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Search Results: 1 - 10 of 1056 matches for " Felizitas Zimmermann "
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Dogs (Canis familiaris), but Not Chimpanzees (Pan troglodytes), Understand Imperative Pointing
Katharina C. Kirchhofer, Felizitas Zimmermann, Juliane Kaminski, Michael Tomasello
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030913
Abstract: Chimpanzees routinely follow the gaze of humans to outside targets. However, in most studies using object choice they fail to use communicative gestures (e.g. pointing) to find hidden food. Chimpanzees' failure to do this may be due to several difficulties with this paradigm. They may, for example, misinterpret the gesture as referring to the opaque cup instead of the hidden food. Or perhaps they do not understand informative communicative intentions. In contrast, dogs seem to be skilful in using human communicative cues in the context of finding food, but as of yet there is not much data showing whether they also use pointing in the context of finding non-food objects. Here we directly compare chimpanzees' (N = 20) and dogs' (N = 32) skills in using a communicative gesture directed at a visible object out of reach of the human but within reach of the subject. Pairs of objects were placed in view of and behind the subjects. The task was to retrieve the object the experimenter wanted. To indicate which one she desired, the experimenter pointed imperatively to it and directly rewarded the subject for handing over the correct one. While dogs performed well on this task, chimpanzees failed to identify the referent. Implications for great apes' and dogs' understanding of human communicative intentions are discussed.
The speed of frogs with drift on $\mathbb{Z}$
Thomas H?felsauer,Felizitas Weidner
Mathematics , 2015,
Abstract: In this article we consider the frog model with drift on $\mathbb{Z}$ and investigate the behaviour of the cloud of the frogs. In particular, we show that the speed of the minimum equals the speed of a single frog and prove some properties of the speed of the maximum. In addition, we show a limit theorem for the empirical distribution.
Effectiveness and efficiency of primary care based case management for chronic diseases: rationale and design of a systematic review and meta-analysis of randomized and non-randomized trials [CRD32009100316]
Tobias Freund, Felizitas Kayling, Antje Miksch, Joachim Szecsenyi, Michel Wensing
BMC Health Services Research , 2010, DOI: 10.1186/1472-6963-10-112
Abstract: According to this protocol Medline, Embase, CINAHL, PsychInfo, the Cochrane Central Register of Controlled trials, DARE, NHS EED, Science Citation Index, The Royal College of Nursing Database, Dissertation Abstracts, registers of clinical trials and the reference lists of retrieved articles will be searched to identify reports on randomized and non-randomized controlled trials of case management interventions in a primary care setting without limitations on language or publication date. We will further ask experts in the field to avoid missing relevant evidence. Study inclusion and data extraction will be performed independently by two reviewers. After assessing risk of bias according to predefined standards, included studies will be described qualitatively. Subgroup analyses are planned for different chronic diseases and intervention strategies. If appropriate, a quantitative synthesis of data will be performed to provide conclusive evidence about the effectiveness and efficiency of primary care based case management in chronic care.Centre for Reviews and Dissemination (University of York): CRD32009100316.The concept of case management is thought to be an effective and efficient approach to manage patients with chronic illness and complex health care needs [1]. Case management can implement key elements of the chronic care model, such as improved continuity of care by redesigning the delivery system and enhancing patients' self-management skills [2]. It can also contribute to better implementation of evidence-based recommendations for diagnostic procedures, pharmaceutical treatment, life style counselling and monitoring of patients.Case management has been implemented in a range of clinical settings [3] but most chronically ill patients receive most of their medical care in primary care settings, at least in countries with a strong primary care system. Therefore this seems to be the most obvious setting for case management programs. A previous review on case manage
Five-year impact of a new departmental protocol on emergency cesarean target times  [PDF]
Visnja Korda, Roland Zimmermann
Open Journal of Obstetrics and Gynecology (OJOG) , 2013, DOI: 10.4236/ojog.2013.31A028

Objective: To evaluate the impact of an emergency cesarean standard operating procedure (SOP) on the decision-to-delivery interval (DDI) and to determine whether a shorter DDI improves neonatal outcome. Methods: Retrospective analysis of emergency cesareans from 2004 (introduction of the new SOP) to 2009 in a Swiss Level 3 perinatal center. Primary endpoints were the DDI, the pathology-to-decision interval (PDI), the 5 year learning curve, and neonatal and maternal outcome. Results: In the emergency cesarean group (175 women and 188 infants), mean DDI decreased over the observation period from 15 to 9 minutes (mean 10 minutes 41 seconds), and mean PDI from 11 to 6 minutes (mean 8 minutes). Not only did the DDI not exceed 15 minutes in over 90% of cases during the 5 years, but it fell consistently below 10 minutes in the latter stages of the learning curve. Only 2/188 infants had an umbilical artery pH < 7.00 and 19/188 had an Apgar score <5 at 5 minutes. Maternal morbidity comprised three cases of superficial wound infection. Conclusion: Logistic prerequisites comprise a surgical capability directly within the delivery suite, a standby surgical and anesthetic team, a crash call system, and clear duty allocation. International guideline target times are readily achievable at no additional significant fetal or maternal cost.

Modelling Turbulent Heat Transfer in a Natural Convection Flow  [PDF]
Claudia Zimmermann, Rodion Groll
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.27073

In this paper a numerical study of a turbulent, natural convection problem is performed with a compressible Large-Eddy simulation. In a natural convection the fluid is accelerated by local density differences and a resulting pressure gradient. Directly at the heated walls the temperature distribution is determinate by increasing temperature gradients. In the centre region convective mass exchange is dominant. Density changes due to temperature differences are considered in the numerical model by a compressible coupled model. The obtained numerical results of this study are compared to an analogue experimental setup. The fluid properties profiles, e.g. temperature and velocity, show an asymmetry which is caused by the non-Boussinesq effects of the fluid. The investigated Rayleigh number of this study lies at Ra = 1.58 × 109.


Experimental and Numerical Investigation of a Rayleigh-Bénard Convection Affected by Coriolis Force  [PDF]
Claudia Zimmermann, Rodion Groll
Journal of Flow Control, Measurement & Visualization (JFCMV) , 2014, DOI: 10.4236/jfcmv.2014.24018
Abstract: In this paper the influence of an impressed Coriolis force field on the configuration of a turbulent Rayleigh-Bénard convection problem is investigated in an experimental and numerical study. The main purpose of both studies lie on the analysis of a possible stabilising effect of a Coriolis acceleration on the turbulent unsteady structures inside the fluid. The relative Coriolis acceleration which is caused in the atmosphere by the earth rotation is realised in the experimental study by a uniform-rotational movement of the setup in a large-scale centrifuge under hyper-gravity. The same conditions as in the atmosphere in the beginning of a twister or hurricane should be realised in the experiment. The investigated Rayleigh numbers lie between 2.33 × 106 ≤ Ra ≤ 4.32 × 107.
Asymptotic Behavior of the Likelihood Function of Covariance Matrices of Spatial Gaussian Processes
Ralf Zimmermann
Journal of Applied Mathematics , 2010, DOI: 10.1155/2010/494070
Abstract: The covariance structure of spatial Gaussian predictors (aka Kriging predictors) is generally modeled by parameterized covariance functions; the associated hyperparameters in turn are estimated via the method of maximum likelihood. In this work, the asymptotic behavior of the maximum likelihood of spatial Gaussian predictor models as a function of its hyperparameters is investigated theoretically. Asymptotic sandwich bounds for the maximum likelihood function in terms of the condition number of the associated covariance matrix are established. As a consequence, the main result is obtained: optimally trained nondegenerate spatial Gaussian processes cannot feature arbitrary ill-conditioned correlation matrices. The implication of this theorem on Kriging hyperparameter optimization is exposed. A nonartificial example is presented, where maximum likelihood-based Kriging model training is necessarily bound to fail. 1. Introduction Spatial Gaussian processing, also known as best linear unbiased prediction, refers to a statistical data interpolation method, which is nowadays applied in a wide range of scientific fields, including computer experiments in modern engineering context; see, for example, [1–5]. As a powerful tool for geostatistics, it has been pioneered by Krige in 1951 [6], and to pay tribute to his achievements, the method is also termed Kriging; see [7, 8] for geostatistical background. In practical applications, the data's covariance structure is modeled through covariance functions depending on the so-called hyperparameters. These, in turn, are estimated by optimizing the corresponding maximum likelihood function. It has been demonstrated by many authors that the accuracy of Kriging predictors relies both heavily on hyperparameter-based model training and, from the numerical point of view, on the condition number of the associated Kriging correlation matrix. In this regard, we relate to the following, nonexhaustive selection of papers: Warnes and Ripley [9] and Mardia and Watkins [10] present numerical examples of difficult-to-optimize covariance model functions. Ababou et al. [11] show that likelihood-optimized hyperparameters may correspond to ill-conditioned correlation matrices. Diamond and Armstrong [12] prove error estimates under perturbation of covariance models, demonstrating a strong dependence on the correlation matrix' condition number. In the same setting, Posa [13] investigates numerically the behavior of this precise condition number for different covariance models and varying hyperparameters. An extensive experimental study of
Grenzen der mast- und schlachtleistung beim schwein und selektion entlang von leistungsgrenzen
F Zimmermann
Genetics Selection Evolution , 1980, DOI: 10.1186/1297-9686-12-1-132c
Where are they going? Directed cell movement in morphogenesis
Frank Zimmermann
Genome Biology , 2001, DOI: 10.1186/gb-2001-2-6-reports4014
Abstract: Many talks at this year's joint spring meeting of the British Societies for Cell and Developmental Biology revealed the importance of regulators of cytoskeleton and signaling events, leading to rearrangement of the cytoskeletal architecture, for a number of cellular processes including morphogenesis, endocytosis and cell motility. In this report, I focus on certain presentations: in the 'cytoskeleton' session, discussions of the role cytoskeletal modulators play in wound healing; in the 'regulation of cell motility' workshop, topics ranging from the control of chemotaxis at different developmental stages of Dictyostelium discoideum to the regulation of the actin cytoskeleton; and in the 'signaling' session, presentations about the integrin-mediated signaling that precedes cell migration and about signaling following intercellular interactions.Paul Martin (University College London, UK) studies dorsal closure in Drosophila embryos as a model for understanding wound healing in epithelia. His analysis of dorsal closure in living fly embryos using actin tagged with green fluorescent protein (GFP) showed that the zippering together of the two epithelial edges relies on the activity of the Rho-family small GTPase Cdc42, a regulator of the actin cytoskeleton. His movies showing dorsal closure and wound healing indicated that the cells at the leading edge extend filopodia to find the opposing cells. The nonmuscle motor protein myosin II is essential for maintenance of the cell morphology required for dorsal closure, as revealed by Daniel Kiehart (Duke University, Durham, USA). Kiehart further demonstrated that the RhoA GTPase mediates wound healing at a time when it is apparently not required for dorsal closure.Sandrine Etienne-Manneville (University College London, UK) demonstrated a wound-healing assay using primary rat astrocytes. In an astrocyte cell-layer model, cells at the leading edge polarize and extend protrusions towards a scratched 'wound'. Wounding induces the
Marriage, sexuality, and holiness: Aspects of marital ethics in the Corpus Paulinum
R Zimmermann
Acta Theologica , 2011,
Abstract: A fundamental change in the understanding of marriage becomes apparent in the first century A.D., described by M. Foucault as the transition from a “matrimonial” to a “conjugal” marital concept. While early Christianity participated in this development, it also influenced it at decisive points and developed its own marital ethics. Through a consideration of philosophical (Musonius, Plutarch) and early Judaic (esp. Qumran, Jubilees) texts, this article outlines the marital concepts existing in the NT environment. In this context, the reciprocal community and the duration of the marital relationship are emphasized while sexuality remains wholly limited to reproduction. The core of the article offers a concrete analysis of texts from the Corpus Paulinum (1Cor 5-7; 1Thess 4:1-5; Eph 5:21-33), in which one can recognize, upon the backdrop of a traditional-hierarchical classification of man and woman, an equal and holistic relationship of the marital partners. Simultaneously – and here the Pauline texts extend beyond the borders of their environment – sexual intercourse is valued as an important component of the relationship between husband and wife. Here, the relationship of marriage, including the physical union of the marital partners, is theologically substantiated, and the frequently occurring semantics of “holiness” clearly plays a central role in the context of the marital texts. In the theologically substantiated union of the sexes one can recognize not only traditional, but especially Judaic forms of speech, created through the close interweaving of relationships between the sexes and the relationship with God. In addition, further norms that regulate early Christianity, such as the condemnation of adultery or the prohibition of divorce, become understandable in new ways.
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