverse clinical advantages that have been documented over the last two decades. Numerous publications attest to the beneficial effects of OL-HDF in terms of removal of a broad spectrum of uremic toxin, anemia control, phosphate reduction, increased hemodynamic stability and blood pressure control and less dialysis-related amyloidosis, to mention just a few. Significantly, the improvement in these conditions is considered to contribute to improved patient outcomes. Despite the extended worldwide clinical experience, elaborate scientific validation of the principles of the therapy and technical innovations that facilitate its prescription, a point of contention is whether OL-HDF leads to a reduction of mortality rates. A number of observational and retrospective analyses have indicated a survival benefit, while prospective investigations involving small numbers of patients but nevertheless specifically addressing survival have further supplied evidence of improved survival with OL-HDF. The quest for large-scale, multicenter prospective randomized controlled trials examining patient survival led to the CONTRAST and the Turkish OL-HDF trials. Both trials have been concluded and published recently. In this chapter, we document and assess the key investigations that have examined the impact of OL-HDF on patient outcome and survival. Based on the findings of previous analyses and of the two recently concluded trials, it appears that the volume of convection appears to be decisive towards the survival benefit accredited to OL-HDF. We consider the implications of this new evidence.
Reasons for the Lack of Salutary Effects of Cholesterol-Lowering Interventions in End-Stage Renal Disease Populations
Authors: Vaziri Nosratola D. , Norris Keith C.
Published: January 2013

Cardiovascular disease (CVD) is the main cause of premature death in patients with chronic kidney disease (CKD). The underlying mechanisms of CVD in patients with mild to moderate CKD are different from those with end-stage renal disease (ESRD). While serum cholesterol is frequently elevated and contributes to atherosclerosis in many CKD patients, particularly those with nephrotic proteinuria, it is usually normal, even subnormal, in most ESRD patients receiving hemodialysis. CVD in the ESRD population is primarily driven by oxidative stress, inflammation, accumulation of the oxidation-prone intermediate-density lipoproteins, chylomicron remnants and small dense low-density lipoprotein particles as well as high-density lipoprotein deficiency and dysfunction, hypertension, vascular calcification, and arrhythmias. Only a minority of hemodialysis patients have hypercholesterolemia which is most likely due to genetic or unrelated factors. In addition, due to peritoneal losses of proteins which simulate nephrotic syndrome, peritoneal dialysis patients often exhibit hypercholesterolemia. Clearly when present, hypercholesterolemia contributes to CVD in the CKD and ESRD population and justifies cholesterol-lowering therapy. However, the majority of ESRD patients and a subpopulation of CKD patients with minimal proteinuria have normal or subnormal serum cholesterol levels and do not benefit from and can be potentially harmed by statin therapy. In fact the lack of efficacy of statins in hemodialysis patients has been demonstrated in several randomized clinical trials. This review is intended to provide an overview of the mechanisms responsible for the failure of statins to reduce cardiovascular morbidity and mortality in most ESRD patients and to advocate the adoption of individualized care principles in the management of dyslipidemia in this population.
Prevention of Sudden Cardiac Death in Dialysis Patients: Drugs, Defibrillators or What Else?
Authors: Passman Rod
Published: January 2013

Death from cardiovascular disease in general and sudden cardiac arrest (SCA) in particular are exponentially proportional to declining renal function and are a major cause of mortality among those with chronic kidney disease (CKD). The greatest risk, however, is reserved for those patients on chronic dialysis. These individuals have an extraordinarily high rate of death, with cardiac disease accounting for 45% and SCA responsible for 25% of all-cause mortality. Once cardiac arrest occurs, survival is extremely poor. Thus, reducing mortality from cardiovascular disease and SCA in dialysis patients is a global health challenge. The main objectives of this review are to elucidate the nature of SCA in the dialysis population, describe possible mechanisms and risk factors, and discuss options for prevention.
The MONitoring Dialysis Outcomes (MONDO) Initiative
Authors: Usvyat Len A. , Haviv Yosef S. , Etter Michael , Kooman Jeroen , Marcelli Daniele , Marelli Cristina , Power Albert , Toffelmire Ted , Wang Yuedong , Kotanko Peter
Published: January 2013

Background: Systematic collection and analysis of global hemodialysis patient data may help to improve patient outcomes. Methods: The MONitoring Dialysis Outcomes (MONDO) initiative comprises data from eight dialysis providers worldwide. Data are combined into one repository. Extensive procedures are employed to merge data across countries and providers. Results: The MONDO database comprises longitudinal data of currently 128,000 hemodialysis patients from 26 countries on five continents. Here we report data from 62,345 incident hemodialysis patients. We found lower catheter rates in South-East Asia and Australia, lower hemoglobin levels in South-East Asia, and a higher prevalence of diabetes in North America. Longitudinal analyses suggest that there is a decline in interdialytic weight gain and serum phosphorus and an increasing neutrophil-to-lymphocyte ratio before death in all regions studied. Conclusions: While organizationally lean and low-cost, MONDO is the largest global dialysis database initiative to date, with a particular focus on high longitudinal data density and geographical diversity.
New Diagnostic Tests and New Therapies for Glomerular Diseases
Authors: Appel Gerald B. , Appel Alice Sue
Published: January 2013

There has recently been considerable progress in our understanding of the pathology and mechanisms of a number of primary glomerulopathies. However, without parallel advancement in both our diagnostic skills and treatment methods, such advances cannot be translated into clinical progress. Fortunately, a number of new promising diagnostic tests are being evaluated in patients with a variety of primary glomerulopathies including focal segmental glomerulosclerosis membranous nephropathy, IgA nephropathy, and C3 glomerulopathies. Likewise, a number of new therapeutic interventions are available to treat these entities, including the pituitary hormone ACTH, the monoclonal antibody rituximab, and the monoclonal blocker of the fifth component of complement, eculizumab. All three are already FDA-approved for at least one glomerular disease. This article will discuss these newer diagnostic tests and therapies as well as their potential roles in patients with glomerular diseases and where they fit in with the rest of our therapeutic armamentarium in treating patients with glomerular diseases.
Vitamin B12 Intake and Status in Early Pregnancy among Urban South Indian Women
Authors: Samuel Tinu Mary , Duggan Christopher , Thomas Tinku , Bosch Ronald , Rajendran Ramya , Virtanen Suvi M. , Srinivasan Krishnamachari , Kurpad Anura V.
Published: January 2013

Aim: To evaluate the vitamin B12 status of South Indian women in early pregnancy and its relationship with sociodemographic, anthropometry and dietary intake. Methods: Cross-sectional study among 366 pregnant urban South Indian women ≤14 weeks of gestation with outcome variables defined as low vitamin B12 blood concentration (<150 pmol/l) and impaired vitamin B12 status [low vitamin B12 plus elevated methylmalonic acid (MMA) >0.26 µmol/l)]. Results: Low plasma vitamin B12 concentration was observed in 51.1% of the women, while 42.4% had impaired B12 status. Elevated MMA, elevated homocysteine (>10 µmol/l) and low erythrocyte folate (<283 nmol/l) were observed among 75.8, 43.3 and 22.2% of the women, respectively. The median (25th, 75th percentile) dietary intake of vitamin B12 was 1.25 (0.86, 1.96) µg/day. Lower maternal body weight was associated with higher vitamin B12 concentration [prevalence ratios (PR) (95% CI) 0.57 (0.39, 0.84)]. The predictors of impaired vitamin B12 status were no consumption of yoghurt [PR (95% CI) 1.63 (1.03, 2.58)] or fish [PR (95% CI) 1.32 (1.01, 1.71)] and primiparity [PR (95% CI) 1.41 (1.05, 1.90)]. Conclusion: A high prevalence of vitamin B12 deficiency in early pregnancy among urban South Indian women was related to primiparity and to a low consumption of yoghurt and fish.
Entropy of Uremia and Dialysis Technology
Authors: Ronco Claudio
Published: January 2013

The second law of thermodynamics applies with local exceptions to patient history and therapy interventions. Living things preserve their low level of entropy throughout time because they receive energy from their surroundings in the form of food. They gain their order at the expense of disordering the nutrients they consume. Death is the thermodynamically favored state: it represents a large increase in entropy as molecular structure yields to chaos. The kidney is an organ dissipating large amounts of energy to maintain the level of entropy of the organism as low as possible. Diseases, and in particular uremia, represent conditions of rapid increase in entropy. Therapeutic strategies are oriented towards a reduction in entropy or at least a decrease in the speed of entropy increase. Uremia is a process accelerating the trend towards randomness and disorder (increase in entropy). Dialysis is a factor external to the patient that tends to reduce the level of entropy caused by kidney disease. Since entropy can only increase in closed systems, energy and work must be spent to limit the entropy of uremia. This energy should be adapted to the system (patient) and be specifically oriented and personalized. This includes a multidimensional effort to achieve an adequate dialysis that goes beyond small molecular weight solute clearance. It includes a biological plan for recovery of homeostasis and a strategy towards long-term rehabilitation of the patient. Such objectives can be achieved with a combination of technology and innovation to answer specific questions that are still present after 60 years of dialysis history. This change in the individual bioentropy may represent a local exception to natural trends as the patient could be considered an isolated universe responding to the classic laws of thermodynamics.
Embryonic Stem Cells Facilitate the Isolation of Persistent Clonal Cardiovascular Progenitor Cell Lines and Leukemia Inhibitor Factor Maintains Their Self-Renewal and Myocardial Differentiation Potential in vitro
Authors: Hoebaus Julia , Heher Philipp , Gottschamel Teresa , Scheinast Matthias , Auner Harmen , Walder Diana , Wiedner Marc , Taubenschmid Jasmin , Miksch Maximilian , Sauer Thomas , Schultheis Martina , Kuzmenkin Alexey , Seiser Christian , Hescheler Juergen , Weitzer Georg
Published: January 2013

Compelling evidence for the existence of somatic stem cells in the heart of different mammalian species has been provided by numerous groups; however, so far it has not been possible to maintain these cells as self-renewing and phenotypically stable clonal cell lines in vitro. Thus, we sought to identify a surrogate stem cell niche for the isolation and persistent maintenance of stable clonal cardiovascular progenitor cell lines, enabling us to study the mechanism of self-renewal and differentiation in these cells. Using postnatal murine hearts with a selectable marker as the stem cell source and embryonic stem cells and leukemia inhibitory factor (LIF)-secreting fibroblasts as a surrogate niche, we succeeded in the isolation of stable clonal cardiovascular progenitor cell lines. These cell lines self-renew in an LIF-dependent manner. They express both stemness transcription factors Oct4, Sox2, and Nanog and early myocardial transcription factors Nkx2.5, GATA4, and Isl-1 at the same time. Upon LIF deprivation, they exclusively differentiate to functional cardiomyocytes and endothelial and smooth muscle cells, suggesting that these cells are mesodermal intermediates already committed to the cardiogenic lineage. Cardiovascular progenitor cell lines can be maintained for at least 149 passages over 7 years without phenotypic changes, in the presence of LIF-secreting fibroblasts. Isolation of wild-type cardiovascular progenitor cell lines from adolescent and old mice has finally demonstrated the general feasibility of this strategy for the isolation of phenotypically stable somatic stem cell lines.
Purity and Stability of Online-Prepared Hemodiafiltration Fluid after Storage
Authors: Corradi V. , Cruz D. , Vázquez-Rangel A. , Furlan F. , Grillone R. , Bonaccorsi A. , Cazzavillan S. , de Cal M. , Frisone P. , Morea A. , Brendolan A. , Rassu M. , Ronco C.
Published: January 2013

Background/Aims: Previous studies have suggested that online hemodiafiltration (OL-HDF) fluid can be used as dialysate for continuous renal replacement therapies, and thus HDF costs can be reduced. The aims of this study were to determine the purity of OL-HDF fluid and to verify the stability of the electrolyte composition and acid-base balance during its storage. Methods: OL-HDF fluid was collected in 70 individual bags and stored for up to 7 days. The following tests were performed daily in 10 bags: natural visible precipitation (macrocrystallization), sample collection for chemical analysis and fluid culture, limulus amebocyte lysate endotoxin test, standard culture of NALGENE® filters after passing of the fluid, and molecular analysis of bacterial DNA. Results: The values of pH and pCO2 showed a significant change starting at 24 h (p < 0.001); after 72 h, their values were beyond the measurable range. Coefficient of variation for pCO2 was as high as 25.7%. Electrolyte composition (Na+, K+, Cl–, Ca2+ and glucose) showed a statistically significant difference over time (p < 0.05); however, their coefficients of variation were low (1.7, 1.4, 0.6, 2.3 and 0.9%, respectively), which might not be considered clinically significant. Negative results were obtained at all points by fluid and filter cultures, endotoxin test and molecular analysis. No macrocrystallization was observed at any time point. Conclusions: We demonstrate the microbiological purity of OL-HDF fluid stored for up to 7 days. The electrolyte composition was stable, except for a relevant change in pCO2 and consequently in pH (first noted at 24 h), emphasizing the need to reassess the acid-base balance in multilayer plastic bags in future studies.
Effect of Percutaneous Ventricular Assist Devices on Renal Function
Authors: Mao Huijuan , Giuliani Anna , Blanca-Martos Lourdes , Kim Jeong Chul , Nayak Akash , Virzi Grazia , Brocca Alessandra , Scalzotto Elisa , Neri Mauro , Katz Nevin , Ronco Claudio
Published: January 2013

Ventricular assist devices (VADs) are used to improve the systemic circulation and to decrease ventricular loading in patients with hemodynamic instability that is refractory to pharmacologic therapies. During an acute critical event, percutaneous devices are preferred because of their rapid deployment, since implantable devices require more extensive procedures. Implantable devices are used for patients with established end-stage heart failure as a bridge to heart transplantation, recovery or destination therapy. This report reviews mechanical principles and clinical studies regarding percutaneous VAD to address their potential renal effects. Since the focus of this study is set on devices that are dedicated to cardiac support only, extracorporeal membrane oxygenation systems are not included.
Clinical Evaluation of a Model for Prediction of End-Dialysis Systemic Ionized Calcium Concentration in Citrate Hemodialysis
Authors: Thijssen Stephan , Kossmann Robert J. , Kruse Anja , Kotanko Peter
Published: January 2013

Background/Aim: Citrate anticoagulation in hemodialysis (HD) is increasingly drawing attention in the nephrology community. One of the major deterrents to a more widespread use are the monitoring requirements for fear of systemic calcium derangements. Means of accurately predicting systemic ionized calcium (iCa) may help to overcome this challenge. We have previously presented a mathematical model of regional citrate anticoagulation (RCA) to address this need. Here, we present a refined model and show results in an independent validation cohort of maintenance HD patients on Citrasate®, a calcium- and citrate-containing dialysate. Methods: A hybrid RCA model was developed, comprising the previously published ‘native’ RCA model and a statistical correction based on levels of alkaline phosphatase as a marker of bone turnover. The model was validated in 120 patients on Citrasate, a dialysate containing 0.8 mmol/l citrate and 1.125 mmol/l calcium. Systemic iCa was measured at the beginning and end of one HD treatment in each subject. Serum iCa predictions were compared between our previously published model and the new hybrid model. Results: On average, the hybrid model predicted end-HD systemic iCa with an error (predicted – measured) of 0.028 mmol/l, compared to –0.051 mmol/l with the previously published model. There were only 4 subjects out of the 120 analyzed in whom the prediction error was <–0.1 mmol/l, and only 6 in whom the error was >+0.1 mmol/l (max: +0.13 mmol/l). Conclusion: This study demonstrates that the novel hybrid model is an improvement over the previously published model and that it is capable of predicting end-dialysis systemic iCa levels with improved accuracy and precision even in a citrate dialysis setting which was much different from the original derivation cohort.
Cytogenetic Elaboration of a Novel Reciprocal Translocation in Sheep
Authors: Iannuzzi A. , Perucatti A. , Genualdo V. , De Lorenzi L. , Di Berardino D. , Parma P. , Iannuzzi L.
Published: January 2013

Reciprocal translocations represent one of the most common structural chromosomal rearrangements observed in both humans and domestic animals. In these translocations, the balanced forms are most frequent but may remain undetected because the carriers show a normal phenotype. For this reason, routine cytogenetic analysis of domestic animals should necessarily rely on banded karyotypes. In fact, during a screening analysis, carried out on phenotypically normal young sheep (Ovis aries, OAR, 2n = 54) from Laticauda-Comisana hybrids, a new structural rearrangement was detected. Two abnormal acrocentric chromosomes (the smallest and the largest one) were found in all metaphases of this carrier animal, suggesting the presence of a reciprocal translocation (rcp). CBA and RBA banding were performed in order to characterize the translocation, and FISH with chromosome-specific BAC probes and telomere probes was applied to confirm the cytogenetic data. The translocation was classified as rcp(4q;12q)(q13;q25).
HIV-Related CD8+ Cutaneous Pseudolymphoma: Efficacy of Methotrexate
Authors: Ingen-Housz-Oro S. , Sbidian E. , Ortonne N. , Penso-Assathiany D. , Chambrin V. , Bagot M. , Bachelez H. , Wolkenstein P. , Chosidow O.
Published: January 2013

Human immunodeficiency virus (HIV)-related CD8+ cutaneous pseudolymphoma (CD8+ cytotoxic T cell skin infiltrative disease) is an inflammatory process resulting from a massive infiltration of the skin by activated, oligoclonal, HIV-specific, cytotoxic T lymphocytes. Usually, CD8+ cutaneous pseudolymphoma affects patients with a deep immunosuppression, and is rare in patients with mild immunosuppression. In deeply immunocompromised patients, highly active antiretroviral therapy (HAART) is considered as the first-line treatment. In contrast, the choice of therapy in moderately immunocompromised patients and/or patients already receiving HAART remains nonconsensual. We report a case of HIV-related CD8+ cutaneous pseudolymphoma in a moderately immunocompromised patient who was successfully and safely treated with methotrexate. We review the literature on HIV-related CD8+ pseudolymphoma and the use of methotrexate in HIV-positive patients.
Exploding Head Syndrome:A Case Report
Authors: Ganguly Gautam , Mridha Banshari , Khan Asif , Rison Richard Alan
Published: January 2013

Introduction: Exploding head syndrome (EHS) is a rare parasomnia in which affected individuals awaken from sleep with the sensation of a loud bang. The etiology is unknown, but other conditions including primary and secondary headache disorders and nocturnal seizures need to be excluded. Case Presentation: A 57-year-old Indian male presented with four separate episodes of awakening from sleep at night after hearing a flashing sound on the right side of his head over the last 2 years. These events were described ‘as if there are explosions in my head’. A neurologic examination, imaging studies, and a polysomnogram ensued, and the results led to the diagnosis of EHS. Conclusion: EHS is a benign, uncommon, predominately nocturnal disorder that is self-limited. No treatment is generally required. Reassurance to the patient is often all that is needed.
Multimodality Imaging of Subclinical Aortic Atherosclerosis
Authors: Cecelja Marina , Hussain Tarique , Greil Gerald , Botnar Rene , Preston Rebecca , Moayyeri Alireza , Spector Tim D. , Chowienczyk Philip
Published: January 2013

Aortic stiffness, an important predictor of cardiovascular events, may relate to aortic calcification rather than noncalcified atherosclerotic plaque. The aim of this study was to determine the relation of aortic stiffness to aortic plaque and aortic calcification in asymptomatic postmenopausal women. One hundred female twins (mean age±standard deviation 64±7 years) underwent computed tomography and magnetic resonance imaging (black-blood sequence) of the aorta. The topographical relation of plaque on magnetic resonance images and calcification on computed tomography images was assessed on magnetic resonance/computed tomography fused images. Carotid–femoral pulse wave velocity was used as a measure of aortic stiffness. Aortic plaque was identified in 87% and calcification in 65% of subjects, both increased with age and were higher in the abdominal compared with thoracic aorta (
P
<0.0001). Plaque correlated with calcification (
R
=0.68;
P
<0.0001), but was also detected in 58% of women who had no calcification. Pulse wave velocity (adjusted for age and blood pressure) increased across quartiles of calcification (
P
<0.01) but not plaque score (
P
=0.56). Shared genetic factors accounted for >99% of the correlation (0.35) between PWV and calcification. In conclusion, there is a high prevalence of subclinical atherosclerosis within the aorta in asymptomatic middle-aged women. Aortic stiffening relates to aortic calcification, but not to atherosclerotic plaque burden, and the association of aortic stiffness with calcification is driven by common genes.
Solving the Distal Reward Problem with Rare Correlations
Authors: Soltoggio Andrea , Steil Jochen J.
Published: January 2013

In the course of trial-and-error learning, the results of actions, manifested as rewards or punishments, occur often seconds after the actions that caused them. How can a reward be associated with an earlier action when the neural activity that caused that action is no longer present in the network? This problem is referred to as the distal reward problem. A recent computational study proposes a solution using modulated plasticity with spiking neurons and argues that precise firing patterns in the millisecond range are essential for such a solution. In contrast, the study reported in this letter shows that it is the rarity of correlating neural activity, and not the spike timing, that allows the network to solve the distal reward problem. In this study, rare correlations are detected in a standard rate-based computational model by means of a threshold-augmented Hebbian rule. The novel modulated plasticity rule allows a randomly connected network to learn in classical and instrumental conditioning scenarios with delayed rewards. The rarity of correlations is shown to be a pivotal factor in the learning and in handling various delays of the reward. This study additionally suggests the hypothesis that short-term synaptic plasticity may implement eligibility traces and thereby serve as a selection mechanism in promoting candidate synapses for long-term storage.
A Self-Organized Neural Comparator
Authors: Ludueña Guillermo A. , Gros Claudius
Published: January 2013

Learning algorithms need generally the ability to compare several streams of information. Neural learning architectures hence need a unit, a comparator, able to compare several inputs encoding either internal or external information, for instance, predictions and sensory readings. Without the possibility of comparing the values of predictions to actual sensory inputs, reward evaluation and supervised learning would not be possible.

Comparators are usually not implemented explicitly. Necessary comparisons are commonly performed by directly comparing the respective activities one-to-one. This implies that the characteristics of the two input streams (like size and encoding) must be provided at the time of designing the system. It is, however, plausible that biological comparators emerge from self-organizing, genetically encoded principles, which allow the system to adapt to the changes in the input and the organism. We propose an unsupervised neural circuitry, where the function of input comparison emerges via self-organization only from the interaction of the system with the respective inputs, without external influence or supervision.

The proposed neural comparator adapts in an unsupervised form according to the correlations present in the input streams. The system consists of a multilayer feedforward neural network, which follows a local output minimization (anti-Hebbian) rule for adaptation of the synaptic weights. The local output minimization allows the circuit to autonomously acquire the capability of comparing the neural activities received from different neural populations, which may differ in population size and the neural encoding used. The comparator is able to compare objects never encountered before in the sensory input streams and evaluate a measure of their similarity even when differently encoded.
Parasite diversity at the Holarctic nexus: species of Arostrilepis (Eucestoda: Hymenolepididae) in voles and lemmings (Cricetidae: Arvicolinae) from greater Beringia
Authors: MAKARIKOV ARSENY A. , GALBREATH KURT E. , HOBERG ERIC P.
Published: January 2013

Previously unrecognized species of hymenolepidid cestodes attributable to Arostrilepis Mas-Coma & Tenora, 1997 in arvicoline rodents from the greater Beringian region and western North America are described. Discovery and characterization of these tapeworms contributes to the recognition of a complex of cryptic species distributed across the Holarctic region. Three species are proposed: Arostrilepis gulyaevi sp. n. is named for cestodes in Myodes rufocanus from the Republic of Buryatia, southeastern Siberia and from the Khabarovskiy Kray, Chukotka Autonomous Okrug, and Magadanskaya Oblast’, Russian Far East (western Beringia); A. cooki sp. n. is named for cestodes in Myodes gapperi from British Columbia, Canada and Montana, USA; and A. rauschorum sp. n. is named for cestodes in Microtus oeconomus, M. longicaudus, M. pennsylvanicus and M. xanthognathus from the Brooks Range, Seward Peninsula, north-central interior, and Arctic coastal plains of Alaska (eastern Beringia) and Montana, USA. Consistent with recent studies defining diversity in the genus, the form, size, and spination (pattern, shape and size) of the cirrus are diagnostic; species are further distinguished by the relative position and length of the cirrus sac, and arrangement of the testes. Assessment of genetic data from the cytochrome b gene of mitochondrial DNA complements differentiation of this complex based on morphological attributes and confirms known species diversity within the genus. New data for geographical distribution and host specificity of known Arostrilepis spp. indicate that 3 of 12 recognized species have Holarctic distributions extending across Beringia. These include Arostrilepis beringiensis (Kontrimavichus & Smirnova, 1991) in lemmings (species of Lemmus and Synaptomys), A. cf. janickii Makarikov & Kontrimavichus, 2011 in root voles (M. oeconomus) MAKARIKOV ET AL. 402 · Zootaxa 3608 (6) © 2013 Magnolia Press and A. macrocirrosa Makarikov, Gulyaev & Kontrimavichus, 2011 in red backed voles (species of Myodes) and less often other rodent host species.
New and poorly known species of Neonesidea (Bairdiidae, Ostracoda, Crustacea) from French Frigate Shoals, the Hawaiian Islands
Authors: MADDOCKS ROSALIE F.
Published: January 2013

Neonesidea tenera and four new species (N. plumulosa, N. holdeni, N. bacata, N. edentulata) are described from scrapings of spur and groove habitats on French Frigate Shoals and O'ahu, Hawaiian Islands. Some anatomical details have potential taxonomic significance for the genus Neonesidea, including the caudal setae of the carapace, the masticatory apparatus, and the antennal claw.
Wave Activity for Large-Amplitude Disturbances Described by the Primitive Equations on the Sphere
Authors: Methven John
Published: January 2013

Pseudomomentum and pseudoenergy are both measures of wave activity for disturbances in a fluid, relative to a notional background state. Together they give information on the propagation, growth, and decay of disturbances. Wave activity conservation laws are most readily derived for the primitive equations on the sphere by using isentropic coordinates. However, the intersection of isentropic surfaces with the ground (and associated potential temperature anomalies) is a crucial aspect of baroclinic wave evolution. A new expression is derived for pseudoenergy that is valid for large-amplitude disturbances spanning isentropic layers that may intersect the ground. The pseudoenergy of small-amplitude disturbances is also obtained by linearizing about a zonally symmetric background state. The new expression generalizes previous pseudoenergy results for quasigeostrophic disturbances on the β plane and complements existing large-amplitude results for pseudomomentum.

The pseudomomentum and pseudoenergy diagnostics are applied to an extended winter from the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis data. The time series identify distinct phenomena such as a baroclinic wave life cycle where the wave activity in boundary potential temperature saturates nonlinearly almost two days before the peak in wave activity near the tropopause. The coherent zonal propagation speed of disturbances at tropopause level, including distinct eastward, westward, and stationary phases, is shown to be dictated by the ratio of total hemispheric pseudoenergy to pseudomomentum. Variations in the lower-boundary contribution to pseudoenergy dominate changes in propagation speed; phases of westward progression are associated with stronger boundary potential temperature perturbations.
Asymmetry in the IOD and ENSO Teleconnection in a CMIP5 Model Ensemble and Its Relevance to Regional Rainfall
Authors: Weller Evan , Cai Wenju
Published: January 2013

Recent studies have shown that the impact of the Indian Ocean dipole (IOD) on southern Australia occurs via equivalent barotropic Rossby wave trains triggered by convective heating in the tropical Indian Ocean. Furthermore, the El Niño–Southern Oscillation (ENSO) influence on southern Australian climate is exerted through the same pathway during austral spring. It is also noted that positive phase [positive IOD (pIOD) and El Niño] events have a much larger impact associated with their respective skewness. These phenomena play a significant role in the region's rainfall reduction in recent decades, and it is essential that climate models used for future projections simulate these features. Here, the authors demonstrate that climate models do indeed simulate a greater climatic impact on Australia for pIOD events than for negative IOD (nIOD) events, but this asymmetric impact is distorted by an exaggerated influence of La Niña emanating from the Pacific. The distortion results from biases in the Pacific in two respects. First, the tropical and extratropical response to La Niña is situated unrealistically too far westward and hence too close to Australia, leading to an overly strong impact on southeast Australia that shows up through the nIOD–La Niña coherence. Second, the majority of models simulate a positive sea surface temperature skewness in the eastern Pacific that is too weak, overestimating the impact of La Niña relative to that of El Niño. As such, the impact of the positive asymmetry in the IOD only becomes apparent when the impact of ENSO is removed. This model bias needs to be taken into account when analyzing projections of regional Australian climate change.
Impact of ASCAT Scatterometer Wind Observations on the High-Resolution Limited-Area Model (HIRLAM) within an Operational Context
Authors: de Haan Siebren , Marseille Gert-Jan , de Valk Paul , de Vries John
Published: January 2013

Denial experiments, also denoted observing system experiments (OSEs), are used to determine the impact of an observing system on the forecast quality of a numerical weather prediction (NWP) model. When the impact is neutral or positive, new observations from this observing system may be admitted to an operational forecasting system based on that NWP model. A drawback of the method applied in most denial experiments is that it neglects the operational time constraint on the delivery of observations. In a 10-week twin experiment with the operational High-Resolution Limited-Area Model (HIRLAM) at KNMI, the impact of additional ocean surface wind observations from the Advanced Scatterometer (ASCAT) on the forecast quality of the model has been verified under operational conditions. In the experiment, the operational model was used as reference, parallel to an augmented system in which the ASCAT winds were assimilated actively. Objective verification of the forecast with independent wind observations from moored buoys and ASCAT winds revealed a slight improvement in forecast skill as measured by a decrease in observation-minus-forecast standard deviation in the wind components for the short range (up to 24 h). A subjective analysis in a case study showed a realistic deepening of a low pressure system over the North Atlantic near the coast of Ireland through the assimilation of scatterometer data that were verified with radiosonde observations over Ireland. Based on these results, the decision was made to include ASCAT in operations at the next upgrade of the forecasting system.
Do Long Journeys to Work Have Adverse Effects on Mental Health?
Authors: Feng Zhiqiang , Boyle Paul
Published: January 2013

This article examines whether long journeys to work are negatively associated with commuters’ mental health. Fixed-effects models were applied to the panel data on 5,216 participants in the British Household Panel Survey who were working at the time of interview and aged between 16 and 64 years. Mental health status was established using the General Health Questionnaire. Long journeys to work are associated with a higher risk of poor mental health for women but not for men, controlling for a number of demographic and socioeconomic factors. Previous studies have asserted that long journeys to work are a stressful event, which affects men and women as an acute stressor. Our results from the 16-year panel data found that the long-term effect applies only for women. The fact that women with children are most likely to suffer from long commuting suggests that such daily travel behavior is particularly difficult for women.
The Effect of Competition on Terrorist Group Operations
Authors: Nemeth Stephen
Published: January 2013

Scholars have long accepted the contention that competition among terrorist organizations raises the level of violence used by the competitors. This article discusses this claim and advances another—that competition among terrorist organizations creates incentives to use less violence. Using insights from the organizational ecology literature—namely that competition occurs within “species”—I create a variable that assesses intraspecies competition. I test both claims using a data set of domestic terrorism created from the Global Terrorism Database (GTD) for the years 1970 to 1997. I find support for the hypothesis that competition leads to more terrorism, validating the claims of outbidding theorists. Furthermore, ideologies have differential effects on whether outbidding occurs, with nationalist and religious terrorist groups responding to competition with more terrorism and left-wing organizations responding with less.
Changes in Criminal Offending around the Time of Marriage
Authors: Lyngstad Torkild Hovde , Skardhamar Torbjørn
Published: January 2013

Objectives:

The authors investigate whether the argument from life-course criminology that marriage leads to reduction in crime or whether the mechanisms leading to lower crime rates might take effect in a period of courtship before the transition to marriage.

Method:

Using data from population-wide, longitudinal Norwegian administrative registers, the authors estimate within-individual offending propensities before and after marriage for all men marrying in Norway 1997–2001. This approach allows for studying how offending develops over a decade around the time of marriage, for those men who actually marry.

Results:

The propensity to offend declines sharply prior to marriage. After marriage, there is a small increase in offending. This holds both for all offenses and when the analysis is restricted to felony offenses.

Conclusions:

The analysis provides no evidence for an effect of marriage on offending. Rather, the results suggest that the lower offending rates of marrieds develop over the years prior to marriage rather than as a consequence of the marriage.
Offenses around Stadiums
Authors: Kurland Justin , Johnson Shane D. , Tilley Nick
Published: January 2013

Objectives: Inspired by ecological theories of crime, the aim of this study was to make use of a natural experiment to see if a U.K. soccer stadium generates or attracts crime in the area that surrounds it. Method: Data for theft and violent crime around Wembley stadium are analyzed to see if the rate (per-unit time and ambient population) of crime differ for days on which the stadium is used and those it is not. In addition, differences in the spatial and temporal distribution of crime are examined for these two types of days. Results: Analyses indicate that on days when the stadium is used, the rate of crime per-unit time is elevated, but that the rate per ambient population at risk is not. The spatial and temporal pattern of crime also clearly differs for the two types of days. For example, the level of crime is elevated in the surrounding area when the stadium is used relative to when it is not. Conclusions. The case study suggests that the facility studied contributes to levels of crime in the area that surrounds it. The research provides further support for ecological theories of crime and their utility in informing criminological understanding and policy-related questions.
Cultural background modulates how we look at other persons’ gaze
Authors: Senju Atsushi , Vernetti Angélina , Kikuchi Yukiko , Akechi Hironori , Hasegawa Toshikazu , Johnson Mark H.
Published: January 2013

The current study investigated the role of cultural norms on the development of face-scanning. British and Japanese adults’ eye movements were recorded while they observed avatar faces moving their mouth, and then their eyes toward or away from the participants. British participants fixated more on the mouth, which contrasts with Japanese participants fixating mainly on the eyes. Moreover, eye fixations of British participants were less affected by the gaze shift of the avatar than Japanese participants, who shifted their fixation to the corresponding direction of the avatar’s gaze. Results are consistent with the Western cultural norms that value the maintenance of eye contact, and the Eastern cultural norms that require flexible use of eye contact and gaze aversion.