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The Wisconsin Twin Project comprises multiple longitudinal studies that span infancy to early adulthood. We summarize recent papers that show how twin designs with deep phenotyping, including biological measures, can inform questions about phenotypic structure, etiology, comorbidity, heterogeneity, and gene–environment interplay of temperamental constructs and mental and physical health conditions of children and adolescents. The general framework for investigations begins with rich characterization of early temperament and follows with study of experiences and exposures across childhood and adolescence. Many studies incorporate neuroimaging and hormone assays.
Filamentary structures can form within the beam of protons accelerated during the interaction of an intense laser pulse with an ultrathin foil target. Such behaviour is shown to be dependent upon the formation time of quasi-static magnetic field structures throughout the target volume and the extent of the rear surface proton expansion over the same period. This is observed via both numerical and experimental investigations. By controlling the intensity profile of the laser drive, via the use of two temporally separated pulses, both the initial rear surface proton expansion and magnetic field formation time can be varied, resulting in modification to the degree of filamentary structure present within the laser-driven proton beam.
To examine neonatal risk factors associated with recurrent Staphylococcus aureus colonization and to determine the genetic relatedness of S. aureus strains cultured from neonates before and after decolonization.
Single-center retrospective cohort study of neonates admitted to the neonatal intensive care unit (NICU) from April 2013 to December 2015, during which weekly nasal cultures from hospitalized NICU patients were routinely obtained for S. aureus surveillance.
Johns Hopkins Hospital’s 45-bed level IV NICU in Baltimore, Maryland.
Demographics and clinical data were collected on all neonates admitted to the NICU with S. aureus nasal colonization who underwent mupirocin-based decolonization during the study period. A decolonized neonate was defined as a neonate with ≥1 negative culture after intranasal mupirocin treatment. Pulsed-field gel electrophoresis was used for strain typing.
Of 2,060 infants screened for S. aureus, 271 (13%) were colonized, and 203 of these 271 (75%) received intranasal mupirocin. Of those treated, 162 (80%) had follow-up surveillance cultures, and 63 of these 162 infants (39%) developed recurrent colonization after treatment. The S. aureus strains were often genetically similar before and after decolonization. The presence of an endotracheal tube or nasal cannula/mask was associated with an increased risk of recurrent S. aureus colonization (hazard ratio [HR], 2.65; 95% confidence interval [CI], 1.19–5.90; and HR, 2.21; 95% CI, 1.02–4.75, respectively).
Strains identified before and after decolonization were often genetically similar, and the presence of invasive respiratory devices increased the risk of recurrent S. aureus nasal colonization in neonates. To improve decolonization efficacy, alternative strategies may be needed.
The ideal sampling method and benefit of qualitative versus quantitative culture for carbapenem-resistant Enterobacteriaceae (CRE) recovery in hospitalized patient rooms and bathrooms is unknown. Although the use of nylon-flocked swabs improved overall gram-negative organism recovery compared with cellulose sponges, they were similar for CRE recovery. Quantitative culture was inferior and unrevealing beyond the qualitative results.
Recent analysis pointed towards visual imaging analysis (VIA), which yields pig body size measures and shape indices from two-dimensional visual images of living pigs, as a potential technique for estimating fat and lean content in pig carcasses (Doeschl et al., 2004). The present analysis further explored the potential of using VIA body size and shape indices as indicators of the proportion of lean and fat in various carcass joints, either alone or in combination with ultrasonic backfat depth of the live animal. Due to increasing interest in the shape of retail cuts in the meat industry, the association between VIA size measures and the dimensions of the longissimus dorsi and gluteobiceps muscles is also assessed.
The weak thermal emission from the largest minor planets can be detected in the microwave regime by the Very Large Array (VLA). Signal-to-noise ratios are sufficiently high to permit precise measurement of the positions of these objects at all points in their orbits with respect to background extragalactic sources. We are in the process of obtaining observations of astrometric accuracy for minor planets 1 Ceres, 2 Pallas, 4 Vesta, and 10 Hygeia.
Minor planets have historically served as “test particles” in the solar system, and optical observations of these objects have been valuable in the determination of fundamental astronomical constants. In particular, optical observations of minor planets have played an important role in the establishment of the fundamental optical reference frame by permitting the determination of the orientation of the Earth's orbit relative to the stars defining the frame.
Similarly, radio observations of these bodies can play a corresponding role in the establishment of a fundamental radio reference frame. Our observations will provide a direct link between the dynamical and radio reference frames, and provide important information on the relationship between the radio and optical reference frames.
The collective response of electrons in an ultrathin foil target irradiated by an ultraintense (
) laser pulse is investigated experimentally and via 3D particle-in-cell simulations. It is shown that if the target is sufficiently thin that the laser induces significant radiation pressure, but not thin enough to become relativistically transparent to the laser light, the resulting relativistic electron beam is elliptical, with the major axis of the ellipse directed along the laser polarization axis. When the target thickness is decreased such that it becomes relativistically transparent early in the interaction with the laser pulse, diffraction of the transmitted laser light occurs through a so called ‘relativistic plasma aperture’, inducing structure in the spatial-intensity profile of the beam of energetic electrons. It is shown that the electron beam profile can be modified by variation of the target thickness and degree of ellipticity in the laser polarization.
In the 1928 report of this Commission, reference was made to differences in the specifications for the production of the red cadmium line adopted by the International Conference of Weights and Measures in 1927 and by the International Astronomical Union in 1925. The difference appears to have arisen mainly from the inadvertent adherence of the International Conference to the text of the provisional recommendation of the Commission on Wave-lengths (Tr. I.A.U. 2, 47) instead of to that finally adopted (p. 232).
The president calls attention to the large and increasing membership of Commission 12 and the policy of concentrating in it all matters relating to the sun. The result makes it comparable in breadth of field and in membership to the former Union for Co-operation in Solar Research. The main point in favour of this policy is the increased interest in the meetings of the Commission and the larger number of individuals reached compared with the meetings of small committees. One recalls the general sessions of the Solar Union in which each one present felt himself a part of the Union and in real touch with the work of different sections and after the discussions went away with fuller knowledge of what it was all about. This was a valuable result not attained to the same degree from the general sessions of the present Union, but in a measure it does follow from the meetings of the Solar Physics Committee. On the other hand the question may be raised whether or not the merging of independent commissions into subdivisions of a large commission lessens their interest to an extent not balanced by the advantages. If the present policy holds, it seems to the president that a re-organisation of Commission 12 is advisable by which more responsibility is laid upon the directors of centres. The basis of membership in the Commission may well be considered and recommendations formulated for transmission to the Executive Committee.
The majority of the members of the Commission have been good enough to send in full reports regarding subjects of interest to this Commission. Extracts from them relating to questions which may be the subject of useful discussion at the forthcoming meeting in Paris are given below; references to research undertaken during the last three years, particulars of which are readily available in recent astronomical publications, are omitted.
At the first meeting of the newly formed Commission on Spectrophotometry, at Paris in 1935, a thorough discussion, aided by several reports, took place on the principles of this branch of astrophysics. So it will be sufficient now to treat only such special points of theory and practice as have won interest by researches of the last few years.
To determine the prevalence and acquisition of extended-spectrum β-lactamases (ESBLs), plasmid-mediated AmpCs (pAmpCs), and carbapenemases (“MDR Enterobacteriaceae”) colonizing children admitted to a pediatric intensive care unit (PICU).
Admission and weekly thereafter rectal surveillance swabs were collected on all pediatric patients during a 6-month study period. Routine phenotypic identification and antibiotic susceptibility testing were performed. Enterobacteriaceae displaying characteristic resistance profiles underwent further molecular characterization to identify genetic determinants of resistance likely to be transmitted on mobile genetic elements and to evaluate relatedness of strains including DNA microarray, multilocus sequence typing, repetitive sequence-based PCR, and hsp60 sequencing typing.
Evaluating 854 swabs from unique children, the overall prevalence of colonization with an MDR Enterobacteriaceae upon admission to the PICU based on β-lactamase gene identification was 4.3% (n=37), including 2.8% ESBLs (n=24), 1.3% pAmpCs (n=11), and 0.2% carbapenemases (n=2). Among 157 pediatric patients contributing 603 subsequent weekly swabs, 6 children (3.8%) acquired an incident MDR Enterobacteriaceae during their PICU stay. One child acquired a pAmpC (E. coli containing blaDHA) related to an isolate from another patient.
Approximately 4% of children admitted to a PICU were colonized with MDR Enterobacteriaceae (based on β-lactamase gene identification) and an additional 4% of children who remained in the PICU for at least 1 week acquired 1 of these organisms during their PICU stay. The acquired MDR Enterobacteriaceae were relatively heterogeneous, suggesting that a single source was not responsible for the introduction of these resistance mechanisms into the PICU setting.
Staphylococcus aureus is a common cause of healthcare-associated infections in neonates.
To examine the impact of methicillin-susceptible S. aureus (MSSA) decolonization on the incidence of MSSA infection and to measure the prevalence of mupirocin resistance.
We retrospectively identified neonates admitted to a tertiary care neonatal intensive care unit (NICU) from April 1, 2011, through September 30, 2014. We compared rates of MSSA-positive cultures and infections before and after implementation of an active surveillance culture and decolonization intervention for MSSA-colonized neonates. We used 2 measurements to identify the primary outcome, NICU-attributable MSSA: (1) any culture sent during routine clinical care that grew MSSA and (2) any culture that grew MSSA and met criteria of the National Healthcare Safety Network’s healthcare-associated infection surveillance definitions. S. aureus isolates were tested for mupirocin susceptibility. We estimated incidence rate ratios using interrupted time-series models.
Before and after the intervention, 1,523 neonates (29,220 patient-days) and 1,195 neonates (22,045 patient-days) were admitted to the NICU, respectively. There was an immediate reduction in the mean quarterly incidence rate of NICU-attributable MSSA-positive clinical cultures of 64% (incidence rate ratio, 0.36 [95% CI, 0.19–0.70]) after implementation of the intervention, and MSSA-positive culture rates continued to decrease by 21% per quarter (incidence rate ratio, 0.79 [95% CI, 0.74–0.84]). MSSA infections also decreased by 73% immediately following the intervention implementation (incidence rate ratio, 0.27 [95% CI, 0.10–0.79]). No mupirocin resistance was detected.
Active surveillance cultures and decolonization may be effective in decreasing S. aureus infections in NICUs.
Infect. Control Hosp. Epidemiol. 2016;37(4):381–387
Combination antibiograms can be used to evaluate organism cross-resistance among multiple antibiotics. As combination therapy is generally favored for the treatment of carbapenemase-producing Enterobacteriaceae (CPE), combination antibiograms provide valuable information about the combination of antibiotics that achieve the highest likelihood of adequate antibiotic coverage against CPE.
Infect. Control Hosp. Epidemiol. 2015;36(12):1458–1460
Clostridium difficile infection (CDI) in hospitalized patients is generally attributed to the current stay, but recent studies reveal high C. difficile colonization rates on admission.
To determine the rate of colonization with toxigenic C. difficile among intensive care unit patients upon admission as well as acquired during hospitalization, and the risk of subsequent CDI.
Prospective cohort study from April 15 through July 8, 2013. Adults admitted to an intensive care unit within 48 hours of admission to the Johns Hopkins Hospital, Baltimore, Maryland, were screened for colonization with toxigenic C. difficile. The primary outcome was risk of developing CDI.
Among 542 patients, 17 (3.1%) were colonized with toxigenic C. difficile on admission and an additional 3 patients were found to be colonized during hospitalization. Both colonization with toxigenic C. difficile on admission and colonization during hospitalization were associated with an increased risk for development of CDI (relative risk, 10.29 [95% CI, 2.24–47.40], P=.003; and 15.66 [4.01–61.08], P<.001, respectively). Using multivariable analysis, colonization on admission and colonization during hospitalization were independent predictors of CDI (relative risk, 8.62 [95% CI, 1.48–50.25], P=.017; and 10.93 [1.49–80.20], P=.019, respectively), while adjusting for potential confounders.
In intensive care unit patients, colonization with toxigenic C. difficile is an independent risk factor for development of subsequent CDI. Further studies are needed to identify populations with higher toxigenic C. difficile colonization rates possibly benefiting from screening or avoidance of agents known to promote CDI.
Infect. Control Hosp. Epidemiol. 2015;36(11):1324–1329