3D Nanolithography by Means of Lipid Ink Spreading Inhibition

While patterning 2D metallic nanostructures are well established through different techniques, 3D printing still constitutes a major bottleneck on the way to device miniaturization. In this work a fluid phase phospholipid ink is used as a building block for structuring with dip-pen nanolithography. Following a bioinspired approach that relies on ink-spreading inhibition, two processes are presented to build 2D and 3D metallic structures. Serum albumin, a widely used protein with an innate capability to bind to lipids, is the key in both processes. Covering the sample surface with it prior to lipid writing, anchors lipids on the substrate, which ultimately allows the creation of highly stable 3D lipid-based scaffolds to build metallic structures.     

Encoding Information on the Excited State of a Molecular Spin Chain

The quantum states of nano-objects can drive electrical transport properties across lateral and local-probe junctions. This raises the prospect, in a solid-state device, of electrically encoding information at the quantum level using spin-flip excitations between electron spins. However, this electronic state has no defined magnetic orientation and is short-lived. Using a novel vertical nanojunction process, these limitations are overcome and this steady-state capability is experimentally demonstrated in solid-state spintronic devices. The excited quantum state of a spin chain formed by Co phthalocyanine molecules coupled to a ferromagnetic electrode constitutes a distinct magnetic unit endowed with a coercive field. This generates a specific steady-state magnetoresistance trace that is tied to the spin-flip conductance channel, and is opposite in sign to the ground state magnetoresistance term, as expected from spin excitation transition rules. The experimental 5.9 meV thermal energy barrier between the ground and excited spin states is confirmed by density functional theory, in line with macrospin phenomenological modeling of magnetotransport results. This low-voltage control over a spin chain's quantum state and spintronic contribution lay a path for transmitting spin wave-encoded information across molecular layers in devices. It should also stimulate quantum prospects for the antiferromagnetic spintronics and oxides electronics communities.     

Aufladung und Sekundärelektronenemission

Ohne ZusammenfassungTeildissertation D 82.Diese Arbeit wurde angeregt von Prof. Dr.-Ing. E. h. Dr.-Ing. W. Rogowski, dem ich auch hier für seine fördernden Ratschläge herzlich danke.     

Diagnosis of learner dropout based on learning styles for online distance learning

The amount of data generated by computer systems in Online Distance Learning (ODL) contains rich information. One example of this information we define as the Learner Learning Trail (LLT), which is the sequence of interactions between the students and the virtual environment. Another example is the Learner Learning Style (LLS), which is associated with the student behavior and choices during the learning process. This information can be used to identify learner behavior and learning style. We perceived, after the study of related literature, that the research field of learner diagnosis for ODL does not apply the conjoint use of LLT and LLS. In this article, we propose a model capable of integrating data generated from the behavior of students in ODL with cognitive aspects of them, such as their Learning Styles, by crossing LLT with LLS. We also propose the CPAD method (Collect, Preprocessing, Analysis, Diagnosis), which is implemented by collecting the raw data regarding learning activities, preprocessing the data into structured time sequences, analyzing the sequences regarding the learning styles and using this analysis to diagnose the learner behavior. We selected the dropout to investigate, once the dropout rate in ODL is a real problem in universities around the world. In addition, the dropout is a student decision which can be associated with previous students behaviors. We performed a study with 202 learners to evaluate if learning styles are capable of explaining aspects of the student behavior. The results suggest that Sequential/Global learning style dimension is more capable of explaining the dropout than the other dimensions. Also, we performed four classification experiments to verify how the dimensions of Felder-Silverman Learning Style Model influence the learner diagnosis. We perceived that the Sequential/Global dimension could provide a higher accuracy average with lower variation independently of the diagnosis technique.     

Emotions evoked by the sound of music: Characterization, classification, and measurement.

One reason for the universal appeal of music lies in the emotional rewards that music offers to its listeners. But what makes these rewards so special? The authors addressed this question by progressively characterizing music-induced emotions in 4 interrelated studies. Studies 1 and 2 (n = 354) were conducted to compile a list of music-relevant emotion terms and to study the frequency of both felt and perceived emotions across 5 groups of listeners with distinct music preferences. Emotional responses varied greatly according to musical genre and type of response (felt vs. perceived). Study 3 (n = 801)--a field study carried out during a music festival--examined the structure of music-induced emotions via confirmatory factor analysis of emotion ratings, resulting in a 9-factorial model of music-induced emotions. Study 4 (n = 238) replicated this model and found that it accounted for music-elicited emotions better than the basic emotion and dimensional emotion models. A domain-specific device to measure musically induced emotions is introduced--the Geneva Emotional Music Scale. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rehabilitation psychology: Realizing the true potential.

As the Division of Rehabilitation Psychology (Division 22) celebrates its 50th anniversary this year, this article reflects on the current status and important trends in health care and technology that are likely to have the largest impact on the science and practice of rehabilitation psychologists in the next decade. These trends include the prevalence of chronic conditions, health disparities, Operation Iraqi Freedom and Operation Enduring Freedom injuries, and caregiver burden. The implications of these trends are also discussed in the context of rehabilitation psychologists' involvement in public policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of on-line adaptive discriminant analysis for EEG-based brain computer interfaces

A study of different on-line adaptive classifiers, using various feature types is presented. Motor imagery brain computer interface (BCI) experiments were carried out with 18 naive able-bodied subjects. Experiments were done with three two-class, cue-based, electroencephalogram (EEG)-based systems. Two continuously adaptive classifiers were tested: adaptive quadratic and linear discriminant analysis. Three feature types were analyzed, adaptive autoregressive parameters, logarithmic band power estimates and the concatenation of both. Results show that all systems are stable and that the concatenation of features with continuously adaptive linear discriminant analysis classifier is the best choice of all. Also, a comparison of the latter with a discontinuously updated linear discriminant analysis, carried out in on-line experiments with six subjects, showed that on-line adaptation performed significantly better than a discontinuous update. Finally a static subject-specific baseline was also provided and used to compare performance measurements of both types of adaptation.     

Integrated portable polymerase chain reaction-capillary electrophoresis microsystem for rapid forensic short tandem repeat typing

A portable forensic genetic analysis system consisting of a microfluidic device for amplification and separation of short tandem repeat (STR) fragments as well as an instrument for chip operation and four-color fluorescence detection has been developed. The microdevice performs polymerase chain reaction (PCR) in a 160-nL chamber and capillary electrophoresis (CE) in a 7-cm-long separation channel. The instrumental design integrates PCR thermal cycling, electrophoretic separation, pneumatic valve fluidic control, and four-color laser excited fluorescence detection. A quadruplex Y-chromosome STR typing system consisting of amelogenin and three Y STR loci (DYS390, DYS393, DYS439) was developed and used for validation studies. The multiplex amplification of these 4 loci with 35 PCR cycles followed by CE separation and 4-color fluorescence detection was completed in 1.5 h. All the amplicons can be detected with a limit of detection of 20 copies of male standard DNA in the reactor. Real-world forensic analyses of oral swab and human bone extracts from case evidence were also successfully performed. Mixture analysis demonstrated that a balanced profile can be obtained even at a male-to-female template ratio of 1:10. The successful development and operation of this portable PCR-CE system establishes the feasibility of rapid point-of-analysis DNA typing of forensic casework, of mass disaster samples or of individuals at a security checkpoint.     

Simultaneous determination of B-group vitamins in enriched Brazilian dairy products

In addition to serving as good natural sources of vitamin B(2), milk and milk products are currently being enriched with the vitamins B(1), B(2), B(6), and nicotinamide in Brazil. The objective of this research was to evaluate the levels of enrichment of these products according to their availability in supermarkets in the Campinas (SP, Brazil) region. The separation of the vitamins was carried out on a C 18 column with gradient elution with acetonitrile and aqueous phase. Detection of vitamins was effected in the ultraviolet region and quantification by an external standard. The levels of vitamin B(2) determined in powdered whole milk, skimmed milk powder, and one brand of flavored lactic beverage, were practically double those stated on the packages. The same occurred with vitamins B(6) and PP (nicotinic acid + nicotinamide), when determined in the same lactic beverage and with vitamin B(6), determined in acidified milk. The high levels of vitamin B(2), naturally present in whole milk, and the predominance of the free form, allowed for the determination of this vitamin in non-enriched milk.     

<Emphasis Type="Italic">Zea Mays</Emphasis>: Benzoxazolinone Detoxification Under Sulfur Deficiency Conditions—A Complex Allelopathic Alliance Including Endophytic <Emphasis Type="Italic">Fusarium Verticillioides</Emphasis>

Benzoxazolinone detoxification is similar in plants grown under sulfur deficiency conditions and in control plants grown with an optimal S supply. However, when S-deficient plants were treated with metolachlor before benzoxazolin-2(3H)-one (BOA) incubation, detoxification was reduced, as indicated by a lower accumulation of the detoxification products BOA-6-O-glucoside and glucoside carbamate and by a loss of BOA-6-OH glucosyltransfease activity. Root colonizing microorganisms and the endophytic fungus Fusarium verticillioides participated in benzoxazolinone detoxification by converting the compound to 2-acetamidophenol (AAP) or O-hydroxyphenyl malonamic acid (OHPMA), a process accompanied by the appearance of phenoxazinone. Maize roots, however, absorbed AAP and OHPMA only in traces. Absorbed traces of OHPMA stimulated maize radicle growth, and traces of AAP stimulated cress. Phenoxazinone inhibited the growth of cress radicles at concentrations higher than 500 μM, whereas maize radicles were hardly affected. F. verticillioides did not convert benzoxazolinone to any known microbial degradation product when the medium of maize seedlings was inoculated with the fungus under sterile condition. Plant–fungus interactions seem to be important in plant survival of allelopathic attacks. This study points to a complicated network of allelopathic interactions that are influenced by biotic and abiotic factors, including herbicides.