Contrasts between organic participation in apatite biomineralization in brachiopod shell and vertebrate bone identified by nuclear magnetic resonance spectroscopy

Unusually for invertebrates, linguliform brachiopods employ calcium phosphate mineral in hard tissue formation, in common with the evolutionarily distant vertebrates. Using solid-state nuclear magnetic resonance spectroscopy (SSNMR) and X-ray powder diffraction, we compare the organic constitution, crystallinity and organic matrix–mineral interface of phosphatic brachiopod shells with those of vertebrate bone. In particular, the organic–mineral interfaces crucial for the stability and properties of biomineral were probed with SSNMR rotational echo double resonance (REDOR). Lingula anatina and Discinisca tenuis shell materials yield strikingly dissimilar SSNMR spectra, arguing for quite different organic constitutions. However, their fluoroapatite-like mineral is highly crystalline, unlike the poorly ordered hydroxyapatite of bone. Neither shell material shows ¹³C{³¹P} REDOR effects, excluding strong physico-chemical interactions between mineral and organic matrix, unlike bone in which glycosaminoglycans and proteins are composited with mineral at sub-nanometre length scales. Differences between organic matrix of shell material from L. anatina and D. tenuis, and bone reflect evolutionary pressures from contrasting habitats and structural purposes. The absence of organic–mineral intermolecular associations in brachiopod shell argues that biomineralization follows different mechanistic pathways to bone; their details hold clues to the molecular structural evolution of phosphatic biominerals, and may provide insights into novel composite design.     

Making sense of surprise: An investigation of the factors influencing surprise judgments.

Surprise is often defined in terms of disconfirmed expectations, whereby the surprisingness of an event is thought to be dependent on the degree to which it contrasts with a more likely, or expected, outcome. The authors investigated the alternative hypothesis that surprise is more accurately modeled as a manifestation of an ongoing sense-making process. In a series of experiments, participants were given a number of scenarios and rated surprise and probability for various hypothetical outcomes that either confirmed or disconfirmed an expectation. Experiment 1 demonstrated that representational specificity influences the relationship that holds between surprise and probability ratings. Experiment 2 demonstrated that the inclusion of an enabling event lowers surprise ratings for disconfirming outcomes. Experiment 3 explored the reason for this effect, revealing that enabling events lower surprise by reducing uncertainty, thus enhancing ease of integration. Experiment 4 evaluated the contrast hypothesis directly, showing that differences in contrast are not correlated with differences in surprise. These results provide converging support for the view that the level of surprise experienced for an event is related to the difficulty of integrating that event with an existing representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of a pseudo-3D imaging system (tomosynthesis) for security screening of passenger baggage

This paper describes a study investigating the potential of tomosynthesis as a post check-in baggage scanning system. A laboratory system has been constructed consisting of a moveable source and detector, arranged around a mini 90° bend conveyor system, from which multiple projection images can be collected. Simulation code has been developed to allow the optimum source and detector positions to be determined. Reconstruction methods are being developed to modify the Shift-And-Add (SAA) algorithm to accommodate the non-typical imaging geometry.     

Depression and anxious apprehension distinguish frontocingulate cortical activity during top-down attentional control.

A network consisting of left dorsolateral prefrontal cortex (LDLPFC) and dorsal anterior cingulate cortex (dACC) has been implicated in top-down attentional control. Few studies have systematically investigated how this network is altered in psychopathology, despite evidence that depression and anxiety are associated with attentional control impairments. Functional MRI and dense-array event-related brain potential (ERP) data were collected in separate sessions from 100 participants during a color–word Stroop task. Functional MRI results guided ERP source modeling to characterize the time course of activity in LDLPFC (300–440 ms) and dACC (520–680 ms). At low levels of depression, LDLPFC activity was indirectly related to Stroop interference and only via dACC activity. In contrast, at high levels of depression, dACC did not play an intervening role, and increased LDLPFC activity was directly related to decreased Stroop interference. Specific to high levels of anxious apprehension, higher dACC activity was related to more Stroop interference. Results indicate that depression and anxious apprehension modulate temporally and functionally distinct aspects of the frontocingulate network involved in top-down attention control. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Military youth and the deployment cycle: Emotional health consequences and recommendations for intervention.

The United States military force includes over 2.2 million volunteer service members. Three out of five service members who are deployed or are preparing for deployment have spouses and/or children. Stressors associated with the deployment cycle can lead to depression, anxiety, and behavior problems in children, as well as psychological distress in the military spouse. Further, the emotional and behavioral health of family members can affect the psychological functioning of the military service member during the deployment and reintegration periods. Despite widespread acknowledgment of the need for emotional and behavioral health services for youth from military families, many professionals in a position to serve them struggle with how to best respond and select appropriate interventions. The purpose of this paper is to provide an empirically based and theoretically informed review to guide service provision and the development of evidence based treatments for military youth in particular. This review includes an overview of stressors associated with the deployment cycle, emotional and behavioral health consequences of deployment on youth and their caretaking parent, and existing preventative and treatment services for youth from military families. It concludes with treatment recommendations for older children and adolescents experiencing emotional and behavioral health symptoms associated with the deployment cycle. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

"Visual analysis of multiple baseline across participants graphs when change is delayed": Correction to Lieberman et al. (2010).

Reports an error in "Visual analysis of multiple baseline across participants graphs when change is delayed" by Rebecca G. Lieberman, Paul J. Yoder, Brian Reichow and Mark Wolery (School Psychology Quarterly, 2010[Mar], Vol 25[1], 28-44). There were several errors in the text. The corrected text is provided in the erratum. (The following abstract of the original article appeared in record 2010-05458-003.) A within-subjects group experimental design was used to test whether three manipulated characteristics of multiple baseline across participants (MBL-P) data showing at least a month delayed change in slope affected experts’ inference of a functional relation and agreement on this judgment. Thirty-six experts completed a survey composed of 16 MBL-P graphs. Graphs with steep slopes, once change began, were far more likely to be judged as showing a functional relation. Generally, experts disagreed with each other regarding functional relation judgments. Implications for the types of dependent variables that fit the requirements of MBL-P are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Distress in spouses of service members with symptoms of combat-related PTSD: Secondary traumatic stress or general psychological distress?

Combat-related posttraumatic stress disorder (PTSD) is linked with elevated psychological distress in service members'/veterans' spouses. Researchers use a variety of terms to describe this distress, and recently, secondary traumatic stress and secondary traumatic stress disorder (STS/STSD) have become increasingly commonly used. Although STS/STSD connotes a specific set of symptoms that are linked to service members'/veterans' symptoms, researchers often use general measures of distress or generically worded measures of PTSD symptoms to assess STS/STSD. To determine how often scores on such measures appear to be an accurate reflection of STS/STSD, we examined responses to a measure of PTSD symptoms in 190 wives of male service members with elevated levels of PTSD symptoms. Wives rated their own PTSD symptoms, and then answered questions about their attributions for the symptoms they endorsed. Fewer than 20% of wives who endorsed symptoms on the PTSD measure attributed these symptoms completely to their husbands' military experiences. Moreover, compared with wives who attributed symptoms only to events in their own lives, wives who attributed symptoms completely or partially to their husbands' military experiences had a greater overlap between some of their responses on the PTSD measure and their responses to a measure of general psychological distress. These results suggest that most wives of service members/veterans with PTSD experience generic psychological distress that is not conceptually consistent with STS/STSD, although a subset does appear to endorse a reaction consistent with this construct. Implications of these findings for intervention and research with this vulnerable population are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Prenatal Exposure to Arsenic and Cadmium Impacts Infectious Disease-Related Genes within the Glucocorticoid Receptor Signal Transduction Pathway

There is increasing evidence that environmental agents mediate susceptibility to infectious disease. Studies support the impact of prenatal/early life exposure to the environmental metals inorganic arsenic (iAs) and cadmium (Cd) on increased risk for susceptibility to infection. The specific biological mechanisms that underlie such exposure-mediated effects remain understudied. This research aimed to identify key genes/signal transduction pathways that associate prenatal exposure to these toxic metals with changes in infectious disease susceptibility using a Comparative Genomic Enrichment Method (CGEM). Using CGEM an infectious disease gene (IDG) database was developed comprising 1085 genes with known roles in viral, bacterial, and parasitic disease pathways. Subsequently, datasets collected from human pregnancy cohorts exposed to iAs or Cd were examined in relationship to the IDGs, specifically focusing on data representing epigenetic modifications (5-methyl cytosine), genomic perturbations (mRNA expression), and proteomic shifts (protein expression). A set of 82 infection and exposure-related genes was identified and found to be enriched for their role in the glucocorticoid receptor signal transduction pathway. Given their common identification across numerous human cohorts and their known toxicological role in disease, the identified genes within the glucocorticoid signal transduction pathway may underlie altered infectious disease susceptibility associated with prenatal exposures to the toxic metals iAs and Cd in humans.