Radioactive and stable cesium isotope distributions and dynamics in Japanese cedar forests

Publication date: Available online 11 October 2017
Source:Journal of Environmental Radioactivity
Author(s): Vasyl Yoschenko, Tsugiko Takase, Thomas G. Hinton, Kenji Nanba, Yuichi Onda, Alexei Konoplev, Azusa Goto, Aya Yokoyama, Koji Keitoku
Dynamics of the Fukushima-derived radiocesium and distribution of the natural stable isotope ¹³³Cs in Japanese cedar (Cryptomeria japonica D. Don) forest ecosystems were studied during 2014–2016. For the experimental site in Yamakiya, Fukushima Prefecture, we present the redistribution of radiocesium among ecosystem compartments during the entire observation period, while the results obtained at another two experimental site were used to demonstrate similarity of the main trends in the Japanese forest ecosystems. Our observations at the Yamakiya site revealed significant redistribution of radiocesium between the ecosystem compartments during 2014–2016. During this same period radionuclide inventories in the aboveground tree biomass were relatively stable, however, radiocesium in forest litter decreased from 20 ± 11% of the total deposition in 2014 to 4.6 ± 2.7% in 2016. Radiocesium in the soil profile accumulated in the 5-cm topsoil layers. In 2016, more than 80% of the total radionuclide deposition in the ecosystem resided in the 5-cm topsoil layer.The radiocesium distribution between the aboveground biomass compartments at Yamakiya during 2014–2016 was gradually approaching a quasi-equilibrium distribution with stable cesium. Strong correlations of radioactive and stable cesium isotope concentrations in all compartments of the ecosystem have not been reached yet. However, in some compartments the correlation is already strong. An increase of radiocesium concentrations in young foliage in 2016, compared to 2015, and an increase in 2015–2016 of the ¹³⁷Cs/¹³³Cs concentration ratio in the biomass compartments with strong correlations indicate an increase in root uptake of radiocesium from the soil profile. Mass balance of the radionuclide inventories, and accounting for radiocesium fluxes in litterfall, throughfall and stemflow, enabled a rough estimate of the annual radiocesium root uptake flux as 2 ± 1% of the total inventory in the ecosystem.



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Phrenic motoneurons: output elements of a highly organized intraspinal network

The pontomedullary respiratory network generates the respiratory pattern and relays it to bulbar and spinal respiratory motor outputs. The phrenic motor system controlling diaphragm contraction receives and processes descending commands to produce orderly, synchronous, and cycle-to-cycle-reproducible spatiotemporal firing. Multiple investigators have studied PhMNs in an attempt to shed light on local mechanisms underlying phrenic pattern formation. We recorded PhMNs in unanesthetized, decerebrate rats and related their activity to simultaneous phrenic nerve (PhN) activity by creating a time-frequency representation of PhMN-PhN power and coherence. Based on their temporal firing patterns and relationship to PhN activity, we categorized PhMNs into three classes, each of which emerges as a result of intrinsic biophysical and network properties and organizes the orderly contraction of diaphragm motor fibers. For example, early inspiratory diaphragmatic activation by the early coherent burst generated by high-frequency PhMNs may be necessary in order to prime it to overcome its initial inertia. We have also demonstrated the existence of a prominent role for local intraspinal inhibitory mechanisms in shaping phrenic pattern formation. The objective of this review is to relate and synthesize recent findings with those of previous studies with the aim of demonstrating that the phrenic nucleus is a region of active local processing, rather than a passive relay of descending inputs.

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Norepinephrine enhances song responsiveness and encoding in the auditory forebrain of male zebra finches

Norepinephrine (NE) can dynamically modulate excitability and functional connectivity of neural circuits in response to changes in external and internal states. Regulation by NE has been demonstrated extensively in mammalian sensory cortices, but whether NE-dependent modulation in sensory cortex alters response properties in downstream sensorimotor regions is less clear. Here, we examine this question in male zebra finches, a songbird species with complex vocalizations and a well-defined neural network for auditory processing of those vocalizations. We test the hypothesis that NE modulates auditory processing and encoding using paired extracellular electrophysiology recordings and pattern classifier analyses. We report that a NE infusion into the auditory cortical region NCM (caudomedial nidopallium; analogous to mammalian secondary auditory cortex) enhances the auditory responses, burst firing, and coding properties of single NCM neurons. Furthermore, we report that NE-dependent changes in NCM coding properties, but not auditory response strength, are transmitted downstream to the sensorimotor nucleus HVC. Lastly, NE modulation in the NCM of males is qualitatively similar to that observed in females: in both sexes, NE increases auditory response-strengths. However, we observed a sex difference in the mechanism of enhancement: whereas NE increases response strength in females by decreasing baseline firing rates, NE increases response strength in males by increasing auditory-evoked activity. Therefore, NE signaling exhibits a compensatory sex difference to achieve a similar, state-dependent enhancement in signal-to-noise ratio and coding accuracy in males and females. In summary, our results provide further evidence for adrenergic regulation of sensory processing and modulation of auditory/sensorimotor functional connectivity.

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Saccades and reaches curve away from the other effector's target in simultaneous eye and hand movements.

Simultaneous eye and hand movements are highly coordinated and tightly coupled. This raises the question whether the selection of eye and hand targets relies on a shared attentional mechanism or separate attentional systems. Previous studies have revealed conflicting results by reporting evidence for both a shared as well as separate systems. Movement properties such as movement curvature can provide novel insights into this question as they provide a sensitive measure for attentional allocation during target selection. In the current study, participants performed simultaneous eye and hand movements to the same or different visual target locations. We show that both saccade and reaching movements curve away from the other effector's target location when they are simultaneously performed to spatially distinct locations. We argue that there is a shared attentional mechanism involved in selecting eye and hand targets which may be found on the level of effector independent priority maps.

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Eye-hand coordination during flexible manual interception of an abruptly appearing, moving target

As a vital skill in an evolving world, interception of moving objects relies on accurate prediction of target motion. In natural circumstances, active gaze shifts often accompany hand movements when exploring targets of interest, but how eye and hand movements are coordinated during manual interception and their dependence on visual prediction remain unclear. Here, we trained gaze-unrestrained monkeys to manually intercept targets appearing at random locations and circularly moving with random speeds. We found that well-trained animals were able to intercept the targets with adequate compensation for both sensory transmission and motor delays. Before interception, the animals' gaze followed the targets with adequate compensation for the sensory delay, but not for extra target displacement during the eye movements. Both hand and eye movements were modulated by target kinematics, and their reaction times were correlated. Moreover, retinal errors and reaching errors were correlated across different stages of reach execution. Our results reveal eye-hand coordination during manual interception, yet the eye and hand movements may show different levels of prediction based on the task context.

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A dual-axis rotation rule for updating the head direction cell reference frame during movement in three dimensions

In the mammalian brain, allocentric (Earth-referenced) head direction, called azimuth, is encoded by head direction (HD) cells, which fire according to the facing direction of the animal's head. On a horizontal surface, rotations of the head around the dorso-ventral (D-V) axis, called yaw, correspond to changes in azimuth, and elicit appropriate updating of the HD 'compass' signal to enable large-scale navigation. However, if the animal moves through three-dimensional (3D) space then there is no longer a simple relationship between yaw rotations and azimuth changes, and so processing of three-dimensional rotations is needed. Construction of a global 3D compass would require complex integration of 3D rotations, and also a large neuronal population, most neurons of which would be silent most of the time since animals rarely sample all available 3D orientations. We propose that instead, the HD system treats the 3D space as a set of interrelated 2D surfaces. It could do this by updating activity according to both yaw rotations around the D-V axis and rotations of the D-V axis around the gravity-defined vertical axis. We present preliminary data to suggest that this rule operates when rats move between walls of opposing orientations. This dual-axis rule, which we show is straightforward to implement using the classic one-dimensional 'attractor' architecture, allows consistent representation of azimuth even in volumetric space, and thus may be a general feature of mammalian directional computations even for animals that swim or fly.

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In vivo beta and gamma subthreshold oscillations in rat mitral cells: origin and gating by respiratory dynamics

In mammals, olfactory bulb (OB) dynamics are paced by slow and fast oscillatory rhythms at multiple levels: local field potential, spike discharge, and/or membrane potential oscillations. Interactions between these levels have been well studied for the slow rhythm linked to animal respiration. However, less is known regarding rhythms in the fast beta (10-35Hz) and gamma (35-100Hz) frequency ranges, particularly at the membrane potential level. Using a combination of intracellular and extracellular recordings in the OB of freely breathing rats, we show that beta and gamma subthreshold oscillations (STO) coexist intracellularly and are related to extracellular LFP oscillations in the same frequency range. However, they are differentially affected by changes in cell excitability and by odor stimulation. This leads us to suggest that beta and gamma STOs may rely on distinct mechanisms: gamma STOs would mainly depend on mitral cell intrinsic resonance while beta STOs could be mainly driven by synaptic activity. In a second part, we found that STO occurrence and timing are constrained by the influence of the slow respiratory rhythm on mitral/tufted cells. First, respiratory-driven excitation seems to favor gamma STOs while respiratory-driven inhibition favors beta STOs. Second, the respiratory rhythm is needed at the subthreshold level in order to lock gamma and beta STOs in similar phases as their LFP counterparts and to favor the correlation between STO frequency and spike discharge. Overall, this study helps to understand how the interaction between slow and fast rhythms at all levels of OB dynamics shapes its functional output.

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Transcriptomic Analysis of Octanoic Acid Response in Drosophila sechellia Using RNA-Sequencing

The dietary specialist fruit fly Drosophila sechellia has evolved to specialize on the toxic fruit of its host plant Morinda citrifolia. Toxicity of Morinda fruit is primarily due to high levels of octanoic acid (OA). Using RNA interference (RNAi), prior work found that knockdown of Osiris family genes Osiris 6 (Osi6), Osi7, and Osi8 led to increased susceptibility to OA in adult D. melanogaster flies, likely representing genes underlying a Quantitative Trait Locus (QTL) for OA resistance in D. sechellia. While genes in this major effect locus are beginning to be revealed, prior work has shown at least five regions of the genome contribute to OA resistance. Here, we identify new candidate OA resistance genes by performing differential gene expression analysis using RNA sequencing (RNA-seq) on control and OA-exposed D. sechellia flies. We found 104 significantly differentially expressed genes with annotated orthologs in D. melanogaster, including six Osiris gene family members, consistent with previous functional studies and gene expression analyses. Gene ontology (GO) term enrichment showed significant enrichment for cuticle development in upregulated genes and significant enrichment of immune and defense responses in downregulated genes suggesting important aspects of the physiology of D. sechellia that may play a role in OA resistance. In addition, we identified 5 candidate OA resistance genes that potentially underlie QTL peaks outside of the major effect region, representing promising new candidate genes for future functional studies.

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Physiological tremor increases when skeletal muscle is shortened: implications for fusimotor control

Abstract

The involuntary force fluctuations associated with physiological (as distinct from pathological) tremor are an unavoidable component of human motor control. While the origins of physiological tremor are known to depend on muscle afferentation, it is possible that the mechanical properties of muscle-tendon systems also affect its generation, amplification and maintenance. In this paper, we investigated the dependence of physiological tremor on muscle length in healthy individuals. We measured physiological tremor during tonic, isometric plantarflexion torque at 30% of maximum at three ankle angles. The amplitude of physiological tremor increased as calf muscles shortened in contrast to the stretch reflex whose amplitude decreases as muscle shortens. We used a published closed-loop simulation model of afferented muscle to explore the mechanisms responsible for this behaviour. We demonstrate that changing muscle lengths does not suffice to explain our experimental findings. Rather, the model consistently required the modulation of γ-static fusimotor drive to produce increases in physiological tremor with muscle shortening—while successfully replicating the concomitant reduction in stretch reflex amplitude. This need to control γ-static fusimotor drive explicitly as a function of muscle length has important implications. First, it permits the amplitudes of physiological tremor and stretch reflex to be decoupled. Second, it postulates neuromechanical interactions that require length-dependent γ drive modulation to be independent from α drive to the parent muscle. Lastly, it suggests that physiological tremor can be used as a simple, non-invasive measure of the afferent mechanisms underlying healthy motor function, and their disruption in neurological conditions.

This article is protected by copyright. All rights reserved

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An investigation of fetal behavioural states during maternal sleep in healthy late gestation pregnancy: an observational study

Abstract

Background

Fetal behavioural states (FBS) are measures of fetal wellbeing. Maternal position affects FBS with supine being associated with an increased likelihood of fetal quiescence consistent with the human fetus adapting to a lower oxygen consuming state. A number of studies now confirm the association of sleep position with risk of late intrauterine death. We designed this study to observe the effects of maternal sleep positions overnight in healthy late gestation pregnancy.

Method

Twenty nine healthy women had continuous fetal ECG recordings overnight. Two blinded observers, assigned fetal states in 5 minute blocks. Measures of fetal heart rate variability (FHRV) were calculated from ECG beat to beat data. Maternal position was determined from infrared video recording.

Results

Compared to state 2F (active sleep), 4F (active awake-high activity) occurred almost exclusively when the mother was in a left or right lateral position. State 1F (quiet sleep) was more common when mother was supine (OR 1.30, 95%CI, 1.11-1.52) and less common on maternal right side with the left being referent position (OR 0.81, 95%CI, 0.70-0.93). State 4F was more common between 2100 and 0100 than between 0100 and 0700 (OR 2 2.83, 95%CI, 2.32-3.47). In each fetal state, maternal position had significant effects on fetal heart rate (FHR) and measures of FHRV.

Conclusion

In healthy late gestation pregnancy, maternal sleep position affects FBS and heart rate variability. These effects are likely fetal adaptations to positions which may produce a mild hypoxic stress.

This article is protected by copyright. All rights reserved

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Accumulation and localization of macrophage phenotypes with human intervertebral disc degeneration

Chronic inflammation is an important component of intervertebral disc (IVD) degeneration, but there is limited knowledge about the identity and source of inflammatory cells involved with the degenerative processes. Macrophages can exhibit multiple phenotypes and are known inflammatory regulators in many tissues, but their phenotypes have not been characterized in IVD degeneration.

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Does Specialty Matter? A survey on 176 italian neurosurgeons and orthopaedic spine surgeons confirms similar competency for common spinal conditions and supports multidisciplinary teams in comprehensive and complex spinal care

Spine surgery is a multi-faceted sub-speciality requiring a breadth of knowledge and skill from different branches of medicine for the treatment of pathologies varying from degenerative to deformity, oncological, and trauma.

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Ear-EEG detects ictal and interictal abnormalities in focal and generalized epilepsy -A comparison with scalp EEG monitoring

The incidence of temporal lobe epilepsy (TLE) has been estimated to 10.4/100.000 (Landino et al., 2014). It is the most common type of epilepsy among patients with refractory epilepsy referred to tertiary centers (Semah et al., 1998) and TLE represents the majority of cases considered for epilepsy surgery (Téllez-Zenteno and Hernández-Ronquillo, 2011). The delay from first seizure to referral to epilepsy surgery is generally more than a decade (Benbadis et al., 2003). It has been estimated that 5-23% of patients with TLE are misdiagnosed (van Donselaar et al., 2006), which may contribute to the delay.

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NEURONOPATHY AND NEUROPATHY IN AUTOSOMAL DOMINANT SPINO-CEREBELLAR ATAXIA (SCA): A PRELIMINARY PERIPHERAL NERVE ULTRASOUND STUDY

Somatosensory or sensorimotor impairment is not uncommon in autosomal dominant spino-cerebellar ataxia (SCA) (Linnemann et al., 2015; Schöls et al., 2004), but it is unclear to what extent this is a primary peripheral nerve pathology, as typically seen in length-dependent neuropathy, or neuronopathy from neuron degeneration in dorsal root ganglia and/or anterior horn cells (van de Warrenburg et al., 2004). It is also unclear if neuropathy and neuronopathy are differently represented in the SCA subtypes.

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CrossTalk proposal: Proton permeation through HV1 requires transient protonation of a conserved aspartate in the S1 transmembrane helix

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CrossTalk opposing view: proton transfer in Hv1 utilizes a water wire, and does not require transient protonation of a conserved aspartate in the S1 transmembrane helix

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Rebuttal from Thomas E. DeCoursey

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Rebuttal from Ashley L. Bennett and Ian Scott Ramsey

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Cover

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Psychological

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Subscriptions

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Psychological Sciences Table of Content

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Social Sciences Table of Content

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Social

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Awareness of Mild Cognitive Impairment and Mild Alzheimer’s Disease Dementia Diagnoses Associated With Lower Self-Ratings of Quality of Life in Older Adults

Abstract

Objective

This study examined how awareness of diagnostic label impacted self-reported quality of life (QOL) in persons with varying degrees of cognitive impairment.

Method

Older adults (n = 259) with normal cognition, Mild Cognitive Impairment (MCI), or mild Alzheimer's disease dementia (AD) completed tests of cognition and self-report questionnaires that assessed diagnosis awareness and multiple domains of QOL: cognitive problems, activities of daily living, physical functioning, mental wellbeing, and perceptions of one's daily life. We compared measures of QOL by cognitive performance, diagnosis awareness, and diagnostic group.

Results

Persons with MCI or AD who were aware of their diagnosis reported lower average satisfaction with daily life (QOL-AD), basic functioning (BADL Scale), and physical wellbeing (SF-12 PCS), and more difficulties in daily life (DEM-QOL) than those who were unaware (all p ≤ .007). Controlling for gender, those expecting their condition to worsen over time reported greater depression (GDS), higher stress (PSS), lower quality of daily life (QOL-AD, DEM-QOL), and more cognitive difficulties (CDS) compared to others (all p < .05).

Discussion

Persons aware of their diagnostic label—either MCI or AD—and its prognosis report lower QOL than those unaware of these facts about themselves. These relationships are independent of the severity of cognitive impairment.

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Grasp Planning in Older Adults

The editorial "Grasp Planning in Older Adults" was erroneously not included in issue 72–3 with its corresponding article. The article to which it is linked is:

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Population Aging and Health Trajectories at Older Ages

There were errors in the notes of Table 1 and in the title of Table 3 of this article. The corrected tables are below.

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Corrigendum

Age-Related Differences in Social Economic Decision Making: The Ultimatum Game

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Longitudinal Trajectories of Quality of Life and Depression by Housing Tenure Status

In the article "Longitudinal Trajectories of Quality of Life and Depression by Housing Tenure Status," there was an error in the keywords. The keywords are as follows: CASP-12—CESD—Home owners—Longitudinal trajectories—Mental health—New Zealand Health, Work and Retirement Study—Tenants.

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Memory Resilience to Alzheimer’s Genetic Risk: Sex Effects in Predictor Profiles

Abstract

Objectives

Apolipoprotein E (APOE) ɛ4 and Clusterin (CLU) C alleles are risk factors for Alzheimer's disease (AD) and episodic memory (EM) decline. Memory resilience occurs when genetically at-risk adults perform at high and sustained levels. We investigated whether (a) memory resilience to AD genetic risk is predicted by biological and other risk markers and (b) the prediction profiles vary by sex and AD risk variant.

Method

Using a longitudinal sample of nondemented adults (n = 642, aged 53–95) we focused on memory resilience (over 9 years) to 2 AD risk variants (APOE, CLU). Growth mixture models classified resilience. Random forest analysis, stratified by sex, tested the predictive importance of 22 nongenetic risk factors from 5 domains (n = 24–112).

Results

For both sexes, younger age, higher education, stronger grip, and everyday novel cognitive activity predicted memory resilience. For women, 9 factors from functional, health, mobility, and lifestyle domains were also predictive. For men, only fewer depressive symptoms was an additional important predictor. The prediction profiles were similar for APOE and CLU.

Discussion

Although several factors predicted resilience in both sexes, a greater number applied only to women. Sex-specific mechanisms and intervention targets are implied.

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Student Debt Spans Generations: Characteristics of Parents Who Borrow to Pay for Their Children’s College Education

Abstract

Objectives

Discussions of student debt often overlook the debt parents take on to pay for their children's education. We identify characteristics of parents with child-related educational debt among the late baby boom cohort.

Method

Data come from the National Longitudinal Survey of Youth 1979, a nationally representative sample of individuals born between 1957 and 1964. We restrict our sample to parents who had any children aged ≥17 and answered questions on educational debt during midlife (n = 6,562). Craggit models estimated (a) having any child-related educational debt and (b) the amount of debt owed among debtors.

Results

Black parents and parents with more education, higher income, and higher net worth were more likely to report child-related educational debt than White parents and parents with no degree, low-income, or negative net worth. Among debtors, high-income parents had more debt than low-income parents.

Discussion

Our findings suggest concerns about the student debt crisis should extend to aging parents.

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Negative Aging Stereotypes Impair Performance on Brief Cognitive Tests Used to Screen for Predementia

Abstract

Objectives

There is today ample evidence that negative aging stereotypes impair healthy older adults' performance on cognitive tasks. Here, we tested whether these stereotypes also decrease performance during the screening for predementia on short cognitive tests widely used in primary care.

Method

An experiment was conducted on 80 healthy older adults taking the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) under Threat or Reduced-threat condition.

Results

Stereotype threat significantly impaired older adults' performance on both tests, resulting in 40% of older adults meeting the screening criteria for predementia, compared with 10% in Reduced-threat condition (MMSE and MoCA averaged).

Discussion

Our research highlights the influence of aging stereotypes on short cognitive tests used to screen for predementia. It is of critical importance that physicians provide a threat-free testing environment. Further research should clarify whether this socially induced bias may also operate in secondary care by generating false positives.

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Feeling Older and the Development of Cognitive Impairment and Dementia

Abstract

Objective

Subjective age is a biopsychosocial marker of aging associated with a range of outcomes in old age. In the domain of cognition, feeling older than one's chronological age is related to lower cognitive performance and steeper cognitive decline among older adults. The present study examines whether an older subjective age is associated with the risk of incident cognitive impairment and dementia.

Method

Participants were 5,748 individuals aged 65 years and older drawn from the Health and Retirement Study. Measures of subjective age, cognition, and covariates were obtained at baseline, and follow-up cognition was assessed over a 2- to 4-year period. Only participants without cognitive impairment were included at baseline. At follow-up, participants were classified into one of the three categories: normal functioning, cognitive impairment without dementia (CIND), and dementia.

Results

An older subjective age at baseline was associated with higher likelihood of CIND (odds ratio [OR] = 1.18; 1.09–1.28) and dementia (OR = 1.29; 1.02–1.63) at follow-up, controlling for chronological age, other demographic factors, and baseline cognition. Physical inactivity and depressive symptoms partly accounted for these associations.

Conclusion

An older subjective age is a marker of individuals' risk of subsequent cognitive impairment and dementia.

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Personal Journal Keeping and Linguistic Complexity Predict Late-Life Dementia Risk: The Cache County Journal Pilot Study

Abstract

Objectives

We determined the feasibility of accessing personal journals and correlating markers of linguistic complexity with all-cause dementia and Alzheimer's disease (AD).

Method

A stratified random sample of 215 older adults reported on lifetime journal writing habits. From 66 of these participants (49% of those with journals), digital photographs of journal text were transcribed then subjected to the Linguistic Inquiry Word Count program to measure linguistic complexity markers: Words per Sentence, Percentage of 6+ Letter Words, Cognitive Mechanics, Percentage of Unique Words, and Percentage of Words that are Numerals. AD diagnosis was made via in-depth clinical protocol.

Results

In the larger sample, ever being a journal writer significantly predicted a 53% reduction in all-cause dementia risk. In the subsample with transcribed writings, Percentage of 6+ Letter Words predicted AD and all-cause dementia risk, with all logistic regression models controlling for age, education, gender, and Latter-Day Saints affiliation.

Discussion

These data suggest the potential viability of adulthood language use as a predictive tool for late-life AD risk, both in the linguistic features and the practice of journal writing itself.

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Is Cancer Protective for Subsequent Alzheimer’s Disease Risk? Evidence From the Utah Population Database

Abstract

Objective

Several studies have suggested that cancer is associated with a reduced risk of the development of Alzheimer's disease (AD). This study seeks to improve our understanding of the association between cancer and the development of AD by showing how mortality selection alters this relationship.

Method

A retrospective cohort study was carried out examining 92,425 individuals (47,873 women and 44,552 men) from the Utah Population Database with and without a history of any primary cancer identified by the Utah Cancer Registry. All individuals were aged 65–79 years and free of dementia in 1992 and followed for upwards of 18 years (1992–2009) for AD ascertainment, which was identified using diagnostic information from Medicare claims data.

Results

We replicate previous results suggesting that cancer is associated with reduced risk of subsequent AD under specific statistical model specifications. However, these results should not be interpreted as evidence of an etiological association. We conclude that higher rates of overall mortality among individuals with cancer relative to those without cancer induce the widely reported putative protective association with cancer.

Conclusion

Careful consideration of model specification and the profound effects of mortality selection in the older adult population is essential when investigating the relationship between aging-related diseases such as cancer and AD. We show that cancer does not provide protection from AD as previously described in the literature. Social scientists seeking to understand social disparities in disease outcomes among older adults may therefore want to strongly consider the role of mortality selection which, if uncorrected, may generate biased associations.

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Predictors of Mortality in Older Homeless Veterans

Abstract

Objectives

In this analysis of a cohort of older homeless veterans, we examined psychosocial, health, housing, and employment characteristics to identify predictors of mortality.

Method

Our sample of 3,620 older veterans entered Veteran Affairs homeless programs in years 2000–2003. Fifteen variables from a structured interview described this sample and served as predictors. National Death Index data for years 2000–2011 were used to ascertain death. Survival table analyses were conducted to estimate and plot cumulative survival functions. To determine predictors and estimate hazard functions, Cox proportional hazards regression analysis was conducted.

Results

Five variables (presence of a serious health issue, hospitalization for alcohol abuse, alcohol dependency, unemployment for 3 years, and age 60+) were associated with increased risk of death; three (non-White, drug dependency, and dental problems) were associated with reduced risk. A risk score, based on total unit-weighted risk for all eight predictors, was used to identify three groups that were found to differ significantly in mortality.

Conclusions

These analyses underline the jeopardy faced by older homeless veterans in terms of early death. We were able to identify several variables associated with mortality; more importantly, we were able to show that a risk score based on status for these variables was significantly related to survival.

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Midlife Work-Related Stress Increases Dementia Risk in Later Life: The CAIDE 30-Year Study

Abstract

Objective

To investigate the associations between midlife work-related stress and mild cognitive impairment (MCI), dementia, and Alzheimer's disease later in life, in a large representative population.

Method

Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study participants were randomly selected from independent population-based surveys (mean age 50 years). A random sample of 2,000 individuals was invited for two reexaminations including cognitive tests (at mean age 71 and mean age 78), and 1,511 subjects participated in at least one reexamination (mean follow-up 28.5 years). Work-related stress was measured using two questions on work demands that were administered in midlife. Analyses adjusted for important confounders.

Results

Higher levels of midlife work-related stress were associated with higher risk of MCI (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.08–1.76), dementia (OR, 1.53; CI, 1.13–2.07), and Alzheimer's disease (OR, 1.55; CI, 1.19–2.36) at the first follow-up among the CAIDE participants. Results remained significant after adjusting for several possible confounders. Work-related stress was not associated with MCI and dementia during the extended follow-up.

Discussion

Midlife work-related stress increases the risk for MCI, dementia, and Alzheimer's disease in later life. The association was not seen after the extended follow-up possibly reflecting selective survival/participation, heterogeneity in dementia among the oldest old, and a critical time window for the effects of midlife stress.

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You’re Just Like Your Dad: Intergenerational Patterns of Differential Treatment of Siblings

Abstract

Objectives

Past work highlights that parents' differential treatment has implications for offspring's mental and relational health across the life course. Although the current body of literature has examined offspring- and parent-level correlates of differential treatment, research has yet to consider whether and how patterns of differential treatment are transmitted across generations.

Method

As part of a two-wave longitudinal study of 157 families, both grandparents (M age = 76.50 years, SD = 6.20) and parents (M age = 51.10 years, SD = 4.41) reported on differential treatment of their own offspring at both phases.

Results

A series of residualized change models revealed support for both continuity and compensation hypotheses. Middle-aged parents tended to model the patterns of differential treatment exhibited by their fathers, but middle-aged men who experienced more differential treatment from their own parents in recent years tended to subsequently exhibit lower levels of differential treatment to their offspring.

Discussion

These findings suggest that patterns of differential treatment both continue and diverge across generations, and those patterns vary by gender. On a broader level, these results also suggest that siblings not only impact one another's development, but in adulthood, they may indirectly influence their nieces' and nephews' development by virtue of their influence on their siblings' parenting.

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Different levels of visual perceptual skills are associated with specific modifications in functional connectivity and global efficiency

Publication date: Available online 5 October 2017
Source:International Journal of Psychophysiology
Author(s): Sabrina Danti, Giacomo Handjaras, Luca Cecchetti, Helen Beuzeron-Mangina, Pietro Pietrini, Emiliano Ricciardi
The disembedding ability (i.e., the ability to identify a simple masked figure within a complex one) depends on attentional mechanisms, executive functions and working memory. Recent cognitive models ascribed different levels of disembedding task performance to the efficiency of the subtended mental processes engaged during visuo-spatial perception.Here we aimed at assessing whether different levels of the disembedding ability were associated to the functional signatures of neural efficiency, defined as a specific modulation in response magnitude and functional connectivity strength in task-related areas. Consequently, brain activity evoked by a visual task involving the disembedding ability was acquired using functional magnetic resonance imaging (fMRI) in a sample of 23 right-handed healthy individuals. Brain activity was analyzed at different levels of information processing, from local responses to connectivity interactions between brain nodes, as far as to network topological properties.All different levels of information processing were significantly modulated by individual behavioral performance. Specifically, single voxel response magnitude, connectivity strength of the right intrahemispheric and interhemispheric edges, and graph measures (i.e., local and global efficiency) were negatively associated to behavioral performance. Altogether, these results indicate that efficiency during a disembedding task cannot be merely attributed to a reduced neural recruitment of task-specific regions, but can be better characterized as an enhanced functional hemispherical asymmetry.



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De novo assembly, characterization and annotation for the transcriptome of Sphaeroma terebrans and microsatellite marker discovery

Abstract

Sphaeroma terebrans, an economically and ecologically important marine wood-boring isopod, is mainly distributed in tropical and subtropical mangroves. Nevertheless, available genomic and transcriptomic information for this isopod is extremely deficient. Here, we first performed the assembly of S. terebrans transcriptome by Illumina sequencing. A total of 51,092 high-quality unigenes with an average length of 641 bp were obtained and 19,915 unigenes were successfully annotated in four public databases. Only 9932 out of 19915 unigenes were commonly annotated by all four databases. In addition, 9609 unigenes were categorized into 54 function categories of Gene Ontology (GO), and 14,512 unigenes were successfully grouped into 25 functional categories of the EuKaryotic Orthologous Groups (KOG) database. Moreover, 11,507 unigenes were assigned to 228 pathways of the Kyoto Encyclopedia of Genes and Genomes (KEGG). Out of 51,092 unigenes, a total of 4257 different microsatellites with motifs range from di- to hexa-nucleotide were identified from 3324 unigene sequences. Among 64 primer pairs selected for validation, 35 were successful in PCR amplification and 13 exhibited obvious repeat polymorphisms in the wild population of S. terebrans in Dongzhaigang (Hainan Island). The transcriptome dataset and the identified microsatellite markers (SSRs) will provide abundant information for researches on the discovery of new genes, metabolic mechanism and genetic diversity of S. terebrans.

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Intracranial source activity (eLORETA) related to scalp-level asymmetry scores and depression status

Abstract

Frontal EEG alpha asymmetry provides a promising index of depression risk, yet very little is known about the neural sources of alpha asymmetry. To identify these sources, this study examined alpha asymmetry using a distributed inverse solution: exact low resolution brain electromagnetic tomography (eLORETA). Findings implicated a generator in lateral midfrontal regions that contributed to both surface asymmetry and depression risk. Participants with any lifetime history of depressive episodes were characterized by less left than right activity in the precentral gyrus and midfrontal gyrus. Anhedonia accounted for a significant portion of the relationship between alpha asymmetry and lifetime major depressive disorder. Results are suggestive of convergence between motivational and capability models of asymmetry and replicate results from experimental studies in a large resting-state data set. The capability model of frontal alpha asymmetry is contextualized in terms of motor preparedness following emotional mobilization.

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Is attention enhanced following performance errors? Testing the adaptive control hypothesis

Abstract

The present study tested whether people adaptively sharpen attentional focus following performance mistakes, as predicted by current theories of cognitive control. Participants completed a reverse Stroop task in which target stimuli were preceded by an informative spatial cue. Cue validity and Stroop interference effects on performance were robust, but neither effect was altered by commission of an error on the prior trial, as predicted by the adaptive control model. Likewise, a prior error did not enhance cue-evoked spatial asymmetries in EEG, nor did it enhance validity effects on neural responses evoked by targets. Instead, errors were followed by poorer overall performance and generalized arousal, as measured by generally suppressed EEG alpha power in postresponse and cue-to-target intervals following errors compared to correct responses. Results support an alternative theory that post-error changes in neural activity and performance reflect arousal, orienting, or cognitive bottlenecking rather than adaptive control of attention.

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Pupil dilation indicates the coding of past prediction errors: Evidence for attentional learning theory

Abstract

The attentional learning theory of Pearce and Hall () predicts more attention to uncertain cues that have caused a high prediction error in the past. We examined how the cue-elicited pupil dilation during associative learning was linked to such error-driven attentional processes. In three experiments, participants were trained to acquire associations between different cues and their appetitive (Experiment 1), motor (Experiment 2), or aversive (Experiment 3) outcomes. All experiments were designed to examine differences in the processing of continuously reinforced cues (consistently followed by the outcome) versus partially reinforced, uncertain cues (randomly followed by the outcome). We measured the pupil dilation elicited by the cues in anticipation of the outcome and analyzed how this conditioned pupil response changed over the course of learning. In all experiments, changes in pupil size complied with the same basic pattern: During early learning, consistently reinforced cues elicited greater pupil dilation than uncertain, randomly reinforced cues, but this effect gradually reversed to yield a greater pupil dilation for uncertain cues toward the end of learning. The pattern of data accords with the changes in prediction error and error-driven attention formalized by the Pearce-Hall theory.

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7 steps to become a credentialed paramedic officer

This video describes seven steps credentialing candidates can take in order to become a credentialed paramedic officer by the American College of Paramedic Executives from the National EMS Management Association (NEMSMA).

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Is use of glycine-containing drugs in anesthesia safe?

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Spinal segmental myoclonus resembling “belly dance” in a pregnant woman

Publication date: November 2017
Source:Clinical Neurophysiology, Volume 128, Issue 11
Author(s): Arens Taga, Irene Florindo, Ariane Kiener, Tiziana Frusca, Giovanni Pavesi




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Fasciculations in nerve and muscle disorders – A prospective study of muscle ultrasound compared to electromyography

Publication date: November 2017
Source:Clinical Neurophysiology, Volume 128, Issue 11
Author(s): M.T. Johansson, H.R. Ellegaard, H. Tankisi, A. Fuglsang-Frederiksen, E. Qerama
ObjectivesWe examined the clinical utility of muscle ultrasound (MUS) in detecting fasciculations in patients with nerve and muscle disorders (NMD) and investigated the impact on diagnostic sensitivity when combining electromyography (EMG) and MUS.MethodsWe included 58 consecutive patients suspected to have NMD and 38 healthy subjects (HS). Patients and HS underwent MUS in 14 skeletal and two bulbar muscles and the video recordings of the MUS were anonymised. Only patients underwent EMG.ResultsThe follow-up diagnoses were: 15 Amyotrophic lateral sclerosis (ALS), 15 polyneuropathy, 14 patients had other diagnoses (disease-control group) and 14 patients had no pathological findings.MUS detected more muscles with fasciculations among ALS patients compared to all other groups. In ALS patients, the dominating pattern of fasciculations was continuous (45%). More proximal muscles showed fasciculations among ALS patients compared to all other patient groups. MUS was more sensitive than EMG in detecting fasciculations (58% vs. 48%). When combining the two methods, the sensitivity in detecting fasciculations increased to 65%. Fasciculations in nine muscles could predict the ALS diagnosis with high sensitivity and specificity.ConclusionsMUS is a sensitive tool in detecting fasciculations in patients with NMD and performs well compared to EMG in diagnosing ALS.SignificanceMUS may add valuable information in the clinic, especially in diagnosing ALS.



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Oxidative phosphorylation: regulation and role in cellular and tissue metabolism

Abstract

Oxidative phosphorylation provides most of the ATP that higher animals and plants use to support life and is responsible for setting and maintaining metabolic homeostasis. The pathway incorporates three consecutive near equilibrium steps for moving reducing equivalents between the intramitochondrial [NAD⁺]/[NADH] pool to molecular oxygen, with irreversible reduction of oxygen to bound peroxide at cytochrome c oxidase determining the net flux. Net flux (oxygen consumption rate) is determined by demand for ATP, with feedback by the energy state ([ATP]/[ADP][Pi]) regulating the pathway. This feedback affects the reversible steps equally and independently, resulting in the rate being coupled to ([ATP]/[ADP][Pi])³. With increasing energy state, oxygen consumption decreases rapidly until a threshold is reached, above which there is little further decrease. In most cells, [ATP] and [Pi] are much higher than [ADP] and change in [ADP] is primarily responsible for the change in energy state. As a result, the rate of ATP synthesis, plotted against [ADP], remains low until [ADP] reaches about 30 μm and then increases rapidly with further increase in [ADP]. The dependencies on energy state and [ADP] near the threshold can be fitted by the Hill equation with a Hill coefficients of about −2.6 and 4.2, respectively. The homeostatic set point for metabolism is determined by the threshold, which can be modulated by the pO₂ and intramitochondrial [NAD⁺]/[NADH]. The ability of oxidative phosphorylation to precisely set and maintain metabolic homeostasis is consistent with it being permissive of, and essential to, development of higher plants and animals.

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