Creat membership Creat membership
Sign in

Forgot password?

  • Forgot password?
    Sign Up
  • Confirm
    Sign In
home > search

Now showing items 1 - 16 of 75


    In order to be able to arrange a master module (M), slave modules (S) and conventional plug modules (K) in a freely configurable manner in a modular plug system, according to the invention, a modular frame (22) is provided with a circuit board (1) which includes at least one continuous conductor path and preferably more than one connection pad.
    Download Collect
  • Composite Respect for Animals Scale Full and Brief Versions

    Randler, Christoph   Binngiesser, Janine   Vollmer, Christian  

    A valid and convenient method to measure nonhuman animal attitudes contributes to feasible survey studies and the evaluation of educational programs. There are established scales for measuring animal attitudes but only some have acceptable psychometric properties: others address only a small fraction of the constructs, and some are overly long. We therefore aimed to develop a short, practicable measurement of animal attitudes that contains the constructs developed previously. Two studies were conducted: in the first one, 127 items were subjected to an exploratory factor analysis, which extracted 51 items in 10 factors. The scale was reduced to 20 items retaining all of the initial constructs with 13 positive and 7 negative items, which were subjected to a confirmatory factor analysis in study 2. Correlations with personality, meat consumption, age, and gender provide evidence for validity. We suggest using this short, unidimensional Composite Respect for Animals Scale covering a broad construct.
    Download Collect

    The invention relates to a plug-in connector module (1) comprising at least one optical waveguide (7) and at least one optical sensor, preferably a photodiode (11, 12), which is arranged near the optical waveguide (7). The optical sensor can reliably detect malfunction of the plug-in connector module (1) in good time. The invention also relates to a method for detecting signal losses during signal transmission in an optical plug-in connector module, in which an optical signal is guided through at least one optical waveguide of the plug-in connector module, and the optical signal is scattered in the event of a structural defect of the optical waveguide or dirt on the front surface of the optical waveguide, the scattered light reaching a photodiode and a current or a voltage being produced thereby on the photodiode. If a threshold value of the current or the voltage on the photodiode is exceeded, an interference signal is generated by an electronic evaluation system.
    Download Collect

    The object of the invention consists of defining a device which enables a data transmission from a plug connector housing, which is designed to be as freely configurable as possible. This problem is solved by a device for transmitting data, which comprises a data module (5) for storing and forwarding data, a plug connector housing (1) with a cable outlet opening (11) and a threaded cable connection (3), and additionally an adapter module (2) which has at least one cable passage area (28), wherein the adapter module (2) has a cable inlet opening (22) on a first end of this cable passage area (28) and a cable outlet opening (23) on a second end of this cable passage area (28), wherein the adapter module (2) can be fastened with its cable inlet opening (22) on the cable outlet opening (11) of the plug connector housing (1), and the threaded cable connection (3) can be fastened to the cable outlet opening (23) of the adapter module (2) so that the adapter module (2) can be fastened between the cable outlet opening (11) and the threaded cable connection (3).
    Download Collect

    The invention relates to a bicycle saddle comprising a saddle shell (22). A seat cushion (26) is arranged on the upper side (24) of the saddle shell (22). A support element (34) which is connected to a saddle frame (18) is also provided. An elastomer body (32) is arranged between the saddle shell (22) and the support element (34) in order to decouple the saddle shell (22) from the support element (34). The saddle shell (22) has a lower stiffness than the support element (34).
    Download Collect
  • Trachyandesitic volcanism in the early Solar System

    Bischoff, Addi   Horstmann, Marian   Barrat, Jean-Alix   Chaussidon, Marc   Pack, Andreas   Herwartz, Daniel   Ward, Dustin   Vollmer, Christian   Decker, Stephan  

    Volcanism is a substantial process during crustal growth on planetary bodies and well documented to have occurred in the early Solar System from the recognition of numerous basaltic meteorites. Considering the ureilite parent body (UPB), the compositions of magmas that formed a potential UPB crust and were complementary to the ultramafic ureilite mantle rocks are poorly constrained. Among the Almahata Sitta meteorites, a unique trachyandesite lava (with an oxygen isotope composition identical to that of common ureilites) documents the presence of volatile-and SiO2-rich magmas on the UPB. The magma was extracted at low degrees of disequilibrium partial melting of the UPB mantle. This trachyandesite extends the range of known ancient volcanic, crust-forming rocks and documents that volcanic rocks, similar in composition to trachyandesites on Earth, also formed on small planetary bodies similar to 4.56 billion years ago. It also extends the volcanic activity on the UPB by similar to 1 million years (Ma) and thus constrains the time of disruption of the body to later than 6.5 Ma after the formation of Ca-Al-rich inclusions.
    Download Collect
  • Morningness and life satisfaction: Further evidence from Spain

    Diaz-Morales, Juan Francisco   Jankowski, Konrad S.   Vollmer, Christian   Randler, Christoph  

    Life satisfaction is a crucial component of well being, thus research of its determinants are of great importance and are conducted worldwide. Recently, morningness has been shown to be related to greater life satisfaction in Polish and German samples; and in the present study, this relationship was tested in a Spanish adult sample. The results provide further evidence for the relationship of morningness with higher life satisfaction, which it seems independent of culture and geographic location.
    Download Collect
  • Asymmetries in commitment in an avian communication network

    Randler, Christoph   Vollmer, Christian  

    Mobbing of predators occurs within a conspecific and heterospecific context but has not been quantified within the framework of a communication network and analysed with respect to heterospecific reciprocity. Here, we used playbacks of mobbing calls to show that mobbing is unequally distributed within a community of deciduous forest birds. Five species (great tit Parus major, blue tit Cyanistes caeruleus, marsh tit Poecile palustris, nuthatch Sitta europaea and chaffinch Fringilla coelebs) responded to each other's playbacks of mobbing calls. Commitment to mob was measured by minimum distance, response latency and uttering of calls. Commitment was higher when conspecific calls were broadcast. Yet, responses to heterospecific calls were significantly different between the five species. Chaffinches had the lowest commitment, and blue tits tended to have the highest. The communication network is asymmetric. Some species invest more than they receive from other species. As mobbing might incur costs, these are unequally distributed across the community.
    Download Collect
  • Morningness is associated with better gradings and higher attention in class

    Vollmer, Christian   P?tsch, Farina   Randler, Christoph  

    There are individual preferences in circadian rhythm, also known as chronotype, ranging from morning-orientation to evening-orientation. In adolescence, the sleep rhythm shifts from morningness to eveningness while school schedules are early. School performance - short-term attention and gradings - may decrease with increasing evening-orientation. One thousand nine hundred and seventy-seven adolescents aged 10-17 provided self-reported information on their chronotype as well as their gradings and completed an attention test. Controlling for age and gender, earlier chronotype was a significant predictor of better gradings and better performance in the attention test. Moreover, concerning the attention test, we found a slower and more considerate completion strategy in morning-types and faster and a more impulsive strategy in evening-types. Using structural equation modeling, age had a negative influence while class level had a positive influence on gradings and attention. The authors suggest a delay of school start times by 1 h as a measure to improve the school performance of late chronotypes. (C) 2013 Elsevier Inc. All rights reserved.
    Download Collect
  • Eveningness is related to men's mating success

    Randler, Christoph   Ebenhoeh, Nadine   Fischer, Arian   Hoechel, Sandra   Schroff, Christina   Stoll, Julia Christin   Vollmer, Christian   Piffer, Davide  

    Men and women differ in sleep duration and timing of sleeping. Men sleep shorter and are later chronotypes, thus go to bed and get up later than women. This sexual dimorphism in chronotype is most striking between the beginning of puberty and beginning of menopause indicating the possibility of a sexually selected trait. Sleep duration, however, is different between the sexes already before and after the reproductive phase, suggesting a trait that is not under sexual section. In men, the most influential predictor of mating success was extraversion, followed by age, propensity to stay out late and evening orientation. This was confirmed by structural equation modeling showing both, an indirect and a direct fitness benefit of eveningness even when imposing extraversion and age as important predictor variables. As eveningness is related to an array of problematic behaviors, we suggest that it can be viewed as a kind of handicap. (C) 2012 Elsevier Ltd. All rights reserved.
    Download Collect
  • Sparse coding of human motion trajectories with non-negative matrix factorization

    Vollmer, Christian   Hellbach, Sven   Eggert, Julian   Gross, Horst-Michael  

    We use shift-invariant Non-negative Matrix Factorization (NMF) for decomposing continuous-valued time series into a number of characteristic primitives, i.e. the basis vectors, and their activations, which results in a model-independent and fully data driven parts-based representation. We interpret the basis vectors as short parts of motion that are shared between all trajectories in the data set, and the activations as onset times of those parts. The extension of the shift-invariant NMF by a new competition term between adjacent activations allows to gain temporally isolated activation events, which further supports this interpretation. We show that the resulting sparse and compact representation can be used for the prediction of motion trajectories, and that it can be beneficial for classification, because it allows the application of simple standard classification models with few parameters. In this paper we show that basis vectors can be extracted, which can be interpreted as short motion segments. We present results on trajectory prediction, and show that the sparse representation can be used for classification of trajectories of a single joint, like the one of a hand, obtained by motion capturing. [All rights reserved Elsevier].
    Download Collect
  • Outdoor Light at Night (LAN) Is Correlated With Eveningness in Adolescents

    Vollmer, Christian   Michel, Ulrich   Randler, Christoph  

    External zeitgebers synchronize the human circadian rhythm of sleep and wakefulness. Humans adapt their chronotype to the day-night cycle, the strongest external zeitgeber. The human circadian rhythm shifts to evening-type orientation when daylight is prolonged into the evening and night hours by artificial light sources. Data from a survey of 1507 German adolescents covering questions about chronotype and electronic screen media use combined with nocturnal satellite image data suggest a relationship between chronotype and artificial nocturnal light. Adolescents living in brightly illuminated urban districts had a stronger evening-type orientation than adolescents living in darker and more rural municipalities. This result persisted when controlling for time use of electronic screen media, intake of stimulants, type of school, age, puberty status, time of sunrise, sex, and population density. Time spent on electronic screen media use-a source of indoor light at night-is also correlated with eveningness, as well as intake of stimulants, age, and puberty status, and, to a lesser degree, type of school and time of sunrise. Adequate urban development design and parents limiting adolescents' electronic screen media use in the evening could help to adjust adolescents' zeitgeber to early school schedules when they provide appropriate lighting conditions for daytime and for nighttime. (Author correspondence:
    Download Collect
  • Organic carbonates as stabilizing solvents for transition-metal nanoparticles

    Vollmer, Christian   Thomann, Ralf   Janiak, Christoph  

    Biodegradable, non-toxic, "green" and inexpensive propylene carbonate (PC) solvent is shown to function as a stabilizing medium for the synthesis of weakly-coordinated transition-metal nanoparticles. Kinetically stable nanoparticles (M-NPs) with a small and uniform particle size (typically <5 +/- 1 nm) have been reproducibly obtained by easy, rapid (3 min) and energy-saving 50 W microwave irradiation under an argon atmosphere from their metal-carbonyl precursors in PC. The M-NP/PC dispersions are stable for up to three weeks according to repeated TEM studies over this time period. The rhodium nanoparticle/PC dispersion is a highly active catalyst for the biphasic liquid-liquid hydrogenation of cyclohexene to cyclohexane with activities of up to and 1875 (mol product) (mol Rh)(-1) h(-1) and near quantitative conversion at 4 to 10 bar H-2 and 90 degrees C. From the PC dispersion the M-NPs can be coated with organic capping ligands such as 3-mercaptopropionic acid or trioctylphosphine oxide for further stabilization.
    Download Collect
  • Hypercapnia counteracts captopril-induced depression of gastric mucosal oxygenation

    Vollmer, Christian   Schwartges, Ingo   Behmke, Robert   Bauer, Inge   Picker, Olaf  

    Hypercapnia (HC) increases systemic oxygen delivery (DO2) and gastric mucosal oxygenation. However, it activates the renin-angiotensin-aldosterone system (RAAS), which conversely reduces mesenteric perfusion. The aims of this study were to evaluate the effect of RAAS inhibition during normocapnia and HC on oral and gastric mucosal oxygenation (mu HbO(2)) and to assess the effect of blood pressure under these circumstances. Five dogs were repeatedly anesthetized to study the effects of ACE inhibition (ACE-I; 5 mg/kg captopril, followed by 0.25 mg/kg per h) on mu HbO(2) (reflectance spectrophotometry) and hemodynamic variables during normocapnia (end-tidal CO2=35 mmHg) and HC (end-expiratory carbon dioxide (etCO(2))=70 mmHg). In the control group, the dogs were subjected to HC alone. To exclude the effects of reduced blood pressure, in one group, blood pressure was maintained at baseline values via titrated phenylephrine (PHE) infusion during HC and additional captopril infusion. ACE-I strongly reduced gastric mu HbO(2) from 72+/-2 to 65+/-2% and mean arterial pressure (MAP) from 64+/-2 to 48+/-4 mmHg, while DO2 remained unchanged. This effect was counteracted in the presence of HC, which increased gastric mu HbO(2) from 73+/-3 to 79+/-6% and DO2 from 15+/-2 to 22+/-4 ml/kg per min during ACE-I without differences during HC alone. However, MAP decreased similar to that observed during ACE-I alone from 66+/-3 to 47+/-5 mmHg, while left ventricular contractility (dP(max)) increased from 492+/-63 to 758+/-119 mmHg/s. Titrated infusion of PHE had no additional effects on mu HbO(2). In summary, our data suggest that RAAS inhibition reduces gastric mucosal oxygenation in healthy dogs. HC not only abolishes this effect, but also increases mu HbO(2), DO2, and dP(max). The increase in mu HbO(2) during ACE-I under HC is in accordance with our results independent of blood pressure.
    Download Collect
  • Learning to Navigate Through Crowded Environments

    Henry, Peter   Vollmer, Christian   Ferris, Brian   Fox, Dieter  

    The goal of this research is to enable mobile robots to navigate through crowded environments such as indoor shopping malls, airports, or downtown side walks. The key research question addressed in this paper is how to learn planners that generate human-like motion behavior. Our approach uses inverse reinforcement learning (IRL) to learn human-like navigation behavior based on example paths. Since robots have only limited sensing, we extend existing IRL methods to the case of partially observable environments. We demonstrate the capabilities of our approach using a realistic crowd flow simulator in which we modeled multiple scenarios in crowded environments. We show that our planner learned to guide the robot along the flow of people when the environment is crowded, and along the shortest path if no people are around.
    Download Collect

    Vollmer, Christian   Padevit, Christian   Horstmann, Marcus   Schwab, Christoph   Horton, Kevin   John, Hubert  

    Download Collect
1 2 3 4 5


If you have any feedback, Please follow the official account to submit feedback.

Turn on your phone and scan

Submit Feedback