Assessment of Ambient Air Toxics and Wood Smoke Pollution among Communities in Sacramento County.

Ambient air monitoring and phone survey data were collected in three environmental justice (EJ) and three non-EJ communities in Sacramento County during winter 2016-2017 to understand the differences in air toxics and in wood smoke pollution among communities. Concentrations of six hazardous air pollutants (HAPs) and black carbon (BC) from fossil fuel (BCff) were significantly higher at EJ communities versus non-EJ communities. BC from wood burning (BCwb) was significantly higher at non-EJ communities. Correlation analysis indicated that the six HAPs were predominantly from fossil fuel combustion sources, not from wood burning. The HAPs were moderately variable across sites (coefficient of divergence (COD) range of 0.07 for carbon tetrachloride to 0.28 for m- and p-xylenes), while BCff and BCwb were highly variable (COD values of 0.46 and 0.50). The BCwb was well correlated with levoglucosan (R2 of 0.68 to 0.95), indicating that BCwb was a robust indicator for wood burning. At the two permanent monitoring sites, wood burning comprised 29-39% of the fine particulate matter (PM2.5) on nights when PM2.5 concentrations were forecasted to be high. Phone survey data were consistent with study measurements; the only significant difference in the survey results among communities were that non-EJ residents burn with indoor devices more often than EJ residents.

Measuring Spatial and Temporal PM2.5 Variations in Sacramento, California, Communities Using a Network of Low-Cost Sensors.

Low-cost sensors can provide insight on the spatio-temporal variability of air pollution, provided that sufficient efforts are made to ensure data quality. Here, 19 AirBeam particulate matter (PM) sensors were deployed from December 2016 to January 2017 to determine the spatial variability of PM2.5 in Sacramento, California. Prior to, and after, the study, the 19 sensors were deployed and collocated at a regulatory air monitoring site. The sensors demonstrated a high degree of precision during all collocated measurement periods (Pearson R2 = 0.98 - 0.99 across all sensors), with little drift. A sensor-specific correction factor was developed such that each sensor reported a comparable value. Sensors had a moderate degree of correlation with regulatory monitors during the study (R2 = 0.60 - 0.68 at two sites). In a multi-linear regression model, the deviation between sensor and reference measurements of PM2.5 had the highest correlation with dew point and relative humidity. Sensor measurements were used to estimate the PM2.5 spatial variability, finding an average pairwise coefficient of divergence of 0.22 and a range of 0.14 to 0.33, indicating mostly homogeneous distributions. No significant difference in the average sensor PM concentrations between environmental justice (EJ) and non-EJ communities (p value = 0.24) was observed.

Planned Out-of-Hospital Birth and Birth Outcomes.

BACKGROUND: The frequency of planned out-of-hospital birth in the United States has increased in recent years. The value of studies assessing the perinatal risks of planned out-of-hospital birth versus hospital birth has been limited by cases in which transfer to a hospital is required and a birth that was initially planned as an out-of-hospital birth is misclassified as a hospital birth. METHODS: We performed a population-based, retrospective cohort study of all births that occurred in Oregon during 2012 and 2013 using data from newly revised Oregon birth certificates that allowed for the disaggregation of hospital births into the categories of planned in-hospital births and planned out-of-hospital births that took place in the hospital after a woman's intrapartum transfer to the hospital. We assessed perinatal morbidity and mortality, maternal morbidity, and obstetrical procedures according to the planned birth setting (out of hospital vs. hospital). RESULTS: Planned out-of-hospital birth was associated with a higher rate of perinatal death than was planned in-hospital birth (3.9 vs. 1.8 deaths per 1000 deliveries, P=0.003; odds ratio after adjustment for maternal characteristics and medical conditions, 2.43; 95% confidence interval [CI], 1.37 to 4.30; adjusted risk difference, 1.52 deaths per 1000 births; 95% CI, 0.51 to 2.54). The odds for neonatal seizure were higher and the odds for admission to a neonatal intensive care unit lower with planned out-of-hospital births than with planned in-hospital birth. Planned out-of-hospital birth was also strongly associated with unassisted vaginal delivery (93.8%, vs. 71.9% with planned in-hospital births; P<0.001) and with decreased odds for obstetrical procedures. CONCLUSIONS: Perinatal mortality was higher with planned out-of-hospital birth than with planned in-hospital birth, but the absolute risk of death was low in both settings. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.).

Proteomic analysis of cervical vaginal fluid proteins among women in recurrent preterm labor.

OBJECTIVE: Proteomic analysis of four cervical-vaginal fluid (CVF) proteins to identify biomarkers of recurrent preterm birth (rPTB) in at-risk women prior to onset of preterm labor. METHODS: Nested case control study from 2007 to 2011 of women with prior spontaneous preterm birth(s) (PTB) who underwent serial CVF sampling. Mass spectrometry analysis was used and ELISA analysis was performed to validate candidates. RESULTS: 108 patients were enrolled and 10 cases and 20 gestational age matched controls were analyzed after exclusions. Of 748 CVF proteins identified, 72 had statistically significant (p < 0.05) expression differences and 38 were highly differentially expressed (p < 0.01). Four candidate proteins were abundant and involved in immune/inflammatory response, but ELISA analysis did not confirm altered expression patterns. CONCLUSION: The lack of confirmation of potential biomarkers identified by mass spectrometry and ELISA demonstrates the challenges of validating PTB biomarkers and suggests that a panel of biomarkers would improve the predictive value of CVF testing.

No evidence for directional biases in inhibition of return.

The phenomenon of "inhibition of return" (IOR) has been the subject of considerable research interest for nearly 30 years. Two reports claiming directional biases in IOR (Spalek & Hammad, Perception & Psychophysics 66:219-233, 2004, Psychological Science 16:15-18, 2005) were examined more closely, as such findings challenge the theoretical role attributed to IOR and imply that this purported mechanism for the facilitation of visual search would bias search in systematic ways. The data from two new experiments, as well as reanalysis of the original data, showed the reports to result from an unconventional method of calculating IOR that confounded visual field with target location. Although we found significant differences in target detection response times between the visual fields, directional biases were absent from all of the examined data when the conventional method of computing IOR was applied.

Knowing where we're heading--when nothing moves.

Past research indicates that observers rely strongly on flow-based and object-based motion information for determining egomotion or direction of heading. More recently, it has been shown that they also rely on displacement information that does not induce motion perception. As yet, little is known regarding the specific displacement cues that are used for heading estimation. In Experiment 1a, we show that the accuracy of heading estimates increases, as more displacement cues are available. In Experiments 1b and 2, we show that observers rely mostly on the displacement of objects and geometric cues for estimating heading. In Experiment 3, we show that the accuracy of detecting changes in heading when displacement cues are used is low. The results are interpreted in terms of two systems that may be available for estimating heading, one relying on movement information and providing navigational mechanisms, the other relying on displacement information and providing navigational planning and orienting mechanisms.

There's little return for attentional momentum.

Inhibition of return (IOR) refers to a delay in response time (RT) to targets appearing at a previously cued location. The prevailing view is that IOR reflects visual-motor inhibition. The "attentional momentum" account rejects this idea, and instead proposes that IOR reflects an automatic shift of attention away from the cued location resulting in slower RTs to targets presented there and speeded RTs to targets opposite the cue (an opposite facilitation effect or OFE). The drawback of this account is that J. J. Snyder, W. C. Schmidt, and A. Kingstone (2001) showed that there are few data to support the OFE, and no evidence that the OFE accounts for the IOR effect. Despite this evidence, several recent studies have promoted attentional momentum as a valid explanation for the IOR effect. Reanalysis of these recent studies and new data reveal, again, that IOR routinely occurs in the absence of the OFE, and when the OFE does occur, the IOR effect need not be present. This double dissociation invalidates attentional momentum as an explanation for the IOR effect. Extant data support an inhibitory explanation of the IOR effect.

The effects of treatment for posterior fossa brain tumors on selective attention.

We sought to identify whether deficits in selective attention are present in pediatric brain tumor patients. Selective attention was assessed with covert-orienting, filtering, and visual-search tasks in 54 patients with either (1) posterior fossa (PF) tumors treated with cranial radiation and surgery (n = 22); (2) PF tumors treated with surgery alone (n = 17); or (3) non-CNS tumors (n = 15), who served as a patient control group. To account for normal development, patient performance was also compared with that of healthy age-matched controls (n = 10). We found that in PF tumor patients selective attention was impaired, regardless of whether they were treated with cranial radiation and surgery or surgery alone. However, patients treated with cranial radiation were most impaired. These patients may have greater damage to posterior brain regions know to mediate selective attention as the result of tumor location, effects of surgery, and higher doses of radiation to the posterior regions of the brain. These findings help to elucidate the potential impact of pediatric brain tumors and their treatment on discrete attentional skills.

Role of the lateral prefrontal cortex in visual object-based selective attention.

We demonstrate that attention to object representations is vitally dependent on the prefrontal cortex. Object-based selective attention was compared in neurologic patients with unilateral damage to either the dorsolateral prefrontal cortex (DLPFC) or the parietal cortex and in healthy controls. Our task required a top-down attentional modulation of object representations in which spatial location played no role. All groups could invoke top-down object-based selection, but the DLPFC patients showed a selective deficit when target stimuli were in the hemifield contralateral to the lesioned hemisphere. Our findings indicate that in the healthy brain, anterior cortical mechanisms are crucial for attending to object-centered representations, whereas posterior cortical mechanisms are necessary for attending to objects at locations in the visual scene.

Inhibition of return: unraveling a paradox.

Although inhibition of return (IOR) is widely believed to aid search by discouraging reexamination of previously inspected locations, its impact actually appears to decline as the number of target locations increases. We test three possible reasons for this paradoxical result: (1) IOR is capacity-limited, (2) IOR is sensitive to subtle changes in target location probability, and (3) IOR decays with distance from a previously attended location. The present investigation provides strong support for the third explanation, indicating that a gradient of inhibition is centered on previously attended locations. We note that this inhibitory gradient resolves a paradox in the literature. Moreover, we speculate that the inhibitory gradient may reflect a "similarity space" within which target locations near to the cue are tagged with inhibition due to their similarity to the cued location. The farther the target location is away, the less similar it is to the cued location, and thus the less inhibition it receives.

The frontal cortex and exogenous attentional orienting.

Normal functioning of the attentional orienting system is critical for effective behavior and is predicated on a balanced interaction between goal-directed (endogenous) processes and stimulus-driven (exogenous) processes. Although both systems have been subject to much investigation, little is known about the neural underpinnings of exogenous orienting. In the present study, we examined the early facilitatory effects and later inhibition of return effects of exogenous cues in patients with frontal and parietal lesions. Three novel findings emerged from this study. First, unilateral frontoparietal damage appears not to affect the early facilitation effects of exogenous cues. Second, dorsolateral prefrontal damage, especially lesions involving the inferior frontal gyrus, produces an exogenous disengage deficit (i.e., the sluggish withdrawal of attention from the ipsilesional to the contralesional field). Third, a subset of patients with dorsolateral prefrontal damage, with lesions involving the middle frontal gyrus, have a reorienting deficit that extends in duration well beyond established boundaries of the normal reflexive orienting system. These results suggest that the dorsolateral prefrontal cortex plays an important role in exogenous orienting and that component processes of this system may be differentially impaired by damage to different parts of the dorsolateral prefrontal cortex.

Spatial-temporal anisometries following right parietal damage.

Patients with right parietal damage often have a lateralized deficit of spatial attention. In addition to a spatial deficit, such patients have also been reported to have a non-spatial deficit in temporal processing. Here, we tested the hypothesis that these spatial and temporal deficits might be linked if the right temporal-parietal cortex is important in integrating spatial and temporal attention. In AF, a patient with an acute right temporal-parietal stroke, we replicated previous observations showing that he was biased to judge ipsilesional stimuli as occurring before contralesional stimuli. More importantly, for vertically aligned stimuli, AF more accurately judged the temporal order of successive ipsilesional than contralesional stimuli. Furthermore, his contralesional performance improved with stimuli with larger vertical separations. Taken together, these findings provide additional evidence that right temporal-parietal damage produces a processing refractory period for stimuli in contralesional space that extends in both space and time. These findings are in agreement with other studies that suggest that the right temporal-parietal cortex is important in integrating the where and when of stimuli.