Left Cerebellar Lesions may be Associated with an Increase in Spatial Neglect-like Symptoms

Each cerebellar hemisphere projects to the contralateral cerebral hemisphere. Previous research suggests a lateralization of cognitive functions in the cerebellum that mirrors the cerebral cortex, with attention/visuospatial functions represented in the left cerebellar hemisphere, and language functions in the right cerebellar hemisphere. Although there is good evidence supporting the role of the right cerebellum with language functions, the evidence supporting the notion that attention and visuospatial functions are left lateralized is less clear. Given that spatial neglect is one of the most common disorders arising from right cortical damage, we reasoned that damage to the left cerebellum would result in increased spatial neglect-like symptoms, without necessarily leading to an official diagnosis of spatial neglect. To examine this disconnection hypothesis, we analyzed neglect screening data (line bisection, cancellation, figure copying) from 20 patients with isolated unilateral cerebellar stroke. Results indicated that left cerebellar patients (n = 9) missed significantly more targets on the left side of cancellation tasks compared to a normative sample. No significant effects were observed for right cerebellar patients (n = 11). A lesion overlap analysis indicated that Crus II (78% overlap), and lobules VII and IX (66% overlap) were the regions most commonly damaged in left cerebellar patients. Our results are consistent with the notion that the left cerebellum may be important for attention and visuospatial functions. Given the poor prognosis typically associated with neglect, we suggest that screening for neglect symptoms, and visuospatial deficits more generally, may be important for tailoring rehabilitative efforts to help maximize recovery in cerebellar patients.

Assessment and recovery of visually guided reaching deficits following cerebellar stroke

The cerebellum is known to play an important role in the coordination and timing of limb movements. The present study focused on how reach kinematics are affected by cerebellar lesions to quantify both the presence of motor impairment, and recovery of motor function over time. In the current study, 12 patients with isolated cerebellar stroke completed clinical measures of cognitive and motor function, as well as a visually guided reaching (VGR) task using the Kinarm exoskeleton at baseline (∼2 weeks), as well as 6, 12, and 24-weeks post-stroke. During the VGR task, patients made unassisted reaches with visual feedback from a central 'start' position to one of eight targets arranged in a circle. At baseline, 6/12 patients were impaired across several parameters of the VGR task compared to a Kinarm normative sample (n = 307), revealing deficits in both feed-forward and feedback control. The only clinical measures that consistently demonstrated impairment were the Purdue Pegboard Task (PPT; 9/12 patients) and the Montreal Cognitive Assessment (6/11 patients). Overall, patients who were impaired at baseline showed significant recovery by the 24-week follow-up for both VGR and the PPT. A lesion overlap analysis indicated that the regions most commonly damaged in 5/12 patients (42% overlap) were lobule IX and Crus II of the right cerebellum. A lesion subtraction analysis comparing patients who were impaired (n = 6) vs. unimpaired (n = 6) on the VGR task at baseline showed that the region most commonly damaged in impaired patients was lobule VIII of the right cerebellum (40% overlap). Our results lend further support to the notion that the cerebellum is involved in both feedforward and feedback control during reaching, and that cerebellar patients tend to recover relatively quickly overall. In addition, we argue that future research should study the effects of cerebellar damage on visuomotor control from a perception-action theoretical framework to better understand how the cerebellum works with the dorsal stream to control visually guided action.

HMGB1 acts as an agent of host defense at the gut mucosal barrier

Mucosal barriers provide the first line of defense between internal body surfaces and microbial threats from the outside world. ¹ In the colon, the barrier consists of two layers of mucus and a single layer of tightly interconnected epithelial cells supported by connective tissue and immune cells. ² Microbes colonize the loose, outer layer of colonic mucus, but are essentially excluded from the tight, epithelial-associated layer by host defenses. ³ The amount and composition of the mucus is calibrated based on microbial signals and loss of even a single component of this mixture can destabilize microbial biogeography and increase the risk of disease. ^4-7 However, the specific components of mucus, their molecular microbial targets, and how they work to contain the gut microbiota are still largely unknown. Here we show that high mobility group box 1 (HMGB1), the prototypical damage-associated molecular pattern molecule (DAMP), acts as an agent of host mucosal defense in the colon. HMGB1 in colonic mucus targets an evolutionarily conserved amino acid sequence found in bacterial adhesins, including the well-characterized Enterobacteriaceae adhesin FimH. HMGB1 aggregates bacteria and blocks adhesin-carbohydrate interactions, inhibiting invasion through colonic mucus and adhesion to host cells. Exposure to HMGB1 also suppresses bacterial expression of FimH. In ulcerative colitis, HMGB1 mucosal defense is compromised, leading to tissue-adherent bacteria expressing FimH. Our results demonstrate a new, physiologic role for extracellular HMGB1 that refines its functions as a DAMP to include direct, virulence limiting effects on bacteria. The amino acid sequence targeted by HMGB1 appears to be broadly utilized by bacterial adhesins, critical for virulence, and differentially expressed by bacteria in commensal versus pathogenic states. These characteristics suggest that this amino acid sequence is a novel microbial virulence determinant and could be used to develop new approaches to diagnosis and treatment of bacterial disease that precisely identify and target virulent microbes.

Stop paying attention to "attention"

Conceptual fragmentation is when a term assumed to have one meaning is found to have many. When these different definitions overlap in meaning and application confusion and wasted effort follows. "Attention" is such a fragmented term. The response to conceptual fragmentation is simple. Stop using the original term. Our reticence to do so reflects false beliefs about attention. "Attention" is not an old term, but a modern one. Its original meaning is not related to our contemporary intuitions. Attention is not a necessary concept; psychology made substantial progress, even in cognitive areas, during the years when its use was banished. Attention is just one among many examples of conceptual fragmentation in psychology. The root cause is a dearth of theory driving cognitive experimentation. Theoretical clarity is enhanced when fundamental concepts can be expressed in a mathematical form. When theories are stated in mathematical language it opens the door to rigorous cross-domain comparisons using tools like category theory. This article is categorized under: Psychology > Attention Neuroscience > Cognition.

Acoustic and vibration isolation for a gravity gradiometer

Vibration in the audio frequency band affects the performance of rotating gravity gradiometers used for airborne mineral exploration. This is probably due to translation to rotation coupling inside the gradiometer platform. It was found that the DC gravity gradient signal was proportional to the square of the third time derivative of position, or jerk squared. The demanding airborne environment for such instrumentation demands a light weight broadband acoustic shield and vibration isolator. This paper presents the design principles for such an isolator, based on vibration isolated spherical shell structures. Performance data are presented as well as flight test data that demonstrated a 14% gravity gradient noise reduction compared with an unshielded instrument.

Cerebellar lesions disrupt spatial and temporal visual attention

The current study represents the first comprehensive examination of spatial, temporal and sustained attention following cerebellar damage. Results indicated that, compared to controls, cerebellar damage resulted in a larger cueing effect at the longest SOA - possibly reflecting a slowed the onset of inhibition of return (IOR) during a reflexive covert attention task, and reduced the ability to detect successive targets during an attentional blink task. However, there was little evidence to support the notion that cerebellar damage disrupted voluntary covert attention or the sustained attention to response task (SART). Lesion overlay data and supplementary voxel-based lesion symptom mapping (VLSM) analyses indicated that impaired performance on the reflexive covert attention and attentional blink tasks were related to damage to Crus II of the left posterior cerebellum. In addition, subsequent analyses indicated our results are not due to either general motor impairments or to damage to the deep cerebellar nuclei. Collectively these data demonstrate, for the first time, that the same cerebellar regions may be involved in both spatial and temporal visual attention.

Breeding systems of floral colour forms in the Drosera cistiflora species complex

Variation in plant breeding systems has implications for pollinator-mediated selection on floral traits and the ecology of populations. Here we evaluate pollinator contribution to seed production, self-compatibility and pollen limitation in different floral colour forms of Drosera cistiflora sensu lato (Droseraceae). These insectivorous perennial plants are endemic to fynbos and renosterveld vegetation in the Cape Floristic Region of South Africa, and the species complex includes five floral colour forms (pink, purple, red, white and yellow), some of which are known to be pollinated by beetles. Controlled hand-pollination experiments were conducted in 15 populations of D. cistiflora s.l. (two to four populations per floral colour form) to test whether the colour forms vary in their degree of self-compatibility and their ability to produce seeds through autonomous self-fertilization. Yellow-flowered forms were highly self-incompatible, while other floral colour forms exhibited partial self-compatibility. Seed set resulting from autonomous selfing was very low, and pollinator dependence indices were high in all populations. Since hand cross-pollination resulted in greater seed set than open pollination in 13 of the 15 populations, we inferred that seed production is generally pollen-limited. Drosera cistiflora s.l. typically exhibits high levels of pollinator dependence and pollen limitation. This is unusual among Drosera species worldwide and suggests that pollinators are likely to mediate strong selection on attractive traits such as floral colour and size in D. cistiflora s.l. These results also suggest that the floral colour forms of D. cistiflora s.l. which are rare and threatened are likely to be vulnerable to local extinction if mutualisms were to collapse indefinitely.

Interlaboratory Study of a Thermospray-Liquid Chromatographic/Mass Spectrometric Method for Selected N-Methyl Carbamates, N-Methyl Carbamoyloximes, and Substituted Urea Pesticides

A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3 N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pesticides (diuron and linuron), and 1 ester of a substituted carbamic acid (carbendazim). The purpose of this study was to establish whether these 9 compounds can be reliably detected and quantitated with this method, and to establish the interlaboratory precision and accuracy of the method with currently available instrumentation. The study design was based on AOAC INTERNATIONAL’S blind replicate design with balanced replicates. The samples consisted of solutions of the 9 test compounds in methanol at 3 concentrations that were unknown to the participating laboratories and that covered the linear range of the method. Nine volunteer laboratories participated in the study. Linear regression equations are presented that calculate the accuracy of the method, i.e., the percent recovery of each of the 9 compounds at any concentration within the range of concentrations tested (5–90 (μg/mL for each compound, except carbendazim, for which the range was 1.25–22.5 μg/mL). The intra laboratory precisions of the TS-LC/MS method ranged from 6.5 to 33.1 % relative standard deviation, depending on the compound. The interlaboratory method precisions ranged from 29.8 to 98.2% relative standard deviation over the concentration range tested. Analysis of variance indicates that for all compounds tested, the variation from laboratory to laboratory is greater than that attributed to analytical error displayed within laboratories. There are many operational parameters that could contribute to interlaboratory variability; one of them, the thermospray tip temperature, can play a major role in adduct formation and ion fragmentation in the case of thermally labile carbamate pesticides and, therefore, needs to be monitored and controlled carefully. The correlation of mass spectral data with the thermospray tip temperature was attempted using principal component analysis.

Idiopathic myointimal hyperplasia is a distinct cause of chronic colon ischaemia

AIM

Colon ischaemia (CI) is most commonly an acute and reversible manifestation of a transient, non-occlusive decrease of blood flow in the colonic microvasculature. Irreversible complications are uncommon and the progression to chronic CI remains controversial. Our objective was to identify cases of chronic CI and assess for distinct clinicopathological features.

METHOD

A retrospective review was performed of CI patients having symptom chronicity of ≥ 1 month and ischaemic histology at our institution from 1994 to 2015. Demographic, clinical, endoscopic, radiological, pathological and outcome variables were abstracted. Histological evaluation was performed by two gastrointestinal pathologists.

RESULTS

Fifteen patients (n = 9; 67% men) with a median age of 65 years (range 22-88) were identified. The most common presenting symptoms were diarrhoea and abdominal pain (n = 6, 86%; n = 5, 71%, respectively). The typical endoscopic appearance was segmental ulceration of the sigmoid colon (n = 6, 75%). Vascular imaging showed patent mesenteric vessels in all patients. Histopathological evaluation revealed venous intimal hyperplasia consistent with idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) in eight patients; the remainder showed non-specific ulceration and fibrosis. Surgical resection was performed in seven IMHMV patients, resulting in symptom resolution. On re-review of pre-resection biopsies, all IMHMV patients had characteristic changes of hyperplastic, thick-walled, hyalinized vessels in the lamina propria.

CONCLUSIONS

IMHMV is a unique histopathological entity causing chronic CI. The small vessel histological changes in IMHMV are distinctive in colonic resections and undetectable by routine vascular imaging. Preoperative diagnosis of IMHMV is possible with endoscopic biopsy and segmental colon resection is curative.

Representational drawing following brain injury

Research has shown that damage to either the left or right hemisphere can lead to deficits in visuoconstructional skills including drawing and figure copying. Nevertheless, research would suggest that the nature of the deficits arising from left and right brain injury are distinct in nature if not severity, with the right hemisphere, and parietal cortex specifically, seen as critical for obtaining accurate spatial relations and the left hemisphere important for effective organisation (i.e., executive function). Much of this work on drawing and figure copying following brain damage has rested on qualitative assessments or crude marking scales with descriptive anchors for what constitutes good or poor performance. We employed quantitative analyses of drawings developed to assess accuracy in novice and expert artists. We analyzed drawings of a cube and a star in 50 patients (23, left brain damaged: LBD; 27 right brain damaged: RBD) who had suffered strokes. Our analysis was sensitive to the presence of neglect on the cube (i.e., missing left sided details) with voxel-wise lesion symptom mapping (VLSM) highlighting involvement of expected brain regions (superior temporal and supramarginal gyri). With left-sided omissions removed from analyses, we failed to find any difference between LBD and RBD patients. While the presence of left neglect appeared to exaggerate errors, this was only significant for errors of scale and proportion for the star drawing. VLSM of the distinct error domains demonstrated white matter involvement (and a minor contribution from the right insula) with respect to scale errors of the cube only. Finally, blinded judgements of hemisphere of lesion based on qualitative assessment of the drawings were no better than chance. These results suggest that figure copying is a complex task relying on large scale neural networks involving both hemispheres. Clearly, models of visuoconstructional capacity that emphasise right hemisphere dominance are not entirely accurate.

Statistical Learning Impairments as a Consequence of Stroke

Statistical learning is the implicit learning of the contingencies between sequential stimuli, typically from mere exposure. It is present from infancy onward, and plays a role in functions from language learning to selective attention. Despite these observations, there are few data on whether statistical learning capacity changes with age or after brain injury. In order to examine how brain injury affects the ability to learn and update statistical representations, we had young control and healthy elder participants, as well as participants with either left or right brain injury, perform an auditory statistical learning task. Participants listened to two languages with made-up words that were defined by the transition probability between syllables. Following passive listening, learning was assessed with a two-alternative forced choice test for the most familiar word. As in previous studies, we found that young controls have a learning capacity limitation for statistical learning; a second language is less well learned than the first, and this statistical learning capacity limit is attenuated with age. Additionally, we found that brain damaged patients, whether with left or right hemispheric damage, showed impaired statistical learning. This impairment was not explained by aphasia or cognitive deficits. As statistical learning is a critical skill for daily life, a better appreciation of the nature of this impairment will improve our understanding of the cognitive effects of brain injury and could lead to new rehabilitation strategies.

Updating impairments and the failure to explore new hypotheses following right brain damage

We have shown recently that damage to the right hemisphere impairs the ability to update mental models when evidence suggests an old model is no longer appropriate. We argue that this deficit is generic in the sense that it crosses multiple cognitive and perceptual domains. Here, we examined the nature of this updating impairment to determine more precisely the underlying mechanisms. We had right (RBD, N = 12) and left brain damaged (LBD, N = 10) patients perform versions of our picture-morphing task in which pictures gradually morph from one object (e.g., shark) to another (e.g., plane). Performance was contrasted against two groups of healthy older controls, one matched on age (HCO-age-matched, N = 9) and another matched on general level of cognitive ability (HCO-cognitively-matched, N = 9). We replicated our earlier findings showing that RBD patients took longer than LBD patients and HCOs to report seeing the second object in a sequence of morphing images. The groups did not differ when exposed to a morphing sequence a second time, or when responding to ambiguous images outside the morphing context. This indicates that RBD patients have little difficulty alternating between known representations or labeling ambiguous images. Instead, the difficulty lies in generating alternate hypotheses for ambiguous information. Lesion overlay analyses, although speculative given the sample size, are consistent with our fMRI work in healthy individuals in implicating the anterior insular cortex as critical for updating mental models.

The neural systems for perceptual updating

In a constantly changing environment we must adapt to both abrupt and gradual changes to incoming information. Previously, we demonstrated that a distributed network (including the anterior insula and anterior cingulate cortex) was active when participants updated their initial representations (e.g., it's a cat) in a gradually morphing picture task (e.g., now it's a rabbit; Stöttinger et al., 2015). To shed light on whether these activations reflect the proactive decisions to update or perceptual uncertainty, we introduced two additional conditions. By presenting picture morphs twice we controlled for uncertainty in perceptual decision making. Inducing an abrupt shift in a third condition allowed us to differentiate between a proactive decision in uncertainty-driven updating and a reactive decision in surprise-based updating. We replicated our earlier result, showing the robustness of the effect. In addition, we found activation in the anterior insula (bilaterally) and the mid frontal area/ACC in all three conditions, indicative of the importance of these areas in updating of all kinds. When participants were naïve as to the identity of the second object, we found higher activations in the mid-cingulate cortex and cuneus - areas typically associated with task difficulty, in addition to higher activations in the right TPJ most likely reflecting the shift to a new perspective. Activations associated with the proactive decision to update to a new interpretation were found in a network including the dorsal ACC known to be involved in exploration and the endogenous decision to switch to a new interpretation. These findings suggest a general network commonly engaged in all types of perceptual decision making supported by additional networks associated with perceptual uncertainty or updating provoked by either proactive or reactive decision making.

Breast cancer survivor's perspectives on the role different providers play in follow-up care

IMPORTANCE

Significant variation in the number and types of oncologists that provide breast cancer follow-up exists. However, there is limited understanding regarding breast cancer survivors' preferences for who provides their follow-up. Our objective was to explore breast cancer survivors' perspectives on the goals of breast cancer follow-up, the preferred role for primary care providers, and the perceived roles of different types of oncologists during follow-up.

METHODS

A convenience sample of stage 0-III breast cancer survivors was identified and in-depth one-on-one interviews conducted. Data were analyzed using inductive content analysis.

RESULTS

Survivors cited a strong preference for oncology-based follow-up within the first 5 years after diagnosis, driven by their need for reassurance that cancer had not recurred. Survivors also thought that their primary care provider needed to be involved. Survivors assumed that oncology follow-up was directed by a standard protocol that included streamlining the follow-up team. Survivors recognized that patients with more complex cancers or challenging treatment courses may require more intensive follow-up and deviate from the standard protocol. Most survivors were comfortable deferring decisions regarding who participated in follow-up to the oncology team.

CONCLUSIONS

Most patients think a streamlined approach to oncology-based breast cancer follow-up already occurs, driven by a standard protocol. The use of a standard protocol to provide guidance for which types of oncology providers should participate in breast cancer follow-up will streamline care and represents a significant opportunity to reduce unnecessary variation. This approach is especially critical given patients' strong preferences for oncology-based follow-up.

Capillary Refill Time in Adults Has Poor Inter-Observer Agreement

Objectives

Capillary refill time (CRT) has been taught as a rapid indicator of circulatory status but to be a useful clinical test, CRT needs to be reproducible when performed by another health care worker. No inter-rater agreement studies have been reported for adult patients. The aim of this study was to determine the inter-observer reliability of CRT in a sample of adult emergency department (ED) patients. Methods This prospective observational study included clinically stable ED patients with a variety of conditions from two community EDs. A doctor and a nurse each measured CRT by estimation to the nearest half-second using a standard method on each patient. They were blinded to each other's measurements. The primary outcome of interest was inter-rater agreement. Secondary outcome was agreement in classification as normal or abnormal according to accepted definitions. Data was analysed using bias plot analysis, correlation, absolute percent agreement and kappa analysis. Results Totally, 209 patients were enrolled; 51% were female and 86% were Caucasian. Median CRT was 2 seconds (95% CI 2–2.35 seconds). The mean difference between measurements by the different observers was 0 second, however the 95% limits of agreement were very wide (–1.7 to +1.9 seconds). Agreement was 70% for classification of ‘normal’ or ‘abnormal’ using the 2-second definition of normal, with a kappa of 0.38. Conclusion Interobserver agreement in measurement of CRT was poor in adult subjects with wide limits of agreement. This is a serious threat to the appropriateness of this test for use in clinical practice.

Tuned by experience: How orientation probability modulates early perceptual processing

Probable stimuli are more often and more quickly detected. While stimulus probability is known to affect decision-making, it can also be explained as a perceptual phenomenon. Using spatial gratings, we have previously shown that probable orientations are also more precisely estimated, even while participants remained naive to the manipulation. We conducted an electrophysiological study to investigate the effect that probability has on perception and visual-evoked potentials. In line with previous studies on oddballs and stimulus prevalence, low-probability orientations were associated with a greater late positive 'P300' component which might be related to either surprise or decision-making. However, the early 'C1' component, thought to reflect V1 processing, was dampened for high-probability orientations while later P1 and N1 components were unaffected. Exploratory analyses revealed a participant-level correlation between C1 and P300 amplitudes, suggesting a link between perceptual processing and decision-making. We discuss how these probability effects could be indicative of sharpening of neurons preferring the probable orientations, due either to perceptual learning, or to feature-based attention.

Orientation Probability and Spatial Exogenous Cuing Improve Perceptual Precision and Response Speed by Different Mechanisms

We are faster and more accurate at detecting frequently occurring objects than infrequent ones, just as we are faster and more accurate at detecting objects that have been spatially cued. Does this behavioral similarity reflect similar processes? To evaluate this question we manipulated orientation probability and exogenous spatial cuing within a single perceptual estimation task. Both increased target probability and spatial cuing led to shorter response initiation times and more precise perceptual reports, but these effects were additive. Further, target probability changed the shape of the distribution of errors while spatial cuing did not. Different routes and independent mechanisms could lead to changes in behavioral measures that look similar to each other and to ‘attentional’ effects.

Not all probabilities are equivalent: Evidence from orientation versus spatial probability learning

Frequently targets are detected faster, probable locations searched earlier, and likely orientations estimated more precisely. Are these all consequences of a single, domain-general "attentional" effect? To examine this issue, participants were shown brief instances of spatial gratings, and were tasked to draw their location and orientation. Unknown to participants, either the location or orientation probability of these gratings were manipulated. While orientation probability affected the precision of orientation reports, spatial probability did not. Further, utilising lowered stimulus contrast (via a staircase procedure) and a combination of behavioral precision and confidence self-report, we clustered trials with perceived stimuli from trials where the target was not detected: Spatial probability only modulated the likelihood of stimulus detection, but not did not modulate perceptual precision. Even when no physical attentional cues are present, acquired probabilistic information on space versus orientation leads to separable 'attention-like' effects on behaviour. We discuss how this could be linked to distinct underlying neural mechanisms. (PsycINFO Database Record

Adapting to change: The role of the right hemisphere in mental model building and updating

We recently proposed that the right hemisphere plays a crucial role in the processes underlying mental model building and updating. Here, we review the evidence we and others have garnered to support this novel account of right hemisphere function. We begin by presenting evidence from patient work that suggests a critical role for the right hemisphere in the ability to learn from the statistics in the environment (model building) and adapt to environmental change (model updating). We then provide a review of neuroimaging research that highlights a network of brain regions involved in mental model updating. Next, we outline specific roles for particular regions within the network such that the anterior insula is purported to maintain the current model of the environment, the medial prefrontal cortex determines when to explore new or alternative models, and the inferior parietal lobule represents salient and surprising information with respect to the current model. We conclude by proposing some future directions that address some of the outstanding questions in the field of mental model building and updating. (PsycINFO Database Record

Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border

Background

Migrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity.

Methods

Participants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results.

Results

Of 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI–1.01–1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51–0.98).

Discussion

Test concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1959-3) contains supplementary material, which is available to authorized users.

Attentional effects on orientation judgements are dependent on memory consolidation processes

Are the effects of memory and attention on perception synergistic, antagonistic, or independent? Tested separately, memory and attention have been shown to affect the accuracy of orientation judgements. When multiple stimuli are presented sequentially versus simultaneously, error variance is reduced. When a target is validly cued, precision is increased. What if they are manipulated together? We combined memory and attention manipulations in an orientation judgement task to answer this question. Two circular gratings were presented sequentially or simultaneously. On some trials a brief luminance cue preceded the stimuli. Participants were cued to report the orientation of one of the two gratings by rotating a response grating. We replicated the finding that error variance is reduced on sequential trials. Critically, we found interacting effects of memory and attention. Valid cueing reduced the median, absolute error only when two stimuli appeared together and improved it to the level of performance on uncued sequential trials, whereas invalid cueing always increased error. This effect was not mediated by cue predictiveness; however, predictive cues reduced the standard deviation of the error distribution, whereas nonpredictive cues reduced “guessing”. Our results suggest that, when the demand on memory is greater than a single stimulus, attention is a bottom-up process that prioritizes stimuli for consolidation. Thus attention and memory are synergistic.

Pollination, mating and reproductive fitness in a plant population with bimodal floral-tube length

Mating patterns and natural selection play important roles in determining whether genetic polymorphisms are maintained or lost. Here, we document an atypical population of Lapeirousia anceps (Iridaceae) with a bimodal distribution of floral-tube length and investigate the reproductive mechanisms associated with this pattern of variation. Flowers were visited exclusively by the long-proboscid fly Moegistorhynchus longirostris (Nemestrinidae), which exhibited a unimodal distribution of proboscis length and displayed a preference for long-tubed phenotypes. Despite being visited by a single pollinator species, allozyme markers revealed significant genetic differentiation between open-pollinated progeny of long- and short-tubed phenotypes suggesting mating barriers between them. We obtained direct evidence for mating barriers between the floral-tube phenotypes through observations of pollinator foraging, controlled hand pollinations and measurements of pollen competition and seed set. Intermediate tube-length phenotypes produced fewer seeds in the field than either long- or short-tubed phenotypes. Although floral-tube length bimodality may not be a stable state over long timescales, reproductive barriers to mating and low 'hybrid' fitness have the potential to contribute to the maintenance of this state in the short term.

Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10^{-12}  GeV^{-1} for ALP masses 0.5≲m_{a}≲5  neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.

Search for Pompe disease among patients with undetermined myopathies

OBJECTIVE

Pompe disease is a rare treatable glycogen storage disease with in adults - a limb-girdle muscle weakness. Muscle biopsy may fail to show the typical vacuolar myopathy. We asked if we had un-diagnosed patients with Pompe disease in western Sweden.

MATERIAL AND METHODS

We searched the muscle biopsy registry during the time period 1986 until 2006 including 3665 biopsies and included patients at our Neuromuscular Center with unspecified myopathy or limb-girdle muscular dystrophy. The dry blood spot test was used to identify patients with Pompe disease.

RESULTS

A total of 82 patients (46 from the biopsy register and 36 from our center) were seen and dry blood spot test was obtained. No patient with Pompe disease was found. The dry blood spot test was low in three cases (11, 16, and 18% of normal) but a second blood sample showed a normal result based on GAA enzyme activity in lymphocytes in all three patients. In one patient with low normal result of the analysis in lymphocytes a genetic test showed no pathogenic mutations. Further investigation gave a definite diagnose of another myopathy in 12 patients.

CONCLUSIONS

The prevalence of Pompe disease in western Sweden (3 in 1.27 million or 0.24 per 100.000 inhabitants) is lower than in the Netherlands and New York. Re-evaluation of patients with myopathies but without definite diagnosis is rewarding since 12 of 82 patients in our study had a definite molecular diagnosis after workup.