Landscape-scale prediction of forest productivity by hyperspectral remote sensing of canopy nitrogen

Foliar nitrogen concentration represents a direct and primary link between carbon and nitrogen cycling in terrestrial ecosystems. Although foliar N is used by many ecosystem models to predict leaf-level photosynthetic rates, it has rarely been examined as a direct scalar to stand-level carbon gain. Significant improvements in remote sensing detector technology in the list decade now allow for improved landscape-level estimation of the biochemical attributes of forest ecosystems. In this study, relationships among forest growth (aboveground net primary productivity (ANPP) and aboveground woody biomass production (AWBP)), canopy chemistry and structure, and high resolution imaging spectrometry were examined for 88 long-term forest growth inventory plots maintained by the USDA Forest Service within the 300,000 ha White Mountain National Forest, New Hampshire. Analysis of plot-level data demonstrates a highly predictive relationship between whole canopy nitrogen concentration (g/100 g) and aboveground forest productivity (ANPP: R2 = 0.81, p \u3c 0.000; AWBP: R 2 = 0.86, p \u3c 0.000) within and among forest types. Forest productivity was more strongly related to mass-based foliar nitrogen concentration than with either total canopy N or canopy leaf area. Empirical relationships were developed among spectral data from the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and field-measured canopy nitrogen concentration (mass basis). Results of this analysis suggest that hyperspectral remote sensing can be used to accurately predict foliar nitrogen concentration, by mean of a full-spectrum partial least squares calibration method, both within a single scene (R2 = 0.84, SECV = 0.23) and across a large number of contiguous images (R2 = 82, SECV = 0.25), as well as between image dates (R2 = 0.69, SECV = 0.25). Forest productivity coverages for the White Mountain National Forest were developed by estimating whole canopy foliar N concentration from AVIRIS spectral response. Image spatial patterns broadly reflect the distribution of functional types, while fine scale spatial variation results from a variety of natural and anthropogenic factors. This approach provides the potential to increase the accuracy of forest growth and carbon gain estimates at the landscape level by providing information at the fine spatial scale over which environmental characteristics and human land use vary

Understanding strategic information use during emotional expression judgments in Williams syndrome

Detailed analysis of expression judgments in Williams syndrome reveals that successful emotion categorization need not reflect ‘classic’ information processing strategies. These individuals draw upon a distinct set of featural details to identify happy and fearful faces that differ from those used by typically developing comparison groups: children and adults. The diagnostic visual information is also notably less interlinked in Williams syndrome, consistent with reports of diminished processing of configural information during face identity judgments. These results prompt reconsideration of typical models of face expertise by revealing that an age-appropriate profile of expression performance can be achieved via alternative routes

Distinct profiles of information-use characterize identity judgments in children and low-expertise adults

Face processing abilities vary across the lifespan: increasing across childhood and adolescence, peaking around 30 years of age, and then declining. Despite extensive investigation, researchers have yet to identify qualitative changes in face processing during development that can account for the observed improvements on laboratory tests. The current study constituted the first detailed characterization of face processing strategies in a large group of typically developing children and adults (N=200) using a novel adaptation of the Bubbles reverse correlation technique (Gosselin & Schyns, 2001). Resultant classification images reveal a compelling age-related shift in strategic information-use during participants’ judgments of face identity. This shift suggests a move from an early reliance upon high spatial frequency details around the mouth, eye-brow and jaw-line in young children (~8yrs) to an increasingly more interlinked approach, focused upon the eye region and the center of the face in older children (~11yrs) and adults. Moreover, we reveal that the early vs. late phases of this developmental trajectory correspond with the profiles of information-use observed in weak vs. strong adult face processors. Together, these results provide intriguing new evidence for an important functional role for strategic information-use in the development of face expertise

Developmental changes in the processing of faces as revealed by EEG decoding

Rapidly and accurately processing information from faces is a critical human function that is known to improve with developmental age. Understanding the underlying drivers of this improvement remains a contentious question, with debate continuing as to the presence of early vs. late maturation of face-processing mechanisms. Recent behavioural evidence suggests an important ‘hallmark’ of expert face processing – the face inversion effect – is present in very young children, yet neural support for this remains unclear. To address this, we conducted a detailed investigation of the neural dynamics of face processing in children spanning a range of ages (6 – 11 years) and adults. Uniquely, we applied multivariate pattern analysis (MVPA) to the electroencephalogram signal (EEG) to test for the presence of a distinct neural profile associated with canonical upright faces when compared both to other objects (houses) and to inverted faces. Results revealed robust discrimination profiles, at the individual level, of differentiated neural activity associated with broad face categorization and further with its expert processing, as indexed by the face inversion effect, from the youngest ages tested. This result is consistent with an early functional maturation of broad face processing mechanisms. Yet, clear quantitative differences between the response profile of children and adults is suggestive of age-related refinement of this system with developing face and general expertise. Standard ERP analysis also provides some support for qualitative differences in the neural response to inverted faces in children in contrast to adults. This neural profile is in line with recent behavioural studies that have reported impressively expert early face abilities during childhood, while also providing novel evidence of the ongoing neural specialisation between child and adulthood

DIRECT ESTIMATION OF ABOVEGROUND FOREST PRODUCTIVITY THROUGH HYPERSPECTRAL REMOTE SENSING OF CANOPY NITROGEN

The concentration of nitrogen in foliage has been related to rates of net photosynthesis across a wide range of plant species and functional groups and thus represents a simple and biologically meaningful link between terrestrial cycles of carbon and nitrogen. Although foliar N is used by ecosystem models to predict rates of leaf‐level photosynthesis, it has rarely been examined as a direct scalar to stand‐level carbon gain. Establishment of such relationships would greatly simplify the nature of forest C and N linkages, enhancing our ability to derive estimates of forest productivity at landscape to regional scales. Here, we report on a highly predictive relationship between whole‐canopy nitrogen concentration and aboveground forest productivity in diverse forested stands of varying age and species composition across the 360 000‐ha White Mountain National Forest, New Hampshire, USA. We also demonstrate that hyperspectral remote sensing can be used to estimate foliar N concentration, and hence forest production across a large number of contiguous images. Together these data suggest that canopy‐level N concentration is an important correlate of productivity in these forested systems, and that imaging spectrometry of canopy N can provide direct estimates of forest productivity across large landscapes

Knowledge, attitudes and practices of primary health care providers towards oral health of preschool children in Qatar

Objective: Health care providers can effectively participate in oral health promotion for children in primary care setting. Currently, there are no oral health promotion programs that involve primary health care professionals in Qatar. Hence, this study was undertaken to examine the knowledge and attitudes of all health professionals who work in the Well baby Clinics in the primary health centers.Method: A 23-item questionnaire was distributed across 20 primary health centers. The questionnaire sought information on the demographic data of health professionals, their knowledge of oral health and their practices and attitudes towards critical oral health issues.  Data were examined by Pearson Chi-squared tests or Fisher’s Exact test(p = 0.05).Results: The response rate of the health professionals was 62.9%. Only 35.7% of the 225 participants received some form of oral health training during their undergraduate programme. The participants would assess the dental problem of the child(p = 0.05) and discuss the importance of tooth brushing with the mother(p = 0.03). A significant number of respondents (p = 0.04) were unlikely to assess the children’s fluoride intake. There was a significant difference in the group of participants that would examine the child’s teeth(p = 0.01) and counsel the mothers on prevention of dental problems(p = 0.01). This group would also refer children to dentist at 12 months of age(p = 0.05). Conclusions: Health professionals had a positive attitude towards the anticipatory guidance elements of oral health. However, the knowledge of healthcare professionals on childhood oral health is rather limited

Orientation effects support specialist processing of upright unfamiliar faces in children and adults

It is considerably harder to generalize identity across different pictures of unfamiliar faces, compared with familiar faces. This finding hints strongly at qualitatively distinct processing of unfamiliar face stimuli—for which we have less expertise. Yet, the extent to which face selective versus generic visual processes drive outcomes during this task has yet to be determined. To explore the relative contributions of each, we contrasted performance on a version of the popular Telling Faces Together unfamiliar face matching task, implemented in both upright and inverted orientations. Furthermore, we included different age groups (132 British children ages 6 to 11 years [69.7% White], plus 37 British White adults) to investigate how participants’ experience with faces as a category influences their selective utilization of specialized processes for unfamiliar faces. Results revealed that unfamiliar face matching is highly orientation-selective. Accuracy was higher for upright compared with inverted faces from 6 years of age, which is consistent with selective utilization of specialized processes for upright versus inverted unfamiliar faces during this task. The effect of stimulus orientation did not interact significantly with age, and there was no graded increase in the magnitude of inversion effects observed across childhood. Still, a numerically larger inversion effect in adults compared to children provides a degree of support for developmental changes in these specialized face abilities with increasing age/experience. Differences in the pattern of errors across age groups are also consistent with a qualitative shift in unfamiliar face processing that occurs some time after 11 years of ag

Use of waveform lidar and hyperspectral sensors to assess selected spatial and structural patterns associated with recent and repeat disturbance and the abundance of sugar maple (Acer saccharum Marsh.) in a temperate mixed hardwood and conifer forest.

Abstract Waveform lidar imagery was acquired on September 26, 1999 over the Bartlett Experimental Forest (BEF) in New Hampshire (USA) using NASA\u27s Laser Vegetation Imaging Sensor (LVIS). This flight occurred 20 months after an ice storm damaged millions of hectares of forestland in northeastern North America. Lidar measurements of the amplitude and intensity of ground energy returns appeared to readily detect areas of moderate to severe ice storm damage associated with the worst damage. Southern through eastern aspects on side slopes were particularly susceptible to higher levels of damage, in large part overlapping tracts of forest that had suffered the highest levels of wind damage from the 1938 hurricane and containing the highest levels of sugar maple basal area and biomass. The levels of sugar maple abundance were determined through analysis of the 1997 Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) high resolution spectral imagery and inventory of USFS Northern Research Station field plots. We found a relationship between field measurements of stem volume losses and the LVIS metric of mean canopy height (r2 = 0.66; root mean square errors = 5.7 m3/ha, p \u3c 0.0001) in areas that had been subjected to moderate-to-severe ice storm damage, accurately documenting the short-term outcome of a single disturbance event