Refine
Has Fulltext
- no (1430) (remove)
Year of publication
- 2016 (1430) (remove)
Document Type
- Article (1181)
- Doctoral Thesis (101)
- Other (69)
- Review (50)
- Part of a Book (14)
- Monograph/Edited Volume (9)
- Conference Proceeding (5)
- Habilitation Thesis (1)
Language
- English (1430) (remove)
Is part of the Bibliography
- yes (1430) (remove)
Keywords
- Magellanic Clouds (8)
- German (7)
- Eye movements (6)
- Sun: magnetic fields (6)
- children (6)
- climate change (6)
- intergalactic medium (6)
- methods: data analysis (6)
- stars: Wolf-Rayet (6)
- techniques: spectroscopic (6)
Institute
- Institut für Biochemie und Biologie (259)
- Institut für Geowissenschaften (246)
- Institut für Physik und Astronomie (224)
- Institut für Chemie (166)
- Institut für Ernährungswissenschaft (66)
- Institut für Mathematik (52)
- Department Psychologie (44)
- Department Linguistik (33)
- Wirtschaftswissenschaften (32)
- Sozialwissenschaften (22)
Recent research has indicated that university students sometimes use caffeine pills for neuroenhancement (NE; non-medical use of psychoactive substances or technology to produce a subjective enhancement in psychological functioning and experience), especially during exam preparation. In our factorial survey experiment, we manipulated the evidence participants were given about the prevalence of NE amongst peers and measured the resulting effects on the psychological predictors included in the Prototype-Willingness Model of risk behavior. Two hundred and thirty-one university students were randomized to a high prevalence condition (read faked research results overstating usage of caffeine pills amongst peers by a factor of 5; 50%), low prevalence condition (half the estimated prevalence; 5%) or control condition (no information about peer prevalence). Structural equation modeling confirmed that our participants’ willingness and intention to use caffeine pills in the next exam period could be explained by their past use of neuroenhancers, attitude to NE and subjective norm about use of caffeine pills whilst image of the typical user was a much less important factor. Provision of inaccurate information about prevalence reduced the predictive power of attitude with respect to willingness by 40-45%. This may be because receiving information about peer prevalence which does not fit with their perception of the social norm causes people to question their attitude. Prevalence information might exert a deterrent effect on NE via the attitude-willingness association. We argue that research into NE and deterrence of associated risk behaviors should be informed by psychological theory.
Filling the Silence
(2016)
In a self-paced reading experiment, we investigated the processing of sluicing constructions (“sluices”) whose antecedent contained a known garden-path structure in German. Results showed decreased processing times for sluices with garden-path antecedents as well as a disadvantage for antecedents with non-canonical word order downstream from the ellipsis site. A post-hoc analysis showed the garden-path advantage also to be present in the region right before the ellipsis site. While no existing account of ellipsis processing explicitly predicted the results, we argue that they are best captured by combining a local antecedent mismatch effect with memory trace reactivation through reanalysis.
Software-as-a-Service (SaaS) offers several advantages to both service providers and users. Service providers can benefit from the reduction of Total Cost of Ownership (TCO), better scalability, and better resource utilization. On the other hand, users can use the service anywhere and anytime, and minimize upfront investment by following the pay-as-you-go model. Despite the benefits of SaaS, users still have concerns about the security and privacy of their data. Due to the nature of SaaS and the Cloud in general, the data and the computation are beyond the users' control, and hence data security becomes a vital factor in this new paradigm. Furthermore, in multi-tenant SaaS applications, the tenants become more concerned about the confidentiality of their data since several tenants are co-located onto a shared infrastructure.
To address those concerns, we start protecting the data from the provisioning process by controlling how tenants are being placed in the infrastructure. We present a resource allocation algorithm designed to minimize the risk of co-resident tenants called SecPlace. It enables the SaaS provider to control the resource (i.e., database instance) allocation process while taking into account the security of tenants as a requirement.
Due to the design principles of the multi-tenancy model, tenants follow some degree of sharing on both application and infrastructure levels. Thus, strong security-isolation should be present. Therefore, we develop SignedQuery, a technique that prevents one tenant from accessing others' data. We use the Signing Concept to create a signature that is used to sign the tenant's request, then the server can verifies the signature and recognizes the requesting tenant, and hence ensures that the data to be accessed is belonging to the legitimate tenant.
Finally, Data confidentiality remains a critical concern due to the fact that data in the Cloud is out of users' premises, and hence beyond their control. Cryptography is increasingly proposed as a potential approach to address such a challenge. Therefore, we present SecureDB, a system designed to run SQL-based applications over an encrypted database. SecureDB captures the schema design and analyzes it to understand the internal structure of the data (i.e., relationships between the tables and their attributes). Moreover, we determine the appropriate partialhomomorphic encryption scheme for each attribute where computation is possible even when the data is encrypted.
To evaluate our work, we conduct extensive experiments with di↵erent settings. The main use case in our work is a popular open source HRM application, called OrangeHRM. The results show that our multi-layered approach is practical, provides enhanced security and isolation among tenants, and have a moderate complexity in terms of processing encrypted data.
Background
Overweight and obesity are increasing health problems that are not restricted to adults only. Childhood obesity is associated with metabolic, psychological and musculoskeletal comorbidities. However, knowledge about the effect of obesity on the foot function across maturation is lacking. Decreased foot function with disproportional loading characteristics is expected for obese children. The aim of this study was to examine foot loading characteristics during gait of normal-weight, overweight and obese children aged 1-12 years.
Methods
A total of 10382 children aged one to twelve years were enrolled in the study. Finally, 7575 children (m/f: n = 3630/3945; 7.0 +/- 2.9yr; 1.23 +/- 0.19m; 26.6 +/- 10.6kg; BMI: 17.1 +/- 2.4kg/m(2)) were included for (complete case) data analysis. Children were categorized to normalweight (>= 3rd and <90th percentile; n = 6458), overweight (>= 90rd and <97th percentile; n = 746) or obese (>97th percentile; n = 371) according to the German reference system that is based on age and gender-specific body mass indices (BMI). Plantar pressure measurements were assessed during gait on an instrumented walkway. Contact area, arch index (AI), peak pressure (PP) and force time integral (FTI) were calculated for the total, fore-, mid-and hindfoot. Data was analyzed descriptively (mean +/- SD) followed by ANOVA/Welch-test (according to homogeneity of variances: yes/no) for group differences according to BMI categorization (normal-weight, overweight, obesity) and for each age group 1 to 12yrs (post-hoc Tukey Kramer/Dunnett's C; alpha = 0.05).
Results
Mean walking velocity was 0.95 +/- 0.25 m/s with no differences between normal-weight, overweight or obese children (p = 0.0841). Results show higher foot contact area, arch index, peak pressure and force time integral in overweight and obese children (p< 0.001). Obese children showed the 1.48-fold (1 year-old) to 3.49-fold (10 year-old) midfoot loading (FTI) compared to normal-weight.
Conclusion
Additional body mass leads to higher overall load, with disproportional impact on the midfoot area and longitudinal foot arch showing characteristic foot loading patterns. Already the feet of one and two year old children are significantly affected. Childhood overweight and obesity is not compensated by the musculoskeletal system. To avoid excessive foot loading with potential risk of discomfort or pain in childhood, prevention strategies should be developed and validated for children with a high body mass index and functional changes in the midfoot area. The presented plantar pressure values could additionally serve as reference data to identify suspicious foot loading patterns in children.
Buyer-seller negotiations have significant impact on a company’s profitability, which makes practitioners aim at maximizing their performance. One lever for increasing bargaining performance is to pursue a clearly defined aspiration, i.e. one’s most desired outcome. In this context, the author explores the role of such aspirations in the three negotiation phases: preparation, bargaining, and striking a deal. She investigates determinants of aspirations, unintended consequences such as unethical bargaining behavior, and the consequences of overly ambitious aspirations. As a result, she does not only close existing gaps in negotiation research, but also derives valuable implications for practitioners
The author examines the cultural identity development of Oromo-Americans in Minnesota, an ethnic group originally located within the national borders of Ethiopia. Earlier studies on language and cultural identity have shown that the degree of ethnic orientation of minorities commonly decreases from generation to generation. Yet oppression and a visible minority status were identified as factors delaying the process of de-ethnicization. Given that Oromos fled persecution in Ethiopia and are confronted with the ramifications of a visible minority status in the U.S., it can be expected that they have retained strong ties to their ethnic culture. This study, however, came to a more complex and theory-building result.
DNA origami nanostructures are a versatile tool to arrange metal nanostructures and other chemical entities with nanometer precision. In this way gold nanoparticle dimers with defined distance can be constructed, which can be exploited as novel substrates for surface enhanced Raman scattering (SERS). We have optimized the size, composition and arrangement of Au/Ag nanoparticles to create intense SERS hot spots, with Raman enhancement up to 1010, which is sufficient to detect single molecules by Raman scattering. This is demonstrated using single dye molecules (TAMRA and Cy3) placed into the center of the nanoparticle dimers. In conjunction with the DNA origami nanostructures novel SERS substrates are created, which can in the future be applied to the SERS analysis of more complex biomolecular targets, whose position and conformation within the SERS hot spot can be precisely controlled.
Sixteen new ionic liquids (ILs) with tetraethylammonium, 1-butyl-3-methylimidazolium, 3-methyl-1-octylimidazolium and tetrabutylphosphonium cations paired with 2-substituted 4,5-dicyanoimidazolate anions (substituent at C2 = methyl, trifluoromethyl, pentafluoroethyl, N,N′-dimethyl amino and nitro) have been synthesized and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of cation and anion type and structure of the resulting ILs, including several room temperature ionic liquids (RTILs), are reflected in the crystallization, melting points and thermal decomposition of the ILs. ILs exhibited large liquid and crystallization ranges and formed glasses on cooling with glass transition temperatures in the range of −22 to −71 °C. We selected one of the newly designed ILs due to its bigger size, compared to the common conventional IL anion and high electron-withdrawing nitrile group leads to an overall stabilization anion that may stabilize the metal nanoparticles. Stable and better separated iron and silver nanoparticles are obtained by the decomposition of corresponding Fe2(CO)9 and AgPF6, respectively, under N2-atmosphere in newly designed nitrile functionalized 4,5-dicyanoimidazolate anion based IL. Very small and uniform size for Fe-nanoparticles of about 1.8 ± 0.6 nm were achieved without any additional stabilizers or capping molecules. Comparatively bigger size of Ag-nanoparticles was obtained through the reduction of AgPF6 by hydrogen gas. Additionally, the AgPF6 precursor was decomposed under microwave irradiation (MWI), fabricating nut-in-shell-like, that is, core-separated-from-shell Ag-nano-structures.
While children acquire new words and simple sentence structures extremely fast and without much effort, the ability to process complex sentences develops rather late in life. Although the conjoint occurrence between brain-structural and brain-functional changes, the decrease of plasticity, and changes in cognitive abilities suggests a certain causality between these processes, concrete evidence for the relation between brain development, language processing, and language performance is rare. Therefore, the current dissertation investigates the tripartite relationship between behavior (in the form of language performance and cognitive maturation as prerequisite for language processing), brain structure (in the form of gray matter maturation), and brain function (in the form of brain activation evoked by complex sentence processing). Previous developmental studies indicate a missing increase of activation in accordance to sentence complexity (functional selectivity) in language-relevant brain areas in children. To determine the factors contributing to the functional development of language-relevant brain areas, different methodologies and data acquisition techniques were used to investigate the processing of center-embedded sentences in 5- and 6-year-old children, 7- and 8-year-old children, and adults. Behavioral results indicate that children between 5 and 8 years show difficulties in processing double embedded sentences and that their performance for these type of sentences is positively correlated with digit span. In 7- and 8-year-old children, it was found that especially the processing of long-distance relations between the initial phrase and its corresponding verb appears to be associated with the subject’s verbal working memory capacity. In contrast, children’s performance for double embedded sentences in the younger age group positively correlated with their performance in a standardized sentence comprehension test. This finding supports the hypothesis that processing difficulties in this age group may be mainly attributed to difficulties in processing case marking information. These findings are discussed with respect to current accounts of language and working memory development. A second study aimed at investigating the structural maturation of brain areas involved in sentence comprehension. To do this, whole-brain magnetic resonance images from 59 children between 5 and 8 years were collected and children’s gray matter was analyzed by using voxel-based morphometry. Children’s grammatical proficiency was assessed by a standardized sentence comprehension test. A confirmatory factory analysis corroborated a grammar-relevant and a verbal working memory-relevant factor underlying the measured performance. While children’s ability to assign thematic roles is positively correlated with gray matter probability (GMP) in the left inferior temporal gyrus and the left inferior frontal gyrus, verbal working memory-related performance is positively correlated with GMP in the left parietal operculum extending into the posterior superior temporal gyrus. These areas have been previously shown to be differentially engaged in adults’ complex sentence processing. Thus, the findings of the second study suggest a specific correspondence between children’s GMP in language-relevant brain regions and differential cognitive abilities which underlie complex sentence comprehension. In a third study, functional brain activity during the processing of center-embedded sentences was investigated in three different age groups (5–6 years, 7–8 years, and adults). Although all age groups engage a qualitatively comparable network of the left pars opercularis (PO), the left inferior parietal lobe extending into the posterior superior temporal gyrus (IPL/pSTG), the supplementary motor area (SMA) and the cerebellum, functional selectivity of these regions was only observable in adults. However, functional activation of the language-related regions (PO and IPL/pSTG) predicted sentence comprehension performance for all age groups. To solve the question of the complex interplay between different maturational factors, a fourth study analyzed the predictive power of gray matter probability, verbal working memory capacity, and behavioral differences in performance for simple and complex sentence for the functional selectivity of each activated region. These analyses revealed that the establishment of the adult-like functional selectivity for complex sentences is predicted by a reduction of the left PO’s gray matter probability across age groups while that of the IPL/pSTG is additionally predicted by verbal working memory capacity. Taken all findings together, the current thesis provides evidence that both structural brain maturation and verbal working memory expansion provide the basis for the emergence of functional selectivity in language-related brain regions leading to more efficient sentence processing during development.
Food and fear
(2016)