Recurrence quantification analysis of resting state EEG signals in autism spectrum disorder - a systematic methodological exploration of technical and demographic confounders in the search for biomarkers.

BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a worldwide prevalence of 1-2%. In low-resource environments, in particular, early identification and diagnosis is a significant challenge. Therefore, there is a great demand for 'language-free, culturally fair' low-cost screening tools for ASD that do not require highly trained professionals. Electroencephalography (EEG) has seen growing interest as an investigational tool for biomarker development in ASD and neurodevelopmental disorders. One of the key challenges is the identification of appropriate multivariate, next-generation analytical methodologies that can characterise the complex, nonlinear dynamics of neural networks in the brain, mindful of technical and demographic confounders that may influence biomarker findings. The aim of this study was to evaluate the robustness of recurrence quantification analysis (RQA) as a potential biomarker for ASD using a systematic methodological exploration of a range of potential technical and demographic confounders. METHODS: RQA feature extraction was performed on continuous 5-second segments of resting state EEG (rsEEG) data and linear and nonlinear classifiers were tested. Data analysis progressed from a full sample of 16 ASD and 46 typically developing (TD) individuals (age 0-18 years, 4802 EEG segments), to a subsample of 16 ASD and 19 TD children (age 0-6 years, 1874 segments), to an age-matched sample of 7 ASD and 7 TD children (age 2-6 years, 666 segments) to prevent sample bias and to avoid misinterpretation of the classification results attributable to technical and demographic confounders. A clinical scenario of diagnosing an unseen subject was simulated using a leave-one-subject-out classification approach. RESULTS: In the age-matched sample, leave-one-subject-out classification with a nonlinear support vector machine classifier showed 92.9% accuracy, 100% sensitivity and 85.7% specificity in differentiating ASD from TD. Age, sex, intellectual ability and the number of training and test segments per group were identified as possible demographic and technical confounders. Consistent repeatability, i.e. the correct identification of all segments per subject, was found to be a challenge. CONCLUSIONS: RQA of rsEEG was an accurate classifier of ASD in an age-matched sample, suggesting the potential of this approach for global screening in ASD. However, this study also showed experimentally how a range of technical challenges and demographic confounders can skew results, and highlights the importance of probing for these in future studies. We recommend validation of this methodology in a large and well-matched sample of infants and children, preferably in a low- and middle-income setting.

A study of genotyping for management of human papillomavirus-positive, cytology-negative cervical screening results.

The effective management of women with human papillomavirus (HPV)-positive, cytology-negative results is critical to the introduction of HPV testing into cervical screening. HPV typing has been recommended for colposcopy triage, but it is not clear which combinations of high-risk HPV types provide clinically useful information. This study included 18,810 women with Hybrid Capture 2 (HC2)-positive, cytology-negative results and who were age ≥30 years from Kaiser Permanente Northern California. The median follow-up was 475 days (interquartile range [IQR], 0 to 1,077 days; maximum, 2,217 days). The baseline specimens from 482 cases of cervical intraepithelial neoplasia grade 3 or cancer (CIN3+) and 3,517 random HC2-positive noncases were genotyped using 2 PCR-based methods. Using the case-control sampling fractions, the 3-year cumulative risks of CIN3+ were calculated for each individual high-risk HPV type. The 3-year cumulative risk of CIN3+ among all women with HC2-positive, cytology-negative results was 4.6%. HPV16 status conferred the greatest type-specific risk stratification; women with HC2-positive/HPV16-positive results had a 10.6% risk of CIN3+, while women with HC-2 positive/HPV16-negative results had a much lower risk of 2.4%. The next most informative HPV types and their risks in HPV-positive women were HPV33 (5.9%) and HPV18 (5.9%). With regard to the etiologic fraction, 20 of 71 cases of cervical adenocarcinoma in situ (AIS) and adenocarcinoma in the cohort were positive for HPV18. HPV16 genotyping provides risk stratification useful for guiding clinical management; the risk among HPV16-positive women clearly exceeds the U.S. consensus risk threshold for immediate colposcopy referral. HPV18 is of particular interest because of its association with difficult-to-detect glandular lesions. There is a less clear clinical value of distinguishing the other high-risk HPV types.

"Give Sorrow Words": Working With Bereavement in Senior Residential Settings.

Bereavement and its consequent grief are frequent in senior residential settings. Failure to manage grief appropriately can have serious medical consequences, principally clinical depression. Focused talk with a grieving person can help ease the pain of grief; it can also help prevent complications that often lead to depression. Along with mental health professionals, staff members and volunteers can be important, and less expensive, participants in reaching this goal.

Neck cooling and cognitive performance following exercise-induced hyperthermia.

PURPOSE: To assess the efficacy of neck cooling on cognitive performance following exertional hyperthermia. METHODS: Twelve healthy men completed two experimental trials [control (CON) and neck cooling collar (NCC)] in a counter-balanced design. They ran on a treadmill at 70% VO2peak under warm and humid conditions (dry bulb temperature: 30.2 ± 0.3 °C, relative humidity: 71 ± 2 %) for 75 min or until volitional exhaustion. Gastrointestinal, neck and skin temperatures, heart rate and subjective ratings were assessed. Serum brain-derived neurotrophic factor (BDNF) levels were measured before and after each run. Cognitive performance comprising symbol digit matching, search and memory, digit span, choice reaction time and psychomotor vigilance test (PVT) were assessed before and after exercise. RESULTS: Mean gastrointestinal temperature was similar after exercise between trials (CON: 39.5 ± 0.4 °C vs. NCC: 39.6 ± 0.3 °C; p = 0.15). Mean neck temperature was lowered in NCC compared to CON after the run (36.4 ± 1.6 °C vs. NCC: 26.0 ± 0.3 °C; p < 0.001). Exercise-induced hyperthermia improved mean reaction time in the symbol digit matching test (-134 ± 154 ms; p < 0.05) and the PVT (-18 ± 30 ms; p < 0.05). Maximum span was increased in the digit span test (1 ± 2; p < 0.05). Application of NCC reduced the number of search errors made in level 3 of the search and memory test (p < 0.05). Mean serum BDNF levels were increased following exercise-induced hyperthermia in both trials (p < 0.05). CONCLUSION: Exercise-induced hyperthermia improves working memory and alertness. Neck cooling may only enhance performance in tasks of higher complexity.

The alpha 3 domain of the Qa-2 molecule is defective for CD8 binding and cytotoxic T lymphocyte activation.

Qa-2 is a nonclassical class I molecule encoded by the Q7 gene within the mouse major histocompatibility complex (MHC). Results from previous experiments on Qa-2, and on a chimeric Ld molecule (LQ3) in which the alpha 3 domain is encoded by Q7b, suggested that the alpha 3 domain of Qa-2 does not carry out the functions typical of the alpha 3 domains in other classical and nonclassical class I antigens. Class I molecules that contain the Qa-2 alpha 3 domain are poorly recognized by primary cytotoxic T lymphocytes (CTLs), and do not function normally in either positive or negative selection in vivo. By employing a cell-cell adhesion assay we demonstrate directly that the Qa-2 alpha 3 domain in the context of the LQ3 hybrid molecule cannot bind to human CD8, although other mouse class I alpha 3 domains bind efficiently. In addition, CD8-dependent CTL-mediated lysis of target cells, in a system which requires mouse CD8-class I alpha 3 domain interactions, is deficient in cells that express the Qa-2 alpha 3 domain. When combined with our earlier work on LQ3 transgenic mice, these results provide additional molecular support for the hypothesis that interaction with CD8 is required for both positive and negative selection of class I restricted T cells in the thymus. As the Qa-2 alpha 3 domain sequence does not differ from the previously defined minimal CD8 binding sequence of other class I molecules, these results also suggest that additional amino acids in the alpha 3 domain must be critical for CD8 binding and CTL activation.

Effect of fiber source and particle size on chick performance and nutrient utilization.

The addition of fiber in chick feeds is known to dilute nutrients; as a result, this may reduce nutrient digestibility and performance. However, recent studies suggest that moderate inclusion of insoluble fibers (2 to 3%) may stimulate gizzard development, which could result in better nutrient utilization and chick growth. The previous fiber sources evaluated were subject to wide fluctuation in their nutritional and chemical composition due to variation in processing. Miscanthus giganteus is a C4 grass purposefully grown for its fiber content which has a consistent fiber composition compared to food process residues. The objectives of this study were to determine the effect of dietary fiber source and particle size on day-old chick performance and nutrient digestibility. Day-old chicks (8 chicks per cage, 5 cages per treatment) were fed diets containing 3% of either sepiolite (SEP), cellulose (CEL), coarse beet pulp (BP), fine BP, coarse Miscanthus grass (MG), and fine MG. At the end of days 7, 14, and 21, chicks and experimental diets were weighed to compute average daily gain and feed intake. In addition, excreta from the previous 48 h of each data capture point was collected to determine nutrient digestibility. In general, chicks fed diets containing fiber consumed more feed, gained more weight, and had better feed conversion rate than birds fed the SEP diet. Particle size of the fiber had no effect on chick performance; however, nutrient utilization was higher (P < 0.05) for chicks fed coarse fiber particles compared to these fed fine fiber particles. Birds fed diets containing MG performed similar to chicks fed CEL (P > 0.05), but digestibility coefficients of birds fed BP diets were generally higher than chicks fed MG diets. In conclusion, chicks performed better with fiber in their diet and MG was comparable to CEL.

The amino acid composition and protein quality of various egg, poultry meal by-products, and vegetable proteins used in the production of dog and cat diets.

New protein ingredients are used to support pet food market growth and the development of new products while maintaining animal dietary needs. However, novel protein sources (e.g., spray-dried chicken, and (or) rice, pea, and potato protein concentrates) have limited data available regarding their protein quality. The objective of this study was to evaluate protein ingredients used in the pet food industry by laboratory analysis and a chick growth assay as a model. Following analysis for proximate and amino acid composition, chicks (six birds per pen with four pens per treatment) were fed experimental diets for 10 d. Diets contained 10% crude protein from each of the experimental protein sources (spray-dried egg-SDEG; spray-dried egg white-SDEW, spray-dried inedible whole egg-SDIE, chicken by-product meal-CBPM, chicken meal-CKML, low-temperature fluid bed air-dried chicken-LTCK, low-temperature and pressure fluid bed dried chicken-LTPC, spray-dried chicken-SDCK, whey protein concentrate-WPCT, corn gluten meal-CGML, corn protein concentrate-CPCT, potato protein isolate-PPIS, rice protein concentrate-RPCT, pea protein isolate-PEPI, soy protein isolate-SPIS, and soybean meal-SBML) along with an N-free diet (negative control). Chicks fed SDEG, SDIE, and LTPC had the highest protein efficiency ratio (PER; P < 0.0001; 5.18, 5.37, and 5.33, respectively), LTCK and SDCK were intermediate (4.54 and 4.79), and the CBPM and CKML were the lowest among the poultry proteins for EAA:NEAA, PER, and Lys availability. Among the vegetable proteins, PPIS and SBML had the highest PER values (3.60 and 3.48, P < 0.0001). In general, the chick PER method ranked the quality of animal protein sources higher than vegetable proteins, and these results were consistent with the EAA:NEAA ratio and Lys availability.

Biosorption of heavy metals from aqueous solutions with tobacco dust.

A typical lignocellulosic agricultural residue, namely tobacco dust, was investigated for its heavy metal binding efficiency. The tobacco dust exhibited a strong capacity for heavy metals, such as Pb(II), Cu(II), Cd(II), Zn(II) and Ni(II), with respective equilibrium loadings of 39.6, 36.0, 29.6, 25.1 and 24.5mg of metal per g of sorbent. Moreover, the heavy metals loaded onto the biosorbent could be released easily with a dilute HCl solution. Zeta potential and surface acidity measurements showed that the tobacco dust was negatively charged over a wide pH range (pH>2), with a strong surface acidity and a high OH(-) adsorption capacity. Changes in the surface morphology of the tobacco dust as visualized by atomic force microscopy suggested that the sorption of heavy metal ions on the tobacco could be associated with changes in the surface properties of the dust particles. These surface changes appeared to have resulted from a loss of some of the structures on the surface of the particles, owing to leaching in the acid metal ion solution. However, Fourier transform infrared spectroscopy (FTIR) showed no substantial change in the chemical structure of the tobacco dust subjected to biosorption. The heavy metal uptake by the tobacco dust may be interpreted as metal-H ion exchange or metal ion surface complexation adsorption or both.

New methodology for hazardous waste classification using fuzzy set theory Part II. Intelligent decision support system.

In part 1 of this paper, factors that influence hazards and eco/toxicity in composite hazardous wastes were described. In part 2, a computer-aided decision support tool based on fuzzy set theory is proposed to support the classification of composite wastes. Given the chemical properties, the nature of microorganisms that may be present, the behaviour of chemicals in humans and ecosystems, and the quantities of wastes, the computer-aided tool automatically classifies the waste as benign, partially hazardous, hazardous or highly hazardous. The functionality of the computer-aided decision tool is demonstrated through nine worked examples and the results are discussed in detail.

New methodology for hazardous waste classification using fuzzy set theory Part I. Knowledge acquisition.

In the literature on hazardous waste classification, the criteria used are mostly based on physical properties, such as quantity (weight), form (solids, liquid, aqueous or gaseous), the type of processes generating them, or a set of predefined lists. Such classification criteria are inherently inadequate to account for the influence of toxic and hazard characteristics of the constituent chemicals in the wastes, as well as their exposure potency in multimedia environments, terrestrial mammals and other biota. Second, none of these algorithms in the literature has explicitly presented waste classification by examining the contribution of individual constituent components of the composite wastes. In this two-part paper, we propose a new automated algorithm for waste classification that takes into account physicochemical and toxicity effects of the constituent chemicals to humans and ecosystems, in addition, to the exposure potency and waste quantity. In part I, available data on the physicochemical and toxicity properties of individual chemicals in humans and ecosystems, their exposure potency in environmental systems and the effect of waste quantity are described, because they fundamentally contribute to the final waste ranking. Knowledge acquisition in this study was accomplished through the extensive review of published and specialized literature to establish facts necessary for the development of fuzzy rule-bases. Owing to the uncertainty and imprecision of various forms of data (both quantitative and qualitative) essential for waste classification, and the complexity resulting from knowledge incompleteness, the use of fuzzy set theory for the aggregation and computation of waste classification ranking index is proposed. A computer-aided intelligent decision tool is described in part II of this paper and the functionality of the fuzzy waste classification algorithm is illustrated through nine worked examples.

Pleiotropic phenotype of cultured murine cells resistant to maytansine, vincristine, colchicine, and adriamycin.

A noncloned subline of 3T3FL cells was developed that was resistant to the toxicity of the ansamycin alkaloid maytansine. Culture of 3T3FL cells with serially increasing concentrations of maytansine resulted in a cell line resistant to maytansine at concentrations 118-fold higher than concentrations cytotoxic for parental cells. Resistant cells (3T3r) exhibited cross-resistance to colchicine, vincristine, adriamycin, and, to a lesser extent, cytochalasin B. Studies of binding and uptake of tritiated colchicine suggested that drug resistance of 3T3r cells might reflect decreased uptake of drug without decreased binding to surface receptors. Murine sarcoma virus transformed 3T3r cells less efficiently than 3T3FL cells.

An aggregate fuzzy hazardous index for composite wastes.

In this paper, a fuzzy waste index for evaluating the hazard posed by composite wastes generated from industrial processes is proposed. Within this methodology, a fuzzy index as a measure of hazardousness of a given composite waste is derived from the crisp inputs of its component's flammability, corrosivity, toxicity and reactivity attributes based on the National Fire Protection Association (NFPA) hazard rankings. The novelty of this work lies in establishing an integrated fuzzy hazardous waste index (FHWI) which provides a single-value representing the hazard ranking of a composite waste. This is contrary to current techniques which do not provide a final aggregated hazard index. The efficacy of the new proposed approach is illustrated through several worked examples. The results demonstrate that the fuzzy algorithm can be useful in aiding policy and decision-makers in conducting comprehensive initial evaluation of the status of waste hazardous status without the need for costly laboratory experiments. As such, the approach offers a robust and transparent decision-making methodology.

The clouded crystal ball: a 35-year follow-up of psychiatrists' predictions.

In 1946-1949 psychiatrists examined in depth more than 200 students from four first-year medical school classes and predicted their future adjustment. Judging by the former students' replies to a questionnaire in 1981-1982, the psychiatrists' favorable predictions were for the most part borne out, whereas the unfavorable predictions were much less likely to have been realized. The psychiatrists appeared to have overemphasized the significance of the psychopathology they discovered and to have underestimated the potential of many of these young adults for spontaneous personality change.

HLA-G1 protein expression is not essential for fetal survival.

HLA-G is a nonclassical, class I HLA gene that is primarily expressed by fetal cells at the maternal-fetal interface and is thought to play a key role in the induction of tolerance in pregnancy. This paper reports the identification of a single base pair deletion at position 1597 (1597delC) in exon 3 (encoding the alpha2-domain) of HLA-G on 20 of 272 (7.4 per cent) African American chromosomes, three of 102 (2.9 per cent) Hispanic chromosomes, and none of 134 Caucasian chromosomes. This relatively common frameshift mutation results in amino acid substitutions in all of the residues in the second half of exon 3 including the conserved cysteine at codon 164. An adult individual was identified who was homozygous for this 'null' allele, and a first trimester placenta that was homozygous for 1597delC had no detectable HLA-G1 protein. These data indicate that expression of HLA-G1 protein is not essential for fetal survival.

Inhibition of duck hepatitis B virus replication by hypericin.

Hypericin was found to be active against a member of the hepatitis B virus family, duck hepatitis B virus (DHBV). After a single 1 h incubation with hypericin, cells stably-transfected with a clone of DHBV stopped producing infectious virus for several days, though virus-like particles continued to be released into the culture medium. Characterization of these virions revealed a buoyant density characteristic of infectious virus preparations and lower than that of virus cores, suggesting that the particles were enveloped. Western blot analysis suggested, however, that the viral preS protein in surface antigen particles and, by inference, in virions, was present in covalently cross-linked aggregates. Evidence of a similar level of aggregation of the core subunit of virion nucleocapsids was not found, nor was there evidence of a similar high level of aggregation of cell-associated core and preS proteins. Hypericin was only slightly virucidal against DHBV and culture medium from treated cultures did not block initiation of infection when added to DHBV susceptible cultures prior to a challenge with infectious DHBV. Thus, the primary antiviral activity of hypericin against DHBV replication appears to be exerted at a late step in viral morphogenesis.

HLA-G polymorphisms: neutral evolution or novel function?

HLA-G is a non-classical class Ib gene with many unusual features. Because of its unique expression pattern, which is primarily limited to fetal cells at the maternal fetal interface, this gene has gained the attention of many investigators. In this paper we review some of the novel features of HLA-G, with particular reference to polymorphic variants in the gene, and discuss the implications of these features for the potential function and evolutionary history of HLA-G.

A null mutation in HLA-G is not associated with preeclampsia or intrauterine growth retardation.

Modulation of the expression of genes of the major histocompatibility complex (MHC) in tissues at the maternal-fetal interface almost certainly plays a role in successful development of the semi-allogeneic fetus. While expression of the classical class I genes (HLA-A, B, C) is low to non-existent at this site, the non-classical molecule, HLA-G, is expressed uniquely in fetal cells at the maternal-fetal interface. The recent demonstration that homozygotes for a deletion mutation in exon 3 (1597DeltaC) of HLA-G do not express the full-length HLA-G1 isoforms indicates a potential reduction in expression of this isoform in heterozygotes. If the full-length isoform of HLA-G (i.e. HLA-G1) contributes to proper invasion of maternal spiral arteries by extravillous cytotrophoblast, then 1597DeltaC heterozygotes could be at increased risk for disorders of trophoblast invasion. Two populations, infants with intrauterine growth retardation (IUGR) and infants of preeclamptic (PE) mothers, were genotyped for the 1597DeltaC polymorphism. The frequency of 1597DeltaC in these samples was not significantly different from healthy controls, suggesting that heterozygotes for this deletion mutation are not at significantly increased risk for PE or IUGR (P = 0.727 and 0.803, respectively).

Fetal cerebral oxygenation measured by near-infrared spectroscopy shortly before birth and acid-base status at birth.

OBJECTIVE: To test the hypothesis that the mean cerebral oxygen saturation measured by near-infrared spectroscopy shortly before delivery correlates with fetal acid-base status in umbilical cord blood. METHODS: A specially designed optical probe was inserted through the dilated cervix and placed against the fetal head during labor in 41 women. Changes in cerebral oxyhemoglobin and deoxyhemoglobin concentrations were measured continuously, and the mean cerebral oxygen saturation was determined over a 10-minute period within 30 minutes of delivery. Umbilical arterial and venous blood acid-base status was assessed immediately after birth and then correlated to the values for mean cerebral saturation. RESULTS: Values for mean cerebral oxygen saturation could be determined in 33 fetuses. Umbilical cord artery and vein pH (r = 0.82 and r = 0.79, respectively) showed significant positive correlations (P < .001), whereas base deficit (r = -0.73 and r = -0.71) and carbon dioxide pressure (r = -0.68 and r = -0.63) showed significant negative correlations (P < .001) with mean cerebral oxygen saturation measured within 30 minutes before birth. There was also a significant positive correlation between umbilical vein oxygen pressure and mean cerebral oxygen saturation (r = 0.51, P < .01). CONCLUSION: Fetal umbilical blood gas and acid-base status at birth showed significant correlations with mean cerebral oxygen saturation measured shortly before delivery. Low values for saturation were related to both respiratory and metabolic acidemia.

Oxidized lipid depresses canine growth, immune function, and bone formation.

Dietary oxidized lipids can increase oxidative stress and potentially contribute to a variety of disease syndromes. This research describes the first use of a canine model to assess the effects of dietary oxidized lipids on growth, antioxidant status, and some immune functions. Three groups of eight, two-month old coon-hound puppies were pair fed diets for 16 weeks. The control diet contained <50 ppm aldehydes, and two additional diets contained thermally oxidized lipids targeted to contain 100 ppm aldehydes (medium-oxidation) and 500 ppm aldehydes (high-oxidation). Dogs fed the high-oxidation diet weighed less than those from the medium-oxidation (P < 0.05) and control groups (P < 0.001) at the end of the study. Oxidized lipids reduced serum vitamin E levels, total body fat content, and bone appositional rate. At different time points of the study, peripheral blood neutrophils and monocytes from dogs fed the HO diet had reduced oxidative burst capacity and produced less superoxide and hydrogen peroxide when stimulated with phorbol esters compared to the control group. Lymphocyte blastogenesis in response to concanavalin A was suppressed by dietary oxidized lipid. This study indicates that dietary oxidized lipids negatively affect the growth, antioxidant status, and some immune functions of dogs. Importantly, some effects are evident at 100 ppm aldehydes in the diet, which is a moderate level of oxidation. The rapid growth and weight gain of the dog during the first 6 months of life may also provide a better model for assessing the risks of dietary oxidized lipid in children and adolescents than previously used rodent models.

Embedding of multidimensional time-dependent observations.

A method is proposed to reconstruct dynamic attractors by embedding of multivariate observations of dynamic nonlinear processes. The Takens embedding theory is combined with independent component analysis to transform the embedding into a vector space of linearly independent vectors (phase variables). The method is successfully tested against prediction of the unembedded state vector in two case studies of simulated chaotic processes.