The Effects of Aging on Orientation Discrimination

Visual perception relies on low-level encoding of local orientation. Recent studies show an age-dependent impairment in orientation discrimination of stimuli embedded in external noise, suggesting that encoding of orientation is inefficient in older adults. In the present study we ask whether aging also reduces decoding, i.e., selecting the neural representations of target orientation while discarding those conflicting with it. We compared younger and older participants capability (mean age 24 and 68 years respectively) in discriminating whether the orientation of a Gabor target was left or right from the vertical. We measured (d0), an index of discrimination sensitivity, for orientation offset ranging from 1 to 12. In the isolated target condition, d0 was reduced by aging and, in the older group, did not increase with orientation offset, thus resulting in a larger group difference at large than small orientation offsets from the vertical. Moreover, oriented elements in the background impaired more discrimination in the older group. However, distractors reduced more d0 when target-background orientation offset was large than when target and flanker had similar orientation, indicating that the effect of the background was not local, i.e., due to target inhibition by similarly oriented flankers. Altogether, these results indicate that aging reduces the efficiency in discarding the response to orientations differing from the target. Our results suggest that neural decision-making mechanisms, involving not only signal enhancement but also non-signal inhibition, become inefficient with age. This suggestion is consistent with the neurophysiological evidence of inefficient visual cortical inhibition in aging

Educational Implications of Spatial Memory

Spatial memory is recruited during many classroom-based activities. As such, it is essential for both educators and students to understand how it operates in a classroom context. This chapter begins by providing a systematic overview of how spatial memory is used across a variety of academic domains including math, language arts, and science. It also reviews some of the typical characteristics of students who have relatively poor spatial memory abilities. Finally, it discusses how to best provide efficacious classroom support for these students. Taken together, it provides an accessible overview of the educational implications of spatial memory that educators and students can consider when trying to optimize learning in their classrooms

Targeting Polymorphonuclear Leukocytes in Acute Myocardial Infarction

Several studies have recognized the strong impact that the acute myocardial infarctions (AMI) have on the morbidity and mortality of patients affected by cardiovascular diseases. Still open, however, is the field concerning the mediators and the pathways involved in the etiology of this cardiovascular event. The present review would support the relatively new discovered role that the polymorphonuclear leukocytes (PMNs) have in the pathogenesis of the AMI, through a brief analysis of past and ongoing research. Particularly, it is reviewed here the possibility that inhibition of the activity of PMNs and inhibition of the signaling pathways related to their activity may result useful in AMI and may improve the prognosis of this pathology. This review, indeed, presents and discusses new data on one of the lipid kinase, the phosphoinositide 3-kinase gamma (PI3Kγ), and its role in neutrophil recruitment during AMI

Relationship and predictive role of the dual expression of FGFR and IL-8 in metastatic renal cell carcinoma treated with targeted agents

Background/Aim: The expression of IL-8 and FGFR has been related to prognosis and pathological features in renal cell carcinoma. We investigated the relationship between IL-8 and FGFR and the outcome in metastatic renal cell carcinoma (mRCC) patients. Materials and Methods: Clinical data and histological samples of patients affected by mRCC and treated with targeted agents were reviewed. The expression of proteins was assessed using immunohistochemistry. Results: FGFR1, FGFR2, and IL-8 were found to be expressed in 16%, 30%, and 50% of cases, respectively. Significant correlations were found between selected proteins. A lack of expression of FGFR2 and IL8 was found to be correlated with increased progression-free survival (PFS). The survival rate at 24 months was 44%, 38%, and 79% of those expressing both, one, or none of the evaluated proteins, respectively (p=0.047). Conclusion: This analysis found a relationship between the expression of IL-8 and FGFR2 in mRCC patients treated with targeted agents

Compendio critico per la certificazione dei contratti di lavoro. I nuovi contratti: lavoro pubblico e lavoro privato

L’opera è primariamente indirizzata ad illustrare le problematiche sulle quali vertono le attività svolte dalle sedi di certificazione dei contratti di lavoro. Esse si incentrano, in particolare, sul ruolo di mediazione tra gli schemi formali predisposti dal legislatore e la complessità di una realtà negoziale in continua evoluzione, in coerenza con i radicali mutamenti intervenuti nei modi di organizzare il lavoro

Effects of Aging on Visual Contour Integration and Segmentation

PURPOSE. Perception of circular disconnected contours requires the integration of relevant local orientation information across space and the suppression of irrelevant orientations. Using a detection of deviation from circularity (DFC) task, the present study examined whether the efficiency of either integrative or suppressive visual mechanisms, or both, declines with age. METHODS. Younger and older observers' sensitivities in detecting the DFC of a contour formed by Gabors were compared in three conditions: when all elements were oriented tangentially to the contour, with and without the presence of randomly oriented background noise; and when they had alternated tangential and orthogonal orientations, without background noise. RESULTS. In agreement with previous studies, the authors found that younger observers were not impaired in the mixed condition with respect to the tangential condition, suggesting the involvement of a high-level mechanism responding to the global closure information provided by tangential local orientations, even if they are interspersed with orthogonal ones. Instead, older observers were specifically impaired in the mixed condition, suggesting a reduced capability of suppressing nontangential information along the contour, and were also less efficient in suppressing irrelevant orientations in the background. CONCLUSIONS. These results support the suggestion that, whereas integrative mechanisms are not affected by age, suppressive mechanisms are. (Invest Ophthalmol Vis Sci. 2011;52: 3955‐3961) DOI:10.1167/iovs.10-543

Fatigue Resistance of Liquid-assisted Self-repairing Aluminum Alloys Reinforced with Shape Memory Alloys

A self-repairing aluminum-based composite system has been developed using a liquid-assisted healing theory in conjunction with the shape memory effect of wire reinforcements. The metal-metal composite was thermodynamically designed to have a matrix with a relatively even dispersion of a low-melting eutectic phase, allowing for repair of cracks at a predetermined temperature. Additionally, shape memory alloy (SMA) wire reinforcements were used within the composite to provide crack closure. Investigators focused the research on fatigue cracks propagating through the matrix in order to show a proof-of-concept Shape Memory Alloy Self-Healing (SMASH) technology for aeronautical applications

Comfort and perceived air quality in refurbished social houses with mechanical ventialtion system: The impact of occupants behaviour

Abstract The ever-growing demand for a better indoor air quality in residential buildings is increasing the number of whole-house ventilation system installations in new constructions and renovation. In Italy, for residential sector, the national code does not prescribe the use of mechanical ventilation (MV) systems, so their installation is left to the choice of house owners. Two three-storey social housing apartment blocks in Northern Italy were studied. To reduce energy consumption, building envelopes as well as heating systems were refurbished. The thermal insulation was increased and the existing gas heater units were replaced with more efficient radiant ceiling systems. The refurbishment measures were the same for both constructions beside the MV system, which was installed in only one building. Indoor temperature and relative humidity were monitored for several apartments during the heating season. The occupants were surveyed to investigate their thermal comfort and perceived air quality. The occupants were interviewed to better understand their responses, and to know how they operate the heating system and the mechanical ventilation system (when present). Survey results show that there are no differences in terms of thermal comfort and perceived air quality between the occupants of the buildings with and without MV systems. The findings may be related to occupants' behaviour

Comfort and perceived air quality in refurbished social houses with mechanical ventilation system: The impact of occupants behaviour

The ever-growing demand for a better indoor air quality in residential buildings is increasing the number of whole-house ventilation system installations in new constructions and renovation. In Italy, for residential sector, the national code does not prescribe the use of mechanical ventilation (MV) systems, so their installation is left to the choice of house owners. Two three-storey social housing apartment blocks in Northern Italy were studied. To reduce energy consumption, building envelopes as well as heating systems were refurbished. The thermal insulation was increased and the existing gas heater units were replaced with more efficient radiant ceiling systems. The refurbishment measures were the same for both constructions beside the MV system, which was installed in only one building. Indoor temperature and relative humidity were monitored for several apartments during the heating season. The occupants were surveyed to investigate their thermal comfort and perceived air quality. The occupants were interviewed to better understand their responses, and to know how they operate the heating system and the mechanical ventilation system (when present). Survey results show that there are no differences in terms of thermal comfort and perceived air quality between the occupants of the buildings with and without MV systems. The findings may be related to occupants' behaviour. © 2015 The Authors

Perceptual learning improves contrast sensitivity, visual acuity, and foveal crowding in amblyopia

BACKGROUND: Amblyopic observers present abnormal spatial interactions between a low-contrast sinusoidal target and high-contrast collinear flankers. It has been demonstrated that perceptual learning (PL) can modulate these low-level lateral interactions, resulting in improved visual acuity and contrast sensitivity. OBJECTIVE: We measured the extent and duration of generalization effects to various spatial tasks (i.e., visual acuity, Vernier acuity, and foveal crowding) through PL on the target's contrast detection. METHODS: Amblyopic observers were trained on a contrast-detection task for a central target (i.e., a Gabor patch) flanked above and below by two high-contrast Gabor patches. The pre- and post-learning tasks included lateral interactions at different target-to-flankers separations (i.e., 2, 3, 4, 8λ) and included a range of spatial frequencies and stimulus durations as well as visual acuity, Vernier acuity, contrast-sensitivity function, and foveal crowding. RESULTS: The results showed that perceptual training reduced the target's contrast-detection thresholds more for the longest target-to-flanker separation (i.e., 8λ). We also found generalization of PL to different stimuli and tasks: contrast sensitivity for both trained and untrained spatial frequencies, visual acuity for Sloan letters, and foveal crowding, and partially for Vernier acuity. Follow-ups after 5-7 months showed not only complete maintenance of PL effects on visual acuity and contrast sensitivity function but also further improvement in these tasks. CONCLUSION: These results suggest that PL improves facilitatory lateral interactions in amblyopic observers, which usually extend over larger separations than in typical foveal vision. The improvement in these basic visual spatial operations leads to a more efficient capability of performing spatial tasks involving high levels of visual processing, possibly due to the refinement of bottom-up and top-down networks of visual areas