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This manuscript explores the topological and optical properties of a Passeriformes bird feather. Inside the feather, the layers of keratin and melanin are responsible for light reflection, transmission, and absorption; notably, the miniature composition of melanosome barbules plays a crucial role in its reflective properties. We adopted a multilayer interference model to investigate light propagation throughout the Passeriformes plume. As a result, we obtained all necessary simulated results, such as resonance band, efficiency, and electromagnetic radiation patterns of the Passeriformes plume, and they were verified with the experimental results reported in the literature study regarding light reflectivity through its internal geometry. Interestingly, we discovered that the interior structure of the Passeriformes plume functions similarly to a UV reflector antenna.

This descriptive cohort study describes the pilot project of a novel partnership between a university college of nursing and 2 low-income housing organizations serving older adults. The partnership allowed for the creation of onsite primary care clinics eliminating transportation as a barrier to care. Data from intake visits and medical record audits indicated this patient population had a higher prevalence of health disparities, such as more chronic conditions, medications, depression, anxiety, and isolation, than the general United States population older than 65 years. Further research is needed to understand patients’ decision to engage or not engage in services.

Latent class analysis (LCA) is a statistical procedure used to identify qualitatively different subgroups within populations who often share certain outward characteristics. The assumption underlying LCA is that membership in unobserved groups (or classes) can be explained by patterns of scores across survey questions, assessment indicators, or scales. The application of LCA is an active area of research and continues to evolve. As more researchers begin to apply the approach, detailed information on key considerations in conducting LCA is needed. In the present article, we describe LCA, review key elements to consider when conducting LCA, and provide an example of its application.

This study examined the relationship between youth health insurance status, insurance type (public versus private), and youths’ unmet health care needs. A secondary analysis was conducted using data from the 2016 National Survey of Children’s Health, a nationally representative, cross-sectional survey of U.S. youth. The sample included data from caregivers of 40,723 Hispanic, non-Hispanic black, and non-Hispanic white youth (0-17 years old) and was 49% female. Mplus 8.2 was used and statistical models accounted for the complex survey design. Using unweighted and weighted descriptive statistics and weighted probit regression models, we found that youth without health insurance were significantly more likely to have unmet health care needs compared to those with either public or private health insurance. We further found no statistically significant difference in unmet needs between youth with public and private health insurance. Our findings suggest that increased access to health insurance coverage, regardless of insurance type, may be an important policy focus when addressing youths’ unmet health care needs. Our findings can be used to guide future social work advocacy regarding health insurance policy.

Medical homes are an effective model of primary care. Historically, however, racial and ethnic minorities have not had equal access to medical homes. The present study estimated the national prevalence of youth’s access to a medical home and its components by race and ethnicity. We conducted secondary data analysis using the 2016–2017 National Survey of Children’s Health, a nationally representative, cross-sectional survey of U.S. youth age 0–17 years (N = 62,308). We obtained weighted and unweighted descriptive statistics and conducted multivariate logit regression models. Although 49% of the total sample had access to a medical home, 57.1% of white youth had access compared to 37% of Hispanic youth and 39.7% of black youth. Among youth without a medical home, black youth had less access than white youth to a usual place for care (64.7% vs. 55.3%, adjusted odds ratio [aOR] = 0.82, 95% confidence interval [CI] 0.69–0.97) and family-centered care (78.1% vs. 66.7%, aOR = 0.64, 95% CI 0.52–0.79). Hispanic youth (68.2%) also had less access to family-centered care than white youth (aOR = 0.73, 95% CI 0.60–0.89). White youth were less likely to have access to effective care coordination, when needed, than Hispanic youth (46.2% vs. 53.5%, aOR = 1.35, 95% CI 1.09–1.66). Our findings suggest racial/ethnic disparities exist in youth’s access to a medical home and its components. We posit the need for continued efforts to enhance access to medical homes for all youth. Future studies need to examine systemic barriers to youth’s access to medical homes.

The educational needs of current social work students have transitioned in time from fully face-to-face to hybrid and for some, to fully online instruction. This helps to address students’ need to ...

Polycystic ovary syndrome (PCOS) is a common condition affecting women of reproductive age. This disorder is characterized by hyperandrogenism and anovulation and is frequently associated with comorbidities such as infertility, metabolic syndrome, type 2 diabetes, and cardiovascular risk factors. Although the causes of PCOS are unknown, this review focuses on the most accepted theory involving insulin action but will also elaborate on a novel concept: the role of lipotoxicity in the development of androgen overproduction, in addition to its known role in insulin resistance. This review will also shed a spotlight on 2 drugs that target lipotoxicity and are, therefore, known or promising for the treatment of PCOS manifestations: peroxisome proliferator-activated receptor γ and angiotensin II type 2 receptor agonists. This paper, therefore, emphasizes the need to further explore the pathophysiology of PCOS and particularly the role of lipotoxicity. Indeed, this new mechanism deserves attention to develop therapeutic approaches that will directly target the root of this condition and not only bandage its associated consequences.

Polycystic ovary syndrome (PCOS) is a common condition affecting women of reproductive age. This disorder is characterized by hyperandrogenism and anovulation and is frequently associated with comorbidities such as infertility, metabolic syndrome, type 2 diabetes, and cardiovascular risk factors. Although the causes of PCOS are unknown, this review focuses on the most accepted theory involving insulin action but will also elaborate on a novel concept: the role of lipotoxicity in the development of androgen overproduction, in addition to its known role in insulin resistance. This review will also shed a spotlight on 2 drugs that target lipotoxicity and are, therefore, known or promising for the treatment of PCOS manifestations: peroxisome proliferator-activated receptor γ and angiotensin II type 2 receptor agonists. This paper, therefore, emphasizes the need to further explore the pathophysiology of PCOS and particularly the role of lipotoxicity. Indeed, this new mechanism deserves attention to develop therapeutic approaches that will directly target the root of this condition and not only bandage its associated consequences.

This paper presents a new compression scheme for interlaced stereoscopic sequences which differentiates between a region of fixation and a peripheral area, and thereby compacts the stereoscopic information into the spectral space of a monocular video channel. Spectral compression is achieved by avoiding transmitting high-frequency information over the entire images, but only within and around the region where the observer acuity is the highest. The proposed approach consists of decomposing the left and right fields of the stereoscopic pairs into low-pass and high-pass components. High-frequency components are then limited to a fixation region, thus allowing a reduction of their spectral extent. A composite video signal is then formed by positioning the different components into the available spectral space through filtering and modulation. The approach is compatible with the NTSC standard in the sense that the same color subcarrier and the same spectral region are used for the chrominance components. Strategies are proposed for the estimation of the fixation region, based upon a psychophysical study on visual strategies during depth discrimination tasks.

Diagnosis of iron deficiency in hemodialysis patients is limited by the inaccuracy of commonly used tests. Reticulocyte hemoglobin content (CHr) is a test that has shown promise for improved diagnosis in preliminary studies. The purpose of this study was to compare iron management guided by serum ferritin and transferrin saturation to management guided by CHr.A total of 157 hemodialysis patients from three centers were randomized to iron management based on (group 1) serum ferritin and transferrin saturation, or (group 2) CHr. Patients were followed for six months. Treatment with intravenous iron dextran, 100 mg for 10 consecutive treatments was initiated if (group 1) serum ferritin100 ng/mL or transferrin saturation20%, or (group 2) CHr29 pg.There was no significant difference between groups in the final mean hematocrit or epoetin dose. The mean weekly dose of iron dextran was 47.7 +/- 35.5 mg in group 1 compared to 22.9 +/- 20.5 mg in group 2 (P = 0.02). The final mean serum ferritin was 399.5 +/- 247.6 ng/mL in group 1 compared to 304.7 +/- 290.6 ng/mL in group 2 (P0.05). There was no significant difference in final TSAT or CHr. Coefficient of variation was significantly lower for CHr than serum ferritin and transferrin saturation (3.4% vs. 43.6% and 39.5%, respectively).CHr is a markedly more stable analyte than serum ferritin or transferrin saturation, and iron management based on CHr results in similar hematocrit and epoetin dosing while significantly reducing IV iron exposure.

In this paper, we present work that started as an interest in visual consciousness with the study of the blindsight phenomena and color processing. This led us to develop an intraocular reflection and absorption model of the human eye that is sufficient to account for luminance and color detection in blindsight subjects. Luminance and color thresholds were obtained in the good and blind field of hemidecorticated patients under controlled conditions. To determine the role of internal scatter and absorption properties of the human eye we tested the model predictions in three ways. By psychophysical means, by measuring absorption and scatter properties of the human eye, and by building an electromechanical sensor apparatus mimicking Lambertian reflection in the eye. The results of the simulations and measurements support the notion that the sensitivity functions obtained with the hemidecorticated patients can be explained by reflection and absorption properties of the human eye that have not been fully accounted for in the blindsight literature. In the light of such findings, future blindsight experiments must necessarily account for intraocular absorption and reflective properties of the human eye of the type described.

Our laboratory previously showed that thalamic neurons in an extrageniculate nucleus, the lateral posterior-pulvinar complex (LP-pulvinar) could perform higher-order neuronal operations that had until then only been attributed to higher-level cortical areas. To further assess the role of the thalamus in the analysis of complex percepts, we have investigated whether neurons in the LP-pulvinar complex can signal the direction of motion of random-dot kinematograms wherein the individual elements of the pattern do not provide coherent motion cues. Our results indicate that a subset of LP-pulvinar cells can integrate the displacement of individual elements into a global motion percept and that their large receptive fields permit the integration of motion for elements separated by large spatial intervals. We also found that almost all of the global motion-sensitive neurons were not systematically pattern-motion-selective when tested with plaid patterns. The results indicate that LP-pulvinar cells can perform the higher-level spatio-temporal integration required to detect the global displacement of objects in a complex visual scene, further supporting the notion that extrageniculate thalamic cells are involved in higher-order motion processing. Furthermore, these results provide some evidence that there may be specialized mechanisms for processing different types of complex motion within the LP-pulvinar complex.

A number of recent studies have explored the role of the chromatic system in motion processes using the isoluminance paradigm. A major concern when using such methodological procedures is potential artefacts produced by chromatic aberrations. In the present study we address the problem of optically induced luminance artefacts produced by transverse chromatic aberrations (TCA), which may contaminate the results obtained in chromatic motion-nulling experiments. Results show that different TCA levels artificially increase chromatic motion sensitivity values to varying degrees above 0.5 cpd for red/green gratings. The data also suggest the notion that naturally occurring TCA can decrease motion-nulling thresholds for chromatic gratings at high spatial frequencies. Furthermore, our data show that the motion-nulling paradigm for chromatic gratings may in fact be an efficient functional method for assessing the amount of TCA produced by optical factors.

The sensory, perceptual, and visual short-term memory (VSTM) capacity of young and older observers for processing luminance-defined shape information was assessed in a series of experiments. The following were assessed: each individual's threshold necessary to detect a square from its background as measured by luminance thresholds; the capacity for making simultaneous size discriminations when compensating for individual differences in sensory input; the capacity for making sequential size discriminations; and the capacity for remembering size differences over time. The results show a selective deficit for simultaneous perceptual processing for older subjects, which cannot be attributed to differences in sensory input, task difficulty, interhemispheric transfer, or VSTM.

The goal of this study was to evaluate the effect of ophthalmic lens-induced transverse chromatic aberrations (TCA) in natural viewing conditions on spatio-temporal thresholds. Three psychophysical experiments were performed; the first isolating the spatial component, the second isolating the temporal component and the third assessing spatio-temporal combinations. Taken together, the results show that TCA has profound effects on medium to high spatial frequencies (above 1 cpd) consistent with previous studies, and that the ratio of deficit TCA/blur can be higher than 2:1 for equivalent dioptric strengths. Furthermore, the results of Experiment 1 and 3 taken together show that the relative sensitivity loss caused by TCA can differ significantly between individuals and that a possible factor for this differential loss is the overall baseline spatio-temporal sensitivity profile of the individual.

The purpose of the study was to investigate the role of subcortical processing in human visual attention. The midbrain contribution to visual attention is unclear. Although evidence exists for a subcortical attentional advantage in ocular motor tasks, such an advantage has not been shown in perceptual tasks. Because retinotectal projections arise predominantly from nasal retina (i.e., temporal hemifield), subcortical attention should be distributed asymmetrically for monocular viewing conditions with an advantage to the temporal hemifield.To test for a subcortical attentional effect, the authors compared the results of binocular and monocular viewing conditions using the split priming motion induction paradigm. In this perceptual attention paradigm, priming cues are presented to the left and right of fixation followed by an instantaneously presented horizontal bar. As a result of attention to the priming cues, motion is perceived within the bar as it appears to draw in from the two lateral cues toward a central collision point. Asymmetrically distributed attention results in an asymmetry in the perception of motion within the bar, and thus the perceived collision point will be shifted away from the center.In two separate studies, one with and one without control of eye movements, the authors found significant differences between the results for monocular and binocular presentation. When the stimulus configuration is presented to the left eye, the perceived collision point is shifted toward the center consistent with a subcortical attentional effect. However, presentation of the stimulus configuration to the right eye yields the same results as those of binocular presentation.This pattern of results can be explained by a separate and additive interaction between cortical and subcortical attentional effects in the visual field. Dominance of the left visual field for cortical attention and dominance of the temporal visual field for subcortical attention act together when the initial priming cue occurs in the temporal (left) visual field of the left eye. However, these influences compete when the same stimulus configuration is presented to the right eye, where cortical attention predominates in the left visual field and subcortical attention predominates in the temporal (right) visual field.