Upgrading of the general AMBER force field 2 for fluorinated alcohol biosolvents: A validation for water solutions and melittin solvation.

The standard GAFF2 force field parameterization has been refined for the fluorinated alcohols 2,2,2-trifluoroethanol (TFE), 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), and 1,1,1,3,3,3-hexafluoropropan-2-one (HFA), which are commonly used to study proteins and peptides in biomimetic media. The structural and dynamic properties of both proteins and peptides are significantly influenced by the biomimetic environment created by the presence of these cosolvents in aqueous solutions. Quantum mechanical calculations on stable conformers were used to parameterize the atomic charges. Different systems, such as pure liquids, aqueous solutions, and systems formed by melittin protein and cosolvent/water solutions, have been used to validate the new models. The calculated macroscopic and structural properties are in agreement with experimental findings, supporting the validity of the newly proposed models.

Intestinal Microbiota Increases Cell Proliferation of Colonic Mucosa in Human-Flora-Associated (HFA) Mice.

Intestinal epithelium renewal strictly depends on fine regulation between cell proliferation, differentiation, and apoptosis. While murine intestinal microbiota has been shown to modify some epithelial cell kinetics parameters, less is known about the role of the human intestinal microbiota. Here, we investigated the rate of intestinal cell proliferation in C3H/HeN germ-free mice associated with human flora (HFA, n = 8), and in germ-free (n = 15) and holoxenic mice (n = 16). One hour before sacrifice, all mice were intraperitoneally inoculated with 5-bromodeoxyuridine (BrdU), and the number of BrdU-positive cells/total cells (labelling index, LI), both in the jejunum and the colon, was evaluated by immunohistochemistry. Samples were also observed by scanning electron microscopy (SEM). Moreover, the microbiota composition in the large bowel of the HFA mice was compared to that of of human donor's fecal sample. No differences in LI were found in the small bowels of the HFA, holoxenic, and germ-free mice. Conversely, the LI in the large bowel of the HFA mice was significantly higher than that in the germ-free and holoxenic counterparts (p = 0.017 and p = 0.048, respectively). In the holoxenic and HFA mice, the SEM analysis disclosed different types of bacteria in close contact with the intestinal epithelium. Finally, the colonic microbiota composition of the HFA mice widely overlapped with that of the human donor in terms of dominant populations, although Bifidobacteria and Lactobacilli disappeared. Despite the small sample size analyzed in this study, these preliminary findings suggest that human intestinal microbiota may promote a high proliferation rate of colonic mucosa. In light of the well-known role of uncontrolled proliferation in colorectal carcinogenesis, these results may deserve further investigation in a larger population study.

[Applicability of H2FPEF and HFA-PEFF Scores in Chinese Patients Suffering From Heart Failure With Preserved Ejection Fraction and Heart Failure With Preserved Ejection Fraction Complicated With Atrial Fibrillation].

Objective To analyze the diagnostic values of H2FPEF and HFA-PEFF scores for heart failure with preserved ejection fraction (HFpEF) and HFpEF complicated with atrial fibrillation (HFpEF-AF) in Chinese patients and explore the related factors. Methods A cross-sectional study was conducted.A total of 835 consecutive HFpEF patients treated in the Department of Geriatric Cardiology,the First Hospital of Lanzhou University from 2009 to 2020 were selected and assigned to a HFpEF-AF group (n=267) and a HFpEF group (n=568) according to the presence of AF or not.HFA-PEFF and H2FPEF scores were used for retrospective diagnosis and the diagnostic consistency of the two scores was assessed.One hundred and thirty-six healthy volunteers with age and sex matching the patients during the same period were selected as healthy controls.The receiver operating characteristic (ROC) curves were established for H2FPEF and HFA-PEFF scores in diagnosing HFpEF-AF and HFpEF,on the basis of which the diagnostic performance of the two scores was evaluated. Results There was no difference in the HFA-PEFF score between the two groups (P=0.070).However,the HFpEF-AF group had higher mean H2FPEF score and higher proportion of patients with the score no less than 6 than the HFpEF group (P<0.001).According to the ROC curves,HFA-PEFF and H2FPEF scores demonstrated high performance in diagnosing all HFpEF patients,with the area under the curve (AUC) of 0.892 and 0.922 and the optimal cut-offs of 4 and 4,respectively.The HFA-PEFF score showed similar performance in diagnosing HFpEF and HFpEF-AF,with the AUC of 0.899 and 0.911,respectively.The H2FPEF score had higher performance in diagnosing HFpEF-AF (AUC of approximately 1.000) and low performance in diagnosing HFpEF (AUC of 0.885). Conclusions The HFA-PEFF score is applicable in the diagnosis of both HFpEF and HFpEF-AF.The H2FPEF score may underestimate HFpEF in Chinese patients,and its applicability in the Chinese patients with HFpEF alone remains to be investigated.

Combination of SVI/S' and diagnostic scores for heart failure with preserved ejection fraction.

The diagnosis of heart failure with preserved ejection fraction (HFpEF) remains a challenge. There are three methods proposed as diagnostic tools. H2 FPEF score was determined by six weighted clinical characteristics and echocardiographic variables. Heart Failure Association (HFA)-PEFF algorithm consists of various functional and morphological variables as well as natriuretic peptides. SVI/S' is a novel echocardiographic parameter calculated by stroke volume index and mitral annulus systolic peak velocity. This study aimed to compare the three approaches in patients with suspected HFpEF. Patients referred to right heart catheterization for suspected HFpEF were classified into low-, intermediate- and high-likelihood groups according to H2 FPEF or HFA-PEFF scores. A diagnosis of HFpEF was confirmed by pulmonary capillary wedge pressure (PCWP) of ≥15 mm Hg according to the guidelines. In result, a total of 128 patients were included. Of these, 71 patients with PCWP ≥15 mm Hg and 57 patients with PCWP <15 mm Hg. Moderate correlations were observed between H2 FPEF score, HFA-PEFF score, SVI/S' and PCWP. The area under curve of SVI/S' was 0.82 for diagnosis of HFpEF, compared with 0.67 for H2 FPEF score and 0.75 for HFA-PEFF score by receiver-operating characteristics analysis. Combining SVI/S' with diagnostic scores showed higher Youden index and accuracy than each score alone. Kaplan-Meier analysis reported that the high-likelihood group showed poorer outcomes regardless the method used for diagnosis. Among the contemporary tools for identifying HFpEF in this study, the combination of SVI/S' with risk scores showed best diagnostic ability. Each of the strategies can determine rehospitalisation because of heart failure.

The relationship of skin autofluorescence with diastolic function and HFA-PEFF score in a general population of older people.

BACKGROUND AND AIMS: Advanced glycation end-products accumulation in tissue as measured by Skin autofluorescence (SAF) is related to diastolic function in specific patient populations. This analysis aims at investigating this relationship in a general population of older persons. METHODS AND RESULTS: Based on data from the CARLA cohort at first follow-up, 245 subjects were analyzed and stratified according to cardiovascular risk factors (CVRF). We used linear regression to investigate the association between diastolic function evaluated by echocardiography, HFA-PEFF score, and SAF. Univariable regression analysis showed an association of SAF with septal-E/e' (standardised beta = 1.11, 95% CI = 0.51-1.71) and A (3.42, 95% CI = 0.72-6.12), the former persisting after adjustment for age, sex and CVRF (0.67, 95% CI = 0.05-1.28). Septal-E/e' remained related to SAF only in the high cardiovascular risk stratum (1.16, 95% CI = 0.26-2.06). SAF was related to HFA-PEFF score (0.27, 95% CI = 0.10-0.43) but not after correcting for age and sex (0.16, 95% CI = 0.00-0.32) and CVRF and glomerular filtration rate (0.12, 95% CI = -0.07 - 0.27). SAF was related to the HFA-PEFF score only for participants with high cardiovascular risk (0.23, 95% CI = 0.02-0.45). CONCLUSION: In a general community-dwelling older population, SAF is related to diastolic function as measured by septal-E/e'. Further research is necessary to assess if SAF is a potential screening tool for diastolic dysfunction in advanced age.

Heart failure with preserved ejection fraction in humans and mice: embracing clinical complexity in mouse models.

Heart failure (HF) with preserved ejection fraction (HFpEF) is a multifactorial disease accounting for a large and increasing proportion of all clinical HF presentations. As a clinical syndrome, HFpEF is characterized by typical signs and symptoms of HF, a distinct cardiac phenotype and raised natriuretic peptides. Non-cardiac comorbidities frequently co-exist and contribute to the pathophysiology of HFpEF. To date, no therapy has proven to improve outcomes in HFpEF, with drug development hampered, at least partly, by lack of consensus on appropriate standards for pre-clinical HFpEF models. Recently, two clinical algorithms (HFA-PEFF and H2FPEF scores) have been developed to improve and standardize the diagnosis of HFpEF. In this review, we evaluate the translational utility of HFpEF mouse models in the context of these HFpEF scores. We systematically recorded evidence of symptoms and signs of HF or clinical HFpEF features and included several cardiac and extra-cardiac parameters as well as age and sex for each HFpEF mouse model. We found that most of the pre-clinical HFpEF models do not meet the HFpEF clinical criteria, although some multifactorial models resemble human HFpEF to a reasonable extent. We therefore conclude that to optimize the translational value of mouse models to human HFpEF, a novel approach for the development of pre-clinical HFpEF models is needed, taking into account the complex HFpEF pathophysiology in humans.

Generalizability of HFA-PEFF and H2FPEF Diagnostic Algorithms and Associations With Heart Failure Indices and Proteomic Biomarkers: Insights From PROMIS-HFpEF.

BACKGROUND: Diagnosing heart failure with preserved ejection fraction (HFpEF) remains challenging. We aimed to evaluate the generalizability of the HFA-PEFF (Heart Failure Association Pre-test assessment, Echocardiography & natriuretic peptide, Functional testing, Final etiology) and weighted H2FPEF (Heavy, 2 or more Hypertensive drugs, atrial Fibrillation, Pulmonary hypertension, Elder age > 60, elevated Filling pressures) diagnostic algorithms and associations with HF severity, coronary microvascular dysfunction and proteomic biomarkers. METHODS AND RESULTS: Diagnostic likelihood of HFpEF was calculated in the prospective, multinational PROMIS-HFpEF (Prevalence of microvascular dysfunction in HFpEF) cohort using current European Society of Cardiology recommendations, HFA-PEFF and H2FPEF algorithms. Associations between the 2 algorithms and left atrial function, Doppler-based coronary flow reserve, 6-minute walk test, quality of life, and proteomic biomarkers were investigated. Of 181 patients with an EF of ≥50%, 129 (71%) and 94 (52%) fulfilled criteria for high likelihood HFpEF as per HFA-PEFF and H2FPEF, and 28% and 46% were classified as intermediate likelihood, requiring additional hemodynamic testing. High likelihood HFpEF patients were older with higher prevalence of atrial fibrillation and lower global longitudinal strain and left atrial reservoir strain (P < .001 for all variables). left atrial reservoir strain and global longitudinal strain were inversely associated with both HFA-PEFF and H2FPEF scores (TauB = -0.35 and -0.46 and -0.21 and -0.31; P < .001 for all). There were no associations between scoring and 6-minute walk test, quality of life, and coronary flow reserve. Both scores were associated with biomarkers related to inflammation, oxidative stress, and fibrosis. CONCLUSIONS: Although the HFA-PEFF and H2FPEF scores were associated with measures of HF severity and biomarkers related to HFpEF, they demonstrated a modest and differential ability to identify HFpEF noninvasively, necessitating additional functional testing to confirm the diagnosis.

Attention Deficits Influence the Development of Motor Abnormalities in High Functioning Autism.

Early attentional dysfunction is one of the most consistent findings in autism spectrum disorder (ASD), including the high functioning autism (HFA). There are no studies that assess how the atypical attentional processes affect the motor functioning in HFA. In this study, we evaluated attentional and motor functioning in a sample of 15 drug-naive patients with HFA and 15 healthy children (HC), and possible link between attentional dysfunction and motor impairment in HFA. Compared to HC, HFA group was seriously impaired in a considerable number of attentional processes and showed a greater number of motor abnormalities. Significant correlations between attention deficits and motor abnormalities were observed in HFA group. These preliminary findings suggest that deficit of attentional processes can be implied in motor abnormalities in HFA.

Eight cylindrical contact lead recordings in the subthalamic region localize beta oscillations source to the dorsal STN.

BACKGROUND: In Parkinson's disease (PD) patients, the subthalamic nucleus (STN) has prominent oscillatory activity in the beta band, which may be related to the motor symptoms severity. Local field potential (LFP) studies using standard four-contact deep brain stimulation (DBS) leads indicate that the source of beta activity in the STN region is the dorsolateral segment of the nucleus. However, these leads have few contacts outside of the STN, making the source localization of beta activity around the STN region uncertain. OBJECTIVE: This study aimed to investigate the electrophysiological characteristics of the STN and the surrounding area in PD to better locate the source of these oscillations and their clinical relevance. METHODS: Eight PD patients were bilaterally implanted in the STN with the eight ring-contact DBS lead (Boston Scientific Corporation). LFPs were recorded intra-operatively from each DBS contact in the off medication state at rest. Each contact location was normalized relative to the STN borders based on microelectrode recordings. For each recording, power spectral density was computed, averaged over multiple frequency bands and phase reversal analysis was used to localize the source of oscillatory activity. Beta burst, high-frequency activity (HFA), and phase-amplitude coupling (PAC) were also computed. Neurophysiological signatures were correlated with hemibody symptoms severity and clinical outcomes. RESULTS: Beta band power and phase reversal localized the beta oscillator to the dorsal STN and correlated with pre-operative off medication hemibody bradykinesia and rigidity score. The contact along the electrode with the largest beta oscillatory power co-localized with the independently chosen optimized contact used for long-term chronic DBS. Lastly, beta bursting, HFA, and Beta-HFA PAC co-localized with the beta oscillator at the dorsal STN, and Beta-HFA PAC correlated with DBS effect. CONCLUSIONS: Our findings support the hypothesis that the primary source of beta oscillations is located in dorsal STN, and argue against the alternative hypothesis that beta activity in the STN region arises from volume conduction from other sources. We demonstrate intrinsic STN beta-HFA PAC as an independent marker of DBS effect.

Assessment of axonal sprouting and motor performance after hypoglossal-facial end-to-side nerve repair: experimental study in rats.

Hypoglossal-facial nerve anastomosis (HFA) aims to reanimate denervated mimic muscles with hypoglossal axons when the transected facial nerve is not accessible. The aim of this study was to evaluate the recovery of HFA using a "Y" tube in two variants: (1) the proximal stump of the hypoglossal nerve was entubulated to the "Y" tube (classic "Y" tube HFA) and (2) the "Y" tube was sutured to an epineurial window of a slightly damaged hypoglossal nerve (end-to-side "Y" tube HFA). A total of 48 adult female rats were divided into four groups: intact controls (group 1), sham operated (group 2), classic "Y" tube HFA (group 3) and end-to-side "Y" tube HFA (group 4). The abdominal aorta with both common iliac arteries of isogeneic male rats served as the Y-tube conduit. Animals from group 4 recovered better than those from group 3: the degree of collateral axonal branching (3 ± 1%) was significantly lower than that determined in group 3 (13 ± 1%). The mean deviation of the tongue from the midline was significantly smaller in group 4 (6 ± 4°) than that measured in animals from group 3 (41 ± 6°). In the determination of vibrissal motor function in group 3 and group 4, a decrease in amplitude was found to be - 66% and - 92%, respectively. No differences in the reinnervation pattern of the target muscles were detected. As a result, these surgical models were not determined to be able to improve vibrissal movements. It was concluded that performance of end-to-side "Y" tube HFA diminishes collateral axonal branching at the lesion site, which in turn, promotes better recovery of tongue- and vibrissal-motor performance.

Home-Field Advantage in Wood Decomposition Is Mainly Mediated by Fungal Community Shifts at "Home" Versus "Away".

The home-field advantage (HFA) hypothesis has been used intensively to study leaf litter decomposition in various ecosystems. However, the HFA in woody substrates is still unexplored. Here, we reanalyzed and integrated existing datasets on various groups of microorganisms collected from natural deadwood of two temperate trees, Fagus sylvatica and Picea abies, from forests in which one or other of these species dominates but where both are present. Our aims were (i) to test the HFA hypothesis on wood decomposition rates of these two temperate tree species, and (ii) to investigate if HFA hypothesis can be explained by diversity and community composition of bacteria and in detail N-fixing bacteria (as determined by molecular 16S rRNA and nifH gene amplification) and fungi (as determined by molecular ITS rRNA amplification and sporocarp surveys). Our results showed that wood decomposition rates were accelerated at "home" versus "away" by 38.19% ± 20.04% (mean ± SE). We detected strong changes in fungal richness (increase 36-50%) and community composition (RANOSIM = 0.52-0.60, P < 0.05) according to HFA hypothesis. The changes of fungi were much stronger than for total bacteria and nitrogen fixing for both at richness and community composition levels. In conclusion, our results support the HFA hypothesis in deadwood: decomposition rate is accelerated at home due to specialization of fungal communities produced by the plant community above them. Furthermore, the higher richness of fungal sporocarps and nitrogen-fixing bacteria (nifH) may stimulate or at least stabilize wood decomposition rates at "home" versus "away."

Isolation of Ceramides from Tagetes patula L. Yellow Flowers and Nematicidal Activity of the Fractions and Pure Compounds against Cyst Nematode, Heterodera zeae.

Investigation of yellow flower extract of Tagetes patula L. led to the identification of an aggregate of five phytoceramides. Among them, (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]icosanamide, (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]heneicosanamide, (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]docosanamide, and (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]tricosanamide were identified as new compounds and termed as tagetceramides, whereas (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]tetracosanamide was a known ceramide. A steroid (ß-sitosterol glucoside) was also isolated from the subsequent fraction. The structures of these compounds were determined on the basis of spectroscopic analyses, as well as chemical method. Several other compounds were also identified by GC/MS analysis. The fractions and some commercial products, a ceramide HFA, ß-sitosterol, and stigmasterol were evaluated against an economically important cyst nematode, Heterodera zeae. Ceramide HFA showed 100 % mortality, whereas, ß-sitosterol and stigmasterol were 40-50 % active, at 1 % concentration after 24 h of exposure time, while ß-sitosterol glucoside revealed no activity against the nematode.

Three Year Patency and Recurrence Rates of Revision Using Distal Inflow with a Venous Interposition Graft for High Flow Brachial Artery Based Arteriovenous Fistula.

OBJECTIVES: Upper arm arteriovenous fistulas (AVF) occasionally develop high flow. Revision using distal inflow (RUDI) effectively reduces flow of high flow accesses (HFA) in the short-term and is also popularised for treatment of haemodialysis access induced distal ischaemia (HAIDI). The long-term efficacy is unknown. The study's aim was to report on 3 year RUDI patency and recurrence rates for HFA with and without HAIDI. MATERIAL AND METHODS: This was a retrospective cohort study of patients with a HFA with or without HAIDI undergoing RUDI using greater saphenous vein (GSV) interposition between March 2011 and October 2017 at three facilities. AVFs were termed HFA if flow volumes exceeded 2 L/min on two consecutive measurements using dilution techniques. HAIDI was diagnosed as recommended. Following RUDI, follow up was not different from standard care in AVF patients. Data on post-operative flows and re-interventions were extracted from electronic patient files. Loss to follow up was avoided. Rates of patency and HFA recurrence were analysed. RESULTS: During the observation period, 21 patients were studied (7 females, 54 years ± 3). Fourteen had uncomplicated HFA whereas seven had additional HAIDI. Immediately post-operatively, flows decreased threefold (3120 mL/min ± 171 vs. 1170 mL/min ± 87, p < .001). Overall 3 year primary patency was 48% ± 12 (HFA, 55% ± 15 vs. HAIDI/HFA, 29% ± 17, p = .042). Secondary patency was identical in both groups (overall, 84% ± 9). Interventions were percutaneous transluminal angioplasty (n = 12, 9 patients), thrombectomy (n = 7, 3 patients), and revision with new interposition grafts (n = 3). After 3 years, 51% ± 12 were free of high flow (HFA, 32% ± 13 vs. HAIDI/HFA, 100%, p = .018). High immediate post-operative access flow predicted recurrence (OR 1.004 [1.000-1.007], p = .044). Patients with recurrence were 12 years younger than those without (p = .055). CONCLUSION: RUDI with GSV interposition for HFA offers acceptable patency rates after 3 years although re-interventions are often required. High immediate post-operative flows and young age are associated with recurrent high flow.

The association between punishment and cooperation in children with high-functioning autism.

This study examined judgment about punishment and whether punishment promoted cooperation in the prisoner's dilemma game (PDG) in children with high-functioning autism (HFA) and typically developing (TD) children. In total, 66 6- to 12-year-olds participated in this study. Children were first asked about judgments regarding rewards and punishment in stories, and then they were asked to play the PDG with a partner in conditions with and without punishment. Results showed that children with HFA believed that hitting others should deserve punishment to a greater extent than TD children did. It indicated that children with HFA understood that bad acts should be punished, suggesting that these children have already acquired the general concept of "punishment." Children displayed higher levels of cooperation in the condition with punishment than in the condition without punishment in the PDG, suggesting that punishment promoted cooperation in the PDG in both children with HFA and TD children.

The relationships among iron supplement use, Hb concentration and linear growth in young children: Ethiopian Demographic and Health Survey.

Growth faltering and anaemia remain unacceptably high among infants and young children in Ethiopia. In this study, we investigated the relationships among Fe supplement use (ISU), Hb concentration and linear growth, hypothesising positive relationships between ISU and Hb, ISU and linear growth and Hb and linear growth. We used a nationally representative data of 2400 children aged 6-24 months from the Ethiopian Demographic and Health Survey (EDHS) 2011, conducted following a stratified, two-stage cluster sampling. We examined the links by Pearson's correlation, bivariate and multivariate linear regression analyses and reported adjusted estimates. We found that ISU was not significantly associated with either Hb (ß=1·09; 95 % CI -2·73, 5·01, P=0·567) or linear growth (ß=0·07; 95 % CI -0·06, 0·21, P=0·217). We found a positive, however, weak, correlation between Hb and linear growth (r 0·09; 95 % CI 0·06, 0·11, P<0·001). Hb predicted linear growth independent of a variety dietary and non-dietary factors (ß=0·08; 95 % CI 0·04, 0·11, P<0·001). Although not the primary focus of the study, our analysis showed that age and breast-feeding duration were independently associated with Hb; age, birth type, size at birth, sex, breast-feeding duration, dietary diversity and deworming were independently associated with linear growth, indicating that Hb and linear growth are multifactorial with both nutritional and non-nutritional factors implicated. Further studies, with better design and exposure assessment, are warranted on the relation of ISU with Hb or linear growth.

Expectation modulates neural representations of valence throughout the human brain.

The brain's sensitivity to unexpected gains or losses plays an important role in our ability to learn new behaviors (Rescorla and Wagner, 1972; Sutton and Barto, 1990). Recent work suggests that gains and losses are ubiquitously encoded throughout the human brain (Vickery et al., 2011), however, the extent to which reward expectation modulates these valence representations is not known. To address this question, we analyzed recordings from 4306 intracranially implanted electrodes in 39 neurosurgical patients as they performed a two-alternative probability learning task. Using high-frequency activity (HFA, 70-200 Hz) as an indicator of local firing rates, we found that expectation modulated reward-related neural activity in widespread brain regions, including regions that receive sparse inputs from midbrain dopaminergic neurons. The strength of unexpected gain signals predicted subjects' abilities to encode stimulus-reward associations. Thus, neural signals that are functionally related to learning are widely distributed throughout the human brain.

A traits-based test of the home-field advantage in mixed-species tree litter decomposition.

BACKGROUND AND AIMS: Litter often decomposes faster in its environment of origin (at 'home') than in a foreign environment ('away'), which has become known as the home-field advantage (HFA). However, many studies have highlighted the conditional nature of the HFA, suggesting that current understanding of this phenomenon is not yet sufficient to generalize across systems. METHODS: The HFA hypothesis was tested for mono-specific and mixed-species litter using a tree-based experiment that manipulated the functional identity and diversity of the host tree community. Litter types of varying quality were transplanted between several host tree communities and decomposition rates were measured using litterbags. Since the decomposer community should respond to traits of the litter input and not their taxonomic identity, a traits-based index of litter-tree similarity was developed. KEY RESULTS: Mono-specific litter exhibited HFA, but when the same litter was decomposed in mixture, this trend was not observed. Mixed-species litter decomposed on average no faster or slower than monoculture litter and exhibited both positive and negative species interactions. These non-additive interactions of decomposition rates in mixture were influenced by the degree of similarity between litter and tree traits. Both synergistic and antagonistic interactions decreased in magnitude with increasing litter-tree similarity such that mixture rates were predictable from monocultures. CONCLUSIONS: The HFA occurred more strongly for mono-specific litter than for the litter types mixed together because interactions between species may have masked this effect. However, when expressed as a function of trait similarity between litters and tree communities, the HFA was not detected.

Role of adenosine 5'-monophosphate-activated protein kinase in α-linolenic acid-induced intestinal lipid metabolism.

n-3 Long-chain PUFA up-regulate intestinal lipid metabolism. However, whether these metabolic effects of PUFA on intestine are mediated by AMP-activated protein kinase (AMPK) remains to be elucidated. To determine the effects of α-linolenic acid (ALA) on intestinal fatty acid (FA) metabolism and whether these effects were affected by AMPK deletion, mice deficient in the catalytic subunit of AMPKα1 or AMPKα2 and wild-type (WT) mice were fed either a high-fat diet (HF) or HF supplemented with ALA (HF-A). The results showed that ALA supplementation decreased serum TAG content in WT mice. ALA also increased mRNA expression of genes (carnitine palmitoyltransferase 1a, acyl-CoA oxidase 1, medium-chain acyl-CoA dehydrogenase, cytochrome P450 4A10 and pyruvate dehydrogenase kinase isoenzyme 4a) involved in intestinal lipid oxidation and mRNA expression of TAG synthesis-related genes (monoacylglycerol O-acyltransferase 2, diacylglycerol O-acyltransferases 1 and 2) in WT mice. Consistent with these, expression levels of phosphorylated AMPKα1 and AMPKα2 were also increased in WT mice after ALA addition. However, in the absence of either AMPKα1 or AMPKα2, ALA supplementation failed to increase intestinal lipid oxidation. In addition, no significant effects of either diet (HF and HF-A) or genotype (WT, AMPKα1(-/-) and AMPKα2(-/-)) on FA uptake in the intestine and faecal TAG output were observed. Our results suggest that AMPK is indispensable for the effects of ALA on intestinal lipid oxidation.

Neural repetition suppression in ventral occipito-temporal cortex occurs during conscious and unconscious processing of frequent stimuli.

Stimulus repetition can produce neural response attenuation in stimulus-category selective networks within the occipito-temporal lobe. It is hypothesized that this neural suppression reflects the functional sharpening of local neuronal assemblies which boosts information processing efficiency. This neural suppression phenomenon has been mainly reported during conditions of conscious stimulus perception. The question remains whether frequent stimuli processed in the absence of conscious perception also induce repetition suppression in those specialized networks. Using rare intracranial EEG recordings in the ventral occipito-temporal cortex (VOTC) of human epileptic patients we investigated neural repetition suppression in conditions of conscious and unconscious visual processing of words. To this end, we used an orthogonal design manipulating respectively stimulus repetition (frequent vs. unique stimuli) and conscious perception (masked vs. unmasked stimuli). By measuring the temporal dynamics of high-frequency broadband gamma activity in VOTC and testing for main and interaction effects, we report that early processing of words in word-form selective networks exhibits a temporal cascade of modulations by stimulus repetition and masking: neuronal attenuation initially is observed in response to repeated words (irrespective of consciousness), that is followed by a second modulation contingent upon word reportability (irrespective of stimulus repetition). Later on (>300ms post-stimulus), a significant effect of conscious perception on the extent of repetition suppression was observed. The temporal dynamics of consciousness, the recognition memory processes and their interaction revealed in this study advance our understanding of their contributions to the neural mechanisms of word processing in VOTC.

Human intracranial high-frequency activity maps episodic memory formation in space and time.

Noninvasive neuroimaging studies have revealed a network of brain regions that activate during human memory encoding; however, the relative timing of such activations remains unknown. Here we used intracranially recorded high-frequency activity (HFA) to first identify regions that activate during successful encoding. Then, we leveraged the high-temporal precision of HFA to investigate the timing of such activations. We found that memory encoding invokes two spatiotemporally distinct activations: early increases in HFA that involve the ventral visual pathway as well as the medial temporal lobe and late increases in HFA that involve the left inferior frontal gyrus, left posterior parietal cortex, and left ventrolateral temporal cortex. We speculate that these activations reflect higher-order visual processing and top-down modulation of attention/semantic information, respectively.