1,337 research outputs found
Maternal warmth and early adolescents' internalizing symptoms and externalizing behavior: Mediation via emotional security
This study examines the relation between maternal warmth and the internalizing and externalizing problems of early adolescents, and the potential mediation of this relation by emotional insecurity. The hypotheses for the study derive from Cummings and Davies (1995) theory of emotional security. The current study extends the theory to security processes within the parent-adolescent relationship. A total of 203 early adolescents drawn from school samples in Spain participated in the study along with their mothers and their classroom teachers. The results supported the hypothesis. Emotional insecurity mediated the relationship between maternal warmth and adolescent internalizing and externalizing problems. Higher maternal warmth was linked to greater emotional security, which in turn was linked to fewer internalizing and externalizing problems. The findings extend the tenets of Emotional Security Theory and imply strategies for prevention and intervention
Signatures of small-world and scale-free properties in large computer programs
A large computer program is typically divided into many hundreds or even
thousands of smaller units, whose logical connections define a network in a
natural way. This network reflects the internal structure of the program, and
defines the ``information flow'' within the program. We show that, (1) due to
its growth in time this network displays a scale-free feature in that the
probability of the number of links at a node obeys a power-law distribution,
and (2) as a result of performance optimization of the program the network has
a small-world structure. We believe that these features are generic for large
computer programs. Our work extends the previous studies on growing networks,
which have mostly been for physical networks, to the domain of computer
software.Comment: 4 pages, 1 figure, to appear in Phys. Rev.
Field and laboratory studies of methane oxidation in an anoxic marine sediment: Evidence for a methanogen‐sulfate reducer consortium
Field and laboratory studies of anoxic sediments from Cape Lookout Bight, North Carolina, suggest that anaerobic methane oxidation is mediated by a consortium of methanogenic and sulfate‐reducing bacteria. A seasonal survey of methane oxidation and CO2 reduction rates indicates that methane production was confined to sulfate‐depleted sediments at all times of year, while methane oxidation occurred in two modes. in the summer, methane oxidation was confined to sulfate‐depleted sediments and occurred at rates lower than those of CO2 reduction. in the winter, net methane oxidation occurred in an interval at the base of the sulfate‐containing zone. Sediment incubation experiments suggest both methanogens and sulfate reducers were responsible for the observed methane oxidation. In one incubation experiment both modes of oxidation were partially inhibited by 2‐bromoethanesulfonic acid (a specific inhibitor of methanogens). This evidence, along with the apparent confinement of methane oxidation to sulfate‐depleted sediments in the summer, indicates that methanogenic bacteria are involved in methane oxidation. In a second incubation experiment, net methane oxidation was induced by adding sulfate to homogenized methanogenic sediments, suggesting that sulfate reducers also play a role in the process. We hypothesize that methanogens oxidize methane and produce hydrogen via a reversal of CO2 reduction. The hydrogen is efficiently removed and maintained at low concentrations by sulfate reducers. Pore water H2 concentrations in the sediment incubation experiments (while net methane oxidation was occurring) were low enough that methanogenic bacteria could derive sufficient energy for growth from the oxidation of methane. The methanogen‐sulfate reducer consortium is consistent not only with the results of this study, but may also be a feasible mechanism for previously documented anaerobic methane oxidation in both freshwater and marine environments
Construction and evaluation of an expression vector allowing the stable expression of foreign antigens in a Salmonella typhimurium vaccine strain at toxic levels.
Salmonella strains have great potential as live carriers of heterologous antigens to induce immunity against a variety of infectious diseases. However, the amount of heterologous antigen required to induce an adequate immune response may be toxic for the bacterium and result in cell death, overattenuation or loss of expression of the heterologous antigen. To solve this problem an expression vector was developed with a strong promoter located on a DNA fragment which is inverted at random. Antigen is only expressed in one particular orientation of the promoter. Thus a bacterial population harbouring the plasmid will consist o
G3DV: A new 3D genome browser and experimental data viewer.
Genomes are tremendous co-evolutionary holistic systems for molecular storage, processing and fabrication of
information. Their system-biological complexity remains, however, still largely mysterious, despite immense
sequencing achievements and huge advances in the understanding of the general sequential, three-dimensional
and regulatory organization. Here, we present the GLOBE 3D Genome Platform a completely novel grid based
virtual “paper” tool and in fact the first system-biological genome browser integrating the holistic complexity of
genomes in a single easy comprehensible platform: Based on a detailed study of biophysical and IT
requirements, every architectural level from sequence to morphology of one or several genomes can be
approached in a real and in a symbolic representation simultaneously and navigated by continuous scale-free
zooming within a unique three-dimensional OpenGL and grid driven environment. In principle an unlimited
number of multi-dimensional data sets can be visualized, customized in terms of arrangement, shape, colour, and
texture etc. as well as accessed and annotated individually or in groups using internal or external data
bases/facilities. Any information can be searched and correlated by importing or calculating simple relations in
real-time using grid resources. A general correlation and application platform for more complex correlative
analysis and a front-end for system-biological simulations both using again the huge capabilities of grid
infrastructures is currently under development. Hence, the GLOBE 3D Genome Platform is an example of a grid
based approach towards a virtual desktop for genomic work combining the three fundamental distributed
resources: i) visual data representation, ii) data access and management, and iii) data analysis and creation. Thus,
the GLOBE 3D Genome Platform is the novel system-biology oriented information system urgently needed to
access, present, annotate, and to simulate the holistic genome complexity in a unique gateway towards a real
understanding, educative presentation and curative manipulation planning of this tremendous evolutionary
information grail – genomes
Analysis of the National Adult Nutrition Survey (Ireland) and the Food4Me Nutrition Survey Databases to Explore the Development of Food Labelling Portion Sizes for the European Union
The present study set out to explore the option of developing food portion size for nutritional labelling purposes using two European Union (EU) dietary surveys. The surveys were selected as they differed in (a) methodologies (food diary versus food frequency questionnaire), (b) populations (Irish National Adult Nutrition Survey (NANS) versus a seven-country survey based on the pan EU study Food4Me), (c) food quantification (multiple options versus solely photographic album) and (d) duration (4 consecutive days versus recent month). Using data from these studies, portion size was determined for 15 test foods, where portion size was defined as the median intake of a target food when consumed. The median values of the portion sizes derived from both the NANS and Food4Me surveys were correlated (r = 0.823; p < 0.00) and the mean of the two survey data sets were compared to US values from the Recognized as Customarily Consumed (RACC) database. There was very strong agreement across all food categories between the averaged EU and the US portion size (r = 0.947; p < 0.00). It is concluded that notwithstanding the variety of approaches used for dietary survey data in the EU, the present data supports using a standardized approach to food portion size quantification for food labelling in the EU
The potential for prevention of dementia across two decades: The prospective, population-based Rotterdam Study
Background: Cardiovascular factors and low education are important risk factors of dementia. We provide contemporary estimates of the proportion of dementia cases that could be prevented if modifiable risk factors were eliminated, i.e., population attributable risk (PAR). Furthermore, we studied whether the PAR has changed across the last two decades. Methods: We included 7,003 participants of the original cohort (starting in 1990) and 2,953 participants of the extended cohort (starting in 2000) of the Rotterdam Study. Both cohorts were followed for dementia until ten years after baseline. We calculated the PAR of overweight, hypertension, diabetes mellitus, cholesterol, smoking, and education. Additionally, we assessed the PAR of stroke, coronary heart disease, heart failure, and atrial fibrillation. We calculated the PAR for each risk factor separately and the combined PAR taking into account the interaction of risk factors. Results: During 57,996 person-years, 624 participants of the original cohort developed dementia, and during 26,177 person-years, 145 participants of the extended cohort developed dementia. The combined PAR in the original cohort was 0.23 (95 % CI, 0.05-0.62). The PAR in the extended cohort was slightly higher at 0.30 (95 % CI, 0.06-0.76). The combined PAR including cardiovascular diseases was 0.25 (95 % CI, 0.07-0.62) in the original cohort and 0.33 (95 % CI, 0.07-0.77) in the extended cohort. Conclusions: A substantial part of dementia cases could be prevented if modifiable risk factors would be eliminated. Although prevention and treatment options of cardiovascular risk factors and diseases have improved, the preventive potential for dementia has not declined over the last two decades
The Solution Space of the Unitary Matrix Model String Equation and the Sato Grassmannian
The space of all solutions to the string equation of the symmetric unitary
one-matrix model is determined. It is shown that the string equation is
equivalent to simple conditions on points and in the big cell \Gr
of the Sato Grassmannian . This is a consequence of a well-defined
continuum limit in which the string equation has the simple form \lb \cp
,\cq_- \rb =\hbox{\rm 1}, with \cp and \cq_- matrices of
differential operators. These conditions on and yield a simple
system of first order differential equations whose analysis determines the
space of all solutions to the string equation. This geometric formulation leads
directly to the Virasoro constraints \L_n\,(n\geq 0), where \L_n annihilate
the two modified-KdV \t-functions whose product gives the partition function
of the Unitary Matrix Model.Comment: 21 page
Evaluation of motivational stages and processes of change for weight management in obesity and after bariatric surgery
Poster abstrac
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