286 research outputs found

    Measles virus glycoprotein-based lentiviral targeting vectors that avoid neutralizing antibodies

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    Lentiviral vectors (LVs) are potent gene transfer vehicles frequently applied in research and recently also in clinical trials. Retargeting LV entry to cell types of interest is a key issue to improve gene transfer safety and efficacy. Recently, we have developed a targeting method for LVs by incorporating engineered measles virus (MV) glycoproteins, the hemagglutinin (H), responsible for receptor recognition, and the fusion protein into their envelope. The H protein displays a single-chain antibody (scFv) specific for the target receptor and is ablated for recognition of the MV receptors CD46 and SLAM by point mutations in its ectodomain. A potential hindrance to systemic administration in humans is pre-existing MV-specific immunity due to vaccination or natural infection. We compared transduction of targeting vectors and non-targeting vectors pseudotyped with MV glycoproteins unmodified in their ectodomains (MV-LV) in presence of α-MV antibody-positive human plasma. At plasma dilution 1:160 MV-LV was almost completely neutralized, whereas targeting vectors showed relative transduction efficiencies from 60% to 90%. Furthermore, at plasma dilution 1:80 an at least 4-times higher multiplicity of infection (MOI) of MV-LV had to be applied to obtain similar transduction efficiencies as with targeting vectors. Also when the vectors were normalized to their p24 values, targeting vectors showed partial protection against α-MV antibodies in human plasma. Furthermore, the monoclonal neutralizing antibody K71 with a putative epitope close to the receptor binding sites of H, did not neutralize the targeting vectors, but did neutralize MV-LV. The observed escape from neutralization may be due to the point mutations in the H ectodomain that might have destroyed antibody binding sites. Furthermore, scFv mediated cell entry via the target receptor may proceed in presence of α-MV antibodies interfering with entry via the natural MV receptors. These results are promising for in vivo applications of targeting vectors in humans

    Fast responsive, optical trace level ammonia sensor for environmental monitoring

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    BACKGROUND: Ammonia is a ubiquitous chemical substance which is created in technical and biological processes and harmful to many different organisms. One specific problem is the toxicity of ammonia in fish at levels of 25 μg/l - a very common issue in today’s aqua culture. In this study we report a development of a fast responsive, optical ammonia sensor for trace concentrations. RESULTS: Different hydrogels have been investigated as host polymers for a pH based sensing mechanism based on fluorescent dyes. A porous hydrophobic fluoropolymer membrane was used as an ion barrier cover layer to achieve a good ammonia permeability. The sensor’s sensitivity towards ammonia as well as crosssensitivity towards pH-value and salinity, and the temperature dependency have been determined. Two different methods to reference fluorescence signals have been employed to eliminate intensity-based measurement drawbacks. CONCLUSION: The presented sensor features high sensitivity and a fast response even at concentrations near 1 ppb. No cross sensitivity towards pH and salinity could be observed and temperature dependency was determined as compensateable. Both referencing approaches prove themselves to be able to provide a simple use of the sensor for in-field applications

    Phase-Sensitive Amplification of 28 GBaud DP-QPSK Signal

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    We demonstrate, for the first time, amplification of a DP-QPSK signal using a vector phase-sensitive amplifier (PSA). The PSA-based receiver shows an about 0.7 dB sensitivity improvement compared to an EDFA-based receiver

    Frequency-Comb Regeneration for Self-Homodyne Superchannels

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    We demonstrate frequency-comb regeneration from two received unmodulated carriers using a parametric mixer. For 10 dB optical signal-to-noise ratio of the unmodulated carriers, up to 60 carriers are generated without linewidth degradation

    The Ursinus Weekly, November 1, 1907

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    Phantom party at Olevian • Football • Historical Political meeting • The Schubert string quartette • Editorial: Smiles • Society • Personals • Seminary notes • College world • Alumni notes • Literary Supplement: The lack of appreciation of the beautiful; A defense of American poetry; The danger of hero worship in a democracy; Hallowe\u27en; The price of an experience; Hannibalhttps://digitalcommons.ursinus.edu/weekly/2882/thumbnail.jp

    How Mechanization Shapes Coups

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    Civil-military relations are characterized by a fundamental dilemma. To lower coup risk, leaders frequently empower the military, which satisfies the armed forces with the status quo and enables them to fight against threats challenging the civilian leadership. Simultaneously, a too powerful military itself constitutes a potential threat that is capable of overthrowing the government. Our research adds to this debate by examining the impact of mechanization, that is, the degree to which militaries rely on armored vehicles relative to manpower, on coup risk. We discuss several (opposing) mechanisms before developing the theoretical expectation that higher levels of mechanization should lower the likelihood of a coup due to the increased costs of coup execution. Empirical evidence strongly supports this claim and, thus, contributes to our understanding of the emergence of coups as an essential breakdown of civil-military relations, while adding to the debate surrounding the many trade-offs leaders face when coup-proofing their regimes

    Students’ perspectives on racism and anti-racism in physical education: a systematic review

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    Sports, with their various social manifestations, exhibit racist structures and incidents. Physical education (PE) has the potential to serve as an environment to combat racism, but it can also perpetuate and (re)produce racist attitudes and behaviors. This study aimed to conduct a systematic review of national (German) and international literature concerning racism and anti-racism within the context of PE specifically from a students’ perspective. The research methodology followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard and encompassed a four-step process: (1) searching 11 electronic databases using 70 keyword combinations in both German and English; (2) selecting studies based on five predetermined inclusion criteria; (3) evaluating the quality of selected studies using established appraisal tools; and (4) conducting descriptive and template analyses. Of 5,213 publications, 16 met the inclusion criteria, demonstrating diverse theoretical frameworks and methodological approaches. Five themes were constructed: “How racism is understood” (1); “What students experience,” encompassing discriminatory incidents in PE, sports, and daily life classified as racial stereotypes, prejudices, and everyday racism (2); and “What physical education teachers (3)/Institutions (4)/researchers (5) can and should do.” These themes provided recommendations for teachers, institutions, and researchers, including training and curriculum reforms. While valuable international literature was identified, no German PE specific publications were found emphasizing the necessity of a local (German) survey to comprehend students’ experiences, knowledge, and potential for anti-racism efforts. Such insights are crucial for shaping teacher-related training programs and policy demands in an informed and targeted manner

    Purchasing Behavior, Setting, Pricing, Family: Determinants of School Lunch Participation

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    Despite growing school lunch availability in Germany, its utilization is still low, and students resort to unhealthy alternatives. We investigated predictors of school lunch participation and reasons for nonparticipation in 1215 schoolchildren. Children reported meal habits, parents provided family-related information (like socioeconomic status), and anthropometry was conducted on-site in schools. Associations between school lunch participation and family-related predictors were estimated using logistic regression controlling for age and gender if necessary. School was added as a random effect. School lunch participation was primarily associated with family factors. While having breakfast on schooldays was positively associated with school lunch participation (ORadj = 2.20, p = 0.002), lower secondary schools (ORadj = 0.52, p < 0.001) and low SES (ORadj = 0.25, p < 0.001) were negatively associated. The main reasons for nonparticipation were school- and lunch-related factors (taste, time constraints, pricing). Parents reported pricing as crucial a reason as an unpleasant taste for nonparticipation. Nonparticipants bought sandwiches and energy drinks significantly more often on school days, whereas participants were less often affected by overweight (OR = 0.66, p = 0.043). Our data stress school- and lunch-related factors as an important opportunity to foster school lunch utilization

    Will We Do If We Can? Habitual Qualitative and Quantitative Physical Activity in Multi-Morbid, Older Persons with Cognitive Impairment

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    This study aimed to identify determinants of quantitative dimensions of physical activity (PA; duration, frequency, and intensity) in community-dwelling, multi-morbid, older persons with cognitive impairment (CI). In addition, qualitative and quantitative aspects of habitual PA have been described. Quantitative PA and qualitative gait characteristics while walking straight and while walking turns were documented by a validated, sensor-based activity monitor. Univariate and multiple linear regression analyses were performed to delineate associations of quantitative PA dimensions with qualitative characteristics of gait performance and further potential influencing factors (motor capacity measures, demographic, and health-related parameters). In 94 multi-morbid, older adults (82.3 ± 5.9 years) with CI (Mini-Mental State Examination score: 23.3 ± 2.4), analyses of quantitative and qualitative PA documented highly inactive behavior (89.6% inactivity) and a high incidence of gait deficits, respectively. The multiple regression models (adjusted R2^{2} = 0.395–0.679, all p < 0.001) identified specific qualitative gait characteristics as independent determinants for all quantitative PA dimensions, whereas motor capacity was an independent determinant only for the PA dimension duration. Demographic and health-related parameters were not identified as independent determinants. High associations between innovative, qualitative, and established, quantitative PA performances may suggest gait quality as a potential target to increase quantity of PA in multi-morbid, older persons
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