High-sensitivity electronic Stark spectrometer featuring a laser-driven light source.

We report developmental details of a high-sensitivity Stark absorption spectrometer featuring a laser-driven light source. The light source exhibits intensity fluctuations of ∼0.3% over timescales ranging from 1 min to 12 h, minimal drift (≤0.1%/h), and very little 1/f noise at frequencies greater than 200 Hz, which are comparable to or better than an arc-driven light source. Additional features of the spectrometer include balanced detection with multiplex sampling, which yielded lower noise in A, and constant wavelength or wavenumber (energy) spectral bandpass modes. We achieve noise amplitudes of ∼7 × 10-4 and ∼6 × 10-6 in measurements of single A and ΔA spectra (with 92 data points) taking ∼7 and ∼19 min, respectively.

Costs and savings of parenting interventions: results of a systematic review.

BACKGROUND: This systematic review of economic evaluations of universal preventative or targeted treatment parenting interventions that aim to enhance parent-infant interaction is primarily intended to inform decision makers who have to make difficult spending decisions, especially at a time of reduced spending allocations. A synthesis of available costs and savings about parenting interventions that set out to enhance parent-infant interaction is presented. This topic is important specifically in view of the UK Governments' emphasis on the equalities agenda and the early years. The benefits of positive early life experiences, which include good parent-infant interaction, are far reaching and may be positively correlated with improved educational, health and well-being outcomes and reduced criminality. METHODS: A literature search was undertaken using on-line indexing databases between 2004 and 2014 that included the search terms 'parent', 'infant', 'interaction', 'cost benefit analysis' and their synonyms. RESULTS: Despite existing economic studies generally focusing upon targeted short-run outcomes, significant savings were observed in the included studies. Parenting interventions could save the health service around £2.5k per family over 25 years and could save the criminal justice system over £145k per person over the life course. In light of the escalating costs of remedial services, these potential savings may provide the UK and other governments with a robust incentive to invest in early years parenting interventions. CONCLUSIONS: Parenting interventions can be economically efficient and return savings on investment. Moreover, and one might argue as a moral imperative of democratic societies, population health can be improved and health inequalities reduced. An important debate is needed about early years policy, to include acknowledgement of the differences between UK and international healthcare systems and the potential savings from the synergistic and spin-off effects of early years interventions to inform decision-making to fund and implement appropriate action.

Effects of dexamethasone on rat dendritic cell function.

Glucocorticoids have been reported to affect immunity at varying concentrations. While glucocorticoids have shown profound effects on innate immunity, their effects on rat dendritic cells have not been fully examined. In this study, we evaluated the effects of the synthetic glucocorticoid dexamethasone on cultured rat dendritic cells (DCs) from spleen and derived from bone marrow cells to determine whether responsiveness to dexamethasone varies between DCs from different organ sites. Cells were analyzed for expression of glucocorticoid receptor (GR), the primary receptor through which dexamethasone exerts its effects and was found to be primarily located in the cytoplasm of immature DCs. Bone marrow-derived DCs showed more sensitivity to dexamethasone treatment compared to splenic DCs. Dexamethasone treatment of LPS-matured DCs had profound dose-dependent effects on cytokine production. Dexamethasone treatment also led to a dose-dependent downregulation of expression of costimulatory molecules by mature DCs. Dexamethasone modified immature DC uptake of antigen (FITC-Dextran), with slightly higher numbers of splenic DCs taking up antigen compared to bone marrow-derived DCs. These data suggest that dexamethasone is able to similarly affect both bone marrow-derived and splenic DC function at the immature and mature DC states and could contribute to exacerbation of infection by hindering DC-mediated immune responses.

Global phylogeography of the scalloped hammerhead shark (Sphyrna lewini).

Large marine fishes typically have little population genetic structure. The exceptions are associated with sedentary behaviour, disjunct distributions, or reproductive philopatry. Scalloped hammerhead sharks (Sphyrna lewini) incorporate the contrasting traits of oceanic habitat (usually associated with high dispersal) and possible fidelity to nursery grounds (for reproductive females). To evaluate the expectations of these contrasting behaviours, we examined the global genetic structure of S. lewini based on collections (n = 271 individuals) from 20 nursery areas. A 548-bp fragment of mitochondrial DNA control region revealed 22 polymorphic sites, 24 haplotypes, and three lineages distinguished by 2.56-3.77% sequence divergence. Coalescence analyses based on a provisional molecular clock indicate an origin in the Indo-West Pacific with late Pleistocene radiations into the central Pacific (Hawaii) and eastern Pacific (Central America), as well as recent interchange between oceans via southern Africa. Population subdivisions are strong (overall Phi(ST) = 0.749, P < 0.0001 and among oceans Phi(ST) = 0.598, P < 0.0098). Genetic discontinuity within oceans (Phi(ST) = 0.519, P < 0.0001) is primarily associated with oceanic barriers (migration across oceans M approximately 0), with much less structure along continental margins (M > 10). We conclude that nursery populations linked by continuous coastline have high connectivity, but that oceanic dispersal by females is rare. Although we cannot rule out philopatry to natal nurseries, oceanic barriers appear to have a much stronger influence on the genetic architecture of this species and may indicate a mechanism for recent evolutionary radiations in the genus Sphyrna.

Alterations in the dynamics of semantic activation in Alzheimer's disease: evidence for the Gain/Decay hypothesis of a disorder of semantic memory.

While it has been commonly assumed that a deficit in semantic memory underlies many of the clinical and cognitive features of early Alzheimer's disease (AD), there has been little agreement on what constitutes a proper theoretical description of this impaired system. Currently, most theories of this disorder fall into two categories: those that posit degraded semantic representations, and those that posit impaired retrieval operations with relatively intact semantic representations. It is argued that each position has both empirical and logical disadvantages that have prevented the development of a consensus on how to describe the pathology of semantic memory in AD. In this paper we present the details and supportive evidence for an alternative account of the semantic memory deficit of AD: the Gain/Decay hypothesis. The core claim of the Gain/Decay hypothesis is that a reduction in the time constant of spreading activation in AD produces dynamic changes in the availability of semantic representations that depend on the time frame in which this information must be accessed. The implications of this hypothesis for a range of experimental and clinical phenomena are discussed, as are possible biological correlates of the hypothesized alterations in the modulation of activation.

Pediatric emergency department analgesic practice.

OBJECTIVE: To review recent acute pain management care issues in a pediatric emergency department (ED) in order to identify opportunities for a performance improvement program. DESIGN: Descriptive, retrospective chart review. SETTING: Urban pediatric hospital ED. PARTICIPANTS: Between January 1 and December 31, 1994 consecutive patients identified by ED chart review with the following three acute painful conditions were included; sickle cell vasoocclusive crisis (VOC) not complicated by fever or neurologic symptoms, isolated lower extremity long bone fractures < 12 hours old that did not require a reduction, and second degree burns < 12 hours old. Data collection concluded when between 50 and 55 episodes of each painful condition were identified. MAIN OUTCOME MEASURES: ED analgesic administration, initial analgesic dose, initial time elapsed to analgesic administration, notation of pain relief, and home analgesic instruction. Recommended analgesic starting doses were chosen from the 1992 Agency for Health Care Policy and Research Clinical Practice Guidelines. INTERVENTIONS: None. RESULTS: ED analgesic use for VOC was 100%, for fracture was 31%, and for burn was 26%. A recommended starting analgesic dose was given to 78% with VOC, 69% with fracture, and 79% with burn. Mean time to initial analgesic for VOC was 52 minutes, for fracture was 86 minutes, and for burn was 29 minutes. In those given analgesics, notation of pain relief for fracture was 19% and for burn was 29%, this improved for VOC where it was 88%. Home analgesic instruction for VOC was 100%, for fracture was 74%, and for burn was 27%. CONCLUSION: These data from 1994 document suboptimal analgesic use and home analgesic instruction for children in our ED with burns and fractures. Other opportunities in our ED for acute pain management improvement include optimizing initial analgesic doses, shortening the time elapsed to initial analgesic administration, and documenting the response to pain management.

A pilot study of the predictive value of plasma tumor necrosis factor alpha and interleukin 1 beta for Streptococcus pneumoniae bacteremia in febrile children.

OBJECTIVE: To determine the value of tumor necrosis factor alpha (TNF) and interleukin 1 beta (IL1) levels in predicting Streptococcus pneumoniae bacteremia in nontoxic-appearing, febrile children who do not have a bacterial source for their fever on physical examination. METHODS: A prospective, nested case-control study was conducted in a children's hospital ED. All febrile children < 3 years old who were believed to be immunocompetent and not in shock, had no obvious bacterial source for their fever on physical examination, and had a blood culture obtained were eligible. Plasma obtained at the time of the blood culture was available for analysis by enzyme-linked immunosorbent assays for TNF and IL1. Children who had positive blood cultures for Streptococcus pneumoniae were the cases. The controls were selected from children who had negative blood cultures. RESULTS: During a 1-year period, 12 cases and 65 controls were identified. There was no significant difference in age, height or duration of fever, or illness acuity between the groups. The following were used as threshold values for positive test: white blood cell (WBC) count > 15.0 x 10(9) cells/L, TNF > 21.5 ng/mL, and IL1 > 9.0 ng/mL. Using an estimated prior probability of bacteremia of 4%, the positive predictive value (PPV) and the negative predictive value (NPV) for bacteremia were 11.7% and 98.6% using the WBC count, 11.1% and 98.6% using the IL1 level, and 9.0% and 98.9% using the TNF level. The combination of WBC count with either TNF or IL1 gave an NPV of 100%, with PPVs of 8.5% for TNF and 9.9% for IL1. CONCLUSIONS: Like the WBC count, TNF and IL1 are good negative but poor positive predictors of Streptococcus pneumoniae bacteremia in nontoxic-appearing, febrile children. At present, the addition of plasma TNF or IL1 levels would add little to emergency physicians' ability to predict Streptococcus pneumoniae bacteremia. However, as the quantification of these cytokines becomes more rapid, available, and standardized, and more knowledge of TNF and IL1 levels during various illnesses is gained, their utility in the clinical setting for ruling out bacteremia should be further assessed.

A national survey of athletic trainer roles and responsibilities in the allied clinical setting.

Data collected from a survey instrument mailed to all 188 NATA-approved allied clinical setting directors were analyzed to assess the current levels of professional preparation as related to the NATA competencies, job roles, and responsibilities of certified athletic trainers in the allied clinical setting. The topics examined included specific roles and responsibilities of certified athletic trainers currently employed in an allied clinical setting. A response rate of 70.5% was obtained. Skills and services provided by the clinical ATC rated as very important were: evaluation, prevention, and rehabilitation/reconditioning of athletic injuries. Competency regarding recognition and evaluation received the highest relative importance score, which is consistent with the findings of the 1982 NATA Role Delineation Study and the 1991 NATA Validation Study. Educational preparation through NATA-approved curriculums had the highest importance in professional preparation for a career in athletic training. The data indicated that educational emphasis for athletic training students interested in employment in the nontraditional setting has diverged from the guidelines established in the 1982 Role Delineation Study. The results of this study suggest that students preparing for a career in a nontraditional (clinical) setting should focus on developing skills in athletic injury evaluation, rehabilitation and reconditioning, and prevention. While these results support findings of the 1982 Role Delineation Study, additional research is needed to address the levels of professional preparation as related to the NATA competencies, job roles, and responsibilities of the clinical athletic trainer.