Macromammalian faunas, biochronology and palaeoecology of the early Pleistocene Main Quarry hominin-bearing deposits of the Drimolen Palaeocave System, South Africa

The Drimolen Palaeocave System Main Quarry deposits (DMQ) are some of the most prolific hominin and primate-bearing deposits in the Fossil Hominids of South Africa UNESCO World Heritage Site. Discovered in the 1990s, excavations into the DMQ have yielded a demographically diverse sample of Paranthropus robustus (including DNH 7, the most complete cranium of the species recovered to date), early Homo, Papio hamadryas robinsoni and Cercopithecoides williamsi. Alongside the hominin and primate sample is a diverse macromammalian assemblage, but prior publications have only provided a provisional species list and an analysis of the carnivores recovered prior to 2008. Here we present the first description and analysis of the non-primate macromammalian faunas from the DMQ, including all 826 taxonomically identifiable specimens catalogued from over two decades of excavation. We also provide a biochronological interpretation of the DMQ deposits and an initial discussion of local palaeoecology based on taxon representation.The current DMQ assemblage consists of the remains of minimally 147 individuals from 9 Orders and 14 Families of mammals. The carnivore assemblage described here is even more diverse than established in prior publications, including the identification of Megantereon whitei, Lycyaenops silberbergi, and first evidence for the occurrence of Dinofelis cf. barlowi and Dinofelis aff. piveteaui within a single South African site deposit. The cetartiodactyl assemblage is dominated by bovids, with the specimen composition unique in the high recovery of horn cores and dominance of Antidorcas recki remains. Other cetartiodactyl and perissodactyl taxa are represented by few specimens, as are Hystrix and Procavia; the latter somewhat surprisingly so given their common occurrence at penecontemporaneous deposits in the region. Equally unusual (particularly given the size of the sample) is the identification of single specimens of giraffoid, elephantid and aardvark (Orycteropus cf. afer) that are rarely recovered from regional site deposits. Despite the diversity within the DMQ macromammalian faunas, there are few habitat- or biochronologically-sensitive species that provide specific ecologic or age boundaries for the deposits. Recovered species can only support the non-specific, mixed open-to-closed palaeohabitats around Drimolen that have been reconstructed for the other penecontemporaneous South African palaeokarst deposits. The identified Equus quagga ssp. specimens recovered from the floor of the current excavation (∾−4.5–5 m below datum) suggests that most, if not all the DMQ specimens, were deposited after 2.33 Ma. Simultaneously, the carnivore specimens (D. cf. barlowi, L. silberbergi) suggest earlier Pleistocene (pre- 2.0–1.8 Ma) to maximally 1.6 Ma deposition (D. aff. piveteaui) for most of the DMQ fossil assemblage.

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A UK general practice population cohort study investigating the association between lipid lowering drugs and 30-day mortality following medically attended acute respiratory illness

Background. Cholesterol lowering drugs HMG-CoA reductase inhibitors (statins) and PPARα activators (fibrates) have been shown to reduce host inflammation via non-disease specific immunomodulatory mechanisms. Recent studies suggest that commonly prescribed drugs in general practice, statins and fibrates, may be beneficial in influenza-like illness related mortality. This retrospective cohort study examines the association between two lipid lowering drugs, statins and fibrates, and all-cause 30-day mortality following a medically attended acute respiratory illness (MAARI). Methods. Primary care patient data were retrospectively extracted from the UK Clinical Practice Research Datalink (CPRD) database. The sample comprised 201,179 adults aged 30 years or older experiencing a MAARI episode. Patient exposure to statins or fibrates was coded as separate dichotomous variables and deemed current if the most recent GP prescription was issued in the 30 days prior to MAARI diagnosis. Multivariable logistic regression and Cox regression were used for analyses. Adjustment was carried out for chronic lung disease, heart failure, metformin and glitazones, comorbidity burden, socio-demographic and lifestyle variables such as smoking status and body mass index (BMI). Statistical interaction tests were carried out to check for effect modification by gender, body mass index, smoking status and comorbidity. Results. A total of 1,096 (5%) patients died within the 30-day follow up period. Of this group, 213 (19.4%) were statin users and 4 (0.4%) were fibrate users. After adjustment, a significant 35% reduction in odds [adj OR; 0.65 (95% CI [0.52–0.80])] and a 33% reduction in the hazard [adj HR: 0.67 (95% CI [0.55–0.83])] of all-cause 30-day mortality following MAARI was observed in statin users. A significant effect modification by comorbidity burden was observed for the association between statin use and MAARI-related mortality. Fibrate use was associated with a non-significant reduction in 30-day MAARI-related mortality. Conclusion. This study suggests that statin use may be associated with a reduction in 30-day mortality following acute respiratory illness that is severe enough to merit medical consultation. Findings from this study support and strengthen similar observational research while providing a strong rationale for a randomised controlled trial investigating the potential role of statins in acute respiratory infections.

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How does agonistic behaviour differ in albino and pigmented fish?

In addition to hypopigmentation of the skin and red iris colouration, albino animals also display distinct physiological and behavioural alterations. However, information on the social interactions of albino animals is rare and has mostly been limited to specially bred strains of albino rodents and animals from unique environments in caves. Differentiating between the effects of albinism and domestication on behaviour in rodents can be difficult, and social behaviour in cave fish changes according to species-specific adaptations to conditions of permanent darkness. The agonistic behaviours of albino offspring of pigmented parents have yet to be described. In this study, we observed agonistic behaviour in albino and pigmented juvenile Silurus glanis catfish. We found that the total number of aggressive interactions was lower in albinos than in pigmented catfish. The distance between conspecifics was also analysed, and albinos showed a tendency towards greater separation from their same-coloured conspecifics compared with pigmented catfish. These results demonstrate that albinism can be associated with lower aggressiveness and with reduced shoaling behaviour preference, as demonstrated by a tendency towards greater separation of albinos from conspecifics.

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Phylogenetic species delimitation for crayfishes of the genus Pacifastacus

Molecular genetic approaches are playing an increasing role in conservation science by identifying biodiversity that may not be evident by morphology-based taxonomy and systematics. So-called cryptic species are particularly prevalent in freshwater environments, where isolation of dispersal-limited species, such as crayfishes, within dendritic river networks often gives rise to high intra- and inter-specific genetic divergence. We apply here a multi-gene molecular approach to investigate relationships among extant species of the crayfish genus Pacifastacus, representing the first comprehensive phylogenetic study of this taxonomic group. Importantly, Pacifastacus includes both the widely invasive signal crayfish Pacifastacus leniusculus, as well as several species of conservation concern like the Shasta crayfish Pacifastacus fortis. Our analysis used 83 individuals sampled across the four extant Pacifastacus species (omitting the extinct Pacifastacus nigrescens), representing the known taxonomic diversity and geographic distributions within this genus as comprehensively as possible. We reconstructed phylogenetic trees from mitochondrial (16S, COI) and nuclear genes (GAPDH), both separately and using a combined or concatenated dataset, and performed several species delimitation analyses (PTP, ABGD, GMYC) on the COI phylogeny to propose Primary Species Hypotheses (PSHs) within the genus. All phylogenies recovered the genus Pacifastacus as monophyletic, within which we identified a range of six to 21 PSHs; more abundant PSHs delimitations from GMYC and ABGD were always nested within PSHs delimited by the more conservative PTP method. Pacifastacus leniusculus included the majority of PSHs and was not monophyletic relative to the other Pacifastacus species considered. Several of these highly distinct P. leniusculus PSHs likely require urgent conservation attention. Our results identify research needs and conservation priorities for Pacifastacus crayfishes in western North America, and may inform better understanding and management of P. leniusculus in regions where it is invasive, such as Europe and Japan.

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In four shallow and mesophotic tropical reef sponges from Guam the microbial community largely depends on host identity

Sponges (phylum Porifera) are important members of almost all aquatic ecosystems, and are renowned for hosting often dense and diverse microbial communities. While the specificity of the sponge microbiota seems to be closely related to host phylogeny, the environmental factors that could shape differences within local sponge-specific communities remain less understood. On tropical coral reefs, sponge habitats can span from shallow areas to deeper, mesophotic sites. These habitats differ in terms of environmental factors such as light, temperature, and food availability, as well as anthropogenic impact. In order to study the host specificity and potential influence of varying habitats on the sponge microbiota within a local area, four tropical reef sponges, Rhabdastrella globostellata, Callyspongia sp., Rhaphoxya sp., and Acanthella cavernosa, were collected from exposed shallow reef slopes and a deep reef drop-off. Based on 16S rRNA gene pyrosequencing profiles, beta diversity analyses revealed that each sponge species possessed a specific microbiota that was significantly different to those of the other species and exhibited attributes that are characteristic of high- and/or low-microbial-abundance sponges. These findings emphasize the influence of host identity on the associated microbiota. Dominant sponge- and seawater-associated bacterial phyla were Chloroflexi, Cyanobacteria, and Proteobacteria. Comparison of individual sponge taxa and seawater samples between shallow and deep reef sites revealed no significant variation in alpha diversity estimates, while differences in microbial beta diversity (variation in community composition) were significant for Callyspongia sp. sponges and seawater samples. Overall, the sponge-associated microbiota is significantly shaped by host identity across all samples, while the effect of habitat differentiation seems to be less predominant in tropical reef sponges.

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Association of the receptor for advanced glycation end-products (RAGE) gene polymorphisms in Malaysian patients with chronic kidney disease

Background: Chronic kidney disease (CKD) is a condition associated with progressive loss of kidney function and kidney damage. The two common causes of CKD are diabetes mellitus and hypertension. Other causes of CKD also include polycystic kidney disease, obstructive uropathy and primary glomerulonephritis. The receptor for advanced glycation end-products (RAGE) is a multi-ligand cell surface receptor of the immunoglobulin superfamily and it has been associated with kidney disease in both non-diabetic and diabetic patients. Presently, data on the association between RAGE polymorphisms and CKD in the Malaysian population is limited, while numerous studies have reported associations of RAGE polymorphisms with diabetic complications in other populations. The present study aims to explore the possibility of using RAGE polymorphisms as candidate markers of CKD in Malaysian population by using association analysis. Methods: A total of 102 non-diabetic CKD patients, 204 diabetic CKD patients and 345 healthy controls were enrolled in the study. DNA isolated from blood samples were subjected to genotyping of RAGE G82S, −374T/A, −429T/C, 1704G/T and 2184A/G polymorphisms using real-time polymerase chain reaction (PCR). The 63-bp deletion, a polymorphism in the RAGE gene promoter, was genotyped using conventional PCR method and visualized using agarose gel electrophoresis. The collective frequencies of genotypes with at least one copy of the minor alleles of the four polymorphisms were compared between the non-diabetic CKD patients, diabetic CKD patients and healthy controls. Results: After adjustment of age, gender and ethnic groups in binary logistic regression analysis, the G82S CT + TT genotypes were associated with non-diabetic CKD patients when compared with diabetic CKD patients (p = 0.015, OR = 1.896, 95% CI = 1.132–3.176). After further adjustment of CKD comorbidities, the G82S CT + TT genotypes were still associated with non-diabetic CKD patients when compared with diabetic CKD patients (p = 0.011, OR = 2.024, 95% CI = 1.178–3.476). However, it cannot be suggested that G82S polymorphism was associated with CKD in non-diabetic patients in this study. This is because there were no significant differences in the frequencies of G82S CT + TT genotypes between non-diabetic CKD patients and healthy controls. In addition, the RAGE −374T/A, −429T/C, 1704G/T, 2184A/G and 63-bp deletion polymorphisms were also not associated with non-diabetic CKD patients and diabetic CKD patients in this study. Conclusion: The G82S, −374T/A, −429T/C, 1704G/T, 2184A/G and 63-bp deletion polymorphisms examined in this study were not associated with chronic kidney disease in the Malaysian patients.

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Does cognitive flexibility predict treatment gains in Internet-delivered psychological treatment of social anxiety disorder, depression, or tinnitus?

Little is known about the individual factors that predict outcomes in Internet-administered psychological treatments. We hypothesized that greater cognitive flexibility (i.e. the ability to simultaneously consider several concepts and tasks and switch effortlessly between them in response to changes in environmental contingencies) would provide a better foundation for learning and employing the cognitive restructuring techniques taught and exercised in therapy, leading to greater treatment gains. Participants in three trials featuring Internet-administered psychological treatments for depression (n = 36), social anxiety disorder (n = 115) and tinnitus (n = 53) completed the 64-card Wisconsin Card Sorting Test (WCST) prior to treatment. We found no significant associations between perseverative errors on the WCST and treatment gains in any group. We also found low accuracy in the classification of treatment responders. We conclude that lower cognitive flexibility, as captured by perseverative errors on the WCST, should not impede successful outcomes in Internet-delivered psychological treatments.

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Old maids have more appeal: effects of age and pheromone source on mate attraction in an orb-web spider

Background. In many insects and spider species, females attract males with volatile sex pheromones, but we know surprisingly little about the costs and benefits of female pheromone emission. Here, we test the hypothesis that mate attraction by females is dynamic and strategic in the sense that investment in mate attraction is matched to the needs of the female. We use the orb-web spider Argiope bruennichi in which females risk the production of unfertilised egg clutches if they do not receive a copulation within a certain time-frame. Methods. We designed field experiments to compare mate attraction by recently matured (young) females with females close to oviposition (old). In addition, we experimentally separated the potential sources of pheromone transmission, namely the female body and the web silk. Results. In accordance with the hypothesis of strategic pheromone production, the probability of mate attraction and the number of males attracted differed between age classes. While the bodies and webs of young females were hardly found by males, the majority of old females attracted up to two males within two hours. Old females not only increased pheromone emission from their bodies but also from their webs. Capture webs alone spun by old females were significantly more efficient in attracting males than webs of younger females. Discussion. Our results suggest that females modulate their investment in signalling according to the risk of remaining unmated and that they thereby economize on the costs associated with pheromone production and emission.

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River sedimentation in the marginal grabens of the Ethiopian Rift Valley

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Synthesis and surface functionalization of titania nanocrystals for low temperature deposition on polymers

A thin film of crystalline titanium dioxide applied as a self-cleaning coating is a versatile system due to its properties of being transparent and colourless, chemically stable, non-toxic and relatively cheap. Most importantly it has the ability to become photocatalytically active and superhydrophilic upon UV-irradiation. These self-cleaning coatings can mitigate staining, fogging and the odour and deterioration caused by dirt. This results in the fact that self-cleaning coatings are an important topic in research, and are highly commercially relevant. In this work, we extend the use of these coatings to polymers, since this opens up a large market of self-cleaning coatings for applications such as (touch)-screens, visors, light-domes and noise barriers on highways. This transition to polymer substrates, however, poses some challenges. It is imperative for the photocatalytic properties that the TiO2 thin film is of the anatase crystal phase. In order to induce crystallinity to a film deposited from a precursor solution, these films need to be subjected to elevated temperatures (>400°C). This is incompatible with the use of polymers as substrates, since these high temperatures will cause deformation or deterioration of the polymer substrate. In order to circumvent this issue, films are deposited on the substrates from colloidal suspensions that already contain anatase nanocrystals. Other challenges are the wettability of the polymer surface by the colloidal suspension and the durability of the coating. Therefore, the use of chemical linkers to bind titania nanocrystals to the surface of a polymer substrate is explored. This covalent linking is envisioned to improve the durability of the final titania coating.

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Mo K-edge EXAFS investigation of the [Mo7O24]6-promoted phosphate ester hydrolysis

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Oldest Plesiadapiform (Mammalia, Proprimates) from Asia and its palaeobiogeographical implications for faunal interchange with North America

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Defective ceramide synthases in mice cause reduced amplitudes in electroretinograms and altered sphingolipid composition in retina and cornea

Abstract

Complex sphingolipids are strongly expressed in neuronal tissue and contain ceramides in their backbone. Ceramides are synthesized by six ceramide synthases (CerS1-6). Although it is known that each tissue has a unique profile of ceramide synthase expression and ceramide synthases are implicated in several neurodegenerative disorders, the expression of ceramide synthase isoforms was never investigated in the retina. Here, we demonstrate CerS1, CerS2 and CerS4 expression in mouse retina and cornea, with CerS4 ubiquitously expressed in all retinal neurons and Müller cells. To test whether ceramide synthase deficiency affects retinal function, we compared electroretinograms and retina morphology between wild-type and CerS1-, CerS2, and CerS4-deficient mice. Electroretinograms were strongly reduced in amplitude in ceramide synthase-deficient mice, suggesting that signaling in the outer retina is affected. However, the number of photoreceptors and cone outer segment length were unaltered and no changes in retinal layer thickness or synaptic structures were found. Mass spectrometric analyses of ceramides, hexosyl-ceramides and sphingomyelins showed that C20 to C24 acyl-containing species were decreased whereas C16-containing species were increased in the retina of ceramide synthase-deficient mice. Similar but smaller changes were also found in the cornea. Thus, we hypothesize that the replacement of very long-chain fatty acyl residues by shorter C16 residues may affect the electrical properties of retina and cornea, alter receptor-mediated signal transduction, vesicle-mediated synaptic transmission or corneal light transmission. Future studies need to identify the molecular targets of ceramides or derived sphingolipids in light signal transduction and transmission in the eye.

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Inhibitory effects of heterotopic noxious counter-stimulation on perception and brain activity related to Aβ-fiber activation

Abstract

Heterotopic noxious counter-stimulation (HNCS) inhibits pain and pain processes through cerebral and cerebrospinal mechanisms. However, it is unclear whether HNCS inhibits non-nociceptive processes, which needs to be clarified for a better understanding of HNCS analgesia. The aim of this study was to examine the effects of HNCS on perception and scalp somatosensory evoked potentials (SEP). Seventeen healthy volunteers participated in two counter-balanced sessions, including non-nociceptive (selective Aβ-fiber activation) or nociceptive electrical stimulation, combined with HNCS. HNCS was produced by a 20-minute cold pressor test (left hand) adjusted individually to produce moderate pain (mean ± SEM: 42.5 ± 5.3 on a 0-100 scale, where 0 is no pain and 100 the worst pain imaginable). Non-nociceptive electrical stimulation was adjusted individually at 80 % of pain threshold and produced a tactile sensation in every subject. Nociceptive electrical stimulation was adjusted individually at 120 % of RIII-reflex threshold and produced moderate pain (45.3 ± 4.5). Shock sensation was significantly decreased by HNCS compared with baseline for non-nociceptive (p<0.001) and nociceptive (p<0.001) stimulation. SEP peak-to-peak amplitude at Cz was significantly decreased by HNCS for non-nociceptive (p<0.01) and nociceptive (p<0.05) stimulation. These results indicate that perception and brain activity related to Aβ-fiber activation are inhibited by HNCS. The mechanisms of this effect remain to be investigated to clarify whether it involves inhibition of spinal wide-dynamic-range neurons by diffuse noxious inhibitory controls, supraspinal processes, or both.

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Role of cAMP signalling in winner and loser effects in crayfish agonistic encounters

Abstract

For territorial animals, establishment of status-dependent dominance order is essential to maintain social stability.In agonistic encounters of the crayfish Procambarus Clarkii, a difference of body length of 3 -7% is enough for larger animals to become dominant. Despite a physical disadvantage, small winners of the first pairings were more likely to win subsequent conflicts with larger inexperienced animals. In contrast, the losers of the first pairings rarely won subsequent conflicts with smaller naive animals. Such experiences of previous winning or losing affected agonistic outcomes for a long period. The winner effects lasted more than 2 weeks and the loser effect lasted about 10 days. Injection of 5HT1 receptor antagonist into the dominant animals 15 - 30 min after establishment of dominance order blocked the formation of the winner effects. In contrast, injection of adrenergic-like octopamine receptor antagonist into subordinate animals blocked the formation of the loser. 5HT1 receptors are negatively coupled to adenylyl cyclase and adrenergic-like octopamine receptors are positively coupled. Consistent with this, dominant animals failed to show the winner effect when injected with pCPT-cAMP, cAMP analog, and subordinate animals failed to show loser effect when injected with adenylyl cyclase inhibitor SQ 22536. These results suggest that increase and decrease of cAMP concentration is essential in mediating loser and winner effects respectively. Furthermore, the formation of the loser effect was blocked by injection of PKA inhibitor H89, suggesting long-term memory of the loser effect is dependent on the cAMP - PKA signalling pathway.

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Construction of 3D Nanostructure Hierarchical Porous Graphitic Carbon by Charge-induced Self-assembly and Nanocrystal-assisted Catalytic Graphitization for supercapacitors

Chem. Commun., 2016, Accepted Manuscript
DOI: 10.1039/C6CC02147F, Communication

Fangwei Ma, Di Ma, Guang Wu, Weidan Geng, Jinqiu Shao, Shijiao Song, Jiafeng Wan, Jieshan QIU
A smart and sustainable strategy based on charge-induced self-assembly and nanocrystal-assisted catalytic graphitization is explored for efficient construction of 3D nanostructure hierarchical porous graphitic carbon from pectin biopolymer. The electrostatic...
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The secondary coordination sphere controlled reactivity of a ferric-superoxo heme: Unexpected conversion to a ferric hydroperoxo intermediate by a reaction with a high-spin ferrous heme

Chem. Commun., 2016, Accepted Manuscript
DOI: 10.1039/C6CC02162J, Communication

Perumandla Nagaraju, Takehiro Ohta, Jin-Gang Liu, Takashi Ogura, Yoshinori Naruta
A bio-inspired heme complex involving both a proton donor and an axial imidazole ligand reduces the activation energy for the formation of a ferric hydroperoxo intermediate. A high-spin ferrous heme...
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Stabilisation of an amorphous form of ROY through a predicted co-former interaction

Chem. Commun., 2016, Accepted Manuscript
DOI: 10.1039/C6CC02949C, Communication

Philip Anthony Corner, J Jonathan Harburn, Jonathan W Steed, James Francis McCabe, David Berry
The highly polymorphic compound ROY, notorious for the colour of its crystals, was the subject of an optimised high-throughput ultrasound-based co-crystal screen. This screen involved a computational pre-screen which highlighted...
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Mu suppression – a good measure of the human mirror neuron system?

Publication date: Available online 15 April 2016
Source:Cortex
Author(s): Hannah M. Hobson, Dorothy V.M. Bishop
Mu suppression has been proposed as a signature of the activity of the human mirror neuron system. However the mu frequency band (8-13 Hz) overlaps with the alpha frequency band, which is sensitive to attentional fluctuation, and thus mu suppression could potentially be confounded by changes in attentional engagement. The specific baseline against which mu suppression is assessed may be crucial, yet there is little consistency in how this is defined. We examined mu suppression in 61 typical adults, the largest mu suppression study so far conducted. We compared different methods of baselining, and examined activity at central and occipital electrodes, to both biological (hands) and non-biological (kaleidoscope) moving stimuli, to investigate the involvement of attention and alpha activity in mu suppression. We also examined changes in beta power, another candidate index of mirror neuron system engagement. We observed strong mu suppression restricted to central electrodes when participants performed hand movements, demonstrating that mu is indeed responsive to the activity of the motor cortex. However, when we looked for a similar signature of mu suppression to passively observed stimuli, the baselining method proved to be crucial. Selective suppression for biological vs non-biological stimuli was seen at central electrodes only when we used a within-trial baseline based on a static stimulus: this method greatly reduced trial-by-trial variation in the suppression measure compared with baselines based on blank trials presented in separate blocks. Even in this optimal condition, 16-21% of participants showed no mu suppression. Changes in beta power also did not match our predicted pattern for mirror neuron system engagement, and did not seem to offer a better measure than mu. Our conclusions are in contrast to those of a recent meta-analysis, which concluded that mu suppression is a valid means to examine mirror neuron activity. We argue that mu suppression can be used to index the human mirror neuron system, but the effect is weak and unreliable and easily confounded with alpha suppression.



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Resilience to the contralateral visual field bias as a window into object representations

Publication date: Available online 13 April 2016
Source:Cortex
Author(s): Frank E. Garcea, Stephanie Kristensen, Jorge Almeida, Bradford Z. Mahon
Viewing images of manipulable objects elicits differential blood oxygen level-dependent (BOLD) contrast across parietal and dorsal occipital areas of the human brain that support object-directed reaching, grasping, and complex object manipulation. However, it is unknown which object-selective regions of parietal cortex receive their principal inputs from the ventral object-processing pathway and which receive their inputs from the dorsal object-processing pathway. Parietal areas that receive their inputs from the ventral visual pathway, rather than from the dorsal stream, will have inputs that are already filtered through object categorization and identification processes. This predicts that parietal regions that receive inputs from the ventral visual pathway should exhibit object-selective responses that are resilient to contralateral visual field biases. To test this hypothesis, adult participants viewed images of tools and animals that were presented to the left or right visual fields during functional magnetic resonance imaging (fMRI). We found that the left inferior parietal lobule showed robust tool preferences independently of the visual field in which tool stimuli were presented. In contrast, a region in posterior parietal/dorsal occipital cortex in the right hemisphere exhibited an interaction between visual field and category: tool-preferences were strongest contralateral to the stimulus. These findings suggest that action knowledge accessed in the left inferior parietal lobule operates over inputs that are abstracted from the visual input and contingent on analysis by the ventral visual pathway, consistent with its putative role in supporting object manipulation knowledge.



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Reduced sensitivity to contrast signals from the eye region in developmental prosopagnosia

Publication date: Available online 13 April 2016
Source:Cortex
Author(s): Katie Fisher, John Towler, Martin Eimer
Contrast-related signals from the eye region are known to be important for the processing of facial identity. Individuals with developmental prosopagnosia (DP) have severe face recognition problems, which may be linked to deficits in the perceptual processing of identity-related information from the eyes. We tested this hypothesis by measuring N170 components in DP participants and age-matched controls in response to face images where the contrast polarity of the eyes and of other face parts was independently manipulated. In different trials, participants fixated either the eye region or the lower part of a face. In the Control group, contrast-reversal of the eyes resulted in enhanced and delayed N170 components, irrespective of the contrast of other face parts and of gaze location. In the DP group, these effects of eye contrast on N170 amplitudes were strongly and significantly reduced, demonstrating that perceptual face processing in DP is less well tuned to contrast information from the eye region. Inverting the contrast of other parts of the face affected N170 amplitudes only when fixation was outside the eye region. This effect did not differ between the two groups, indicating that DPs are not generally insensitive to the contrast polarity of face images. These results provide new evidence that a selective deficit in detecting and analysing identity-related information provided by contrast signals from the eye region may contribute to the face recognition impairment in DP.



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Object representations in visual working memory change according to the task context

Publication date: Available online 13 April 2016
Source:Cortex
Author(s): Halely Balaban, Roy Luria
This study investigated whether an item's representation in visual working memory (VWM) can be updated according to changes in the global task context. We used a modified change detection paradigm, in which the items moved before the retention interval. In all of the experiments, we presented identical color-color conjunction items that were arranged to provide a common fate Gestalt grouping cue during their movement. Task context was manipulated by adding a condition highlighting either the integrated interpretation of the conjunction items or their individuated interpretation. We monitored the contralateral delay activity (CDA) as an online marker of VWM. Experiment 1 employed only a minimal global context; the conjunction items were integrated during their movement, but then were partially individuated, at a late stage of the retention interval. The same conjunction items were perfectly integrated in an integration context (Experiment 2). An individuation context successfully produced strong individuation, already during the movement, overriding Gestalt grouping cues (Experiment 3). In Experiment 4, a short priming of the individuation context managed to individuate the conjunction items immediately after the Gestalt cue was no longer available (Experiment 4). Thus, the representations of identical items changed according to the task context, suggesting that VWM interprets incoming input according to global factors which can override perceptual cues.



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The use of repetition suppression paradigms in developmental cognitive neuroscience

Publication date: Available online 12 April 2016
Source:Cortex
Author(s): Marisa Nordt, Stefanie Hoehl, Sarah Weigelt
Repetition suppression paradigms allow a more detailed look at brain functioning than classical paradigms and have been applied vigorously in adult cognitive neuroscience. These paradigms are well suited for studies in the field of developmental cognitive neuroscience as they can be applied without collecting a behavioral response and across all age groups. Furthermore, repetition suppression paradigms can be employed in various neuroscience techniques, such as functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG) and magnetoencephalography (MEG). In the present article we review studies using repetition suppression paradigms in developmental cognitive neuroscience covering the age range from infancy to adolescence. Our first goal is to point out characteristics of developmental repetition suppression effects. In doing so, we discuss the relationship of the direction of repetition effects (suppression versus enhancement) with developmental factors, and address the question how the direction of repetition effects might be related to looking-time effects in behavioral infant paradigms, the most prominently used behavioral measure in infant research. To highlight the potential of repetition suppression paradigms, our second goal is to provide an overview on the insights recently obtained by applying repetition paradigms in neurodevelopmental studies, including research on children with autism spectrum disorders. We conclude that repetition suppression paradigms are valuable tools for investigating neurodevelopmental processes, while at the same time we highlight the necessity for further studies that disentangle methodological and developmental factors.



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Dorsal and ventral language pathways in persistent developmental stuttering

Publication date: Available online 12 April 2016
Source:Cortex
Author(s): Vered Kronfeld-Duenias, Ofer Amir, Ruth Ezrati-Vinacour, Oren Civier, Michal Ben-Shachar
Persistent developmental stuttering is a speech disorder that affects an individual's ability to fluently produce speech. While the disorder mainly manifests in situations that require language production, it is still unclear whether persistent developmental stuttering is indeed a language impairment, and if so, which language stream is implicated in people who stutter. In this study, we take a neuroanatomical approach to this question by examining the structural properties of the dorsal and ventral language pathways in adults who stutter and fluent controls. We use diffusion magnetic resonance imaging and individualized tract-identification to extract white matter volumes and diffusion properties of these tracts in samples of adults who do and do not stutter. We further quantify diffusion properties at multiple points along the tract and examine group differences within these diffusivity profiles. Our results show differences in the dorsal, but not in the ventral, language-related tracts. Specifically, adults who stutter show reduced volume of the left dorsal stream, as well as lower anisotropy in the right dorsal stream. These data provide neuroanatomical support for the view that stuttering involves an impairment in the bidirectional mapping between auditory and articulatory cortices supported by the dorsal pathways, not in lexical access and semantic aspects of language processing which are thought to rely more heavily on the left ventral pathways.



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The effect of brain death and coma on gastric myoelectrical activity

The Turkish Journal of Gastroenterology

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Randomized, open-label phase 2 study comparing frontline dovitinib vs sorafenib in patients with advanced hepatocellular carcinoma

Hepatology

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Deep sequencing of hepatitis C virus reveals genetic compartmentalization in cerebrospinal fluid from cognitively impaired patients

Liver International

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Hearing loss in patients with inflammatory bowel disease

Digestive Diseases and Sciences

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Frequent detection of HCV RNA and HCVcoreAg in stool of patients with chronic hepatitis C

Journal of Clinical Virology

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Clinical features and outcomes of complementary and alternative medicine induced acute liver failure and injury

The American Journal of Gastroenterology

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Poor performance status is associated with increased mortality in patients with cirrhosis

Clinical Gastroenterology and Hepatology

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Randomized, multicenter study: on-demand versus continuous maintenance treatment with esomeprazole in patients with non-erosive gastroesophageal reflux disease

BMC Gastroenterology

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Preliminary analysis of clinical situations involved in quantification of contrast-enhanced ultrasound in Crohn's disease

Ultrasound in Medicine and Biology

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Transmission of Hepatitis B core Antibody and Galactomannan Enzyme Immunoassay positivity via immunoglobulin products: a comprehensive analysis

Clinical Infectious Diseases

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Linkage to care for suburban heroin users with hepatitis C virus infection, New Jersey, USA

Emerging Infectious Diseases

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Safety and efficacy of endoscopic mucosal resection for sporadic, nonampullary duodenal adenomas: a single U.S. center experience

Gastrointestinal Endoscopy

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Efficacy and safety profile of anti–tumor necrosis factor-α versus anti-integrin agents for the treatment of crohn's disease: a network meta-analysis of indirect comparisons

Clinical Therapeutics

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Loss of peristaltic reserve, determined by multiple rapid swallows is the most frequent esophageal motility abnormality in patients with systemic sclerosis

Clinical Gastroenterology and Hepatology

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Metagenomics reveals dysbiosis and a potentially pathogenic n. flavescens strain in duodenum of adult celiac patients

The American Journal of Gastroenterology

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Prediction model for sustained hepatitis B e antigen seroconversion to peginterferon alfa-2a in chronic hepatitis B

Journal of Gastroenterology and Hepatology

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Decreasing mortality among Danish alcoholic cirrhosis patients: a nationwide cohort study

The American Journal of Gastroenterology

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Quantification of core antigen monitors efficacy of direct-acting antiviral agents in patients with chronic HCV infection

Clinical Gastroenterology and Hepatology

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Clinical relevance of dual-energy X-ray absorptiometry (DXA) as a simultaneous evaluation of fatty liver disease and atherosclerosis in patients with type 2 diabetes

Cardiovascular Diabetology

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Assessing the durability of entecavir-treated hepatitis B using quantitative HBsAg

The American Journal of Gastroenterology

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Unlocking the role of soil and water resources for rural development in marginal grabens of northern Ethiopia

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Use of LiDAR data for geomorphological analysis of regressive erosion related to surface karst (Chantoir de Grandchamps, Sprimont, Belgium)

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3D modelling of the amphidial aperture in the genus Malenchus

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Nematode diversity and first observations of marine taxa from phytotelmata of Nephenthes spp. in Mt Hamiguitan Range Wildlife Sanctuary

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Soil and litter nematode diversity of Mount Hamiguitan, the Philippines, with description of Bicirronema hamiguitanense n. sp. (Rhabditida: Bicirronematidae)

The nematode diversity in soil and litter was investigated on Mount Hamiguitan, the Philippines, along four eco-habitats from elevations of 75-1600 m a.s.l. A total of 155 and 467 nematodes were identified to 39 and 62 genera from litter and soil, respectively. The nematode assemblages and diversity did not show any relation to eco-habitat or elevation. Bacterivorous nematodes were the most common group (37.5%). Acrobeloides was most abundant from the soil and Aphelenchoides from the litter. Bicirronema hamiguitanense n. sp. is herein described based on morphology, morphometrics and molecular data. The new species has the following diagnostic features: a wide lateral field one-fifth of its body diam. with four incisures forming two ornamented ridges; gubernaculum with proximal thickening; spicules (35-38 mu m) and gubernaculum (18-20 mu m) longer than B. caledoniense; and with 37 molecular autapomorphies supporting its new species status. The phylogenetic position of the new species within Cephalobomorpha is discussed.

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Effects of the antibiotic tetracycline on the reproduction, growth and population growth rate of the nematode Caenorhabditis elegans

The antibiotic tetracycline (TC) has been reported in natural systems, a consequence of its abundant usage in farming. TCs are protein synthesis inhibitors that are effective against bacteria but adverse effects on non-target organisms, whilst less well understood, have also been demonstrated. This study is the first investigation into the effects of this common antibiotic on the growth, reproduction and population growth rate (PGR) of the nematode Caenorhabditis elegans. All toxicological endpoints were shown to be affected negatively. TC concentrations as low as 5 mg l(-1) (5 ppm) significantly reduced growth and reproduction, and even lower concentrations (3 mg l(-1) or 3 ppm) significantly decreased the PGR. These levels are much higher than the TC concentrations detected in surface waters, sediments and soils (0.005-300 ppb). However, although the antibiotic might not pose a direct significant risk to nematodes in the natural environment, its use in RNAi experiments involving C. elegans may cause unwanted effects that influence interpretations of the results.

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