bluuebunny/crossref_metadata_2025 huggingface dataset:
Lens-free optical tomographic microscope with a large imaging volume on a chip
Authors: Isikman Serhan O. , Bishara Waheb , Mavandadi Sam , Yu Frank W. , Feng Steve , Lau Randy , Ozcan Aydogan
Published: April 2011

We present a lens-free optical tomographic microscope, which enables imaging a large volume of approximately 15 mm
3
on a chip, with a spatial resolution of < 1 μm ×  < 1 μm ×  < 3 μm in
x
,
y
and
z
dimensions, respectively. In this lens-free tomography modality, the sample is placed directly on a digital sensor array with, e.g., ≤ 4 mm distance to its active area. A partially coherent light source placed approximately 70 mm away from the sensor is employed to record lens-free in-line holograms of the sample from different viewing angles. At each illumination angle, multiple subpixel shifted holograms are also recorded, which are digitally processed using a pixel superresolution technique to create a single high-resolution hologram of each angular projection of the object. These superresolved holograms are digitally reconstructed for an angular range of ± 50°, which are then back-projected to compute tomograms of the sample. In order to minimize the artifacts due to limited angular range of tilted illumination, a dual-axis tomography scheme is adopted, where the light source is rotated along two orthogonal axes. Tomographic imaging performance is quantified using microbeads of different dimensions, as well as by imaging wild-type
Caenorhabditis elegans
. Probing a large volume with a decent 3D spatial resolution, this lens-free optical tomography platform on a chip could provide a powerful tool for high-throughput imaging applications in, e.g., cell and developmental biology.
High-efficiency channelrhodopsins for fast neuronal stimulation at low light levels
Authors: Berndt André , Schoenenberger Philipp , Mattis Joanna , Tye Kay M. , Deisseroth Karl , Hegemann Peter , Oertner Thomas G.
Published: April 2011

Channelrhodopsin-2 (ChR2) has become an indispensable tool in neuroscience, allowing precise induction of action potentials with short light pulses. A limiting factor for many optophysiological experiments is the relatively small photocurrent induced by ChR2. We screened a large number of ChR2 point mutants and discovered a dramatic increase in photocurrent amplitude after threonine-to-cysteine substitution at position 159. When we tested the T159C mutant in hippocampal pyramidal neurons, action potentials could be induced at very low light intensities, where currently available channelrhodopsins were unable to drive spiking. Biophysical characterization revealed that the kinetics of most ChR2 variants slows down considerably at depolarized membrane potentials. We show that the recently published E123T substitution abolishes this voltage sensitivity and speeds up channel kinetics. When we combined T159C with E123T, the resulting double mutant delivered fast photocurrents with large amplitudes and increased the precision of single action potential induction over a broad range of frequencies, suggesting it may become the standard for light-controlled activation of neurons.
Licensing of gametogenesis, dependent on RNA binding protein DAZL, as a gateway to sexual differentiation of fetal germ cells
Authors: Gill Mark E. , Hu Yueh-Chiang , Lin Yanfeng , Page David C.
Published: April 2011

Mammalian oocytes and spermatozoa derive from fetal cells shared by the sexes. These primordial germ cells (PGCs) migrate to the developing somatic gonad, giving rise to oocytes or spermatozoa. These opposing sexual fates are determined not by the PGCs’ own sex chromosome constitution (XX or XY), but by the sexual identity of the fetal gonad that they enter. We asked whether PGCs undergo a developmental transition that enables them to respond to feminizing or masculinizing cues from fetal ovary or testis. We conducted in vivo genetic studies of DAZL, an RNA-binding protein expressed in both ovarian and testicular germ cells. We found that germ cells in C57BL/6
Dazl
-deficient fetuses—whether XX or XY—migrate to the gonad but do not develop either male or female features. Instead, they remain in a sexually undifferentiated state similar to that of migrating PGCs. Thus, germ cells in C57BL/6
Dazl
-deficient fetuses do not respond to sexual cues from ovary or testis, whereas the earlier processes of germ cell specification and migration are unaffected. We propose that PGCs of both XX and XY fetuses undergo licensing, an active developmental transition that enables the resultant gametogenesis-competent cells to respond to feminizing or masculinizing cues produced by the fetal ovary or testis and hence to embark on oogenesis or spermatogenesis. In C57BL/6 mice,
Dazl
is required for licensing. Licensing serves as a gateway from the embryonic processes shared between the sexes—germ cell specification and migration—to the sex-specific pathways of oogenesis and spermatogenesis.
Manifesto of Martyrdom: Similarities and Differences between Avini's Ravaayat-e Fath [Chronicles of Victory] and more Traditional Manifestoes
Authors: Karimabadi Mehrzad
Published: April 2011

Unlike most manifestoes that are created as mere written documents, Avini's Ravaayat e Fath is a manifesto in motion. The voiceover is a manifesto of martyrdom woven together with laments and a poetic account of what was happening in and around the battlefields during the Iran–Iraq war in about seventy episodes. Although Ravaayat e Fath is in film format, it aligns itself with the characteristics of a formal manifesto. Ravaayat e Fath, as mentioned in Janet Lyon's account of a formal Manifesto, is “the testimony of a historical present tense spoken in the impassioned voice of its participants” and “embellishes the urgency of struggle through a variety of conventions”.
Role of doctoral scientists in corporate R&D in laser diode research in Japan
Authors: Shimizu Hiroshi , Hara Yasushi
Published: April 2011

With the advancement of technology and increase in its complexity, the use of external information and resources provides companies with an important competitive advantage. In addition, the university–industry relationship has received attention with increases in the importance of science. Exploring papers on laser diodes published inApplied Physics Lettersand patents from 1960 to 2000, this study analyses the roles of corporate scientists with doctoral degrees in laser diode technology. The study focuses on the different roles played by two types of doctoral scientists: university‐based and industry‐based. It explores both direct and indirect contributions of doctoral corporate scientists to R&D by examining their papers and patents. The results indicate that both types achieved a higher average number of papers and patents than non‐doctoral scientists. Exploring the co‐authors of doctoral scientists to determine the indirect effect of doctoral scientists on corporate R&D, this study observes that the co‐authors of industry‐based doctoral corporate scientists published more papers or filed more patents. This study confirms that industry‐based doctoral corporate scientists play an important role in promoting corporate R&D by linking corporate R&D with university research.
Knowledge management in practice: insights into a medium‐sized enterprise's exposure to knowledge loss
Authors: Durst Susanne , Wilhelm Stefan
Published: April 2011

The purpose of our paper is to examine how a medium‐sized enterprise characterised by slow executive turnover might identify and manage its critical knowledge. The main interest is in the management's handling of the potential danger of knowledge loss due to turnover or long‐term absence. A qualitative research approach is adopted through semi‐structured interviews with seven members of top and middle management of a German medium‐sized enterprise operating in the printing sector. Our findings contribute to the literature on knowledge management in SMEs and provide fresh insights into the management of knowledge attrition. A knowledge map of the firm is derived and used to demonstrate how smaller firms can identify key organisation members and their relevance to the firm's business model. This may provide a better overview of potential areas of knowledge attrition. The information provided by the knowledge map can raise awareness of the perils of knowledge loss and suggest initiatives that not only help firms defend competitiveness and save financially but also sustain their intangible resources.
Fabrication and magnetic properties of small FePt dot arrays
Authors: Yan Z J , Takahashi S , Kondo Y , Ariake J , Sakon T , Xue D S , Ishio S
Published: April 2011

FePt dot arrays with dot sizes ranging from 100 down to 15 nm were fabricated using sputtering, annealing and patterning techniques. The dot diameter distribution and dot position deviation are greater for smaller dot arrays than for larger dot arrays. The dot arrays produced through a sequence of annealing followed by patterning have a large perpendicular magnetic anisotropy resulting from the highly L10-ordered structure and the perpendicular orientation of the [0 0 1] crystalline axis, whereas samples of annealing after patterning display a magnetic vortex structure. As the dot size reduces from 100 to 29.9 nm, the arrays produced by annealing and then patterning exhibit an increase in the remanent coercivity H
cr from 15.7 to 21 kOe because fewer defects are contained by the smaller dots. This result is explained by nucleation and domain wall propagation mechanisms. For 15.4 nm dot arrays, a model of dot with damaged edge may interpret the decreasing coercivity behaviour.
Design of magnetoelectric multiferroic heterostructures by topology optimization
Authors: Sun Kyung Ho , Kim Yoon Young
Published: April 2011

Composite BaTiO3–CoFe2O4 nanostructures deposited on a SrTiO3 substrate are known to produce the magnetoelectric coupling effect. Although the coupling efficiency is significantly influenced by the composite layout, there appears no systematic simulation approach for configuring optimal layouts. In this study, a formulation to find optimal heterostructures using the topology optimization method is developed. For the formulation, the macroscopic extrinsic magnetoelectric coupling factor is maximized while numerical calculation is performed by finite element analysis. The proposed method yields an optimal piezoelectric and piezomagnetic material distribution. Numerical simulations are used to explain why the optimized distribution indeed maximizes the magnetoelectric coupling effect. As an application of the developed method, a magnetic read head sensor using the magnetoelectric effect is also designed.
Top predators suppress rather than facilitate plants in a trait-mediated tri-trophic cascade
Authors: Griffin John N. , Butler Jack , Soomdat Nicole N. , Brun Karen E. , Chejanovski Zachary A. , Silliman Brian R.
Published: April 2011

Classical ecological theory states that in tri-trophic systems, predators indirectly facilitate plants by reducing herbivore densities through consumption, while more recent work has revealed that predators can generate the same positive effect on plants non-consumptively by inducing changes in herbivore traits (e.g. feeding rates). Based on observations in US salt marshes dominated by vast monocultures of cordgrass, we hypothesized that sit-and-wait substrate-dwelling predators (crabs) could actually strengthen
per capita
impacts of potent grazers (snails), by non-consumptively inducing a vertical habitat shift of snails to their predation refuge high on canopy leaves that are vulnerable to grazing. A two-month field experiment supported this hypothesis, revealing that predators non-consumptively increased the mean climbing height of snails on grasses, increased grazing damage per leaf and ultimately suppressed cordgrass biomass, relative to controls. While seemingly counterintuitive, our results can be explained by (i) the vulnerability of refuge resources to grazing, and (ii) universal traits that drove the vertical habitat shift—i.e. relative habitat domains of predator and prey, and the hunting mode of the top predator. These results underline the fact that not only should we continue to incorporate non-consumptive effects into our understanding of top-down predator impacts, but we should do so in a spatially explicit manner.
Why do some adult birds skip breeding? A hormonal investigation in a long-lived bird
Authors: Goutte Aurélie , Kriloff Marion , Weimerskirch Henri , Chastel Olivier
Published: April 2011

Skipping reproduction is often observed in long-lived organisms, but proximate mechanisms remain poorly understood. Since young and/or very old snow petrels (
Pagodroma nivea
) commonly skip breeding, we tested whether they are physiologically able to breed during the pre-laying stage. To do so, we measured the ability of known-age (11–45 years old) petrels to release luteinizing hormone (LH, a crucial driver for breeding), by injecting exogenous gonadotropin-releasing hormone (GnRH). Although young petrels exhibited low baseline LH levels, they were able to elevate LH levels after a GnRH challenge. Moreover, young and very old petrels showed a stronger decrease in LH levels after the 10 min post-GnRH injection compared with middle-aged petrels. Birds that skipped breeding were as able as breeders to release LH after a GnRH challenge, indicating that they had functional pituitaries. However, the decision to skip reproduction was linked to a strong LH decrease after the 10 min post-GnRH injection. Our result suggests that the youngest and the oldest petrels fail to maintain elevated baseline LH levels, thereby do not initiate reproductive activities. Skipping reproduction in long-lived birds probably results from age-related changes in the dynamics of the hypothalamic–pituitary–gonadal (HPG) axis function.
A refined modelling approach to assess the influence of sampling on palaeobiodiversity curves: new support for declining Cretaceous dinosaur richness
Authors: Lloyd Graeme T.
Published: April 2011

Modelling has been underdeveloped with respect to constructing palaeobiodiversity curves, but it offers an additional tool for removing sampling from their estimation. Here, an alternative to subsampling approaches, which often require large sample sizes, is explored by the extension and refinement of a pre-existing modelling technique that uses a geological proxy for sampling. Application of the model to the three main clades of dinosaurs suggests that much of their diversity fluctuations cannot be explained by sampling alone. Furthermore, there is new support for a long-term decline in their diversity leading up to the Cretaceous–Paleogene (K–Pg) extinction event. At present, use of this method with data that includes either Lagerstätten or ‘Pull of the Recent’ biases is inappropriate, although partial solutions are offered.
Ants inhabiting myrmecophytic ferns regulate the distribution of lianas on emergent trees in a Bornean tropical rainforest
Authors: Tanaka Hiroshi O. , Itioka Takao
Published: April 2011

Little is known about the spatial distribution of lianas on emergent trees in tropical rainforests and the factors affecting this distribution. The present study investigated the effects of an arboreal ant species,Crematogaster difformis, which forms myrmecophytic symbioses with two epiphytic ferns,Lecanopterissp. andPlatyceriumsp., on the spatial distribution of lianas associated with emergent trees. Living lianas were placed onto trunk surfaces inside and outside the territories of the ants in the canopy, to examine their ability to remove them. The number of leaves pruned by the ants was significantly higher on lianas inside than outside their territories. The spatial overlap of the distributions of lianas and the two ferns on emergent trees were then examined. The frequency of liana colonization of tree crowns was found to be significantly lower on trees with than without ferns. Under the natural conditions,C. difformisworkers were observed biting and pruning the lianas. These results suggest thatC. difformisregulates the distribution of lianas on emergent trees.
Are soils in urban ecosystems compacted? A citywide analysis
Authors: Edmondson Jill L. , Davies Zoe G. , McCormack Sarah A. , Gaston Kevin J. , Leake Jonathan R.
Published: April 2011

Soil compaction adversely influences most terrestrial ecosystem services on which humans depend. This global problem, affecting over 68 million ha of agricultural land alone, is a major driver of soil erosion, increases flood frequency and reduces groundwater recharge. Agricultural soil compaction has been intensively studied, but there are no systematic studies investigating the extent of compaction in urban ecosystems, despite the repercussions for ecosystem function. Urban areas are the fastest growing land-use type globally, and are often assumed to have highly compacted soils with compromised functionality. Here, we use bulk density (BD) measurements, taken to 14 cm depth at a citywide scale, to compare the extent of surface soil compaction between different urban greenspace classes and agricultural soils. Urban soils had a wider BD range than agricultural soils, but were significantly less compacted, with 12 per cent lower mean BD to 7 cm depth. Urban soil BD was lowest under trees and shrubs and highest under herbaceous vegetation (e.g. lawns). BD values were similar to many semi-natural habitats, particularly those underlying woody vegetation. These results establish that, across a typical UK city, urban soils were in better physical condition than agricultural soils and can contribute to ecosystem service provision.
Straight as an arrow: humpback whales swim constant course tracks during long-distance migration
Authors: Horton Travis W. , Holdaway Richard N. , Zerbini Alexandre N. , Hauser Nan , Garrigue Claire , Andriolo Artur , Clapham Phillip J.
Published: April 2011

Humpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 1° precision, despite the effects of variable sea-surface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored.
Volumetric imaging of fish locomotion
Authors: Flammang Brooke E. , Lauder George V. , Troolin Daniel R. , Strand Tyson E.
Published: April 2011

Fishes use multiple flexible fins in order to move and maintain stability in a complex fluid environment. We used a new approach, a volumetric velocimetry imaging system, to provide the first instantaneous three-dimensional views of wake structures as they are produced by freely swimming fishes. This new technology allowed us to demonstrate conclusively the linked ring vortex wake pattern that is produced by the symmetrical (homocercal) tail of fishes, and to visualize for the first time the three-dimensional vortex wake interaction between the dorsal and anal fins and the tail. We found that the dorsal and anal fin wakes were rapidly (within one tail beat) assimilated into the caudal fin vortex wake. These results show that volumetric imaging of biologically generated flow patterns can reveal new features of locomotor dynamics, and provides an avenue for future investigations of the diversity of fish swimming patterns and their hydrodynamic consequences.
Lateralization of lateral displays in convict cichlids
Authors: Arnott Gareth , Ashton Charlotte , Elwood Robert W.
Published: April 2011

We examine lateralization of lateral displays in convict cichlids,
Amatitlania nigrofasciata
, and show a population level preference for showing the right side. This enables contesting pairs of fish to align in a head-to-tail posture, facilitating other activities. We found individuals spent a shorter mean time in each left compared with each right lateral display. This lateralization could lead to contesting pairs using a convention to align in a predictable head-to-tail arrangement to facilitate the assessment of fighting ability. It has major implications for the common use of mirror images to study fish aggression, because the ‘opponent’ would never cooperate and would consistently show the incorrect side when the real fish shows the correct side. With the mirror, the ‘normal’ head-to-tail orientation cannot be achieved.
The singular terms in the fundamental matrix of crystal optics
Authors: Wagner Peter
Published: April 2011

We derive an explicit formula for the singular part of the fundamental matrix of crystal optics. It consists of a singularity remaining fixed at the origin
x
=0, of delta terms located on the positively curved parts of the wave surface, the well-known Fresnel surface and of a Cauchy principal value distribution on the negatively curved part of the wave surface.
Post-glacial partitioning of mitochondrial genetic variation in the field vole
Authors: Herman Jeremy S. , Searle Jeremy B.
Published: April 2011

Genetic markers are often used to examine population history. There is considerable debate about the behaviour of molecular clock rates around the population-species transition. Nevertheless, appropriate calibration is critical to any inference regarding the absolute timing and scale of demographic changes. Here, we use a mitochondrial cytochrome b gene genealogy, based entirely on modern sequences and calibrated from recent geophysical events, to date the post-glacial expansion of the Eurasian field vole (
Microtus agrestis
), a widespread temperate mammal species. The phylogeographic structure reflects the subsequent expansion of populations that went through bottlenecks at the time of the Younger Dryas (
ca
12 000 years BP) rather than the Last Glacial Maximum (LGM,
ca
24 000 years BP), which is usually seen as the time when present-day patterns were determined. The nucleotide substitution rate that was estimated here,
ca
4 × 10
−7
substitutions/site/year, remains extremely high throughout the relevant time frame. Calibration with similarly high population-based substitution rates, rather than long-term rates derived from species divergence times, will show that post-LGM climatic events generated current phylogeographic structure in many other organisms from temperate latitudes.
Maternity-related plasticity in circadian rhythms of bumble-bee queens
Authors: Eban-Rothschild Ada , Belluci Selma , Bloch Guy
Published: April 2011

Unlike most animals studied so far in which the activity with no circadian rhythms is pathological or linked to deteriorating performance, worker bees and ants naturally care for their sibling brood around the clock with no apparent ill effects. Here, we tested whether bumble-bee queens that care alone for their first batch of offspring are also capable of a similar chronobiological plasticity. We monitored locomotor activity of
Bombus terrestris
queens at various life cycle stages, and queens for which we manipulated the presence of brood or removed the ovaries. We found that gynes typically emerged from the pupae with no circadian rhythms, but after several days showed robust rhythms that were not affected by mating or diapauses. Colony-founding queens with brood showed attenuated circadian rhythms, irrespective of the presence of ovaries. By contrast, queens that lost their brood switched again to activity with strong circadian rhythms. The discovery that circadian rhythms in bumble-bee queens are regulated by the life cycle and the presence of brood suggests that plasticity in the circadian clock of bees is ancient and related to maternal behaviour or physiology, and is not a derived trait that evolved with the evolution of the worker caste.
OsSGO1 maintains synaptonemal complex stabilization in addition to protecting centromeric cohesion during rice meiosis
Authors: Wang Mo , Tang Ding , Wang Kejian , Shen Yi , Qin Baoxiang , Miao Chunbo , Li Ming , Cheng Zhukuan
Published: April 2011

Shugoshin is a conserved protein in eukaryotes that protects the centromeric cohesin of sister chromatids from cleavage by separase during meiosis. In this study, we identify the rice (Oryza sativa, 2n = 2x = 24) homolog of ZmSGO1 in maize (Zea mays), named OsSGO1. During both mitosis and meiosis, OsSGO1 is recruited from nucleoli onto centromeres at the onset of prophase. In the Tos17‐insertional Ossgo1‐1 mutant, centromeres of sister chromatids separate precociously from each other from metaphase I, which causes unequal chromosome segregation during meiosis II. Moreover, the release of OsSGO1 from nucleoli is completely blocked in Ossgo1‐1, which leads to the absence of OsSGO1 in centromeric regions after the onset of mitosis and meiosis. Furthermore, the timely assembly and maintenance of synaptonemal complexes during early prophase I are affected in Ossgo1 mutants. Finally, we found that the centromeric localization of OsSGO1 depends on OsAM1, not other meiotic proteins such as OsREC8, PAIR2, OsMER3, or ZEP1.
Association between a polymorphism in the promoter of a glutamate receptor subunit gene (GRIN2A) and alcoholism
Authors: Domart Marie‐Charlotte , Benyamina Amine , Lemoine Antoinette , Bourgain Catherine , Blecha Lisa , Debuire Brigitte , Reynaud Michel , Saffroy Raphaël
Published: April 2011

A variable (GT)n repeat in the 5′‐regulatory region of N‐methyl‐D‐aspartate GRIN2A subtype has recently been identified and associated with psychiatric disorders. In this study, we examined the association of this polymorphism with alcohol dependence. Subject–control analysis included 206 alcohol‐dependent and 168 control subjects. Average observed repeat numbers and genotype distributions were significantly different (P‐value = 0.001) in alcohol‐dependent subjects versus control subjects. Short alleles were significantly less frequent among alcohol‐dependent subjects (odds ratio = 0.58, P‐value = 7 × 10−4). These results could be replicated in an independent sample of 116 alcohol‐dependent subjects. For the first time, a significant association was identified between this polymorphism and alcoholism.
The impact of CMV prevention on long‐term recipient and graft survival in heart transplant recipients: analysis of the Scientific Registry of Transplant Recipients (SRTR) database
Authors: Snydman David R. , Kistler Kristin D. , Ulsh Paula , Bergman Garrett E. , Vensak Judith , Morris Jonathan
Published: April 2011

Snydman DR, Kistler KD, Ulsh P, Bergman GE, Vensak J, Morris J. The impact of CMV prevention on long‐term recipient and graft survival in heart transplant recipients: analysis of the Scientific Registry of Transplant Recipients (SRTR) database. Clin Transplant 2011: 25: E455–E462. © 2011 John Wiley & Sons A/S.

Abstract:  The association between cytomegalovirus immunoglobulin (CMVIG) and long‐term clinical outcomes in heart transplantation has not been evaluated using data from large national databases. We examined the association between CMVIG, with and without antivirals, or antivirals alone, and long‐term recipient and graft survival in heart transplantation using data from the Scientific Registry of Transplant Recipients. Recipients transplanted between January 1995 and October 2008, ≤80 yr old, of primary, single‐organ heart transplants, recorded as receiving CMVIG with or without antivirals (n = 2112), antivirals without CMVIG (n = 12 089), or no prophylaxis (n = 14 661), at hospital discharge, were included. Kaplan–Meier analysis was used to examine death and graft loss at seven yr post‐transplantation; Cox proportional hazards regression was used to estimate the adjusted risk of graft loss and death for prophylaxis vs. no prophylaxis. CMVIG use (± other antivirals) was associated with increased recipient (69% vs. 64%, p < 0.001) and graft (67% vs. 63%, p < 0.001) survival. Antivirals alone also demonstrated increased recipient (68% vs. 64%, p < 0.001) and graft survival (66% vs. 63%, p < 0.001). Cox models demonstrated that CMVIG (± other antivirals) was independently associated with decreased risk for death (hazard ratio, HR 0.79, p < 0.001) and graft loss (HR 0.78, p < 0.001) as were antivirals alone (mortality HR: 0.79, p < 0.001; graft loss: HR 0.78, p < 0.001).
Cholestasis as the leading sign of a transmesenteric hernia in a split‐liver transplanted child – A case report and review of literature
Authors: Eberhardt Christiane S. , Merlini Laura , McLin Valérie A. , Wildhaber Barbara E.
Published: April 2011

Eberhardt CS, Merlini L, McLin VA, Wildhaber BE. Cholestasis as the leading sign of a transmesenteric hernia in a split‐liver transplanted child – A case report and review of literature.

Abstract:  Internal hernias are an extremely rare complication after pediatric liver transplantation, and its presentation with cholestasis has not been described to date. We report the case of a 12‐yr‐old boy who presented with moderate abdominal pain 11 yr after split liver transplantation and biliary‐enteric anastomosis. He developed severe jaundice within 24 h of initial presentation. Imaging studies revealed ascites, dilation of the intrahepatic bile ducts, a dilated Roux‐en‐Y‐loop, with the loop truncated at the level of the mesenteric artery, which performed a narrow right‐to‐left loop. At laparotomy, a transmesenteric internal hernia at the root of the jejunal mesentery was identified, originating from the creation of the Y‐loop; the Roux‐en‐Y‐loop and its adjacent intestinal loops had slipped through the opening. The Roux‐en‐Y loop was ischemic from strangulation, and the rest of the intestine well perfused. No surgical resection was necessary following reduction. The patient recovered completely. We discuss diagnosis and management of internal hernias, and review radiological signs. Internal transmesenteric hernias can occur at any time after liver transplantation and prompt diagnosis and surgical treatment are vital.
Chronic norovirus infection in pediatric hematopoietic stem cell transplant recipients: A cause of prolonged intestinal failure requiring intensive nutritional support
Authors: Saif M. A. , Bonney D. K. , Bigger B. , Forsythe L. , Williams N. , Page J. , Babiker Z. O. , Guiver M. , Turner A. J. , Hughes S. , Wynn R. F.
Published: April 2011

Saif MA, Bonney DK, Bigger B, Forsythe L, Williams N, Page J, Babiker ZO, Guiver M, Turner AJ, Hughes S, Wynn RF. Chronic norovirus infection in pediatric hematopoietic stem cell transplant recipients: A cause of prolonged intestinal failure requiring intensive nutritional support.  Pediatr Transplantation 2011: 15: 505–509. © 2011 John Wiley & Sons A/S.

Abstract:  Norovirus infection is a major cause of nonbacterial gastroenteritis. In immunocompetent individuals the illness caused by norovirus is mostly self limiting. Excretion of norovirus has been reported to be prolonged in the immunocompromised including adult HSCT recipients. We report a case series of 13 children who received HSCT and required prolonged parenteral and enteral nutrition due to severe gut dysfunction accompanying protracted norovirus excretion that was monitored by RT‐PCR. The median duration of viral excretion was 150 days (range 60‐380) and the eventual clearance of norovirus from feces was closely associated with donor T cell recovery in the peripheral blood. There was no disease manifestation beyond the gut but the severity and length of norovirus associated illness suggests that HSCT should be delayed where possible in patients excreting the virus prior to conditioning therapy.
Incidental hepatic schistosomiasis in a liver transplant recipient
Authors: Ariza‐Heredia E. , Razonable R.R.
Published: April 2011

E. Ariza‐Heredia & R.R. Razonable. Incidental hepatic schistosomiasis in a liver transplant recipient. Transpl Infect Dis 2011. All rights reserved

Abstract: Hepatic schistosomiasis is a well recognized cause of chronic liver disease and portal hypertension. Herein, we describe a case of a 62‐year‐old Kuwaiti man who underwent liver transplantation for non‐alcoholic steatohepatitis and, as an incidental finding in the histopathology of the explanted liver, eggs consistent with Schistosoma were found. In endemic regions, hepatic schistosomiasis is often observed as an incidental finding in explanted livers of patients who receive liver transplantation for other indications. In the context of this case, we provide a brief review of the management of schistosomiasis in transplant recipients.
Two children with differing outcomes after treatment for pulmonary tuberculosis diagnosed after allogeneic hematopoietic stem cell transplantation
Authors: Lee J.W. , Kwon H.‐J. , Jang P.‐S. , Chung N.‐G. , Cho B. , Jeong D.‐C. , Kang J.‐H. , Kim H.‐K.
Published: April 2011

J.W. Lee, H.‐J. Kwon, P.‐S. Jang, N.‐G. Chung, B. Cho, D.‐C. Jeong, J.‐H. Kang, H.‐K. Kim. Two children with differing outcomes after treatment for pulmonary tuberculosis diagnosed after allogeneic hematopoietic stem cell transplantation. Transpl Infect Dis 2011: 13: 520–523. All rights reserved.

Abstract: Tuberculosis (TB) is a rare infectious complication after hematopoietic stem cell transplantation (HSCT), but may be more significant in areas where the disease is endemic. Here, we present the clinical course of 2 children with acute lymphoblastic leukemia who were diagnosed with pulmonary  TB after allogeneic HSCT. Both patients were treated for either probable or possible invasive fungal infection, as well as  TB. One patient, diagnosed with TB 3 months after HSCT, showed remittent fever and symptoms that progressed to acute respiratory distress syndrome and death, despite 3 modifications to the anti‐TB regimen. In contrast, another patient who was diagnosed with TB 8 months after transplantation, responded well to anti‐TB medication and completed 1 year of treatment with resolution of lung lesions. Co‐morbid opportunistic infections, profound host immunosuppression early after transplantation, and potential risk of multi‐drug resistant‐TB may act as major barriers to effective treatment of TB after HSCT despite appropriate anti‐TB medication.
Spatial variation in the temporal change of male and female melanic ornamentation in the barn owl
Authors: ROULIN A. , ANTONIAZZA S. , BURRI R.
Published: April 2011

Because the magnitude of selection can vary between sexes and in space and time, sexually antagonistic selection is difficult to demonstrate. In a Swiss population of barn owls (Tyto alba), a heritable eumelanic colour trait (size of black spots on ventral feathers) was positively selected with respect to yearling survival only in females. It remains unclear whether the absence of negative selection in males is typical in this species. To tackle this issue indirectly, we measured the size of black spots in 1733 skin specimens collected by museums from 1816 to 2001 in seven European countries and in the Middle‐East. The temporal change in spot size was sex‐ and country‐specific. In males, spots became smaller particularly in three countries (Middle‐East, Italy and Switzerland). In females, the size of spots increased significantly in two countries (UK and Spain) and decreased in two others (Germany and Switzerland). Because migration and phenotypic plasticity cannot explain these results, selection is the most likely cause. The weaker temporal change in spot size in females than males may be because of the combined effect of strong genetic correlation between the sexes and stronger negative selection in males than positive selection in females. We thus suggest that in the barn owl, spot size (or genetically correlated traits) is sexually antagonistically selected and that its pattern of selection may account for the maintenance of its variation and sexual dimorphism.
Coxiella burnetii Seropositivity Is Highly Stable Throughout Gestation in Lactating High‐Producing Dairy Cows
Authors: Garcia‐Ispierto I , Almería S , López‐Gatius F
Published: April 2011

Contents

The aims of this study were to analyse, in high‐producing dairy cows, plasma Coxiella burnetii antibody titres and seroconversion throughout gestation, along with possible factors affecting such titres. The study was performed on 65 lactating pregnant non‐aborting animals in a commercial Holstein‐Friesian dairy herd in northeastern Spain. Blood samples for antibody determinations were collected on days 40, 90, 120, 150, 180 and 210 of gestation. By General Linear Model (GLM) repeated measures analysis of variance, the effects of milk production and reproductive variables as well as Neospora caninum‐seropositivity on C. burnetii antibody levels for all animals and for seropositive animals were established. Significant effects were observed of day of gestation, parity and N. caninum‐seropositivity (between subject effects) on the C. burnetii antibody levels recorded for the whole population of animals throughout the gestation period. C. burnetii antibody levels were higher in primiparous than in multiparous cows, with titres in primiparous cows diminishing during the post‐partum period. In seropositive cows, significant effects were observed of milk production and inseminating bull on gestational C. burnetii antibody levels. When the data were subjected to binary logistic regression considering C. burnetii‐seropositivity as the dependent variable, the resultant odds ratios indicated that the likelihood of C. burnetii‐seropositivity was lower in N. caninum‐seropositive animals (OR 0.12) compared to N. caninum‐seronegative animals, and in multiparous cows (OR 0.12) compared to primiparous cows. In conclusion, Coxiella‐infected dams remained seropositive during the whole gestation period, though primiparous cows showed a drop in antibody titres post‐partum. No seronegative cow suffered seroconversion. Presence of both, N. caninum and C. burnetii antibodies in the same animal, was associated with a decrease in antibody titres against C. burnetii, perhaps indicating some cross‐protection in animals infected by both pathogens.
PHARMACOKINETICS OF SEVERAL SUBCUTANEOUS DOSES OF ERYTHROPOIETIN: POTENTIAL IMPLICATIONS FOR BLOOD TRANSFUSION
Authors: Sans T. , Joven J. , Vilella E. , Masdeu G. , Farrè M.
Published: April 2011

The aim of the present study was to assess the effectiveness of repeated subcutaneous low‐dose recombinant human erythropoietin (rHuEPO) on parameters associated with improved procurement of autologous blood; a procedure regularly used to preclude the need for homologous blood transfusion at the time of elective surgery.

Three groups of three volunteers each (n= 9) were administered one of three low doses of rHuEPO (30, 60 or 100 IU/kg body weight, s.c.) on days 1,4 and 8. The plasma pharmacokinetic profile of rHuEPO was studied after the first and third injections. Statistical evaluations were intragroup and intra‐individual comparisons.

There was a linear relationship between maximum plasma concentration (Cmax) and dose. In the overall study group, Cmax and area under the curve (AUC) were significantly decreased, while the mean residence time (MRT) and elimination half‐life (t1/2β) were significantly increased on day 8 relative to day 1. Significant and sustained increases in reticulocytes were observed after rHuEPO administration, which were maintained above the predose values throughout the study period.

In conclusion, rHuEPO, by subcutaneous repeat‐dose, was eliminated more slowly and remained longer in the circulation, despite lowered plasma concentrations. Repeated low rHuEPO administration at doses ≥ 60 IU/kg bodyweight stimulated modest but sustained reticulocyte concentrations, suggesting that cost may be substantially decreased in autologous blood donation or perioperative treatment programmes.
Comparison of the clinical features of rapid eye movement sleep behavior disorder in patients with Parkinson's disease and multiple system atrophy
Authors: Nomura Takashi , Inoue Yuichi , Högl Birgit , Uemura Yusuke , Yasui Kenichi , Sasai Taeko , Namba Kazuyoshi , Nakashima Kenji
Published: April 2011

Aims:  The aim of this study was to evaluate differences in the clinical presentation and polysomnographic characteristics of rapid eye movement sleep behavior disorder (RBD) between patients with Parkinson's disease (PD) and those with multiple system atrophy (MSA).

Methods:  We conducted clinical interviews examining RBD symptoms, including violent and non‐violent behaviors, in 49 patients with PD and 16 patients with MSA (as well as their bed partners) and performed polysomnography on all subject patients.

Results:  Twenty‐seven patients with PD (55.1%) and 11 patients with MSA (68.8%) had rapid eye movement sleep without atonia (RWA) on polysomnogram. The relative amounts of RWA were quite similar between the two groups. For most of the RWA‐positive patients in both groups, RBD symptoms remained non‐violent or silent. RBD symptoms in PD patients seemed to increase with the course of PD, while most of the RBD symptoms in the MSA patients occurred just prior to or at the onset of MSA and then disappeared within a short period.

Conclusion:  Although PD and MSA frequently accompany RWA, RBD symptoms often remain non‐violent or silent. Differences in the course of RBD symptoms in patients with PD and MSA may reflect the difference in the degeneration process of the two disorders.
Suicide in a large population of former psychiatric inpatients
Authors: Sani Gabriele , Tondo Leonardo , Koukopoulos Athanasios , Reginaldi Daniela , Kotzalidis Giorgio D. , Koukopoulos Alexia E. , Manfredi Giovanni , Mazzarini Lorenzo , Pacchiarotti Isabella , Simonetti Alessio , Ambrosi Elisa , Angeletti Gloria , Girardi Paolo , Tatarelli Roberto
Published: April 2011

Aims:  The aim of this study was to identify predictors of completed suicide in a wide sample of psychiatric inpatients receiving retrospective and prospective DSM‐IV diagnoses.

Methods:  We followed up 4441 severe psychiatric patients who were hospitalized for some time during a 35‐year period in a private hospital setting. We collected sociodemographic, clinical and temperamental data.

Results:  Ninety‐six patients from the sample committed suicide. There were no sex differences in suicide completion and no differences between major psychiatric disorders, but people who had been hospitalized for anxiety disorders did not commit suicide and people with bipolar disorders were more likely to commit suicide than people with unipolar major depression. Shorter‐term treatment with lithium and anticonvulsants, longer‐term treatment with antidepressants, history of suicide attempts, suicidal thinking, and single status positively predicted completed suicide. Suicide tended to occur after a mean period of about 14 years of duration of disease. Patients' symptoms during the period preceding suicide were assessed through interviewing patients' physicians or family members. Symptoms occurring in >10% of cases were, in decreasing order, inner tension, racing/crowded thoughts, aggressive behavior, guilt, psychomotor agitation, persecutory ideation, anxiety, and hallucinations. Surprisingly, cyclothymic temperament was less associated with completed suicide as compared to other temperaments.

Conclusions:  Suicide is likely to occur in a milieu of agitation, mixed anxiety and depression, and psychosis. Longer‐term mood stabilizer treatment may reduce the rate of completed suicide.
Genetic variation relevant for the conservation of the narrow endemic Senecio carbonensis (Asteraceae) from the southern Andes
Authors: FERNÁNDEZ MARTINA , EZCURRA CECILIA , QUIROGA MARIA PAULA , PREMOLI ANDREA C.
Published: April 2011

We studied morphological variation, reproductive biology and genetic structure of Senecio carbonensis, a narrow endemic from high elevations of the southern Andes, and compared it to Senecio peteroanus, a closely related widespread congeneric species. Using ANOVAs and discriminant analysis we showed that populations of S. carbonensis were more similar to each other in their morphology, had comparatively limited reproductive capacity and presented lower plant density and more reduced plant cover than populations of S. peteroanus. Similar high genetic variation was found at the population and species level in both species, based on isozyme variation at 14 and 11 putative gene loci that were resolved in S. carbonensis and S. peteroanus, respectively. The two species were genetically distinct. However, the small genetic distance between populations of each species suggests that either they were recently founded and that genetic drift did not have time to promote divergence, or that its effects are masked by significant current gene flow. These results show that ecological and reproductive characteristics of S. carbonensis may limit its extension and abundance. In contrast, high genetic variation at the population level is probably favored by self‐incompatibility. Despite the restricted geographical distribution and low plant density of S. carbonensis populations, genetic characteristics do not seem to be limiting their long‐term persistence. This information suggests that populations of S. carbonensis are not at risk of extinction as a result of genetic factors, although it is important to study and monitor population dynamics to further assess the degree of recruitment through time.
Vitamin D deficiency among healthy infants and toddlers: A prospective study from Irbid, Jordan
Authors: Abdul‐Razzak Khalid K. , Ajlony Mohammed‐Jafar A. , Khoursheed Abeer M. , Obeidat Bayan A.
Published: April 2011

Background:  The aim of this study was to estimate the prevalence of vitamin D deficiency among healthy infants and toddlers, as well as its associated factors, in Irbid, Jordan.

Methods:  A total of 275 subjects (136 infants and 139 toddlers) aged 6–36 months participated in this study. Information concerning sociodemographic characterastics and early feeding patterns was collected using a self‐guided questionnaire. Plasma vitamin D, calcium, phosphorous, and alkaline phosphatase activity were measured.

Results:  The prevalence of vitamin D deficiency was 28% (16.7% for severe vitamin D deficiency and 11.3% for vitamin D deficiency) and vitamin D insufficiency was 28.4%. Plasma calcium and alkaline phosphatase levels showed no correlation with the vitamin D status of the study population. For both age groups, a significant association was found between vitamin D status and sun exposure (P < 0.001). A significant association between infant feeding practices and vitamin D status was found (P < 0.001). Infants who were exclusively breast‐fed had higher risk for vitamin D deficiency and vitamin D insufficiency than those who were bottle‐fed. Multivariate logistic regression analyses results showed that female sex, low sun exposure and exclusive breast‐feeding were the main determents of vitamin D levels.

Conclusion:  The prevalence of vitamin D deficiency is considered to be high among northern Jordanian infants and toddlers. Sun exposure of less than 30 min daily and exclusively breast‐feeding are the main factors for developing vitamin D deficiency.
Blood transfusion: old blood, new blood or no blood
Authors: Duggan J. M.
Published: April 2011

Vigorous blood transfusion has long been regarded as having an essential role in the management of acute gastrointestinal haemorrhage. Two new studies, one a nationwide audit of acute gastrointestinal haemorrhage in the UK and another, a complex physiological study of stored blood from the USA, offer new insights.
Medically refractory neurosarcoidosis treated with infliximab
Authors: Pereira J. , Anderson N. E. , McAuley D. , Bergin P. , Kilfoyle D. , Fink J.
Published: April 2011

Neurosarcoidosis can worsen despite standard immunosuppressive therapy, a situation for which there is no established medical management. We present three cases of medically refractory neurosarcoidosis treated with infliximab. All three patients showed a clinical response to this treatment and side effects were limited. A summary of reported cases of neurosarcoidosis treated with infliximab is included. This case series supports a role for infliximab in the treatment of patients with medically refractory neurosarcoidosis.