The X-ray emission spectra ( M ~-K B , , ~, Mg-LZ.3 M, and 0-K,), X-ray photoelectron spectra, and 0-KLL Auger spectra from brucite, Mg[OH],, are reported. The electronic structure of brucite is discussed using these spectra and a simple Huckel molecular-orbital model. The spectra indicate that the strongest interaction exists between the oxygen and hydrogen of the hydroxide group, but that the Mg-0 bond has some covalent character. An attempt to interpret the 2 ~-~ peak in the oxygen Auger spectrum using the 0 -K , X-ray profile has met with only I im i ted success. Chemistry, Queen Mary College, Mile End Road, London El 4NS * Throughout this paper: 1 eV E 1.60 x lO-lS J ; 1 Torr = (101 325/760) Pa.

Autism spectrum disorder (ASD) can be reliably diagnosed at 18 months, yet significant diagnostic delays persist in the United States. This double-blinded, multi-site, prospective, active comparator cohort study tested the accuracy of an artificial intelligence-based Software as a Medical Device designed to aid primary care healthcare providers (HCPs) in diagnosing ASD. The Device combines behavioral features from three distinct inputs (a caregiver questionnaire, analysis of two short home videos, and an HCP questionnaire) in a gradient boosted decision tree machine learning algorithm to produce either an ASD positive, ASD negative, or indeterminate output. This study compared Device outputs to diagnostic agreement by two or more independent specialists in a cohort of 18–72-month-olds with developmental delay concerns (425 study completers, 36% female, 29% ASD prevalence). Device output PPV for all study completers was 80.8% (95% confidence intervals (CI), 70.3%–88.8%) and NPV was 98.3% (90.6%–100%). For the 31.8% of participants who received a determinate output (ASD positive or negative) Device sensitivity was 98.4% (91.6%–100%) and specificity was 78.9% (67.6%–87.7%). The Device’s indeterminate output acts as a risk control measure when inputs are insufficiently granular to make a determinate recommendation with confidence. If this risk control measure were removed, the sensitivity for all study completers would fall to 51.6% (63/122) (95% CI 42.4%, 60.8%), and specificity would fall to 18.5% (56/303) (95% CI 14.3%, 23.3%). Among participants for whom the Device abstained from providing a result, specialists identified that 91% had one or more complex neurodevelopmental disorders. No significant differences in Device performance were found across participants’ sex, race/ethnicity, income, or education level. For nearly a third of this primary care sample, the Device enabled timely diagnostic evaluation with a high degree of accuracy. The Device shows promise to significantly increase the number of children able to be diagnosed with ASD in a primary care setting, potentially facilitating earlier intervention and more efficient use of specialist resources.

AI-Kfil,a and AI-L,,, X-ray emission spectra and also the X-ray photoelectron spectrum of spinel, MgAl,O,, are reported. A model for the bonding is derived using simple molecular-orbital theory, which is adequate for a qualitative rationalisation of the observed spectra. The shape of particular X-ray emission peaks is shown to be strongly dependent on the bonding commitments and co-ordination of the emitting atoms.BY means of X-ray emission spectroscopy ls2 it is possible to investigate the bonding role of particular atomic orbitals from specified atoms. The Laporte selection rule (AZ = &l) for the dipole component of electromagnetic radiation ensures that a vacancy in an s orbital shall be filled only by electronic transitions from 9 orbitals, a vacancy in a p orbital by transitions from s and d orbitals, etc. Furthermore, simple calculations suffice to demonstrate that ' cross-over ' transitions from ligand atoms are unimportant, i.e. the intensity of X-radiation that derives from an electronic transition from one atom to a vacancy on another is negligible. These preliminary considerations show that X-ray emission is essentially an atomic phenomenon, which can, however, be severely perturbed by molecular bond formation. Obviously those X-rays which result from electronic transit ions from valence-band orbitals to inner vacancies will be the most affected. An atom A may make a variety of molecular orbitals (m.0.s) of different energies ( E l , Ez, . . . En) with say atom B. If valence-shell p orbitals of A contribute to these orbitals with coefficients (using the LCAO approximation) a,, a2, . . . a,, then the structure of the A K-emission band that arises from the (valence band+A 1s) transition will be n peaks corresponding to X-rays with energiesls) -E2, . . . E ( A , 1s) -E,& and with relative intensities (a1)2, ( c z ~) ~, . . . (a,J2. If p character from B were found in the same m.0.s with coefficients bl, bz, b,t then the structure of the corresponding K-emission peak for R would be a series o f peaks of energies E ( B , Is) -El, E(B, 1s) -E2, . . . E(B, 1s) -E , , with relative intensities (b1)2, ( l 1 2 ) ~, . . . A study of the structure of individual X-ray peaks thus reveals the bonding commitments of particular atomic orbitals, but a much more complete dissection of the chemical bond can be obtained by assembling com-(bfJ2.

NIH) Toolbox is a diverse set of brief measures assessing cognitive, motor, emotional, and sensory function in individuals ranging in age from 3 to 85. As shown by recent research, it has promising applications as new measure of cognition.Following the NIH plan for developing unifying criteria for clinically based research studies (the NIH Blueprint for Neuroscience), the Toolbox is a composition of a set of existing standardized neuropsychological instruments (e.g., Rey AVLT). The goals of the Cognitive portion of this measure are to offer improved clinical screening of a variety of neurocognitive disorders and facilitate comparison across empirical designs. The entire Toolbox measure is computer mediated, although some components (sensory, motor) also employ a more hands on operating component.The NIH Toolbox purports to monitor neurological, cognitive, behavioral, and emotional function and follows these domain constructs across the lifespan. The stated goal of these measures includes evaluating the efficacy of various interventions and treatment. Although the test has a main website (www.nihtoolbox.org), the tests are accessed via an alternate website, Assessment Center (http://www.assessmentcenter.net). Although the tests are free, one must apply (by submitting their credentials and purpose for using the tests) to have access to the Toolbox.The Cognitive portion of the Toolbox is designed to measure the following cognitive functions: executive function, attention, episodic memory, language, processing speed, and working memory. It contains two batteries: the Toolbox Cognition Battery and the Early Childhood Cognition Battery.

A method for the indirect detection of light elements, L (L = C, N, 0 or F), by using X-ray emission spectroscopy is described. The technique relies upon the formation of certain low-energy satellite peaks to those X-ray emission peaks which originate from electronic transitions involving the valence shell of an element, A, when A-L bonds are made. The energy difference between the main peak and the satellite peak is characteristic of the ligand (F, 20 f 1 eV; 0, 14 j, 2 eV; N, 9 f 2 eV; and C , about 5 eV). Applications to compounds that contain more than one type of ligand are described and experimental limitations are discussed.X-RAY emission spectroscopy is widely used for both qualitative and quantitative analyses for the elements present in a wide variety of minerals, glasses, ceramics and other materials.l-s Characteristic X-ray emission can be brought about either by irradiation with electrons (e.g., microprobe and betaprobe) or with X-rays (X-ray fluorescence), but in either instance it is found that the efficiency of X-ray emission diminishes with decrease in atomic number.Coupled with the inherent difficulties in the production of characteristic X-ray emission from light elements there are concomitant difficulties in detection. The wavelengths of the Ka lines of the light elements are boron 6-76 nm, carbon 4-47 nm, nitrogen 3.16 nm, oxygen 2.36 nm and fluorine 1.83 nm. Only the last two elements can be detected easily by the use of acid phthalate crystals with 2d spacings of about 2.6 nm. Other crystals and "soap films'' have been developed6 with larger 2d spacings but these are not in universal use. A second difficulty in detecting radiations from light elements is again associated with their low energies. Not only will the sample itself readily absorb them but so also will any gas present in the spectrometer. This difficulty can be overcome by carrying out the operation in a vacuum. Even so, it remains true to say that the light elements cannot readily be detected by X-ray emission spectroscopy. The purpose of this paper is to demonstrate that the presence of such light elements in a sample can, however, easily be established by a detailed investigation of specific low-energy satellite peaks associated with characteristic X-ray emissions of other elements in the sample.