bluuebunny/crossref_metadata_2025 huggingface dataset:
Hic Sunt Dracones
Authors: Culyer Anthony J.
Published: November 2011

The dragons mentioned in the title are (a) the failure of HTA methodologists to develop[em dash]and hence practitioners to use—tools for the consideration of equity in economic appraisals of health care technologies; (b) a similar and reinforcing failure to devise and implement processes of decision making that would facilitate the incorporation of equity in HTA. The draconian consequence is that equity is hardly considered at all and certainly does not get the same consideration as efficiency. Some initial suggestions are made as to how these dragons may be slain.
Race and ethnicity
Authors: Price Patricia L.
Published: November 2011

Over the past 20 years, Latino/a immigration to the USA has transformed how place and race are lived. The scale of the city-region has emerged as key to understanding these changes. Latino/a immigrants challenge the stark black-white binary that has long shaped race relations in the USA. Labor relations, racial stereotyping, and Latino/a alliances with other demographic groups have emerged as provocative themes in the recent scholarship on Latino/a immigration. Because race and place work iteratively to shape one another, geographic thought on place may be used to sophisticate our conceptual understanding of race. In particular, the fluidity of race is challenged through its close relationship with place.
Lift and drag on a sphere above ground by a sliding shock
Authors: Igra D , Falcovitz J
Published: November 2011

We consider the diffraction of a planar shock propagating parallel to a plate with a static sphere located above the flat plate. The shock wave reflection produces, in addition to a drag force, a lift component due to the asymmetric interaction with the flat plate. Spheres ranging from 10 µm to 10 mm diameter are considered, with a gap ratio h/ D in the range 0.0001–0.1. The shock Mach numbers are from 1.1 to 2. Both inviscid and laminar viscous flow computations are presented.
Emotional Psychological and Related Problems Among Truant Youths
Authors: Dembo Richard , Briones-Robinson Rhissa , Ungaro Rocío Aracelis , Gulledge Laura M. , Karas Lora M. , Winters Ken C. , Belenko Steven , Greenbaum Paul E.
Published: November 2011

Latent class analysis was conducted on the psychosocial problems experienced by truant youths. Data were obtained from baseline interviews completed on 131 youths and their parents/guardians involved in a NIDA-funded, Brief Intervention Project. Results identified two classes of youths: Class 1(n=9) - youths with low levels of delinquency, mental health and substance abuse issues; and Class 2(n=37) - youths with high levels of these problems. Comparison of these two classes on their urine analysis test results and parent/guardian reports of traumatic events found significant (p<.05) differences between them that were consistent with their problem group classification. Our results have important implications for research and practice.
Sustainability of the Dissemination of an Occupational Sun Protection Program in a Randomized Trial
Authors: Buller David B. , Walkosz Barbara J. , Andersen Peter A. , Scott Michael D. , Dignan Mark B. , Cutter Gary R. , Zhang Xiao , Kane Ilima L.
Published: November 2011

Sustainability of an occupational sun safety program, Go Sun Smart (GSS), was explored in a randomized trial, testing dissemination strategies at 68 U.S. and Canadian ski areas in 2004-2007. All ski areas received GSS from the National Ski Areas Association through a Basic Dissemination Strategy (BDS) using conference presentations and free materials. Half of the ski areas were randomly assigned to a theory-based Enhanced Dissemination Strategy (EDS) with personal contact supporting GSS use. GSS use was assessed at immediate and long-term follow-up posttests by on-site observation. Use of GSS declined from immediate ( M = 6.24) to long-term follow-up ( M = 4.72), F(1, 62) = 6.95, p = .01, but EDS ski areas ( M = 6.53) continued to use GSS more than BDS ski areas ( M = 4.49), F(1, 62) = 5.75, p = .02, regardless of timing of posttest, strategy × observation F(1, 60) = 0.05, p = .83. Despite declines over time, a group of ski areas had sustained high program use and active dissemination methods had sustained positive effects on implementation.
Thoughts, Attitudes, and Feelings of HIV-Positive MSM Associated With High Transmission-Risk Sex
Authors: Skinta Matthew D. , Murphy Jessie L. , Paul Jay P. , Schwarcz Sandra K. , Dilley James W.
Published: November 2011

This study presents survey data collected from a sample of HIV-positive men ( N = 182) who had high transmission-risk sex, defined as unprotected anal intercourse with a man whose HIV-status was negative or unknown, in the previous 6 months. Despite the tremendous changes in HIV treatment and their impact on people living with HIV, little recent research has examined current trends in their thoughts toward unprotected anal intercourse. Here, the authors describe the self-justifications reported by HIV-positive men who have sex with men (MSM) in their current study conducted between 2006 and 2009 and explore key differences between the those of the HIV-positive MSM and those collected from a previous cohort of HIV-negative men ( n = 124), who previously reported engaging in high transmission-risk sex. Whereas HIV-negative men focused on themes related to the impulsivity of and gratification from unprotected intercourse, HIV-positive men focused on themes regarding the deferral of responsibility/assumption the partner is positive (i.e., “If he’s doing X, he must be positive . . .”), or the role of condomless sex fulfilling emotional needs. The findings highlight unique aspects of how HIV-positive men approach decision making regarding the use of condoms, as well as how they perceive issues of responsibility for initiating safer sex practices.
Iterative Krylov solution methods for geophysical electromagnetic simulations on throughput-oriented processing units
Authors: Commer Michael , Maia Filipe RNC , Newman Gregory A
Published: November 2011

Many geo-scientific applications involve boundary value problems arising in simulating electrostatic and electromagnetic fields for geophysical prospecting and subsurface imaging of electrical resistivity. Modeling complex geological media with three-dimensional finite-difference grids gives rise to large sparse linear systems of equations. For such systems, we have implemented three common iterative Krylov solution methods on graphics processing units and compared their performance with parallel host-based versions. The benchmarks show that the device efficiency improves with increasing grid sizes. Limitations are currently given by the device memory resources.
Directionally unsplit hydrodynamic schemes with hybrid MPI/OpenMP/GPU parallelization in AMR
Authors: Schive Hsi-Yu , Zhang Ui-Han , Chiueh Tzihong
Published: November 2011

We present the implementation and performance of a class of directionally unsplit Riemann-solver-based hydrodynamic schemes on graphics processing units (GPUs). These schemes, including the MUSCL-Hancock method, a variant of the MUSCL-Hancock method, and the corner-transport-upwind method, are embedded into the adaptive-mesh-refinement (AMR) code GAMER. Furthermore, a hybrid MPI/OpenMP model is investigated, which enables the full exploitation of the computing power in a heterogeneous CPU/GPU cluster and significantly improves the overall performance. Performance benchmarks are conducted on the Dirac GPU cluster at NERSC/LBNL using up to 32 Tesla C2050 GPUs. A single GPU achieves speed-ups of 101 (25) and 84 (22) for uniform-mesh and AMR simulations, respectively, as compared with the performance using one (four) CPU core(s), and the excellent performance persists in multi-GPU tests. In addition, we make a direct comparison between GAMER and the widely adopted CPU code Athena in adiabatic hydrodynamic tests and demonstrate that, with the same accuracy, GAMER is able to achieve two orders of magnitude performance speed-up.
Open content creation: The issues of voice and the challenges of listening
Authors: Tacchi Jo
Published: November 2011

This article explores the potential role of participatory or open content creation for development. It does so by examining ideas around voice and listening, and their relevance to the field of information and communication technology for development (ICT4D). It first explores participatory development and the idea of open ICT4D before elaborating on issues of voice as process, and as value. Research findings from a project in Asia that experimented with participatory content creation are discussed in relation to notions of voice. The research was concerned with the ways in which processes of voice might lead to wider social action and change. Findings are explored, and discussed in relation to the importance and challenges of ensuring that voice is valued through listening, and the implications of this for ICT4D.
Political balance in the news: A review of concepts, operationalizations and key findings
Authors: Hopmann David Nicolas , Van Aelst Peter , Legnante Guido
Published: November 2011

Balance is a notoriously difficult concept to operationalize. It has typically been investigated by examining the issues raised in elections, as well as the volume and favorability of coverage of political actors. However, even after collecting these measures, it is difficult to determine precisely what would constitute ‘balanced’ coverage. Based on a comprehensive overview of previous research in western democracies, we argue that political balance can be defined according to a political system perspective (where coverage reflects politically defined norms or regulation) or a media routine perspective (where coverage results from journalistic norms). Unless forced to follow norms, western broadcasting seems to comply with a media routine perspective. Empirically, newspaper coverage is sometimes imbalanced according to both perspectives. Finally, we discuss why only a systematic analysis of explanations across time and space makes it possible to determine whether politically ‘imbalanced’ news is the result of partisan bias or not.
The Examination of Process Evaluation Use in Church-Based Health Interventions
Authors: Yeary Karen Hye-cheon Kim , Klos Lori A. , Linnan Laura
Published: November 2011

Churches have been a popular site for the implementation of health promotion interventions. Although the efficacy of church-based health programs have been established, it is unknown which aspects of church-based health promotion drive health behavior change. Process evaluation is a way to increase our understanding of key components of church-based health promotion and to move the field forward. Thus, a systematic review of the utilization of process evaluation in church-based health programs was conducted. Articles from 1990 to 2008 were screened for eligibility, resulting in the analysis of 67 articles. The majority of church-based health programs assessed recruitment (88.1%) and reach (80.6%). About 28.4% assessed dose delivered, and 27.3% measured dose received. Context and fidelity was assessed by 34.3% and 20.9%, respectively, of church-based interventions. Approximately 9% of church-based programs measured fidelity. On average, only three of seven possible components of process evaluation were measured among the studies reviewed. The number of process evaluation components assessed did not differ by program feature (e.g., target population, target health condition, program objective, etc.). Consistency in the conceptualization and measurement of process evaluation may facilitate the implementation of a comprehensive process evaluation effort in church-based and other health promotion interventions.
Money and Finance as Global Public Goods
Authors: Montani Guido
Published: November 2011

The 2007-2008 financial crisis caused not only a dramatic fall in global output and employment but also a serious deterioration of public indebtedness for many governments, forced to rescue the banking system from failure. The crisis showed that national governments are not able to regulate the global market by means of the traditional instruments of political economy. The aim of this article is to identify new supranational instruments of economic policy. As a first step, to avoid a new financial crisis, it is necessary to understand the intimate connection between the international monetary system, founded on the dollar as key currency, and the international financial system. Only some economists were able to see the causes of the recent crisis as a by-product of an asymmetric monetary system. In this article, after having discussed the monetary roots of the financial crisis, the discussion is focused on monetary sovereignty, financial sovereignty, and fiscal sovereignty as the main economic responsibilities of a national government, to show that, today, a supranational economic government should have similar powers. An appendix (disposable on the website of the author) on “Global imbalances: A false objective of economic policy” shows how the balance of payments imposes wrong goals to national economic policies. The discussion is focused on (a) the neo-Ricardian theory of economic integration, (b) financial capital flows, and (c) the Keynesian equations of an open economy.
Low BCR-ABL expression levels in hematopoietic precursor cells enable persistence of chronic myeloid leukemia under imatinib
Authors: Kumari Ashu , Brendel Cornelia , Hochhaus Andreas , Neubauer Andreas , Burchert Andreas
Published: November 2011

BCR-ABL overexpression and stem cell quiescence supposedly contribute to the failure of imatinib mesylate (IM) to eradicate chronic myeloid leukemia (CML). However, BCR-ABL expression levels of persisting precursors and the impact of long-term IM therapy on the clearance of CML from primitive and mature bone marrow compartments are unclear. Here, we have shown that the number of BCR-ABL–positive precursors decreases significantly in all bone marrow compartments during major molecular remission (MMR). More importantly, we were able to demonstrate substantially lower BCR-ABL expression levels in persisting MMR colony-forming units (CFUs) compared with CML CFUs from diagnosis. Critically, lower BCR-ABL levels may indeed cause IM insensitivity, because primary murine bone marrow cells engineered to express low amounts of BCR-ABL were substantially less sensitive to IM than BCR-ABL–overexpressing cells. BCR-ABL overexpression in turn catalyzed the de novo development of point mutations to a greater extent than chemical mutagenesis. Thus, MMR is characterized by the persistence of CML clones with low BCR-ABL expression that may explain their insensitivity to IM and their low propensity to develop IM resistance through kinase point mutations. These findings may have implications for future treatment strategies of residual disease in CML.
Desialylation accelerates platelet clearance after refrigeration and initiates GPIbα metalloproteinase-mediated cleavage in mice
Authors: Jansen A. J. Gerard , Josefsson Emma C. , Rumjantseva Viktoria , Liu Qiyong Peter , Falet Hervé , Bergmeier Wolfgang , Cifuni Stephen M. , Sackstein Robert , von Andrian Ulrich H. , Wagner Denisa D. , Hartwig John H. , Hoffmeister Karin M.
Published: November 2011

When refrigerated platelets are rewarmed, they secrete active sialidases, including the lysosomal sialidase Neu1, and express surface Neu3 that remove sialic acid from platelet von Willebrand factor receptor (VWFR), specifically the GPIbα subunit. The recovery and circulation of refrigerated platelets is greatly improved by storage in the presence of inhibitors of sialidases. Desialylated VWFR is also a target for metalloproteinases (MPs), because GPIbα and GPV are cleaved from the surface of refrigerated platelets. Receptor shedding is inhibited by the MP inhibitor GM6001 and does not occur in Adam17ΔZn/ΔZn platelets expressing inactive ADAM17. Critically, desialylation in the absence of MP-mediated receptor shedding is sufficient to cause the rapid clearance of platelets from circulation. Desialylation of platelet VWFR therefore triggers platelet clearance and primes GPIbα and GPV for MP-dependent cleavage.
Ionizing radiation–induced expression of INK4a/ARF in murine bone marrow–derived stromal cell populations interferes with bone marrow homeostasis
Authors: Carbonneau Cynthia L. , Despars Geneviève , Rojas-Sutterlin Shanti , Fortin Audrey , Le Oanh , Hoang Trang , Beauséjour Christian M.
Published: November 2011

Alterations of the BM microenvironment have been shown to occur after chemoradiotherapy, during aging, and after genetic manipulations of telomere length. Nevertheless, whether BM stromal cells adopt senescent features in response to these events is unknown. In the present study, we provide evidence that exposure to ionizing radiation (IR) leads murine stromal BM cells to express senescence markers, namely senescence-associated β-galactosidase and increased p16INK4a/p19ARF expression. Long (8 weeks) after exposure of mice to IR, we observed a reduction in the number of stromal cells derived from BM aspirates, an effect that we found to be absent in irradiated Ink4a/arf-knockout mice and to be mostly independent of the CFU potential of the stroma. Such a reduction in the number of BM stromal cells was specific, because stromal cells isolated from collagenase-treated bones were not reduced after IR. Surprisingly, we found that exposure to IR leads to a cellular nonautonomous and Ink4a/arf-dependent effect on lymphopoiesis. Overall, our results reveal the distinct sensitivity of BM stromal cell populations to IR and suggest that long-term residual damage to the BM microenvironment can influence hematopoiesis in an Ink4a/arf-dependent manner.
The recombinant lectin-like domain of thrombomodulin inhibits angiogenesis through interaction with Lewis Y antigen
Authors: Kuo Cheng-Hsiang , Chen Po-Ku , Chang Bi-Ing , Sung Meng-Chen , Shi Chung-Sheng , Lee Jeng-Shin , Chang Chuan-Fa , Shi Guey-Yueh , Wu Hua-Lin
Published: November 2011

Lewis Y Ag (LeY) is a cell-surface tetrasaccharide that participates in angiogenesis. Recently, we demonstrated that LeY is a specific ligand of the recombinant lectin-like domain of thrombomodulin (TM). However, the biologic function of interaction between LeY and TM in endothelial cells has never been investigated. Therefore, the role of LeY in tube formation and the role of the recombinant lectin-like domain of TM—TM domain 1 (rTMD1)—in antiangiogenesis were investigated. The recombinant TM ectodomain exhibited lower angiogenic activity than did the recombinant TM domains 2 and 3. rTMD1 interacted with soluble LeY and membrane-bound LeY and inhibited soluble LeY-mediated chemotaxis of endothelial cells. LeY was highly expressed on membrane ruffles and protrusions during tube formation on Matrigel. Blockade of LeY with rTMD1 or Ab against LeY inhibited endothelial tube formation in vitro. Epidermal growth factor (EGF) receptor in HUVECs was LeY modified. rTMD1 inhibited EGF receptor signaling, chemotaxis, and tube formation in vitro, and EGF-mediated angiogenesis and tumor angiogenesis in vivo. We concluded that LeY is involved in vascular endothelial tube formation and rTMD1 inhibits angiogenesis via interaction with LeY. Administration of rTMD1 or recombinant adeno-associated virus vector carrying TMD1 could be a promising antiangiogenesis strategy.
Induction of acute GVHD by sex-mismatched H-Y antigens in the absence of functional radiosensitive host hematopoietic–derived antigen-presenting cells
Authors: Toubai Tomomi , Tawara Isao , Sun Yaping , Liu Chen , Nieves Evelyn , Evers Rebecca , Friedman Thea , Korngold Robert , Reddy Pavan
Published: November 2011

It is currently thought that acute GVHD cannot be elicited in the absence of Ag presentation by radiosensitive host hematopoietic-derived APCs after allogeneic BM transplantation. Because clinical data suggest that sex-mismatched H-Y Ags may be important minor histocompatibility Ags for GVH responses, we directly tested their relevance and ability to initiate GVHD when presented by either the hematopoietic- (host or donor) or the nonhematopoietic-derived APCs. H-Y minor Ag incompatibility elicited both CD4+ and CD8+ T-cell driven GVHD lethality. Studies with various well-established BM chimera recipients, in contrast to the current views, have reported that in the absence of functional radiosensitive host hematopoietic-derived APCs, H-Y Ag presentation by either the donor hematopoietic-derived or the host nonhematopoietic-derived APCs is sufficient for inducing GVHD. Our data further suggest that infusion of sufficient numbers of alloreactive donor T cells will induce GVHD in the absence of radiosensitive host hematopoietic-derived APCs.
Strategies to facilitate the development of uncloned or cloned infectious full-length viral cDNAs: Apple chlorotic leaf spot virus as a case study
Authors: Youssef Fater , Marais Armelle , Faure Chantal , Gentit Pascal , Candresse Thierry
Published: November 2011

Background

Approaches to simplify and streamline the construction of full-length infectious cDNA clones (FL-cDNAs) are needed. Among desirable improvements are the ability to use total nucleic acids (TNA) extracts from infected hosts (to bypass viral purification limitations) for the direct one-step amplification of large FL-cDNAs, the possibility to inoculate plants with uncloned FL-cDNAs and the simplified cloning of these large molecules.

Results

Using the 7.55 kb genome of Apple chlorotic leaf spot trichovirus (ACLSV) approaches allowing the rapid generation from TNA extracts of FL-cDNAs under the control of the T7 promoter and the successful inoculation of plants using in vitro transcripts obtained from these uncloned amplification products have been developed. We also show that the yeast homologous recombination system permits efficient cloning of FL-cDNAs and the simultaneous one-step tailoring of a ternary Yeast-Escherichia coli-Agrobacterium tumefaciens shuttle vector allowing efficient inoculation of both herbaceous and woody host plants by agroinfiltration.

Conclusions

The fast and efficient strategies described here should have broad applications, in particular for the study of "difficult" plant viruses, such as those infecting woody hosts, and potentially for other, non plant-infecting viral agents.
Bioinformatics analysis of rabbit haemorrhagic disease virus genome
Authors: Tian Xiao-ting , Li Bao-yu , Zhang Liang , Jiao Wen-qiang , Liu Ji-xing
Published: November 2011

Background

Rabbit haemorrhagic disease virus (RHDV), as the pathogeny of Rabbit haemorrhagic disease, can cause a highly infectious and often fatal disease only affecting wild and domestic rabbits. Recent researches revealed that it, as one number of the Caliciviridae, has some specialties in its genome, its reproduction and so on.

Results

In this report, we firstly analyzed its genome and two open reading frameworks (ORFs) from this aspect of codon usage bias. Our researches indicated that mutation pressure rather than natural is the most important determinant in RHDV with high codon bias, and the codon usage bias is nearly contrary between ORF1 and ORF2, which is maybe one of factors regulating the expression of VP60 (encoding by ORF1) and VP10 (encoding by ORF2). Furthermore, negative selective constraints on the RHDV whole genome implied that VP10 played an important role in RHDV lifecycle.

Conclusions

We conjectured that VP10 might be beneficial for the replication, release or both of virus by inducing infected cell apoptosis initiate by RHDV. According to the results of the principal component analysis for ORF2 of RSCU, we firstly separated 30 RHDV into two genotypes, and the ENC values indicated ORF1 and ORF2 were independent among the evolution of RHDV.
End point prick test: could this new test be used to predict the outcome of oral food challenge in children with cow's milk allergy?
Authors: Bellini Federica , Ricci Giampaolo , Dondi Arianna , Piccinno Valentina , Angelini Federico , Pession Andrea
Published: November 2011

Background

Cow's milk allergy (CMA) is the most frequent food allergy in childhood; the trend of CMA is often characterized by a progressive improvement to achieve tolerance in the first 4 to 5 years of life.

It has been observed that specific IgE (sIgE) towards cow's milk proteins decrease when the age increases.

Although food allergy can be easily diagnosed, it is difficult to predict the outcome of the oral food challenge (OFC), that remains the gold standard in the diagnosis of food allergy, by allergometric tests.

Methods

We considered 44 children with CMA diagnosed through OFC who returned to our Allergy and Immunology Pediatric Department between January to December 2010 to evaluate the persistence of allergy or the achievement of tolerance.

On the basis of the history, we performed both allergometric skin tests and OFC in children that were still following a milk-free diet, whereas only allergometric skin tests those that had already undergone spontaneous introduction of milk protein at home without presenting symptoms.

Objective

The aim of this study was to investigate the relationship between the persistence of CMA or the acquisition of tolerance and the results of the end point prick test (EPT).

Results and Discussion

The OFC with cow's milk was performed on 30 children, 4 children were excluded because of a history of severe reactions to cow's milk, and 10 because they had spontaneously already taken milk food derivates at home without problems. 16/30 (53%) children showed clinical reactions and the challenge was stopped, 14/30 (47%) did not have any reaction.

Comparing the mean wheal diameter of every EPT's dilution between the group of allergic children and the tolerant ones, we obtained a significant difference (p < 0.05) for the first 4 dilutions.

We have also calculated sensitivity (SE), specificity (SP), the positive predictive value (PPV) and the negative predictive value (NPV) for each EPT dilution.

Conclusions

EPT is a safe and cheap test, easy to be executed and that could provide good prediction of the outcome of OFC; so it might be used to avoid OFC-induced anaphylaxis in children affected by CMA. It can also help avoiding dietetic restrictions in tolerant children who show sensitization towards cow's milk proteins.
Neutrophil-derived matrix metalloproteinase-9 is a potent activator of trypsinogen in acinar cells in acute pancreatitis
Authors: Awla Darbaz , Abdulla Aree , Syk Ingvar , Jeppsson Bengt , Regnér Sara , Thorlacius Henrik
Published: November 2011

MMPs are generally considered to regulate degradation and remodeling of the ECM. Convincing data also implicate a role for MMPs in inflammatory conditions, such as AP, although the mechanisms are not known. The aim of this study was to define the role of MMPs in regulating activation of trypsinogen and tissue damage in AP, which was induced by infusion of taurocholate into the pancreatic duct in mice. A broad-spectrum MMP inhibitor (BB-94) and MMP-9 gene-deficient mice were used. Neutrophil secretions and rMMP-9 were used to stimulate trypsinogen activation in isolated acinar cells. Taurocholate challenge increased serum amylase, neutrophil infiltration, MIP-2 (CXCL2) formation, trypsinogen activation, and tissue damage in the pancreas. Treatment with the broad-spectrum inhibitor of MMPs, BB-94, markedly reduced activation of trypsinogen, levels of CXCL2, infiltration of neutrophils, and tissue damage in AP. Taurocholate challenge increased serum levels of MMP-9 but not MMP-2. Taurocholate-induced amylase levels, neutrophil accumulation, production of CXCL2, trypsinogen activation, and tissue damage in the pancreas were abolished in MMP-9-deficient mice. Moreover, secretions from activated neutrophils isolated from WT but not from MMP-9-deficient animals stimulated trypsinogen activation in acinar cells. Notably, rMMP-9 greatly enhanced activation of trypsinogen in acinar cells. These findings demonstrate that neutrophil-derived MMP-9 is a potent activator of trypsinogen in acinar cells and regulates pathological inflammation and tissue damage in AP.
Rab28 function in trypanosomes: interactions with retromer and ESCRT pathways
Authors: Lumb Jennifer H. , Leung Ka Fai , DuBois Kelly N. , Field Mark C.
Published: November 2011

Early endosomal cargo is typically targeted to either a degradative or recycling pathway. Despite established functions for the retromer and ESCRT complexes at late endosomes/multivesicular bodies, the mechanisms integrating and coordinating these functions remain largely unknown. Rab family GTPases are key membrane trafficking organizers and could contribute. Here, in the unicellular organism Trypanosoma brucei, we demonstrate that Rab28 locates to the endosomal pathway and partially colocalizes with Vps23, an ESCRT I component. Rab28 is required for turnover of endocytosed proteins and for lysosomal delivery of protein cargo. Using RNA interference we find that in Rab28-depleted cells, protein levels of ESCRT I (Vps23/28) and retromer (Vps26) are also decreased, suggesting that Rab28 is an important regulator of these factors. We suggest that Rab28 coordinates the activity of retromer-dependent trafficking and ESCRT-mediated degradative pathways.
RanGTP is required for meiotic spindle organization and the initiation of embryonic development inDrosophila
Authors: Cesario J. , McKim K. S.
Published: November 2011

RanGTP is important for chromosome-dependent spindle assembly in Xenopus extracts. Here we report on experiments to determine the role of the Ran pathway on microtubule dynamics in Drosophila oocytes and embryos. Females expressing a dominant-negative form of Ran have fertility defects, suggesting that RanGTP is required for normal fertility. This is not, however, because of a defect in acentrosomal meiotic spindle assembly. Therefore, RanGTP does not appear to be essential or sufficient for the formation of the acentrosomal spindle. Instead, the most important function of the Ran pathway in spindle assembly appears to be in the tapering of microtubules at the spindle poles, which might be through regulation of proteins such as TACC and the HURP homolog, Mars. One consequence of this spindle organization defect is an increase in the nondisjunction of achiasmate chromosomes. However, the meiotic defects are not severe enough to cause the decreased fertility. Reductions in fertility occur because RanGTP has a role in microtubule assembly that is not directly nucleated by the chromosomes. This includes microtubules nucleated from the sperm aster, which are required for pronuclear fusion. We propose that following nuclear envelope breakdown, RanGTP is released from the nucleus and creates a cytoplasm that is activated for assembling microtubules, which is important for processes such as pronuclear fusion. Around the chromosomes, however, RanGTP might be redundant with other factors such as the chromosome passenger complex.
A dominant-negative form of POM121 binds chromatin and disrupts the two separate modes of nuclear pore assembly
Authors: Shaulov Lihi , Gruber Rita , Cohen Ilana , Harel Amnon
Published: November 2011

Nuclear pore complexes (NPCs) are formed during two separate stages of the metazoan cell cycle. They are assembled into the re-forming nuclear envelope (NE) at the exit from mitosis and into an intact, expanding NE during interphase. Here, we show that a soluble internal fragment of the membrane nucleoporin POM121 has a dominant-negative effect on both modes of assembly in a cell-free reconstitution system. The soluble POM121 fragment binds chromatin at sites that are distinct from ELYS–Nup107–160 ‘seeding’ sites and prevents membrane enclosure and NPC formation. Importin-β negatively regulates chromatin binding by the POM121 fragment through a conserved NLS motif and is also shown to affect the recruitment of the endogenous membrane protein to chromatin in the full assembly system. When an intact NE is present before the addition of the dominant-negative fragment, NPCs are inserted into the NE but membrane expansion is inhibited. This results in densely packed NPCs with no intervening membrane patches, as visualized by scanning electron microscopy. We conclude that POM121 plays an important role in both modes of assembly and links nuclear membrane formation and expansion to nuclear pore biogenesis.
Spindle positioning in human cells relies on proper centriole formation and on the microcephaly proteins CPAP and STIL
Authors: Kitagawa Daiju , Kohlmaier Gregor , Keller Debora , Strnad Petr , Balestra Fernando R. , Flückiger Isabelle , Gönczy Pierre
Published: November 2011

Patients with MCPH (autosomal recessive primary microcephaly) exhibit impaired brain development, presumably due to the compromised function of neuronal progenitors. Seven MCPH loci have been identified, including one that encodes centrosome protein 4.1 associated protein (CPAP; also known as centromere protein J, CENPJ). CPAP is a large coiled-coil protein enriched at the centrosome, a structure that comprises two centrioles and surrounding pericentriolar material (PCM). CPAP depletion impairs centriole formation, whereas CPAP overexpression results in overly long centrioles. The mechanisms by which CPAP MCPH patient mutations affect brain development are not clear. Here, we identify CPAP protein domains crucial for its centriolar localization, as well as for the elongation and the formation of centrioles. Furthermore, we demonstrate that conditions that resemble CPAP MCPH patient mutations compromise centriole formation in tissue culture cells. Using adhesive micropatterns, we reveal that such defects correlate with a randomization of spindle position. Moreover, we demonstrate that the MCPH protein SCL/TAL1 interrupting locus (STIL) is also essential for centriole formation and for proper spindle position. Our findings are compatible with the notion that mutations in CPAP and STIL cause MCPH because of aberrant spindle positioning in progenitor cells during brain development.
A role for seipin in lipid droplet dynamics and inheritance in yeast
Authors: Wolinski Heimo , Kolb Dagmar , Hermann Sandra , Koning Roman I. , Kohlwein Sepp D.
Published: November 2011

Malfunctions of processes involved in cellular lipid storage and mobilization induce the pathogenesis of prevalent human diseases such as obesity, type 2 diabetes and atherosclerosis. Lipid droplets are the main lipid storage depots for neutral lipids in eukaryotic cells, and as such fulfil an essential function to balance cellular lipid metabolism and energy homeostasis. Despite significant progress in identifying key metabolic enzymes involved in lipid storage and their regulation in various model organisms, some fundamental questions as to the biogenesis, subcellular distribution and inheritance of lipid droplets are as yet unsolved. In this study, we applied a set of imaging techniques such as high-resolution four-dimensional (4D) live-cell imaging, quantitative microscopy, transmission electron microscopy and electron tomography to gain insight into the spatio-temporal organization of lipid droplets during cellular growth in the yeast Saccharomyces cerevisiae. This analysis revealed a high level of organization of the subcellular positioning of lipid droplets in individual cells, their directed migration towards the cellular periphery and a coordinated transfer of a subpopulation of lipid droplets into daughter cells during cell division. Lipid droplets appear to remain associated with ER membranes during cellular growth independently of their size and subcellular localization. Deletion of FLD1, the functional orthologue of the human BSCL2 gene encoding seipin, leads to impaired dynamics of yeast lipid droplets and defective lipolysis, which might be due to aberrant ER structures in these mutants. Our data suggest a role for yeast seipin as a scaffolding protein that is required for the dynamics of a specific subdomain of the ER, and provide a new aspect for the interpretation of abnormal lipid droplets phenotypes in yeast mutants lacking seipin.
p31comet-mediated extraction of Mad2 from the MCC promotes efficient mitotic exit
Authors: Westhorpe Frederick G. , Tighe Anthony , Lara-Gonzalez Pablo , Taylor Stephen S.
Published: November 2011

Accurate chromosome segregation requires the spindle assembly checkpoint to be active at the onset of mitosis, before being silenced following chromosome alignment. p31comet is a checkpoint antagonist in that its inhibition delays mitotic exit, whereas its overexpression overrides the checkpoint. How exactly p31comet antagonises the checkpoint is unclear. A prevalent model is that p31comet acts as a ‘cap’ by inhibiting recruitment of the open conformation form of Mad2 (O-Mad2) to the kinetochore-bound complex of Mad1–C-Mad2 (closed conformation Mad2), an essential step that is required for checkpoint activation. Here, we show that although p31comet localises to kinetochores in mitosis, modulation of its activity has no effect on recruitment of O-Mad2 to kinetochores. Rather, our observations support a checkpoint-silencing role for p31comet downstream of kinetochores. We show that p31comet binds Mad2 when it is bound to the mitotic checkpoint complex (MCC) components BubR1 and Cdc20. Furthermore, RNAi-mediated inhibition of p31comet results in more Mad2 bound to BubR1–Cdc20, and conversely, overexpression of p31comet results in less Mad2 bound to BubR1–Cdc20. Addition of recombinant p31comet to checkpoint-arrested extracts removes Mad2 from the MCC, whereas a p31comet mutant that cannot bind Mad2 has no effect. Significantly, expression of a Mad2 mutant that cannot bind p31comet prolongs the metaphase to anaphase transition. Taken together, our data support the notion that p31comet negatively regulates the spindle assembly checkpoint by extracting Mad2 from the MCC.
White matter in autism spectrum disorders – evidence of impaired fiber formation
Authors: Bode Michaela K , Mattila Marja-Leena , Kiviniemi Vesa , Rahko Jukka , Moilanen Irma , Ebeling Hanna , Tervonen Osmo , Nikkinen Juha
Published: November 2011

Background

Diffusion tensor imaging (DTI) enables measurements and visualization of the microstructure of neural fiber tracts. The existing literature on autism spectrum disorders (ASDs) and DTI is heterogenous both regarding methodology and results.

Purpose

To compare brain white matter of high-functioning individuals with ASDs and controls.

Material and Methods

Tract-based spatial statistics (TBSS), a voxel-based approach to DTI, was used to compare 27 subjects with ASDs (mean age 14.7 years, range 11.4–17.6 years, 20 boys, 7 girls) and 26 control subjects (mean age 14.5 years, range 11.7–17.3 years, 17 boys, 9 girls). Mean fractional anisotropy (FA) image (skeleton) was created and each subject's aligned FA data were then projected onto this skeleton. Voxelwise cross-subject statistics on the skeletonized FA data, mean diffusivity (MD), and measures of diffusion direction were calculated. Importantly, the data were corrected across the whole image instead of using ROI-based methods.

Results

The ASD group showed significantly greater FA ( P < 0.05, corrected) in the area containing clusters of optic radiation and the right inferior fronto-occipital fasciculus (iFOF). In the same area, λ3 (representing transverse diffusion) was significantly reduced in the ASD group. No age-related changes were found.

Conclusion

The results suggest that the reduced transverse diffusion within the iFOF is related to abnormal information flow between the insular salience processing areas and occipital visual areas.
Inflammatory cues modulate the expression of secretory product genes, Golgi sulfotransferases and sulfomucin production in LS174T cells
Authors: Croix Jennifer A , Bhatia Shikha , Gaskins H Rex
Published: November 2011

The signals that mediate goblet cell expression of specific mucin chemotypes are poorly defined. Animal and in vitro studies show that acidomucin chemotypes may be altered by inflammation and changes in intestinal microbiota. To examine factors that may elicit this response, human adenocarcinoma-derived LS174T cells, which have a goblet cell-like phenotype and produce both sulfo- and sialomucins, were used to examine the effects of selected microbial and host factors on expression of goblet cell secretory product genes, sulfotransferases and sulfomucin production. Expression of genes encoding mucin 2 ( MUC2), resistin-like molecule β ( RETNLB), and trefoil factor 3 ( TFF3) and Golgi sulfotransferases, carbohydrate ( N-acetylglucosamine 6-O) sulfotransferase 5 ( CHST5) and galactose-3-O-sulfotransferase 2 ( GAL3ST2), was measured by quantitative reverse transcriptase-polymerase chain reaction following treatment with bacterial flagellin, tumor necrosis factor α (TNF- α) or the mucogenic cytokine interleukin-13 (IL-13). Expression of the toll-like receptor 5 (TLR5) gene was also analysed. Sulfomucin expression was examined via high-iron diamide/alcian blue (HID/AB) histochemistry and immunofluorescent staining for the Sulfo Lea antigen, which is synthesized in part by GAL3ST2. Flagellin, IL-13 and TNF- α all significantly increased GAL3ST2, MUC2, TFF3 and TLR5 expression, while only IL-13 increased RETNLB and CHST5 expression. Based on HID/AB histochemistry, mucin sulfation was significantly increased in response to both flagellin and IL-13 but not TNF- α. Only treatment with flagellin increased the expression of the Sulfo Lea antigen. Collectively, these results indicate that bacterial flagellin, IL-13 and TNF- α differentially modulate the expression of goblet cell secretory product genes, sulfotransferases and sulfomucin production.
A quick and simple FISH protocol with hybridization-sensitive fluorescent linear oligodeoxynucleotide probes
Authors: Wang Dan Ohtan , Matsuno Hitomi , Ikeda Shuji , Nakamura Akiko , Yanagisawa Hiroyuki , Hayashi Yasunori , Okamoto Akimitsu
Published: November 2011

Fluorescence in situ hybridization (FISH) is a powerful tool used in karyotyping, cytogenotyping, cancer diagnosis, species specification, and gene-expression analysis. Although widely used, conventional FISH protocols are cumbersome and time consuming. We have now developed a FISH method using exciton-controlled hybridization-sensitive fluorescent oligodeoxynucleotide (ECHO) probes. ECHO–FISH uses a 25-min protocol from fixation to mounting that includes no stringency washing steps. We use ECHO–FISH to detect both specific DNA and RNA sequences with multicolor probes. ECHO–FISH is highly reproducible, stringent, and compatible with other fluorescent cellular labeling techniques. The resolution allows detection of intranuclear speckles of poly(A) RNA in HeLa cells and dissociated hippocampal primary cultures, and mRNAs in the distal dendrites of hippocampal neurons. We also demonstrate detection of telomeric and centromeric DNA on metaphase mouse chromosomes. The simplicity of the ECHO–FISH method will likely accelerate cytogenetic and gene-expression analysis with high resolution.
Widespread generation of alternative UTRs contributes to sex-specific RNA binding by UNR
Authors: Mihailovich Marija , Wurth Laurence , Zambelli Federico , Abaza Irina , Militti Cristina , Mancuso Francesco M. , Roma Guglielmo , Pavesi Giulio , Gebauer Fátima
Published: November 2011

Upstream of N-ras (UNR) is a conserved RNA-binding protein that regulates mRNA translation and stability by binding to sites generally located in untranslated regions (UTRs). In Drosophila, sex-specific binding of UNR to msl2 mRNA and the noncoding RNA roX is believed to play key roles in the control of X-chromosome dosage compensation in both sexes. To investigate broader sex-specific functions of UNR, we have identified its RNA targets in adult male and female flies by high-throughput RNA binding and transcriptome analysis. Here we show that UNR binds to a large set of protein-coding transcripts and to a smaller set of noncoding RNAs in a sex-specific fashion. The analyses also reveal a strong correlation between sex-specific binding of UNR and sex-specific differential expression of UTRs in target genes. Validation experiments indicate that UNR indeed recognizes sex-specifically processed transcripts. These results suggest that UNR exploits the transcript diversity generated by alternative processing and alternative promoter usage to bind and regulate target genes in a sex-specific manner.
A green metrics assessment of phosgene and phosgene-free syntheses of industrially important commodity chemicals
Authors: Andraos John
Published: November 2011

Synthesis plans for the following important industrial commodity chemicals using phosgene and phosgene-free chemistries have been analyzed and compared by green metrics to determine the most material-efficient routes so far developed (number of plans given in parentheses): dimethyl carbonate (DMC) (31), diphenyl carbonate (DPC) (40), diphenylurea (DPU) (23), methyl carbamate (MC) (8), methyl chloroformate (MCF) (6), methyl N-phenylcarbamate (MNPC) (25), methyl phenyl carbonate (MPC) (32), phenyl isocyanate (PI) (19), phenyl chloroformate (PCF) (10), and urea (13). Implications of these results are discussed.
Phosgene-free carbamoylation of aniline via dimethyl carbonate
Authors: Grego Sandra , Aricò Fabio , Tundo Pietro
Published: November 2011

The synthesis of N-phenylcarbamate from aniline and dimethyl carbonate (DMC) in the presence of homogeneous, supported heterogeneous, and heterogeneous catalysts was investigated in batch conditions. First, a selection of homogeneous catalysts was studied and their reactivity in the same reaction conditions was compared to zinc acetate, a catalyst extensively used for this reaction. Then the best homogeneous catalysts were supported on silica or alumina, and the resulting heterogeneous supported catalysts were tested for the carbamoylation of aniline. Finally, several heterogeneous catalysts were investigated. Zinc carbonate basic was shown to be the best catalyst, giving quantitative conversion and selectivity for the N-phenylcarbamate. Its catalytic activity was fully investigated taking into account substrate concentration, amount of catalysts, and temperature influence. Zinc carbonate was also shown to be recyclable, once it was recovered from the reaction mixture and calcinated.