439 research outputs found
Synthesis of empty bacterial microcompartments, directed organelle protein incorporation, and evidence of filament-associated organelle movement
Compartmentalization is an important process, since it allows the segregation of metabolic activities and, in the era of synthetic biology, represents an important tool by which defined microenvironments can be created for specific metabolic functions. Indeed, some bacteria make specialized proteinaceous metabolic compartments called bacterial microcompartments (BMCs) or metabolosomes. Here we demonstrate that the shell of the metabolosome (representing an empty BMC) can be produced within E. coil cells by the coordinated expression of genes encoding structural proteins. A plethora of diverse structures can be generated by changing the expression profile of these genes, including the formation of large axial filaments that interfere with septation. Fusing GFP to PduC, PduD, or PduV, none of which are shell proteins, allows regiospecific targeting of the reporter group to the empty BMC. Live cell imaging provides unexpected evidence of filament-associated BMC movement within the cell in the presence of Pdu
Pathways of self-reported problem behaviors from adolescence into adulthood
OBJECTIVE: The authors determined the impact of different pathways of
psychopathological development on adult outcome in subjects followed from
ages 11-18 to ages 21-28. METHOD: Problem behaviors of subjects from a
general population sample were assessed through the Youth Self-Report and
the Young Adult Self-Report given at four time points (1987, 1989, 1991,
and 1997). In addition, DSM-IV diagnoses, information pertaining to signs
of maladjustment, and measures of social functioning were obtained at the
last assessment. On the basis of the self-report ratings, four contrasting
developmental pathways of psychopathology were determined: persistent,
decreasing, increasing, and consistently normal. RESULTS: Subjects whose
overall level of psychopathology was persistent over time had a higher
lifetime prevalence of DSM-IV diagnoses and a poorer general outcome in
adulthood than did subjects whose level of psychopathology increased.
Subjects whose level of psychopathology returned to normal after high
levels of problems in adolescence were only slightly different in terms of
outcome from subjects with consistently normal ratings. CONCLUSIONS: 1)
People who showed high levels of problems in early adolescence but whose
level of psychopathology diminished by adulthood seemed to be as healthy
as people who never attained a serious level of psychopathology. 2) An
ongoing devious pathway into adulthood had negative effects on many
domains of functioning. These two findings are both powerful arguments for
early intervention in adolescence
Nanostructure-modulated planar high spectral resolution spectro-polarimeter
We present a planar spectro-polarimeter based on Fabry-P{\'e}rot cavities
with embedded polarization-sensitive high-index nanostructures. A
m-thick spectro-polarimetric system for 3 spectral bands and 2 linear
polarization states is experimentally demonstrated. Furthermore, an optimal
design is theoretically proposed, estimating that a system with a bandwidth of
127~nm and a spectral resolution of 1~nm is able to reconstruct the first three
Stokes parameters \textcolor{black}{with a signal-to-noise ratio of -13.14~dB
with respect to the the shot noise limited SNR}. The pixelated
spectro-polarimetric system can be directly integrated on a sensor, thus
enabling applicability in a variety of miniaturized optical devices, including
but not limited to satellites for Earth observation
Stable prediction of mood and anxiety disorders based on behavioral and emotional problems in childhood: a 14-year follow-up during childhood, adolescence, and young adulthood
OBJECTIVE: The goal of this study was to predict the onset of mood and
anxiety disorders from parent-reported emotional and behavioral problems
in childhood across a 14-year period from childhood into young adulthood.
METHOD: In 1983, parent reports of behavioral and emotional problems were
obtained with the Child Behavior Checklist for children and adolescents
4-16 years of age from the Dutch general population. At follow-up 14 years
later, lifetime mood and anxiety diagnoses were obtained by a standardized
DSM-IV interview for 1,580 subjects. Cox proportional hazards models were
used to predict the incidence of mood and anxiety disorders from childhood
problems and demographic covariates. RESULTS: Mood disorders were
significantly predicted by high scores on the anxious/depressed scale and
on the internalizing composite (withdrawn, somatic complaints, and
anxious/depressed). Anxiety disorders were significantly predicted by the
social problems scale and the externalizing composite (delinquent behavior
and aggressive behavior). Anxiety disorders predominantly started in
childhood and early adolescence, whereas the incidence of mood disorders
increased sharply in adolescence and young adulthood. CONCLUSIONS: These
results suggest different developmental pathways for mood and anxiety
disorders. The predictions based on problem behavior remained stable
during the 14-year period across adolescence and young adulthood. The
results therefore underline the importance of early intervention and
prevention of behavioral and emotional problems in childhood
Level of motion sickness based on heart rate variability when reading inside a fully automated vehicle
This study investigates the level of experienced motion sickness when performing reading while being driven in fully automated driving under three different conditions. One condition was without any intervention while the other two conditions were with the visual (VPIS) and haptic (HPIS) peripheral information system. Both systems provided the upcoming navigational information in the lateral direction three seconds before the turning/cornering was done. It was hypothesized that with the peripheral information systems, the experienced motion sickness would be reduced compared to the condition where a peripheral information system was not present. Eighteen participants with severe motion sickness susceptibility were carefully chosen to undergo the conditions using an instrumented vehicle with the Wizard-of-Oz approach. The participants were required to read from a tablet during the whole 15-minutes of automated driving. Results from the heart rate variability (beats per minute, root means square of successive differences, and high-frequency component) indicated no statistically significant changes (p < 0.05) in motion sickness found with the presence of HPIS and VPIS when performing reading when being driven in automated mode. However, results from this study were mixed and inconclusive, but overall findings indicated mild motion sickness was found in both VPIS and HPIS conditions.</p
Development of a Clinical Simulation Protocol for the Transfer of a Premature Fetal Manikin to the Perinatal-Life-Support System
Introduction:At present, Perinatal-Life-Support (PLS) research is progressing to offer extreme premature infants an extracorporeal environment for extended growth that mimics the natural womb closely. During the early phase development of this novel life-support technology, validation and training could be facilitated by the use of a medical simulation. By doing so, the need for animal testing can be greatly reduced. Within this abstract, the development to realize a wellorchestrated clinical simulation protocol is described, tailored to the specific needs of novel procedure(s) regarding the transfer of a premature fetus from the maternal uterus to the PLS system.Materials & Methods:Throughout protocol development an iterative approach is used, initiated with a literature analysis and a review of existing obstetrics guidelines for premature births. Next, co-creation sessions and interviews with medical and engineering experts led to a holistic understanding of fetal physiology, patient and specialist needs, current procedures, task divisions, hospital resources and drug specifications. Expert feedback on drafts, checklists and an explanatory step-by-step video, led to multiple re-designs as unforeseen procedural difficulties arose. Verified with available data from literature, multiple perspectives and options were analyzed and weighed to ensure the advancement of a safe, hygienic, effective, and user-friendly simulation protocol.Results:We describe the development process of a simulation protocol and showcase an overview of the current protocol design through an infographic, outlining the different phases and tasks during a transfer procedure and the planning of involved medical experts within the operating theatre. We demonstrate that an iterative approach to protocol development for an unprecedented procedure allows for a comprehensive understanding of the challenges that a transfer to the PLS-system could bring.Conclusions:Using medical simulation during the early phase development process of the PLS-system allows us to train and validate novel practices, in particular the transfer procedure. With the demonstrated approach we aim to establish a thorough simulation protocol by providing a step-by-step plan, informed by literature and expert consultation. We expect to offer a realistic simulation training whilst also informing requirements for the future development of PLS-related devices and their validation
Mesons as qbar-q Bound States from Euclidean 2-Point Correlators in the Bethe-Salpeter Approach
We investigate the 2-point correlation function for the vector current. The
gluons provide dressings for both the quark self energy as well as the vector
vertex function, which are described consistently by the rainbow
Dyson-Schwinger equation and the inhomogeneous ladder Bethe-Salpeter equation.
The form of the gluon propagator at low momenta is modeled by a 2-parameter
ansatz fitting the weak pion decay constant. The quarks are confined in the
sense that the quark propagator does not have a pole at timelike momenta. We
determine the ground state mass in the vector channel from the Euclidean time
Fourier transform of the correlator, which has an exponential falloff at large
times. The ground state mass lies around 590 MeV and is almost independent of
the model form for the gluon propagator. This method allows us to stay in
Euclidean space and to avoid analytic continuation of the quark or gluon
propagators into the timelike region.Comment: 21 pages (REVTEX), 8 Postscript figure
Electromagnetic form factors of light vector mesons
The electromagnetic form factors G_E(q^2), G_M(q^2), and G_Q(q^2), charge
radii, magnetic and quadrupole moments, and decay widths of the light vector
mesons rho^+, K^{*+} and K^{*0} are calculated in a Lorentz-covariant,
Dyson-Schwinger equation based model using algebraic quark propagators that
incorporate confinement, asymptotic freedom, and dynamical chiral symmetry
breaking, and vector meson Bethe-Salpeter amplitudes closely related to the
pseudoscalar amplitudes obtained from phenomenological studies of pi and K
mesons. Calculated static properties of vector mesons include the charge radii
and magnetic moments: r_{rho+} = 0.61 fm, r_{K*+} = 0.54 fm, and r^2_{K*0} =
-0.048 fm^2; mu_{rho+} = 2.69, mu_{K*+} = 2.37, and mu_{K*0} = -0.40. The
calculated static limits of the rho-meson form factors are similar to those
obtained from light-front quantum mechanical calculations, but begin to differ
above q^2 = 1 GeV^2 due to the dynamical evolution of the quark propagators in
our approach.Comment: 8 pages of RevTeX, 5 eps figure
Analytic reproducibility in articles receiving open data badges at the journal <i>Psychological Science</i>: an observational study
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