Street crossing behavior in younger and older pedestrians: an eye- and head-tracking study

BACKGROUND: Crossing a street can be a very difficult task for older pedestrians. With increased age and potential cognitive decline, older people take the decision to cross a street primarily based on vehicles' distance, and not on their speed. Furthermore, older pedestrians tend to overestimate their own walking speed, and could not adapt it according to the traffic conditions. Pedestrians' behavior is often tested using virtual reality. Virtual reality presents the advantage of being safe, cost-effective, and allows using standardized test conditions. METHODS: This paper describes an observational study with older and younger adults. Street crossing behavior was investigated in 18 healthy, younger and 18 older subjects by using a virtual reality setting. The aim of the study was to measure behavioral data (such as eye and head movements) and to assess how the two age groups differ in terms of number of safe street crossings, virtual crashes, and missed street crossing opportunities. Street crossing behavior, eye and head movements, in older and younger subjects, were compared with non-parametric tests. RESULTS: The results showed that younger pedestrians behaved in a more secure manner while crossing a street, as compared to older people. The eye and head movements analysis revealed that older people looked more at the ground and less at the other side of the street to cross. CONCLUSIONS: The less secure behavior in street crossing found in older pedestrians could be explained by their reduced cognitive and visual abilities, which, in turn, resulted in difficulties in the decision-making process, especially under time pressure. Decisions to cross a street are based on the distance of the oncoming cars, rather than their speed, for both groups. Older pedestrians look more at their feet, probably because of their need of more time to plan precise stepping movement and, in turn, pay less attention to the traffic. This might help to set up guidelines for improving senior pedestrians' safety, in terms of speed limits, road design, and mixed physical-cognitive trainings.

Robust indoor localization of narrowband signals

Many location-based services target users in indoor environments. Similar to the case of dense urban areas where many obstacles exist, indoor localization techniques suffer from outlying measurements caused by severe multipath propaga??tion and non-line-of-sight (NLOS) reception. Obstructions in the signal path caused by static or mobile objects downgrade localization accuracy. We use robust multipath mitigation techniques to detect and filter out outlying measurements in indoor environments. We validate our approach using a power-based lo??calization system with GSM. We conducted experiments without any prior knowledge of the tracked device's radio settings or the indoor radio environment. We obtained localization errors in the range of 3m even if the sensors had NLOS links to the target device.

Detection of convergent genome-wide signals of adaptation to tropical forests in humans

Tropical forests are believed to be very harsh environments for human life. It is unclear whether human beings would have ever subsisted in those environments without external resources. It is therefore possible that humans have developed recent biological adaptations in response to specific selective pressures to cope with this challenge. To understand such biological adaptations we analyzed genome-wide SNP data under a Bayesian statistics framework, looking for outlier markers with an overly large extent of differentiation between populations living in a tropical forest, as compared to genetically related populations living outside the forest in Africa and the Americas. The most significant positive selection signals were found in genes related to lipid metabolism, the immune system, body development, and RNA Polymerase III transcription initiation. The results are discussed in the light of putative tropical forest selective pressures, namely food scarcity, high prevalence of pathogens, difficulty to move, and inefficient thermoregulation. Agreement between our results and previous studies on the pygmy phenotype, a putative prototype of forest adaptation, were found, suggesting that a few genetic regions previously described as associated with short stature may be evolving under similar positive selection in Africa and the Americas. In general, convergent evolution was less pervasive than local adaptation in one single continent, suggesting that Africans and Amerindians may have followed different routes to adapt to similar environmental selective pressures.

Adapting a driving simulator to study pedestrians' street-crossing decisions: A feasibility study

The decision when to cross a street safely is a challenging task that poses high demands on perception and cognition. Both can be affected by normal aging, neurodegenerative disorder, and brain injury, and there is an increasing interest in studying street-crossing decisions. In this article, we describe how driving simulators can be modified to study pedestrians' street-crossing decisions. The driving simulator's projection system and the virtual driving environment were used to present street-crossing scenarios to the participants. New sensors were added to measure when the test person starts to cross the street. Outcome measures were feasibility, usability, task performance, and visual exploration behavior, and were measured in 15 younger persons, 15 older persons, and 5 post-stroke patients. The experiments showed that the test is feasible and usable, and the selected difficulty level was appropriate. Significant differences in the number of crashes between young participants and patients (p = .001) as well as between healthy older participants and patients (p = .003) were found. When the approaching vehicle's speed is high, significant differences between younger and older participants were found as well (p = .038). Overall, the new test setup was well accepted, and we demonstrated that driving simulators can be used to study pedestrians' street-crossing decisions.

Crossing the Chasm: from Cutting Edge to Practical Application

Presentation to the Capital District Library Council, Albany New York. Audience was public, school, academic, and special librarians. Topics covered: * Trends & buzzwords - Based on LITA's recent Top Tech Trends * Blogging - What is it? Who's using it? See examples of cool library blogs! * RSS - What is it? Why do we care? See examples of how to use it * Wikis - What the heck is a wiki? Why should you care (again)? See examples of how to use wikis * Information Overload - How can I keep up?! Wiki for presentation is available at http://crossingchasm.pbwiki.com/ ; this includes links to all sites shown in presentation.

Responding to Price Signals in Communal Agriculture: Shaker Hog Production, 1788-1850

Isolated Shaker communal farms stressed self-sufficiency as an ideal but carefully chose which goods to buy and sell in external markets and which to produce and consume themselves. We use records of hog slaughter weights to investigate the extent to which the Shakers incorporated market-based price information in determining production levels of a consumption good which they did not sell in external markets: pork. Granger causality tests indicate that Shaker pork production decisions were influenced as hypothesized, strongly by corn prices and weakly by pork prices. We infer that attention to opportunity costs of goods that they produced and consumed themselves was a likely factor aiding the longevity of Shaker communal societies.

Crossing the border for dental care: Factors related to dental health among the south Texas border region

Objectives. The purpose of this thesis is to understand the underlying socioeconomic characteristics affecting dental insurance coverage, yearly dental visits, and factors related to visiting a dentist in Mexico among border region residents. Methods. Using data from the Border Epidemiological Study of Aging, dental utilization in the previous 12 months, dental visits to Mexico, and dental insurance (proxy) were calculated utilizing logistic regression. Three different models were utilized for the dependent variables adjusting for diverse socioeconomic characteristics such as gender, age, marital status, income, education, years of residence in the United States (for immigrants), English proficiency, general health status, employment and dental insurance. Results. After adjustment, diverse variables were significant for the three different models calculated. Conclusion. Although the Mexican health market constitutes a viable option for dental services for border residents, dental insurance and dental yearly visits were lower in this region when compared to national averages. ^

Regulation of myogenesis by growth signals -growth factors, oncogenes and protein kinases

Establishment of a myogenic phenotype involves antagonism between cell proliferation and differentiation. The recent identification of the MyoD family of muscle-specific transcription factors provides opportunities to dissect at the molecular level the mechanisms through which defined cell type-specific transcription factors respond to environmental cues and regulate differentiation programs. This project is aimed at elucidation of the molecular mechanism whereby growth factors repress myogenesis. Initial studies demonstrated that nuclear oncogenes such as c-fos, junB and c-jun are immediate early genes that respond to serum and TGF-$\beta$. Using the muscle creatine kinase (MCK) enhancer linked to the reporter gene CAT as a marker for differentiation, we showed that transcriptional function of myogenin can be disrupted in the presence of c-Fos, JunB and cjun. In contrast, JunD, which shares DNA-binding specificity with JunB and c-Jun but is expressed constitutively in muscle cells, failed to show the inhibition. The repression by Fos and Jun is targeted at KE-2 motif, the same sequence that mediates myogenin-dependent activation and muscle-specific transactivation. Deletion analysis indicated that the transactivation domain of c-Jun at the N-terminus is responsible for the repression. Considering that myogenin is a phosphoprotein and cAMP and TPA are able to regulate myogenesis, we examined whether constitutively active protein kinase C (PKC) and protein kinase A (PKA) could substitute for exogenous growth factors and prevent transcription activation by myogenin. Indeed, the basic region of myogenin is phosphorylated by PKC at a threonine that is conserved in all members of the MyoD family. Phosphorylation at this site attenuates DNA binding activity of myogenin. Protein kinase A can also phosphorylate myogenin in a region adjacent to the DNA binding domain. However, phosphorylation at this site is insufficient to abrogate myogenin's DNA binding capacity, suggesting that PKA and PKC may affect myogenin transcriptional activity through different mechanisms. These findings provide insight into the mechanisms through which growth factor signals negatively regulate the muscle differentiation program and contribute to an understanding of signal transducing pathways between the cell membrane and nucleus. ^

Assemblages and isotopic signals of modern ostracodes and host waters from Patagonia, Argentine

Ostracode species assemblages and stable oxygen and carbon isotope ratios of living and recent ostracodes, together with delta18O and delta13C_DIC values of host water samples, provide a first data set that characterizes a wide range of modern aquatic environments in the Laguna Cari-Laufquen (41°S, 68 - 69°W) and the Lago Cardiel area (48 - 49°S, 70 - 71°W) in Patagonia, Argentina. This data set will ultimately be used to interpret and calibrate data acquired from lake sediment cores with the goal of reconstructing past climate. Species assemblages and isotope values can be assigned to three groups; (1) springs, seeps and streams, (2) permanent ponds and lakes, and (3) ephemeral ponds and lakes. Springs, seeps and streams are characterized by Darwinula sp., Heterocypris incongruens, Eucypris fontana, Amphicypris nobilis and Ilyocypris ramirezi. Ostracode and water isotope values range between -13 and -5 per mil for oxygen, and between -15 and -3 per mil for carbon. They are the most negative of the entire sample set, reflecting ground water input with little or no evaporative enrichment. Limnocythere patagonica, Eucypris labyrinthica, Limnocythere sp. and Eucypris aff. fontana are typical species of permanent ponds and lakes. Isotope values indicate high degree of evaporation of lake waters relative to feeder springs and streams and range between -7 and +5 per mil for oxygen, and -5 and +4 per mil for carbon. Limnocythere rionegroensis is the dominant species in ephemeral ponds and lakes. These systems display the most enriched isotope values in both ostracodes and host waters, extending from -5 to +7 per mil for oxygen, and from -5 to +6 per mil for carbon. Living ostracodes show a positive offset from equilibrium values of up to 2 per mil for oxygen. Carbon-isotope values are up to 6? more negative than equilibrium values in highly productive pools. Comparison of ostracode and host water isotope signals permits assessment of the life span of the aquatic environments. Valves from dead ostracodes collected from ephemeral ponds and lakes show a wide scatter with each sample providing a snapshot of the seasonal history of the host water. The presence of the stream species Ilyocypris ramirezi and a wide range of ostracode isotope values suggest that ephemeral ponds and lakes are fed by streams during spring run-off and seasonally dry. A temporary character is also indicated by Heterocypris incongruens, a drought-resistant species that occupies most springs and seeps. In addition, Limnocythere rionegroensis has adjusted its reproduction strategies to its environment. Whereas only females were collected in fresh host waters, males were found in ephemeral ponds and lakes with higher solute content. Sexual reproduction seems to be the more successful reproduction strategy in high and variable salinities and seasonal droughts. The temporary character of the aquatic environments shows that the availability of meteoric water controls the life span of host waters and underlines the sensitivity of the area to changes in precipitation.

Surface sediment samples from several fore-arc basins west and southwest of the Indonesian Archipelago, analyzed by planktonic foraminifera, stable oxygen and carbon isotopic signals and opal and CaCO3 contents in bulk sediment

A total of 69 surface sediment samples from several fore-arc basins located west and southwest of the Indonesian Archipelago was analyzed with respect to the faunal composition of planktonic foraminifera, the stable oxygen and carbon isotopic signal of a surface-dwelling (Globigerinoides ruber) and a thermocline-dwelling (Neogloboquadrina dutertrei) species, and the opal and CaCO3 contents in bulk sediment. Our results show that the distribution pattern of opal in surface sediments corresponds well to the upwelling-induced chlorophyll concentration in the upper water column and thus, represents a reliable proxy for marine productivity in the coastal upwelling area off S and SW Indonesia. Present-day oceanography and marine productivity are also reflected in the tropical to subtropical and upwelling assemblages of planktonic foraminifera in the surface sediments, which in part differ from previous studies in this region probably due to different coring methods and dissolution effects. The average stable oxygen isotopic values (d18O) of G. ruber in surface sediments vary between 2.9 per mill and 3.2 per mill from basin to basin and correspond to the oceanographic settings during the SE monsoon (July-October) off west Sumatra, whereas off southern Indonesia, they reflect the NW monsoon (December-March) or annual average conditions. The d18O values of N. dutertrei show a stronger interbasinal variation between 1.6 per mill and 2.2 per mill and correspond to the upper thermocline hydrology in July-October. In addition, the difference between the shell carbon isotopic values (d13C) of G. ruber and N. dutertrei (Delta d13C) appears to be an appropriate productivity recorder only in the non-upwelling areas off west Sumatra. Consequently, joint interpretation of the isotopic values of these species is distinctive for different fore-arc basins W and SW of Indonesia and should be considered in paleoceanographic studies.

Reseña del libro Crossing borders, claiming a nation. A History of Argentine Jewish Women, 1880-1955 de Sandra Mac Gee Deutsh

Fil: Bordagaray, María Eugenia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

Reseña del libro Crossing borders, claiming a nation. A History of Argentine Jewish Women, 1880-1955 de Sandra Mac Gee Deutsh

Fil: Bordagaray, María Eugenia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.

Reseña del libro Crossing borders, claiming a nation. A History of Argentine Jewish Women, 1880-1955 de Sandra Mac Gee Deutsh

Fil: Bordagaray, María Eugenia. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales (UNLP-CONICET); Argentina.