Disentangling the effects of CO2 and short-lived climate forcer mitigation.

Anthropogenic global warming is driven by emissions of a wide variety of radiative forcers ranging from very short-lived climate forcers (SLCFs), like black carbon, to very long-lived, like CO2. These species are often released from common sources and are therefore intricately linked. However, for reasons of simplification, this CO2-SLCF linkage was often disregarded in long-term projections of earlier studies. Here we explicitly account for CO2-SLCF linkages and show that the short- and long-term climate effects of many SLCF measures consistently become smaller in scenarios that keep warming to below 2 °C relative to preindustrial levels. Although long-term mitigation of methane and hydrofluorocarbons are integral parts of 2 °C scenarios, early action on these species mainly influences near-term temperatures and brings small benefits for limiting maximum warming relative to comparable reductions taking place later. Furthermore, we find that maximum 21st-century warming in 2 °C-consistent scenarios is largely unaffected by additional black-carbon-related measures because key emission sources are already phased-out through CO2 mitigation. Our study demonstrates the importance of coherently considering CO2-SLCF coevolutions. Failing to do so leads to strongly and consistently overestimating the effect of SLCF measures in climate stabilization scenarios. Our results reinforce that SLCF measures are to be considered complementary rather than a substitute for early and stringent CO2 mitigation. Near-term SLCF measures do not allow for more time for CO2 mitigation. We disentangle and resolve the distinct benefits across different species and therewith facilitate an integrated strategy for mitigating both short and long-term climate change.

A comparison of visible wavelength reflectance hyperspectral imaging and Acid Black 1 for the detection and identification of blood stained fingerprints.

Bloodstains are often encountered at scenes of violent crime and have significant forensic value for criminal investigations. Blood is one of the most commonly encountered types of biological evidence and is the most commonly observed fingerprint contaminant. Presumptive tests are used to test blood stain and blood stained fingerprints are targeted with chemical enhancement methods, such as acid stains, including Acid Black 1, Acid Violet 17 or Acid Yellow 7. Although these techniques successfully visualise ridge detail, they are destructive, do not confirm the presence of blood and can have a negative impact on DNA sampling. A novel application of visible wavelength hyperspectral imaging (HSI) is used for the non-contact, non-destructive detection and identification of blood stained fingerprints on white tiles both before and after wet chemical enhancement using Acid Black 1. The identification was obtained in a non-contact and non-destructive manner, based on the unique visible absorption spectrum of haemoglobin between 400 and 500nm. Results from the exploration of the selectivity of the setup to detect blood against ten other non-blood protein contaminants are also presented. A direct comparison of the effectiveness of HSI with chemical enhancement using Acid Black 1 on white tiles is also shown.

The non-contact detection and identification of blood stained fingerprints using visible wavelength reflectance hyperspectral imaging: Part 1.

Blood is one of the most commonly encountered types of biological evidence found at scenes of violent crime and one of the most commonly observed fingerprint contaminants. Current visualisation methods rely on presumptive tests or chemical enhancement methods. Although these can successfully visualise ridge detail, they are destructive, do not confirm the presence of blood and can have a negative impact on DNA sampling. A novel application of visible wavelength reflectance hyperspectral imaging (HSI) has been used for the detection and positive identification of blood stained fingerprints in a non-contact and non-destructive manner on white ceramic tiles. The identification of blood was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. HSI has been used to successfully visualise ridge detail in blood stained fingerprints to the ninth depletion. Ridge detail was still detectable with diluted blood to 20-fold dilutions. Latent blood stains were detectable to 15,000-fold dilutions. Ridge detail was detectable for fingerprints up to 6 months old. HSI was also able to conclusively distinguish blood stained fingerprints from fingerprints in six paints and eleven other red/brown media with zero false positives.

The non-contact detection and identification of blood stained fingerprints using visible wavelength hyperspectral imaging: Part II effectiveness on a range of substrates.

Biological samples, such as blood, are regularly encountered at violent crime scenes and successful identification is critical for criminal investigations. Blood is one of the most commonly encountered fingerprint contaminants and current identification methods involve presumptive tests or wet chemical enhancement. These are destructive however; can affect subsequent DNA sampling; and do not confirm the presence of blood, meaning they are susceptible to false positives. A novel application of visible wavelength reflectance hyperspectral imaging (HSI) has been used for the non-contact, non-destructive detection and identification of blood stained fingerprints across a range of coloured substrates of varying porosities. The identification of blood was based on the Soret γ band absorption of haemoglobin between 400 nm and 500 nm. Ridge detail was successfully visualised to the third depletion across light coloured substrates and the stain detected to the tenth depletion on both porous and non-porous substrates. A higher resolution setup for blood stained fingerprints on black tiles, detected ridge detail to the third depletion and the stain to the tenth depletion, demonstrating considerable advancements from previous work. Diluted blood stains at 1500 and 1000 fold dilutions for wet and dry stains respectively were also detected on pig skin as a replica for human skin.

Presynaptic inhibition by α2 receptor/adenylate cyclase/PDE4 complex at retinal rod bipolar synapse.

G-protein-coupled receptor (GPCR)-mediated presynaptic inhibition is a fundamental mechanism regulating synaptic transmission in the CNS. The classical GPCR-mediated presynaptic inhibition in the CNS is produced by direct interactions between the G(ßγ) subunits of the G-protein and presynaptic Ca(2+) channels, K(+) channels, or synaptic proteins that affect transmitter release. This mode of action is shared by well known GPCRs such as the α2, GABA(B), and CB1 receptors. We report that the α2 receptor-mediated inhibition of presynaptic Ca(2+) channel and transmitter release in rat retinal rod bipolar cells depends on the G(α) subunit via a G(α)-adenylate cyclase-cAMP cascade and requires participation of the type 4 phosphodiesterase (PDE4), a new role for phosphodiesterase in neural signaling. By using the G(α) instead of the G(ßγ) subunits, this mechanism is able to use a cyclase/PDE enzyme pair to dynamically control a cyclic nucleotide second messenger (i.e., cAMP) for the regulation of synaptic transmission, an operating strategy that shows remarkable similarity to that of dynamic control of cGMP and transmitter release from photoreceptors by the guanylate cyclase/PDE6 pair in phototransduction. Our results demonstrate a new paradigm of GPCR-mediated presynaptic inhibition in the CNS and add a new regulatory mechanism at a critical presynaptic site in the visual pathway that controls the transmission of scotopic information. They also provide a presynaptic mechanism that could contribute to neuroprotection of retinal ganglion cells by α2 agonists, such as brimonidine, in animal models of glaucoma and retinal ischemia and in glaucoma patients.

Greenhouse-gas emission targets for limiting global warming to 2 degrees C.

More than 100 countries have adopted a global warming limit of 2 degrees C or below (relative to pre-industrial levels) as a guiding principle for mitigation efforts to reduce climate change risks, impacts and damages. However, the greenhouse gas (GHG) emissions corresponding to a specified maximum warming are poorly known owing to uncertainties in the carbon cycle and the climate response. Here we provide a comprehensive probabilistic analysis aimed at quantifying GHG emission budgets for the 2000-50 period that would limit warming throughout the twenty-first century to below 2 degrees C, based on a combination of published distributions of climate system properties and observational constraints. We show that, for the chosen class of emission scenarios, both cumulative emissions up to 2050 and emission levels in 2050 are robust indicators of the probability that twenty-first century warming will not exceed 2 degrees C relative to pre-industrial temperatures. Limiting cumulative CO(2) emissions over 2000-50 to 1,000 Gt CO(2) yields a 25% probability of warming exceeding 2 degrees C-and a limit of 1,440 Gt CO(2) yields a 50% probability-given a representative estimate of the distribution of climate system properties. As known 2000-06 CO(2) emissions were approximately 234 Gt CO(2), less than half the proven economically recoverable oil, gas and coal reserves can still be emitted up to 2050 to achieve such a goal. Recent G8 Communiqués envisage halved global GHG emissions by 2050, for which we estimate a 12-45% probability of exceeding 2 degrees C-assuming 1990 as emission base year and a range of published climate sensitivity distributions. Emissions levels in 2020 are a less robust indicator, but for the scenarios considered, the probability of exceeding 2 degrees C rises to 53-87% if global GHG emissions are still more than 25% above 2000 levels in 2020.

Climate change risks for African agriculture.

The Intergovernmental Panel on Climate Change (IPCC) assessment of major risks for African agriculture and food security caused by climate change during coming decades is confirmed by a review of more recent climate change impact assessments (14 quantitative, six qualitative). Projected impacts relative to current production levels range from -100% to +168% in econometric, from -84% to +62% in process-based, and from -57% to +30% in statistical assessments. Despite large uncertainty, there are several robust conclusions from published literature for policy makers and research agendas: agriculture everywhere in Africa runs some risk to be negatively affected by climate change; existing cropping systems and infrastructure will have to change to meet future demand. With respect to growing population and the threat of negative climate change impacts, science will now have to show if and how agricultural production in Africa can be significantly improved.

The application of visible wavelength reflectance hyperspectral imaging for the detection and identification of blood stains.

Current methods of detection and identification of blood stains rely largely on visual examination followed by presumptive tests such as Kastle-Meyer, Leuco-malachite green or luminol. Although these tests are useful, they can produce false positives and can also have a negative impact on subsequent DNA tests. A novel application of visible wavelength reflectance hyperspectral imaging has been used for the detection and positive identification of blood stains in a non contact and non destructive manner on a range of coloured substrates. The identification of blood staining was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. Images illustrating successful discrimination of blood stains from nine red substances are included. It has also been possible to distinguish between blood and approximately 40 other reddish stains. The technique was also successfully used to detect latent blood stains deposited on white filter paper at dilutions of up to 1 in 512 folds and on red tissue at dilutions of up to 1 in 32 folds. Finally, in a blind trial, the method successfully detected and identified a total of 9 blood stains on a red T-shirt.

Discrimination of Sri Lankan black teas using fluorescence spectroscopy and linear discriminant analysis.

BACKGROUND: The quality of teas is currently graded using trained tea tasters, whose evaluation can sometimes be subjective. In this study the simple fluorescence-based technique of total luminescence spectroscopy (TLS) in conjunction with data classification using principal component analysis (PCA) was applied to discriminate between teas from 11 different Sri Lankan plantations. Solvent extraction of the tea samples was followed by TLS to record excitation-emission matrices in the excitation range 250-590 nm and emission range 300-700 nm. RESULTS: The application of PCA and linear discriminant analysis (LDA) allowed the successful classification of all 11 teas using only the first two principal components. LDA demonstrated how the technique was able to discriminate between all teas correctly with 100% classification. CONCLUSION: Further development of this work could lead to a simple device that could be used by tea manufacturers instead of or alongside trained tea tasters to grade teas.

The age estimation of blood stains up to 30 days old using visible wavelength hyperspectral image analysis and linear discriminant analysis.

A novel application of visible wavelength hyperspectral image analysis has been applied to determine the age of blood stains up to 30 days old. Reflectance spectra from selected locations within the hyperspectral image, obtained from a portable instrument, were subjected to spectral pre-processing. This was followed by the application of a linear discriminant classification model, making estimations possible with an average error of ±0.27days for the first 7 days and an overall average error of ±1.17days up to 30 days. This is also the first reported study of the determination of the age of fresh blood stains (less than one day old) with an error of ±0.09h. The studies have been made under controlled conditions and represent, at this stage, proof of concept results but also are the most accurate age estimation results for measurements between 0 and 30 days reported to date. The results are consistent with well-established kinetic processes suggesting that the pre-processing stages described are revealing spectroscopic changes which are reliably following the time dependent oxidation of HbO2. The potential for parameterisation of environmental factors to make the method generally applicable at crime scenes is discussed, along with the developments required to further improve classification and to make the instrument genuinely portable.

Fluoridated toothpaste: usage and ingestion of fluoride by 4- to 6-yr-old children in England.

Fluoridated toothpaste is effective for dental caries control, yet may be a risk factor for dental fluorosis. This study aimed to quantify fluoride ingestion from toothpaste by children and to investigate the effects of age, gender, and social class on the amount of fluoride ingested per toothbrushing session. Sixty-one children, 4-6 yr of age, were recruited: 38 were from low socio-economic (LSE) areas of Newcastle, UK, and 23 were from high socio-economic (HSE) areas of Newcastle, UK. All expectorated saliva, rinse water (if used), and residual toothpaste were collected after brushing at home and were analysed for fluoride. Of the children, 74% and 69% from HSE and LSE areas, respectively, claimed that they brushed twice per day. The mean (SD) weight of toothpaste dispensed was 0.67 (0.36) g. The mean (SD) amount of fluoride ingested per toothbrushing session and per day was 17.0 (14.7) and 29.3 (32.8) µg kg(-1) of body weight, respectively. Daily fluoride intake per kilogram of body weight did not differ significantly between children from LSE and HSE areas. Fluoride intake per toothbrushing session was significantly influenced by weight of toothpaste, its fluoride concentration, and the child's age. Whilst the average amount of toothpaste used per toothbrushing session was more than twice the recommended amount (of 0.25 g), only one child had a daily fluoride intake that exceeded the tolerable upper intake level of 0.1 mg kg(-1) of body weight for this age group.

Assessing dangerous climate change through an update of the Intergovernmental Panel on Climate Change (IPCC) "reasons for concern".

Article 2 of the United Nations Framework Convention on Climate Change [United Nations (1992) http://unfccc.int/resource/docs/convkp/conveng.pdf. Accessed February 9, 2009] commits signatory nations to stabilizing greenhouse gas concentrations in the atmosphere at a level that "would prevent dangerous anthropogenic interference (DAI) with the climate system." In an effort to provide some insight into impacts of climate change that might be considered DAI, authors of the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) identified 5 "reasons for concern" (RFCs). Relationships between various impacts reflected in each RFC and increases in global mean temperature (GMT) were portrayed in what has come to be called the "burning embers diagram." In presenting the "embers" in the TAR, IPCC authors did not assess whether any single RFC was more important than any other; nor did they conclude what level of impacts or what atmospheric concentrations of greenhouse gases would constitute DAI, a value judgment that would be policy prescriptive. Here, we describe revisions of the sensitivities of the RFCs to increases in GMT and a more thorough understanding of the concept of vulnerability that has evolved over the past 8 years. This is based on our expert judgment about new findings in the growing literature since the publication of the TAR in 2001, including literature that was assessed in the IPCC Fourth Assessment Report (AR4), as well as additional research published since AR4. Compared with results reported in the TAR, smaller increases in GMT are now estimated to lead to significant or substantial consequences in the framework of the 5 "reasons for concern."

An illicit economy: scavenging and recycling of medical waste.

This paper discusses a significant illicit economy, including black and grey aspects, associated with medical waste scavenging and recycling in a megacity, considering hazards to the specific group involved in scavenging as well as hazards to the general population of city dwellers. Data were collected in Dhaka, Bangladesh, using a variety of techniques based on formal representative sampling for fixed populations (such as recycling operatives) and adaptive sampling for roaming populations (such as scavengers). Extremely hazardous items (including date expired medicines, used syringes, knives, blades and saline bags) were scavenged, repackaged and resold to the community. Some HCE employees were also observed to sell hazardous items directly to scavengers, and both employees and scavengers were observed to supply contaminated items to an informal plastics recycling industry. This trade was made possible by the absence of segregation, secure storage and proper disposal of medical waste. Corruption, a lack of accountability and individual responsibility were also found to be contributors. In most cases the individuals involved with these activities did not understand the risks. Although motivation was often for personal gain or in support of substance abuse, participants sometimes felt that they were providing a useful service to the community.

Ribosomal RNA-based analysis of the bacterial flora from the conjunctivae of cattle with bovine keratoconjunctivitis (BKC).

Bovine keratoconjunctivitis (BKC), colloquially referred to as 'pinkeye', is a disease affecting cattle worldwide; it costs cattle producers millions of dollars in economic loss annually. While Moraxella spp. are the primary etiologic agent of pinkeye, surveys of flora from the conjunctivae of livestock from around the world have indicated that a variety of bacterial commensals occupy this niche. We used molecular biology-based methods to determine the composition of bacterial flora in the conjunctivae of normal dairy and beef cattle from Maryland (n=113), and beef cattle with clinical BKC from Louisiana (n=42). Three regimens were used: 16S rRNA PCR and DGGE analysis of amplicons; 16S rRNA PCR and cloning of amplicons into Escherichia coli followed by screening and sequencing of clones harboring inserts; and culture of bacteria on chromogenic agar followed by 16S rRNA PCR and sequencing. Most taxa were comprised of saprophytes found in the environment, such as Bacillus, Pantoea, E. coli, and Exiguobacterium. Moraxella spp. were infrequently observed. Some species, such as Propionibacterium acnes, represent taxa not previously associated with the conjunctivae. Bacillus pumilus and Bacillus licheniformis isolates from the conjunctivae of Maryland cattle were genetically distinct from isolates previously implicated in septic infections in cattle at the same location. We conclude that employing 16S rRNA-based methods for bacterial identification can be useful in defining the flora present in the conjunctivae of normal cattle, and those with BKC.

Alpha2 adrenergic receptor-mediated modulation of cytosolic Ca++ signals at the inner plexiform layer of the rat retina.

PURPOSE: Compelling evidence suggests that alpha2 agonists, such as brimonidine, protect retinal ganglion cells (RGCs) from injury in a wide range of animal models. However, the mechanism of action for this protection and the physiological role of the alpha2 adrenergic system in the retina is not well understood. A major goal of this work was to explore the role of the alpha2 adrenergic system in the modulation of cytosolic Ca(2+) signaling at retinal synaptic layers, particularly the inner plexiform layer (IPL), where communication between RGCs and their presynaptic cells takes place. METHODS: Functional Ca(2+) imaging at the inner plexiform layer (IPL) and outer plexiform layer (OPL) of living rat retinal slices was conducted with a high-speed confocal system. The relative changes of cytosolic free Ca(2+) were monitored with the fluorescent Ca(2+) dye fluo-4. The Ca(2+) signal was elicited by membrane depolarization produced by a high K(+) (40 mM) Ringer solution that was delivered rapidly and briefly to the test regions of the retinal slice by a custom-made multichannel local perfusion system. RESULTS: A brief application (8 seconds) of high K(+) Ringer elicited a robust cytosolic Ca(2+) increase at the IPL and OPL. In both cases, this Ca(2+) signal was eliminated by nimodipine, a selective L-type voltage-gated Ca(2+)-channel blocker, or when the extracellular Ca(2+) in the Ringer was replaced with equal molar EGTA. At IPL, the Ca(2+) signal was also suppressed in a dose-dependent manner by brimonidine and other alpha2 receptor agonists, such as medetomidine. The suppressive action of brimonidine and medetomidine was completely blocked by classic alpha2 receptor antagonists, such as yohimbine, rauwolscine, and atipamezole. Interestingly, the alpha2 receptor agonists had no effect on the high K(+) Ringer-elicited cytosolic Ca(2+) signal at OPL. Blocking the N-methyl-d-aspartate (NMDA) type of ionotropic glutamate receptor with D-AP5 attenuated this high K(+)-elicited Ca(2+) signal by approximately 20% at IPL. D-AP5 had no effect on the Ca(2+) signal at OPL. CONCLUSIONS: These findings provide the first direct evidence of alpha2 receptor-mediated modulation of L-type Ca(2+) channel activity in the CNS (the retina is part of the CNS). This alpha2 modulation appears to occur at the IPL but not at the OPL of the retina. These findings suggest that a physiological function of the retinal alpha2 system is the regulation of synaptic transmission at IPL and that brimonidine and other alpha2 agonists may protect RGCs under disease conditions by preventing abnormal elevation of cytosolic free Ca(2+) either in RGCs, in their presynaptic cells, or in both.

Predicting perchlorate exposure in milk from concentrations in dairy feed.

Perchlorate has been detected in U.S. milk samples from many different states. Applying data from a recently reported 9-week experiment in which 16 Holstein dairy cows were administered perchlorate allowed us to derive an equation for the dose-response relationship between perchlorate concentrations in feed/drinking water and its appearance in milk. Examination of background concentrations of perchlorate in the total mixed ration (TMR) fed in addition to the variable dose supplied to treated cows as a ruminal infusate revealed that cows receive significant and variable exposure to perchlorate from the TMR. Weekly examination of the TMR disclosed that a change in ingredients midway through the experiment caused a significant (78%) change in TMR perchlorate concentration. Analyses of the ingredients comprising the TMR revealed that 41.9% of the perchlorate came from corn silage, 22.9% came from alfalfa hay and 11.7% was supplied by sudan grass. Finally, USDA Food and Nutrition Survey data on fluid milk consumption were used to predict potential human exposure from milk that contained concentrations of perchlorate observed in our previous dosing study. The study suggests that reducing perchlorate concentration in dairy feed may reduce perchlorate concentrations in milk as well as the potential to reduce human exposure to perchlorate in milk.

Total daily fluoride intake and fractional urinary fluoride excretion in 4- to 6-year-old children living in a fluoridated area: weekly variation?

OBJECTIVES: Risk of development of dental fluorosis may increase with even a short-term increase in fluoride (F) intake during tooth formation. Considering the wide variations in F concentrations of different food and drinks, it is important to assess short-term differences in F intake and consequently fractional urinary F excretion (FUFE) in children, which provide an indication of F body burden. Therefore, the aim of this study was to investigate weekly variation in total daily F intake (TDFI) and its sources and fractional urinary F excretion (FUFE) in 4- to 6-year-olds living in a fluoridated area in the UK. METHODS: Sixty-one children were surveyed twice with a 1-week gap between surveys. Dietary F intake was assessed by 'food-diary' and 'duplicate-plate collection'. Toothbrushing expectorate (saliva/toothpaste) was collected to estimate F intake from toothpaste ingestion. TDFI was calculated from dietary F intake and toothpaste ingestion. Daily urinary F excretion (DUFE) was estimated by collecting 24-h urine samples and FUFE was calculated from DUFE and TDFI [FUFE = (DUFE/TDFI) × 100]. RESULTS: The overall mean TDFI, DUFE and FUFE for all children were 0.056 (SD 0.036) mg/kgbw/day, 0.018 (SD 0.007) mg/kgbw/day and 39 (SD 20)%, respectively. The mean (95% CI) difference between the 2 weeks studied was 0.004 (-0.004, 0.011) mg/kgbw/day for TDFI, 0.002 (-0.001, 0.004) mg/kgbw/day for DUFE and 1 (-6, 8)% for FUFE. CONCLUSIONS: Mean TDFI and FUFE did not vary statistically significantly with week and therefore one set of data collection from a group of children living in a temperate climate could be sufficient to monitor F exposure and F body burden in community prevention programmes for oral health.

The Effect of Light Level and Small Pupils on Presbyopic Reading Performance.

PURPOSE: To examine the impact of small pupils and light levels on reading performance of distance-corrected presbyopes. To determine whether small pupils would enable presbyopes to read at near even at low light levels. METHODS: To establish the lower range of text luminances, we quantified the space-averaged luminance of text in nine different artificially lit interior environments, and examined the impact of the text characters on space-averaged luminance of electronic and printed displays. Distance and near reading speeds of 20 presbyopes (ages 40-60 years) were measured while viewing through artificial pupils (diameters 1-4.5 mm), natural pupils, or with a multifocal contact lens. Space-averaged text luminance levels varied from 0.14 to 140 cd/m2 (including the range of measured environmental text luminances). RESULTS: Adding black text to a white computer display or paper reduces luminance by approximately 15% to 31%, and the lowest encountered environmental text luminance was approximately 2 to 3 cd/m2. For both distance and near reading performance, the 2- to 3-mm small pupil yielded the best overall reading acuity for space-averaged text light levels ≥ 2 cd/m2. The 2- to 3-mm artificial pupils and the multifocal contact lenses both enabled maximum or near-maximum reading speeds for 0.5 logMAR characters at distance and near, but with natural pupils, reading speeds were significantly reduced at near. CONCLUSIONS: Although photon noise at low luminance reduces the visual benefits of small pupils, the benefits of 2- to 3-mm artificial pupils are sufficient to enable >80% of distance-corrected presbyopes to read proficiently at near, even at the lowest text luminances found in interior environments.

Assessing Spatial and Temporal Differences in State-Level Child Well-Being Based on Tests of Statistical Significance.

The concept of child well-being is central to the study of children and are reflected in data books, statistical indices, and report cards. Statistical indicators of child well-being are increasingly used to examine the quality of life for children. Such reports are often used to examine differences across geographic areas (spatial differences) and changes over time (temporal differences). In this study, indicators from a widely used report on child well-being are used to compare spatial differences and temporal differences among states in the U.S. based on tests of statistical significance. Results show that currently available indicators are better at detecting differences in child well-being between states at one point in time rather than state-level changes over time. Additionally, a state index of child well-being is constructed using only indicators that are statistically significant different than the national rate; the results of the new index proved to be similar to the more traditional z-score method.