Bacterial Colonization of Toys in Neonatal Intensive Care Cots

Objectives. To investigate the bacteria and fungi contaminating toys in neonatal intensive care unit (NICU) cots, the colonization rates, and factors that influence them. Methods. A cross-sectional, longitudinal bacteriologic survey of all toys in the cots of infants in an NICU. All the toys in an infant's cot were cultured weekly for 4 weeks. Data were collected on the infant's postnatal age, the type of cot, whether humidity was added, characteristics of the toy, and any infant infections. Results. Over the 4-week period, there were 86 cultures from 34 toys of 19 infants. Bacteria were grown from 84/86 (98%): 84 of the cultures grew coagulase-negative Staphylococcus, 50 Micrococcus sp, 21 Bacillus sp, 13 methicillin-resistant Staphylococcus aureus, 12 diphtheroids, 4 group B streptococcus, 3 S aureus, 3 nonhemolytic streptococci, 3 group D streptococci, 4 -hemolytic streptococci, and 2 coliforms. None grew fungi. The colonization rate did not differ with cot type, presence of humidity, size of the toy, toy fiber length, or the fluffiness score. Eight (42%) of the infants had positive blood culture results and 5/8 of the isolates (63%) were of the same type as that colonizing their corresponding toy. Implications. With time, all the toys in NICU cots became colonized with bacteria. Many were potentially pathogenic. Toys may be reservoirs for potential infantile nosocomial sepsis

Two Randomized Trials Provide No Consistent Evidence for Nonmusical Cognitive Benefits of Brief Preschool Music Enrichment

Young children regularly engage in musical activities, but the effects of early music education on children’s cognitive development are unknown. While some studies have found associations between musical training in childhood and later nonmusical cognitive outcomes, few randomized controlled trials (RCTs) have been employed to assess causal effects of music lessons on child cognition and no clear pattern of results has emerged. We conducted two RCTs  with preschool children investigating the cognitive effects of a brief series of music classes, as  compared to a similar but non-musical form of arts instruction (visual arts classes, Experiment 1) or to a no-treatment control (Experiment 2). Consistent with typical preschool arts enrichment programs, parents attended classes with their children, participating in a variety of developmentally appropriate arts activities. After six weeks of class, we assessed children’s skills  in four distinct cognitive areas in which older arts-trained students have been reported to excel: spatial-navigational reasoning, visual form analysis, numerical discrimination, and receptive vocabulary. We initially found that children from the music class showed greater spatial-navigational ability than did children from the visual arts class, while children from the visual arts class showed greater visual form analysis ability than children from the music class (Experiment 1). However, a partial replication attempt comparing music training to a no-treatment control failed to confirm these findings (Experiment 2), and the combined results of  the two experiments were negative: overall, children provided with music classes performed no better than those with visual arts or no classes on any assessment. Our findings underscore the need for replication in RCTs, and suggest caution in interpreting the positive findings from past studies of cognitive effects of music instruction.Psycholog

Energy densities of key prey species in the California Current Ecosystem

The energetic content of primary and secondary consumers is central to understanding ecosystem functioning, community assembly, and trophodynamics. However, these foundational data are often limited, especially for marine ecosystems. Here we report the energy densities of important prey species in the California Current Ecosystem. We investigated variation in energy density within and between species and explored potential underlying causes of these differences. Northern anchovy (Engraulis mordax) is the most energy dense of the species analyzed with a median value nearly twice as high as was found in krill (Euphausia pacifica and Thysanoessa spinifera). Relationships with body size varied among species; krill energy density increased, with both length and wet weight. In addition, we find that anchovy, sardine (Sardinops sagax), and market squid (Doryteuthis opalescens) have higher energy content in the summer and fall as compared to the spring. This aligns with the ecosystem phenology of strong upwelling during spring (March – May) driving high primary productivity, followed by widespread predator presence through the summer and fall (June – October). Our results inform food web studies in the California Current and suggest new avenues for investigating differences in species and ecosystem energetics in an era of rapid global change

An adjuvant free mouse model of oral allergenic sensitization to rice seeds protein

<p>Abstract</p> <p>Background</p> <p>Rice is commonly known as a staple crop consumed worldwide, though with several rice proteins being reported for allergic properties in clinical studies. Thus, there is a growing need for the development of an animal model to better understand the allergenicity of rice proteins and the immunological and pathophysiological mechanisms underlying the development of food allergy.</p> <p>Methods</p> <p>Groups of BALB/c mice were sensitized daily with freshly homogenized rice flour (30 mg or 80 mg) without adjuvant by intragastric gavage. In addition, the mice were challenged with extracted rice flour proteins at several time points intragastrically. Hypersensitivity symptoms in mice were evaluated according to a scoring system. Vascular leakage, ELISA of rice protein-specific IgE, histopathology of small intestine, and passive cutaneous anaphylaxis were conducted on challenged mice.</p> <p>Results</p> <p>An adjuvant free mouse model of rice allergy was established with sensitized mice showing increased scratching behaviors and increased vascular permeability. Rice protein-specific IgE was detected after eighteen days of sensitization and from the fifth challenge onwards. Inflammatory damage to the epithelium in the small intestine of mice was observed beyond one month of sensitization. Passive cutaneous anaphylaxis results confirmed the positive rice allergy in the mouse model.</p> <p>Conclusions</p> <p>We introduced a BALB/c mouse model of rice allergy with simple oral sensitization without the use of adjuvant. This model would serve as a useful tool for further analysis on the immunopathogenic mechanisms of the various rice allergens, for the evaluation of the hypersensitivity of rice or other cereal grains, and to serve as a platform for the development of immunotherapies against rice allergens.</p

In-situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. A unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. Birefringent light propagation has been examined as a possible explanation for this effect. The predictions of a first-principles birefringence model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties do not only include the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube LED calibration data, the theory and parametrization of the birefringence effect, the fitting procedures of these parameterizations to experimental data as well as the inferred crystal properties.</p

In situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole. It uses 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. An unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. We examine birefringent light propagation through the polycrystalline ice microstructure as a possible explanation for this effect. The predictions of a first-principles model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties include not only the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empirical corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the experimental signature of ice optical anisotropy observed in IceCube light-emitting diode (LED) calibration data, the theory and parameterization of the birefringence effect, the fitting procedures of these parameterizations to experimental data, and the inferred crystal properties.Peer Reviewe