739 research outputs found
A Winged Zorotypus in Miocene Amber from the Dominician Republic (Zoraptera: Zorotypidae), with Discussion on Relationships of and within the Order
A new fossil zorapteran is described and figured in Miocene Dominican amber. The specimen is the first winged Zorotypus fossil, and is described as Zorotypus goeleti n.sp. The species is distinguished from the only other fossil zorapteran, Z. palaeus also in Dominican amber, as well as an extant species to which it appears most similar, Z. snyderi. The new fossil is significant in the possession of segmented cerci, a plesiomorphic character unique for the order. The classification of the order is briefly summarized and genera proposed by Kukalová - Peck and Peck (1993) and Chao and Chen (2000) are new ly synonymized under Zorotypus. Phylogenetic affinities within Zoraptera and of the order among other lower Neoptera are briefly discussed. The order is considered to be most closely allied to the webspinners, order Embiidina
Functional properties of two mutants of human glucose 6-phosphate dehydrogenase, R393G and R393H, corresponding to the clinical variants G6PD Wisconsin and Nashville
AbstractTwo severe Class I human glucose-6-phosphate dehydrogenase (G6PD, EC1.1.1.49) mutations, G6PDWisconsin (nt1177 C→G, R393G) and G6PDNashville (nt1178 G→A, R393H), affect the same codon, altering a residue in the dimer interface close to the “structural” NADP+ site. These mutations are predicted to influence interaction with the bound “structural” NADP+, long supposed to be crucial for enzyme stability. Recombinant proteins corresponding to these mutants have been constructed, expressed and purified to homogeneity. Steady-state kinetic parameters of the mutant enzymes were comparable to those of normal human G6PD, indicating that the mutations do not alter catalytic efficiency drastically. However, investigations of thermostability, urea denaturation, protease digestion, and hydrophobic exposure demonstrated that G6PD R393H is less stable than normal G6PD or R393G, and stability was more NADP+-dependent. Apoenzymes were prepared by removal of “structural” NADP+. Again the G6PDNashville protein was markedly less stable, and its dissociation constant for “structural” NADP+ is ∼500 nM, about 10 times higher than values for R393G (53 nM) and normal G6PD (37 nM). These results, together with structural information, suggest that the instability of the R393H protein, enhanced by the weakened binding of “structural” NADP+, is the likely cause of the severe clinical manifestation observed for G6PDNashville. They do not, however, explain the basis of disease in the case of G6PDWisconsin
Psocoptera (Insecta) in Eocene Rovno Amber (Ukraine)
A brief,
annotated checklist of the described barklouse (Paraneoptera, Psocodea, Psocoptera) fauna from Rovno
amber is provided. All species are also documented in the roughly contemporaneous Baltic amber fauna.
The fauna includes representatives of all three suborders and most major lineages of the Psocoptera,
including the interesting families Archipsocidae and Sphaeropsocidae.Впервые приведен краткий аннотированный список сеноедов (Paraneoptera, Psocodea, Psocoptera) эоценового ровенского янтаря. Все виды известны также из одновозрастного балтийского янтаря. Фауна включает в себя представителей всех трех подотрядов и большинства филогенетических линий Psocoptera, включая интересные семейства Archipsocidae и Sphaeropsocidae
Prenatal exposure to pyrethroid pesticides and childhood behavior and executive functioning
Several previous studies of pyrethroid biomarkers and behavior have reported associations between concurrent pyrethroid levels and adverse behavioral problems in children. One geospatial study reported associations between prenatal exposure to pyrethroids and autism. However, the association between prenatal pyrethroid biomarkers and childhood behavior is unknown. The Mount Sinai Children's Environmental Health Center is a prospective birth cohort with urinary pyrethroid biomarkers during pregnancy and behavioral measurements at 4, 6, and 7–9 years of age. Primiparous women were enrolled between 1998 and 2002. 162 mother/child pairs with complete exposure and behavioral outcomes data were used to investigate associations between detectable levels of prenatal pyrethroid metabolites and scores on the Behavioral Assessment System for Children and the Behavior Rating Inventory of Executive Function. Overall, detection frequencies of pyrethroid metabolites were low (<30%). In longitudinal mixed models, detectable levels of 3-PBA during pregnancy were associated with worse Internalizing (β −4.50, 95% CI −8.05, −0.95), Depression (β −3.21, 95% CI −6.38, −0.05), Somatization (β −3.22, 95% CI −6.38, −0.06), Behavioral Regulation (β −3.59, 95% CI −6.97, −0.21), Emotional Control (β −3.35, 95% CI −6.58, −0.12), Shifting (β −3.42, 95% CI −6.73, −0.11), and Monitoring (β −4.08, 95% CI −7.07, −1.08) scales. Detectable levels of cis-DCCA were associated with worse Externalizing (β −4.74, 95% CI −9.37, −0.10), Conduct Problems (β −5.35, 95% CI −9.90, −0.81), Behavioral Regulation (β −6.42, 95% CI −11.39, −1.45), and Inhibitory Control (β −7.20, 95% CI −12.00, −2.39). Although detection frequencies of pyrethroid metabolites were low, we found suggestive evidence that prenatal exposure to 3-PBA and cis-DCCA may be associated with a variety of behavioral and executive functioning deficits
Early Life Characteristics and Neurodevelopmental Phenotypes in the Mount Sinai Children’s Environmental Health Center
Neurodevelopmental outcomes including behavior, executive functioning, and IQ exhibit complex correlational structures, although they are often treated as independent in etiologic studies. We performed a principal components analysis of the behavioral assessment system for children, the behavior rating inventory of executive functioning, and the Wechsler scales of intelligence in a prospective birth cohort, and estimated associations with early life characteristics. We identified seven factors: (1) impulsivity and externalizing, (2) executive functioning, (3) internalizing, (4) perceptual reasoning, (5) adaptability, (6) processing speed, and (7) verbal intelligence. Prenatal fish consumption, maternal education, preterm birth, and the home environment were important predictors of various neurodevelopmental factors. Although maternal smoking was associated with more adverse externalizing, executive functioning, and adaptive composite scores in our sample, of the orthogonally-rotated factors, smoking was only associated with the impulsivity and externalizing factor (β^ − 0.82, 95% CI − 1.42, − 0.23). These differences may be due to correlations among outcomes that were accounted for by using a phenotypic approach. Dimension reduction may improve upon traditional approaches by accounting for correlations among neurodevelopmental traits
Backpropagation training in adaptive quantum networks
We introduce a robust, error-tolerant adaptive training algorithm for
generalized learning paradigms in high-dimensional superposed quantum networks,
or \emph{adaptive quantum networks}. The formalized procedure applies standard
backpropagation training across a coherent ensemble of discrete topological
configurations of individual neural networks, each of which is formally merged
into appropriate linear superposition within a predefined, decoherence-free
subspace. Quantum parallelism facilitates simultaneous training and revision of
the system within this coherent state space, resulting in accelerated
convergence to a stable network attractor under consequent iteration of the
implemented backpropagation algorithm. Parallel evolution of linear superposed
networks incorporating backpropagation training provides quantitative,
numerical indications for optimization of both single-neuron activation
functions and optimal reconfiguration of whole-network quantum structure.Comment: Talk presented at "Quantum Structures - 2008", Gdansk, Polan
Prenatal phthalate exposures and child temperament at 12 and 24 months
Introduction Gestational phthalate exposures have been adversely associated with attention, externalizing, and internalizing behaviors in childhood. Early childhood temperament may be a marker of later behavioral patterns. We therefore sought to determine whether gestational phthalate exposures were associated with infant and toddler temperament. Methods The Mount Sinai Children's Environmental Health Study is a prospective cohort study of children born between May 1998 and July 2001 in New York City (N = 404). Phthalate metabolites were measured in spot urine samples collected from pregnant women in their third trimester. Child temperament was assessed by parental report at 12-months using the Infant Behavior Questionnaire (IBQ) (N = 204) and at 24-months using the Toddler Behavior Assessment Questionnaire (TBAQ) (N = 279). We used multiple linear regression to evaluate associations between urinary phthalate metabolites and eleven temperament domains. Results Phthalate biomarker concentrations were weakly associated with lower gross motor activity levels as well as higher duration of orienting at the 12-month assessment. Mono(3-carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP) and the sum of metabolites of di(2-ethylhexyl) phthalate (∑DEHP) were associated with lower levels of smiling and laughing at 12 months. At 24-months, social fear and lower pleasure was linked to higher concentrations of MCPP and MBzP, and higher ∑DEHP was weakly associated with increased anger levels at 24-months. Conclusions Though we observed some weak associations between biomarkers of prenatal exposure to phthalates and temperament at 12- and 24-months, overall phthalates biomarkers were not strongly associated with alterations in temperament
- …