bluuebunny/crossref_metadata_2025 huggingface dataset:
Dose reconstruction for real‐time patient‐specific dose estimation in CT
Authors: De Man Bruno , Wu Mingye , FitzGerald Paul , Kalra Mannudeep , Yin Zhye
Published: May 2015

Purpose:

Many recent computed tomography (CT) dose reduction approaches belong to one of three categories: statistical reconstruction algorithms, efficient x‐ray detectors, and optimized CT acquisition schemes with precise control over the x‐ray distribution. The latter category could greatly benefit from fast and accurate methods for dose estimation, which would enable real‐time patient‐specific protocol optimization.

Methods:

The authors present a new method for volumetrically reconstructing absorbed dose on a per‐voxel basis, directly from the actual CT images. The authors’ specific implementation combines a distance‐driven pencil‐beam approach to model the first‐order x‐ray interactions with a set of Gaussian convolution kernels to model the higher‐order x‐ray interactions. The authors performed a number of 3D simulation experiments comparing the proposed method to a Monte Carlo based ground truth.

Results:

The authors’ results indicate that the proposed approach offers a good trade‐off between accuracy and computational efficiency. The images show a good qualitative correspondence to Monte Carlo estimates. Preliminary quantitative results show errors below 10%, except in bone regions, where the authors see a bigger model mismatch. The computational complexity is similar to that of a low‐resolution filtered‐backprojection algorithm.

Conclusions:

The authors present a method for analytic dose reconstruction in CT, similar to the techniques used in radiation therapy planning with megavoltage energies. Future work will include refinements of the proposed method to improve the accuracy as well as a more extensive validation study. The proposed method is not intended to replace methods that track individual x‐ray photons, but the authors expect that it may prove useful in applications where real‐time patient‐specific dose estimation is required.
Self-Regulation, Motivation and Teaching Styles in Physical Education Classes: An Intervention Study
Authors: Chatzipanteli Athanasia , Digelidis Nikolaos , Papaioannou Athanasios G.
Published: May 2015

The aim of the study was to investigate the influence of student-activated teaching styles through a specific intervention program on students’ self-regulation, lesson satisfaction, and motivation. Six hundred and one 7th grade students (318 boys and 283 girls), aged 13 years were randomly assigned to an experimental group and a comparison group. The teachers who taught the students assigned to the experimental group used student-activated teaching styles, and specifically the reciprocal, self-check, inclusion, guided discovery, convergent discovery, and divergent discovery styles. Repeated measures analysis of variance revealed that the experimental group, compared with the comparison group, had higher scores in lesson satisfaction, intrinsic motivation, identified regulation, and metacognitive activities, and lower scores in external motivation, and amotivation. The study revealed that going beyond the command and/or the practice style of teaching, PE teachers can enhance students’ metacognitive skills, lesson satisfaction and intrinsic motivation.
Experiential Learning Through a Physical Activity Program for Children With Disabilities
Authors: Richards K. Andrew R. , Eberline Andrew D. , Padaruth Sookhenlall , Templin Thomas J.
Published: May 2015

Service-learning has become a popular pedagogical tool to promote academic and civic learning. One form of service-learning provides physical activity for underrepresented community groups, including children with disabilities. Using experiential learning theory, the purpose of this descriptive case study was to evaluate college students’ experiences in a physical activity-based service learning program for children with disabilities. Through convenience sampling, 97 program participants (82 female, 15 male), most of whom were White (N = 85), were recruited for participation. Data included a pre- and postsurvey of civic learning, participant interviews, reflective journaling, and program observations. Qualitative data were analyzed using constant comparison and inductive analysis, and quantitative data were analyzed using Mixed ANOVAs. Results revealed that the program resulted in enhanced civic and academic learning. Themes included making a difference, academic and career connections, emotional and personal growth, and program reflection. Implications of the study and future directions for research are discussed.
A multifaceted program causes lasting progress for the very poor: Evidence from six countries
Authors: Banerjee Abhijit , Duflo Esther , Goldberg Nathanael , Karlan Dean , Osei Robert , Parienté William , Shapiro Jeremy , Thuysbaert Bram , Udry Christopher
Published: May 2015

Attacking the problem of extreme poverty

A persistent concern about wellintentioned efforts to improve living standards for the 1.2 billion people who survive (if it can be called that) on less than $1.25 US per day is figuring out what works. A second concern is figuring out whether what works in one setting can be made to work in another. Banerjee
et al.
describe encouraging results from a set of pilot projects in Ethiopia, Ghana, Honduras, India, Pakistan, and Peru encompassing 11,000 households. Each project provided short-term aid and longer-term support to help participants graduate to a sustainable level of existence.

Science
, this issue
10.1126/science.1260799
In from the cold
Authors: Stone Richard
Published: May 2015

After keeping science alive during decades of scarcity, Cuba's “guerrilla scientists” are ready to rejoin the world.
Response to Comment on “Morality in everyday life”
Authors: Hofmann Wilhelm , Wisneski Daniel C. , Brandt Mark J. , Skitka Linda J.
Published: May 2015

Voelkle challenges our conclusions regarding the relationship between morality and momentary happiness/sense of purpose based on methodological concerns. We show that our main conclusions are not affected by this methodological critique and clarify that the discrepancies between our and Voelkle’s effect size estimates can be reconciled by the realization that two different (but compatible) research questions are being asked.
Regulated assembly of a supramolecular centrosome scaffold in vitro
Authors: Woodruff Jeffrey B. , Wueseke Oliver , Viscardi Valeria , Mahamid Julia , Ochoa Stacy D. , Bunkenborg Jakob , Widlund Per O. , Pozniakovsky Andrei , Zanin Esther , Bahmanyar Shirin , Zinke Andrea , Hong Sun Hae , Decker Marcus , Baumeister Wolfgang , Andersen Jens S. , Oegema Karen , Hyman Anthony A.
Published: May 2015

A little bit of this and a little bit of that

Centrosomes are the major microtubule-organizing centers in animal cells. Key to this function is the somewhat mysterious pericentriolar material (PCM). Woodruff
et al.
describe the in vitro reconstitution of PCM assembly. In cells, PCM is recruited by centrioles to form centrosomes that nucleate and anchor microtubules. SPD-5, the main component of the PCM matrix in
Caenorhabiditis elegans
, polymerized in vitro to form micrometer-sized porous networks. SPD-5 polymerization was directly controlled by the polo family kinase Plk1 and Cep192/SPD-2, two conserved regulators that control PCM assembly across metazoans.

Science
, this issue p.
808
Whole-body endothermy in a mesopelagic fish, the opah,
Lampris guttatus
Authors: Wegner Nicholas C. , Snodgrass Owyn E. , Dewar Heidi , Hyde John R.
Published: May 2015

A cold-water fish with a warm heart

Mammals and birds warm their entire bodies above the ambient temperature. Generally, this ability is lacking in other vertebrates, although some highly active fish can temporarily warm their swim muscles. Wegner
et al.
show that the opah, a large deepwater fish, can generate heat with its swim muscles and use this heat to warm both its heart and brain. This ability increases its metabolic function in cold deep waters, which will help the fish compete with other, colder-blooded species.

Science
, this issue p.
786
Science in U.S.-Cuba relations
Authors: Pastrana Sergio Jorge
Published: May 2015

Last month, after more than half a century of estrangement, the presidents of Cuba and the United States sat together for talks in Panama at the Summit of the Americas. This truly symbolic step in the already agreed-upon path toward restoring diplomatic ties has increased expectations in scientific circles. However, any impact will depend on what policy-makers and researchers make of this long-awaited opportunity.
Probing the underbelly of a supervolcano
Authors: Shapiro Nikolai M. , Koulakov Ivan
Published: May 2015

Seismic imaging of Yellowstone provides a better understanding of large volcanic systems

[Also see Report by

Huang
et al.

]
Backs against the Wall: Novel and Existing Strategies Used during the 2014-2015 Ebola Virus Outbreak
Authors: Wong Gary , Kobinger Gary P.
Published: May 2015

The 2014-2015 outbreak of Ebola virus (EBOV), originating from Guinea, is now responsible for the infection of >20,000 people in 9 countries. Whereas past filovirus outbreaks in sub-Saharan Africa have been rapidly brought under control with comparably few cases, this outbreak has been particularly resistant to containment efforts. Both the general population and primary health care workers have been affected by this outbreak, with hundreds of doctors and nurses being infected in the line of duty. In the absence of approved therapeutics, several caregivers have turned to investigational new drugs as well as experimental therapies in an effort to save lives. This review aims to summarize the candidates currently under consideration for postexposure use in infected patients during the largest EBOV outbreak in history.
Simple Real-Time PCR and Amplicon Sequencing Method for Identification of Plasmodium Species in Human Whole Blood
Authors: Lefterova Martina I. , Budvytiene Indre , Sandlund Johanna , Färnert Anna , Banaei Niaz
Published: May 2015

Malaria is the leading identifiable cause of fever in returning travelers. Accurate
Plasmodium
species identification has therapy implications for
P. vivax
and
P. ovale
, which have dormant liver stages requiring primaquine. Compared to microscopy, nucleic acid tests have improved specificity for species identification and higher sensitivity for mixed infections. Here, we describe a SYBR green-based real-time PCR assay for
Plasmodium
species identification from whole blood, which uses a panel of reactions to detect species-specific non-18S rRNA gene targets. A pan-
Plasmodium
18S rRNA target is also amplified to allow species identification or confirmation by sequencing if necessary. An evaluation of assay accuracy, performed on 76 clinical samples (56 positives using thin smear microscopy as the reference method and 20 negatives), demonstrated clinical sensitivities of 95.2% for
P. falciparum
(20/21 positives detected) and 100% for the
Plasmodium
genus (52/52),
P. vivax
(20/20),
P. ovale
(9/9), and
P. malariae
(6/6). The sensitivity of the
P. knowlesi
-specific PCR was evaluated using spiked whole blood samples (100% [10/10 detected]). The specificities of the real-time PCR primers were 94.2% for
P. vivax
(49/52) and 100% for
P. falciparum
(51/51),
P. ovale
(62/62),
P. malariae
(69/69), and
P. knowlesi
(52/52). Thirty-three specimens were used to test species identification by sequencing the pan-
Plasmodium
18S rRNA PCR product, with correct identification in all cases. The real-time PCR assay also identified two samples with mixed
P. falciparum
and
P. ovale
infection, which was confirmed by sequencing. The assay described here can be integrated into a malaria testing algorithm in low-prevalence areas, allowing definitive
Plasmodium
species identification shortly after malaria diagnosis by microscopy.
Comparison of Sample Preparation Methods, Instrumentation Platforms, and Contemporary Commercial Databases for Identification of Clinically Relevant Mycobacteria by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry
Authors: Wilen Craig B. , McMullen Allison R. , Burnham Carey-Ann D.
Published: May 2015

When mycobacteria are recovered in clinical specimens, timely species-level identification is required to establish the clinical significance of the isolate and facilitate optimization of antimicrobial therapy. Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has recently been reported to be a reliable and expedited method for identification of mycobacteria, although various specimen preparation techniques and databases for analysis are reported across studies. Here we compared two MALDI-TOF MS instrumentation platforms and three databases: Bruker Biotyper Real Time Classification 3.1 (Biotyper), Vitek MS Plus Saramis Premium (Saramis), and Vitek MS v3.0. We evaluated two sample preparation techniques and demonstrate that extraction methods are not interchangeable across different platforms or databases. Once testing parameters were established, a panel of 157 mycobacterial isolates (including 16
Mycobacterium tuberculosis
isolates) was evaluated, demonstrating that with the appropriate specimen preparation, all three methods provide reliable identification for most species. Using a score cutoff value of ≥1.8, the Biotyper correctly identified 133 (84.7%) isolates with no misidentifications. Using a confidence value of ≥90%, Saramis correctly identified 134 (85.4%) isolates with one misidentification and Vitek MS v3.0 correctly identified 140 (89.2%) isolates with one misidentification. The levels of accuracy were not significantly different across the three platforms (
P
= 0.14). In addition, we show that Vitek MS v3.0 requires modestly fewer repeat analyses than the Biotyper and Saramis methods (
P
= 0.04), which may have implications for laboratory workflow.
Comparison of Inoculation with the InoqulA and WASP Automated Systems with Manual Inoculation
Authors: Croxatto Antony , Dijkstra Klaas , Prod'hom Guy , Greub Gilbert
Published: May 2015

The quality of sample inoculation is critical for achieving an optimal yield of discrete colonies in both monomicrobial and polymicrobial samples to perform identification and antibiotic susceptibility testing. Consequently, we compared the performance between the InoqulA (BD Kiestra), the WASP (Copan), and manual inoculation methods. Defined mono- and polymicrobial samples of 4 bacterial species and cloudy urine specimens were inoculated on chromogenic agar by the InoqulA, the WASP, and manual methods. Images taken with ImagA (BD Kiestra) were analyzed with the VisionLab version 3.43 image analysis software to assess the quality of growth and to prevent subjective interpretation of the data. A 3- to 10-fold higher yield of discrete colonies was observed following automated inoculation with both the InoqulA and WASP systems than that with manual inoculation. The difference in performance between automated and manual inoculation was mainly observed at concentrations of >106bacteria/ml. Inoculation with the InoqulA system allowed us to obtain significantly more discrete colonies than the WASP system at concentrations of >107bacteria/ml. However, the level of difference observed was bacterial species dependent. Discrete colonies of bacteria present in 100- to 1,000-fold lower concentrations than the most concentrated populations in defined polymicrobial samples were not reproducibly recovered, even with the automated systems. The analysis of cloudy urine specimens showed that InoqulA inoculation provided a statistically significantly higher number of discrete colonies than that with WASP and manual inoculation. Consequently, the automated InoqulA inoculation greatly decreased the requirement for bacterial subculture and thus resulted in a significant reduction in the time to results, laboratory workload, and laboratory costs.
Cooperativity of HIV-Specific Cytolytic CD4 T Cells and CD8 T Cells in Control of HIV Viremia
Authors: Johnson Susan , Eller Michael , Teigler Jeffrey E. , Maloveste Sebastien M. , Schultz Bruce T. , Soghoian Damien Z. , Lu Richard , Oster Alexander F. , Chenine Agnès-Laurence , Alter Galit , Dittmer Ulf , Marovich Mary , Robb Merlin L. , Michael Nelson L. , Bolton Diane , Streeck Hendrik
Published: May 2015

CD4
+
T cells play a pivotal role in the control of chronic viral infections. Recently, nontraditional CD4
+
T cell functions beyond helper effects have been described, and a role for cytolytic CD4
+
T cells in the control of HIV infection has been suggested. We define here the transcriptional, phenotypic, and functional profiles of HIV-specific cytolytic CD4
+
T cells. Fluidigm BioMark and multiparameter flow cytometric analysis of HIV-specific cytolytic CD4
+
T cells revealed a distinct transcriptional signature compared to Th1 CD4
+
cells but shared similar features with HIV-specific cytolytic CD8
+
T cells. Furthermore, HIV-specific cytolytic CD4
+
T cells showed comparable killing activity relative to HIV-specific CD8
+
T cells and worked cooperatively in the elimination of virally infected cells. Interestingly, we found that cytolytic CD4
+
T cells emerge early during acute HIV infection and tightly follow acute viral load trajectory. This emergence was associated to the early viral set point, suggesting an involvement in early control, in spite of CD4 T cell susceptibility to HIV infection. Our data suggest cytolytic CD4
+
T cells as an independent subset distinct from Th1 cells that show combined activity with CD8
+
T cells in the long-term control of HIV infection.

IMPORTANCE
The ability of the immune system to control chronic HIV infection is of critical interest to both vaccine design and therapeutic approaches. Much research has focused on the effect of the ability of CD8
+
T cells to control the virus, while CD4
+
T cells have been overlooked as effectors in HIV control due to the fact that they are preferentially infected. We show here that a subset of HIV-specific CD4
+
T cells cooperate in the cytolytic control of HIV replication. Moreover, these cells represent a distinct subset of CD4
+
T cells showing significant transcriptional and phenotypic differences compared to HIV-specific Th1 cells but with similarities to CD8
+
T cells. These findings are important for our understanding of HIV immunopathology.
Vinexin β Interacts with Hepatitis C Virus NS5A, Modulating Its Hyperphosphorylation To Regulate Viral Propagation
Authors: Xiong Wei , Yang Jie , Wang Mingzhen , Wang Hailong , Rao Zhipeng , Zhong Cheng , Xin Xiu , Mo Lin , Yu Shujuan , Shen Chao , Zheng Congyi
Published: May 2015

Hepatitis C virus (HCV) nonstructural protein 5A (NS5A) is essential for HCV genome replication and virion production and is involved in the regulation of multiple host signaling pathways. As a proline-rich protein, NS5A is capable of interacting with various host proteins containing Src homology 3 (SH3) domains. Previous studies have suggested that vinexin, a member of the sorbin homology (SoHo) adaptor family, might be a potential binding partner of NS5A by yeast two-hybrid screening. However, firm evidence for this interaction is lacking, and the significance of vinexin in the HCV life cycle remains unclear. In this study, we demonstrated that endogenously and exogenously expressed vinexin β coimmunoprecipitated with NS5A derived from different HCV genotypes. Two residues, tryptophan (W307) and tyrosine (Y325), in the third SH3 domain of vinexin β and conserved Pro-X-X-Pro-X-Arg motifs at the C terminus of NS5A were indispensable for the vinexin-NS5A interaction. Furthermore, downregulation of endogenous vinexin β significantly suppressed NS5A hyperphosphorylation and decreased HCV replication, which could be rescued by expressing a vinexin β short hairpin RNA-resistant mutant. We also found that vinexin β modulated the hyperphosphorylation of NS5A in a casein kinase 1α-dependent on manner. Taken together, our findings suggest that vinexin β modulates NS5A phosphorylation via its interaction with NS5A, thereby regulating HCV replication, implicating vinexin β in the viral life cycle.

IMPORTANCE
Hepatitis C virus (HCV) nonstructural protein NS5A is a phosphoprotein, and its phosphorylation states are usually modulated by host kinases and other viral nonstructural elements. Additionally, cellular factors containing Src homology 3 (SH3) domains have been reported to interact with proline-rich regions of NS5A. However, it is unclear whether there are any relationships between NS5A phosphorylation and the NS5A-SH3 interaction, and little is known about the significance of this interaction in the HCV life cycle. In this work, we demonstrate that vinexin β modulates NS5A hyperphosphorylation through the NS5A-vinexin β interaction. Hyperphosphorylated NS5A induced by vinexin β is casein kinase 1α dependent and is also crucial for HCV propagation. Overall, our findings not only elucidate the relationships between NS5A phosphorylation and the NS5A-SH3 interaction but also shed new mechanistic insight on
Flaviviridae
NS5A (NS5) phosphorylation. We believe that our results may afford the potential to offer an antiviral therapeutic strategy.
Hepatitis B Virus-Infected HepG2hNTCPCells Serve as a Novel Immunological Tool To Analyze the Antiviral Efficacy of CD8+T CellsIn Vitro
Authors: Hoh Alexander , Heeg Maximilian , Ni Yi , Schuch Anita , Binder Benedikt , Hennecke Nadine , Blum Hubert E. , Nassal Michael , Protzer Ulrike , Hofmann Maike , Urban Stephan , Thimme Robert
Published: May 2015

CD8+T cells are the main effector lymphocytes in the control of hepatitis B virus (HBV) infection. However, limitations of model systems, such as low infection rates, restrict mechanistic studies of HBV-specific CD8+T cells. Here, we established a novel immunological cell culture model based on HBV-infected HepG2hNTCPcells that endogenously processed viral antigens and presented them to HBV-specific CD8+T cells. This induced cytolytic and noncytolytic CD8+T-cell effector functions and reduction of viral loads.
Bacterial Swarms Recruit Cargo Bacteria To Pave the Way in Toxic Environments
Authors: Finkelshtein Alin , Roth Dalit , Ben Jacob Eshel , Ingham Colin J.
Published: May 2015

Swarming bacteria are challenged by the need to invade hostile environments. Swarms of the flagellated bacterium
Paenibacillus vortex
can collectively transport other microorganisms. Here we show that
P. vortex
can invade toxic environments by carrying antibiotic-degrading bacteria; this transport is mediated by a specialized, phenotypic subpopulation utilizing a process not dependent on cargo motility. Swarms of beta-lactam antibiotic (BLA)-sensitive
P. vortex
used beta-lactamase-producing, resistant, cargo bacteria to detoxify BLAs in their path. In the presence of BLAs, both transporter and cargo bacteria gained from this temporary cooperation; there was a positive correlation between BLA resistance and dispersal.
P. vortex
transported only the most beneficial antibiotic-resistant cargo (including environmental and clinical isolates) in a sustained way.
P. vortex
displayed a bet-hedging strategy that promoted the colonization of nontoxic niches by
P. vortex
alone; when detoxifying cargo bacteria were not needed, they were lost. This work has relevance for the dispersal of antibiotic-resistant microorganisms and for strategies for asymmetric cooperation with agricultural and medical implications.

IMPORTANCE
Antibiotic resistance is a major health threat. We show a novel mechanism for the local spread of antibiotic resistance. This involves interactions between different bacteria: one species provides an enzyme that detoxifies the antibiotic (a sessile cargo bacterium carrying a resistance gene), while the other (
Paenibacillus vortex
) moves itself and transports the cargo.
P. vortex
used a bet-hedging strategy, colonizing new environments alone when the cargo added no benefit, but cooperating when the cargo was needed. This work is of interest in an evolutionary context and sheds light on fundamental questions, such as how environmental antibiotic resistance may lead to clinical resistance and also microbial social organization, as well as the costs, benefits, and risks of dispersal in the environment.
Dengue Virus NS Proteins Inhibit RIG-I/MAVS Signaling by Blocking TBK1/IRF3 Phosphorylation: Dengue Virus Serotype 1 NS4A Is a Unique Interferon-Regulating Virulence Determinant
Authors: Dalrymple Nadine A. , Cimica Velasco , Mackow Erich R.
Published: May 2015

Dengue virus (DENV) replication is inhibited by the prior addition of type I interferon or by RIG-I agonists that elicit RIG-I/MAVS/TBK1/IRF3-dependent protective responses. DENV infection of primary human endothelial cells (ECs) results in a rapid increase in viral titer, which suggests that DENV inhibits replication-restrictive RIG-I/interferon beta (IFN-β) induction pathways within ECs. Our findings demonstrate that DENV serotype 4 (DENV4) nonstructural (NS) proteins NS2A and NS4B inhibited RIG-I-, MDA5-, MAVS-, and TBK1/IKKε-directed IFN-β transcription (>80%) but failed to inhibit IFN-β induction directed by STING or constitutively active IRF3-5D. Expression of NS2A and NS4B dose dependently inhibited the phosphorylation of TBK1 and IRF3, which suggests that they function at the level of TBK1 complex activation. NS2A and NS4B from DENV1/2/4, as well as the West Nile virus NS4B protein, commonly inhibited TBK1 phosphorylation and IFN-β induction. A comparative analysis of NS4A proteins across DENVs demonstrated that DENV1, but not DENV2 or DENV4, NS4A proteins uniquely inhibited TBK1. These findings indicate that DENVs contain conserved (NS2A/NS4B) and DENV1-specific (NS4A) mechanisms for inhibiting RIG-I/TBK1-directed IFN responses. Collectively, our results define DENV NS proteins that restrict IRF3 and IFN responses and thereby facilitate DENV replication and virulence. Unique DENV1-specific NS4A regulation of IFN induction has the potential to be a virulence determinant that contributes to the increased severity of DENV1 infections and the immunodominance of DENV1 responses during tetravalent DENV1-4 vaccination.

IMPORTANCE
Our findings demonstrate that NS2A and NS4B proteins from dengue virus serotypes 1, 2, and 4 are inhibitors of RIG-I/MDA5-directed interferon beta (IFN-β) induction and that they accomplish this by blocking TBK1 activation. We determined that IFN inhibition is functionally conserved across NS4B proteins from West Nile virus and DENV1, -2, and -4 viruses. In contrast, DENV1 uniquely encodes an extra IFN regulating protein, NS4A, that inhibits TBK1-directed IFN induction. DENV1 is associated with an increase in severe patient disease, and added IFN regulation by the DENV1 NS4A protein may contribute to increased DENV1 replication, immunodominance, and virulence. The regulation of IFN induction by nonstructural (NS) proteins suggests their potential roles in enhancing viral replication and spread and as potential protein targets for viral attenuation. DENV1-specific IFN regulation needs to be considered in vaccine strategies where enhanced DENV1 replication may interfere with DENV2-4 seroconversion within coadministered tetravalent DENV1-4 vaccines.
Use of patient video cases in medical education
Authors: Roland Damian , Balslev Thomas
Published: May 2015

Patient video cases (PVCs) are brief video recordings of patients during spontaneous or instructed activity. PVCs are true to life and can be replayed, enabling the establishment of highly interactive, contextual and safe learning environments, with a minimum of facilitation. This article describes the use of workshops in which PVCs are used to assist with the development of observational skills and clinical reasoning in medical students and postgraduates. We describe why PVCs are a valuable addition to an educator's portfolio of resources, what evidence there is for their effectiveness, how to use videos for teaching, and some practical advice and tips on their collection and storage.
Bleeding from a gut lesion as a cause of seizure
Authors: Watari Takashi , Tokuda Yasuharu
Published: May 2015

The differential diagnosis of causes of seizure is important since appropriate management depends on correct diagnosis. Making a misdiagnosis of epilepsy may lead to erroneous clinical management, and can be minimised with careful history taking and physical examination. Our educational case illustrates a patient with presumed epilepsy based on a witnessed generalised tonic–clonic seizure; he was ultimately diagnosed as upper gastrointestinal bleeding initially considered by careful attention of vital signs and rectal examination, and confirmed and treated by emergent endoscopy. Paying careful attention to the symptoms and signs in patients with seizure episodes is crucial to establishing a correct causative diagnosis for seizure.
Mesenterial involvement ofMycobacterium genavenseinfection: hard to find, hard to treat
Authors: Wassilew Nasstasja , Ciaffi Laura , Calmy Alexandra
Published: May 2015

Mycobacterium genavenseis a rare pathogen affecting severely immunosuppressed patients. We report the case of persistent relapsingM. genavenseinfection in a 48-year-old African man with a positive diagnosis of HIV infection. Despite being under effective antiretroviral therapy with partial immune reconstitution, he developed irreversible long-term abdominal complications, possibly due to persistentM. genavenseinfection and sustained inflammation. Case management consists of individual risk assessment, close follow-up and personalised treatment strategies concerning the duration of antimycobacterial therapy and early application of steroids. Patients with profound immunosuppression, a high viral load at HIV diagnosis and a high burden ofM. genavense, appear to be at higher risk. The pathogenicity of this complication is not well known and its optimal management has still to be determined.
Glomus tumour: a rare differential for subungual lesions
Authors: Newman Michael Joseph , Pocock Georgina , Allan Peter
Published: May 2015

A 21-year-old, usually fit and well man, presented with a 10-year history of intermittent, paroxysmal pain and temperature sensitivity to his right thumb. He felt this was associated with a subungual lesion present on the same digit. He was diagnosed as having a glomus tumour and was referred to the hand surgeons for surgical excision.
Hunter syndrome with late age of presentation: clinical description of a case and review of the literature
Authors: Gupta Ashish , Uttarilli Anusha , Dalal Ashwin , Girisha Katta M
Published: May 2015

Hunter syndrome is an X linked recessive mucopolysaccharidosis (type II) caused by the deficiency of iduronate 2-sulfatase. This in turn leads to the accumulation of glycosaminoglycans, dermatan and heparan sulfate. The intracellular and extracellular accumulation of these substances lead to multisystemic organ abnormality. It is a rare syndrome with a very low prevalence of 1.3:100 000 male live births. Usual presentation is in early childhood although milder variants have been documented to present at a later age. We present a rare case of Hunter syndrome in a 24-year-old male patient who presented with joint contractures and recent onset hoarseness of voice. X-rays were suggestive of dysostosis multiplex. Clinical diagnosis of Hunter syndrome was confirmed by enzyme assay and further by mutational analysis.
Quetiapine-induced hypertriglyceridaemia causing acute pancreatitis
Authors: Franco John Mark , Vallabhajosyula Saraschandra , Griffin Timothy John
Published: May 2015

Second-generation antipsychotics have well-known metabolic side effects such as hyperlipidaemia and hyperglycaemia. A middle-aged man presented with epigastric and flank pain associated with nausea, and was noted to have elevated triglycerides (3590 mg/dL or 40.53 mmol/L), lipase and glucose. Haematological parameters revealed neutropenia with pancytopaenia. The patient was started on conservative management for acute pancreatitis, and on intravenous insulin and oral gemfibrozil for lowering of his triglycerides. He gradually improved and was transitioned to oral atorvastatin and fenofibrate. His triglycerides, glucose and leucocyte counts normalised at discharge and he was transitioned to ziprasidone. The combination of hypertriglyceridaemia, worsening hyperglycaemia and neutropenia made us suspect quetiapine as the causative agent. Medications cause only 0.1–7% of acute pancreatitis cases, with quetiapine implicated in only five-reported cases. Hypertriglyceridaemia (>600 mg/dL or 6.77 mmol/L) is frequently reported with quetiapine use, but severe hypertriglyceridaemia (>1000 mg/dL or 11.29 mmol/L) has been reported in <10 patients.
Severe vitamin B12deficiency in a 15-year-old boy: presentation with haemolysis and pancytopenia
Authors: Keskin Ebru Yılmaz , Keskin Mahmut
Published: May 2015

A 15-year-old boy on a vegetarian diet presented with severe macrocytic anaemia (haemoglobin, 5.1 g/dL; mean corpuscular volume, 116 fL) in addition to leucopenia and thrombocytopaenia (pancytopenia), icterus secondary to haemolysis and splenomegaly. Laboratory investigations revealed severe vitamin B12(cobalamin) deficiency. Following cobalamin replacement therapy, the patient reported increased well-being, including appetite and weight gain, and his icterus resolved. In the follow-up laboratory examinations, leucocyte and platelet counts in addition to serum bilirubin and lactate dehydrogenase levels normalised. At the end of 2 months, laboratory findings, including haemoglobin level, were all within the normal range. We present this case as a reminder that severe vitamin B12deficiency may present with findings mimicking acute leukaemia (pancytopenia and splenomegaly) and findings suggestive of pseudothrombotic microangiopathy.
A population-based study comparing patterns of care delivery on the quality of care for persons living with HIV in Ontario
Authors: Kendall Claire E , Taljaard Monica , Younger Jaime , Hogg William , Glazier Richard H , Manuel Douglas G
Published: May 2015

Objectives

Physician specialty is often positively associated with disease-specific outcomes and negatively associated with primary care outcomes for people with chronic conditions. People with HIV have increasing comorbidity arising from antiretroviral therapy (ART) related longevity, making HIV a useful condition to examine shared care models. We used a previously described, theoretically developed shared care framework to assess the impact of care delivery on the quality of care provided.

Design

Retrospective population-based observational study from 1 April 2009 to 31 March 2012.

Participants

13 480 patients with HIV and receiving publicly funded healthcare in Ontario were assigned to one of five patterns of care.

Outcome measures

Cancer screening, ART prescribing and healthcare utilisation across models using adjusted multivariable hierarchical logistic regression analyses.

Results

Models in which patients had an assigned family physician had higher odds of cancer screening than those in exclusively specialist care (colorectal cancer screening, exclusively primary care adjusted OR (AOR)=3.12, 95% CI (1.90 to 5.13), family physician-dominant co-management AOR=3.39, 95% CI (1.94 to 5.93), specialist-dominant co-management AOR=2.01, 95% CI (1.23 to 3.26)). The odds of having one emergency department visit did not differ among models, although the odds of hospitalisation and HIV-specific hospitalisation were lower among patients who saw exclusively family physicians (AOR=0.23, 95% CI (0.14 to 0.35) and AOR=0.15, 95% CI (0.12 to 0.21)). The odds of antiretroviral prescriptions were lower among models in which patients’ HIV care was provided predominantly by family physicians (exclusively primary care AOR=0.15, 95% CI (0.12 to 0.21), family physician-dominant co-management AOR=0.45, 95% CI (0.32 to 0.64)).

Conclusions

How care is provided had a potentially important influence on the quality of care delivered. Our key limitation is potential confounding due to the absence of HIV stage measures.
Republished: Importance of carcinoma-associated fibroblast-derived proteins in clinical oncology
Authors: Valcz Gabor , Sipos Ferenc , Tulassay Zsolt , Molnar Bela , Yagi Yukako
Published: May 2015

Carcinoma-associated fibroblast (CAF) as prominent cell type of the tumour microenvironment has complex interaction with both the cancer cells and other non-neoplastic surrounding cells. The CAF-derived regulators and extracellular matrix proteins can support cancer progression by providing a protective microenvironment for the cancer cells via reduction of chemotherapy sensitivity. On the other hand, these proteins may act as powerful prognostic markers as well as potential targets of anticancer therapy. In this review, we summarise the clinical importance of the major CAF-derived signals influencing tumour behaviour and determining the outcome of chemotherapy.
Large-parameter limits of conformal blocks
Authors: Behan Connor
Published: May 2015

Conformally invariant quantum field theories can be “bootstrapped” because they can be defined without reference to a Lagrangian or a Hamiltonian. When they are instead defined in terms of spins and scaling dimensions of local operators, much of the parameter space can be ruled out as unphysical. We review recent results about conformal blocks — special functions important in these numerical studies. Our new result is that they approach monomials as the dimension difference between two operators becomes large. We also discuss the case of large space–time dimension and the question of which limits are useful for the bootstrap.
Emission spectrum for a multi-photon Ξ-type three-level atom driven by a binomial field with nonlinearities
Authors: Eied A.A.
Published: May 2015

A treatment of a multi-photon Ξ-type three-level atom interacting with a single-mode field in a cavity, taking explicitly the existence of forms of nonlinearities of both the field and the intensity-dependent atom–field coupling into account. Analytical expressions of the emission spectrum are presented using the dressed states of the system. The characteristics of the emission spectrum, considering the field to be initially in a binomial state, are exhibited. The effects of the photon multiplicities, mean number of photons, detuning, and the nonlinearities on the spectrum are investigated.
Magnetohydrodynamic (MHD) mixed convection stagnation point flow of a nanofluid over a vertical plate with viscous dissipation
Authors: Mustafa Irfan , Javed Tariq , Majeed Abid
Published: May 2015

In this study, magnetohydrodynamic effects on the mixed convection flow of nanofluid particles, namely, Cu (copper) and Al2O3 (alumina) near a stagnation region over a vertical plate in the presence of viscous dissipation is investigated. The governing equations of the nanofluid flow model proposed by Tiwari and Das (Int. J. Heat Mass Transfer, 50, 2002 (2007). doi:10.1016/j.ijheatmasstransfer.2006.09.034) are converted into a dimensionless nonlinear system of ordinary differential equations by using the similarity transformation. The solution of the resulting equations is obtained numerically by using a very efficient implicit scheme known as the Keller box method. A comparison with previous studies is shown in tabular form and excellent agreement is found. The effects of pertinent parameters like magnetic parameter M, Eckert number Ec, and volume fraction parameter ϕ on velocity, temperature, skin friction coefficient, and local Nusselt number with fixed value of Prandtl number Pr = 6.2 are shown graphically and discussed. These results show that the skin friction coefficient increases for both nanoparticles in assisting and opposing flow cases because of increasing absolute values of M and Ec, on the other hand heat transfer rate is enhanced in the opposing flow case and reduced in the assisting flow case. The values of skin friction coefficient for both nanoparticles, namely, Cu and Al2O3 increase with the increase in volume fraction parameter ϕ in both assisting and opposing flow cases and Cu has a higher value than Al2O3. The same behavior is observed for local Nusselt number in opposing flow, but in assisting flow the value of local Nusselt number decreases with the increase of ϕ in the presence of magnetic and viscous dissipation effects and Cu has a smaller value than Al2O3.
Generation of amphidiploids from hybrids of wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum as a source of genetic variation for wheat improvement
Authors: Nemeth Csilla , Yang Cai-yun , Kasprzak Paul , Hubbart Stella , Scholefield Duncan , Mehra Surbhi , Skipper Emma , King Ian , King Julie
Published: May 2015

We aim to improve diversity of domesticated wheat by transferring genetic variation for important target traits from related wild and cultivated grass species. The present study describes the development of F1 hybrids between wheat and related species from the genera Aegilops, Secale, Thinopyrum, and Triticum and production of new amphidiploids. Amphidiploid lines were produced from 20 different distant relatives. Both colchicine and caffeine were successfully used to double the chromosome numbers. The genomic constitution of the newly formed amphidiploids derived from seven distant relatives was determined using genomic in situ hybridization (GISH). Altogether, 42 different plants were analysed, 19 using multicolour GISH separating the chromosomes from the A, B, and D genomes of wheat, as well as the distant relative, and 23 using single colour GISH. Restructuring of the allopolyploid genome, both chromosome losses and aneuploidy, was detected in all the genomes contained by the amphidiploids. From the observed chromosome numbers there is an indication that in amphidiploids the B genome of wheat suffers chromosome losses less frequently than the other wheat genomes. Phenotyping to realize the full potential of the wheat – related grass germplasm is underway, linking the analyzed genotypes to agronomically important target traits.
Welschinger invariants of real del Pezzo surfaces of degree ≥ 2
Authors: Itenberg Ilia , Kharlamov Viatcheslav , Shustin Eugenii
Published: May 2015

We compute the purely real Welschinger invariants, both original and modified, for all real del Pezzo surfaces of degree ≥ 2. We show that under some conditions, for such a surface X and a real nef and big divisor class D ∈ Pic (X), through any generic collection of - DKX - 1 real points lying on a connected component of the real part ℝX of X one can trace a real rational curve C ∈ |D|. This is derived from the positivity of appropriate Welschinger invariants. We furthermore show that these invariants are asymptotically equivalent, in the logarithmic scale, to the corresponding genus zero Gromov–Witten invariants. Our approach consists in a conversion of Shoval–Shustin recursive formulas counting complex curves on the plane blown up at seven points and of Vakil's extension of the Abramovich–Bertram formula for Gromov–Witten invariants into formulas computing real enumerative invariants.
Spectral and parametric averaging for integrable systems
Authors: Ma Tao , Serota R. A.
Published: May 2015

We analyze two theoretical approaches to ensemble averaging for integrable systems in quantum chaos, spectral averaging (SA) and parametric averaging (PA). For SA, we introduce a new procedure, namely, rescaled spectral averaging (RSA). Unlike traditional SA, it can describe the correlation function of spectral staircase (CFSS) and produce persistent oscillations of the interval level number variance (IV). PA while not as accurate as RSA for the CFSS and IV, can also produce persistent oscillations of the global level number variance (GV) and better describes saturation level rigidity as a function of the running energy. Overall, it is the most reliable method for a wide range of statistics.
Electromagnetic and gravitational signatures of accretion into black holes
Authors: Degollado Juan Carlos
Published: May 2015

In this paper, the gravitational and electromagnetic signals due to accretion of charged fluids into a Schwarzschild black hole is revisited. We set up the perturbed Einstein equations and Maxwell equations coupled to the fluid equations on a stationary black hole as a system of differential equations that can be integrated as an initial value problem. We numerically investigate cases in which we varied the properties of the fluid. Our scenario may provide an electromagnetic counterpart to gravitational waves in many situations of interest, enabling easier extraction and verification of gravitational waveforms from gravitational wave detection. We find that the features of the resulting electromagnetic signals depend on the properties and dynamics of the flow.
Information and Bargaining Power: Evidence from SME Lending in China
Authors: Wang Xiao-Yong , Zhang Wei , Xiong Xiong , Che Hong-Li , Shen Dehua
Published: May 2015

The bank has the access to hard and soft information about small and medium-sized enterprises (SMEs) in order to manage the informational opacity. We carry out the study about the information and bargaining power between lenders and borrowers. Bargaining power is depicted based on more favorable loan rate. The proxy is regressed on hard information, soft information and other variables. We find out that more favorable hard information (Registered Capital and Proceeds of Sale) increases borrowers' bargaining power in China. We also obtain evidence suggesting that the length of borrowers' business affect the bargaining power.
Facile synthesis, spectroscopic and electrochemical properties, and theoretical calculations of porphyrin dimers with a bridging amide-bonded xanthene moiety
Authors: Liang Xu , Xu Li , Li Minzhi , Mack John , Stone Justin , Nyokong Tebello , Jiang Yu , Kobayashi Nagao , Zhu Weihua
Published: May 2015

A free base porphyrin dimer bridged by a flexible amide-bonded xanthene moiety and its binuclear zinc(II) complex zinc(II) complex were synthesized and characterized. Structural characterization by MS and 1 H NMR spectroscopy confirmed the bridged porphyrin dimer structure. The properties of the dimers were characterized by IR, UV-visible absorption, fluorescence and magnetic circular dichroism (MCD) spectroscopy, and electrochemistry studies. Theoretical calculations were carried out to analyze the electronic structures of porphyrin dimers with a bridging amide-bonded xanthene moiety.
Genetic Fuzzy Trees and their Application Towards Autonomous Training and Control of a Squadron of Unmanned Combat Aerial Vehicles
Authors: Ernest Nicholas , Cohen Kelly , Kivelevitch Elad , Schumacher Corey , Casbeer David
Published: May 2015

This study introduces the technique of Genetic Fuzzy Trees (GFTs) through novel application to an air combat control problem of an autonomous squadron of Unmanned Combat Aerial Vehicles (UCAVs) equipped with next-generation defensive systems. GFTs are a natural evolution to Genetic Fuzzy Systems, in which multiple cascading fuzzy systems are optimized by genetic methods. In this problem a team of UCAV's must traverse through a battle space and counter enemy threats, utilize imperfect systems, cope with uncertainty, and successfully destroy critical targets. Enemy threats take the form of Air Interceptors (AIs), Surface to Air Missile (SAM) sites, and Electronic WARfare (EWAR) stations. Simultaneous training and tuning a multitude of Fuzzy Inference Systems (FISs), with varying degrees of connectivity, is performed through the use of an optimized Genetic Algorithm (GA). The GFT presented in this study, the Learning Enhanced Tactical Handling Algorithm (LETHA), is able to create controllers with the presence of deep learning, resilience to uncertainties, and adaptability to changing scenarios. These resulting deterministic fuzzy controllers are easily understandable by operators, are of very high performance and efficiency, and are consistently capable of completing new and different missions not trained for.