66 research outputs found
Neural Circuitry of Novelty Salience Processing in Psychosis Risk: Association With Clinical Outcome
Psychosis has been proposed to develop from dysfunction in a hippocampal-striatal-midbrain circuit, leading to aberrant salience processing. Here, we used functional magnetic resonance imaging (fMRI) during novelty salience processing to investigate this model in people at clinical high risk (CHR) for psychosis according to their subsequent clinical outcomes. Seventy-six CHR participants as defined using the Comprehensive Assessment of At-Risk Mental States (CAARMS) and 31 healthy controls (HC) were studied while performing a novelty salience fMRI task that engaged an a priori hippocampal-striatal-midbrain circuit of interest. The CHR sample was then followed clinically for a mean of 59.7 months (~5 y), when clinical outcomes were assessed in terms of transition (CHR-T) or non-transition (CHR-NT) to psychosis (CAARMS criteria): during this period, 13 individuals (17%) developed a psychotic disorder (CHR-T) and 63 did not. Functional activation and effective connectivity within a hippocampal-striatal-midbrain circuit were compared between groups. In CHR individuals compared to HC, hippocampal response to novel stimuli was significantly attenuated (P = .041 family-wise error corrected). Dynamic Causal Modelling revealed that stimulus novelty modulated effective connectivity from the hippocampus to the striatum, and from the midbrain to the hippocampus, significantly more in CHR participants than in HC. Conversely, stimulus novelty modulated connectivity from the midbrain to the striatum significantly less in CHR participants than in HC, and less in CHR participants who subsequently developed psychosis than in CHR individuals who did not become psychotic. Our findings are consistent with preclinical evidence implicating hippocampal-striatal-midbrain circuit dysfunction in altered salience processing and the onset of psychosis
Influence of temperature on microstructure, structural and ferroelectricity evolution properties with nano and micrometer grain size in multiferroic HoMnO3 ceramics
The influence of temperature on microstructural, structural and ferroelectric evolution properties of multiferroic holmium manganese oxide (HoMnO3) ceramics were investigated. HoMnO3 ceramics were synthesized using a mechanochemical reaction of Ho2O3 and Mn2O3 powders in a high energy ball milling machine. The powder were sintered from 600 to 1250 °C with 50 °C increments. The results shows the microstructural, structural and ferroelectric hysteresis loop were observed to be dependent on sintering temperatures. The XRD characterization suggests an improvement of crystallinity with increasing sintering temperature. The hexagonal HoMnO3 were observed at temperature ≥1200 °C with the grain size of around 1600 nm. SEM micrographs showed larger grain size as the sintering temperature increased. The SEM results revealed a transformation of crystal structure occurs from orthorhombic to hexagonal at larger grain size regime. Polarization P—electric field E ferroelectric properties were observed to be enhanced with the increase of grain size through sintering temperature. The ferroelectric behavior was observed to change with the change of microstructure along with the structure transformation from orthorhombic to hexagonal. A complete systematic studies of the micron-nanometer grain size on microstructure-properties evolution of HoMnO3 multiferrroic ceramics is higlighted
Basic self-disturbances related to reduced anterior cingulate volume in subjects at ultra-high risk for psychosis
Introduction: Alterations of the “pre-reflective” sense of first-person perspective (e.g., of the “basic self”) are characteristic features of schizophrenic spectrum disorders and are significantly present in the prodromal phase of psychosis and in subjects at ultra-high risk for psychosis (UHR). Studies in healthy controls suggest that neurobiological substrate of the basic self involves cortical midline structures, such as the anterior and posterior cingulate cortices. Neuroimaging studies have identified neuroanatomical cortical midline structure abnormalities in schizophrenic spectrum disorders.
Objectives: i) To compare basic self-disturbances levels in UHR subjects and controls and ii) to assess the relationship between basic self-disturbances and alterations in cortical midline structures volume in UHR subjects.
Methods: Thirty-one UHR subjects (27 antipsychotic-naïve) and 16 healthy controls were assessed using the 57-item semistructured Examination of Anomalous Self-Experiences (EASE) interview. All subjects were scanned using magnetic resonance imaging (MRI) at 3 T, and gray matter volume was measured in a priori defined regions of interest (ROIs) in the cortical midline structures.
Results: EASE scores were much higher in UHR subjects than controls (p < 0.001). The UHR group had smaller anterior cingulate volume than controls (p = 0.037). There were no structural brain imaging alterations between UHR individuals with or without self-disturbances. Within the UHR sample, the subgroup with higher EASE scores had smaller anterior cingulate volumes than UHR subjects with lower EASE scores and controls (p = 0.018). In the total sample, anterior cingulate volume was inversely correlated with the EASE score (R = 0.52, p < 0.016).
Conclusions: Basic self-disturbances in UHR subjects appear to be related to reductions in anterior cingulate volume
Tail biting in pigs: a multi-causal behavioural disorder
Grizenje repova poremećaj je ponašanja svinja, multikauzalne prirode, a smatra se da motivacija za grizenje proizlazi iz nemogućnosti izražavanja vrsti specifičnog ponašanja (rovanje ili žvakanje). Stoga, životinje preusmjeravaju svoje ponašanje na druge objekte koji su im na raspolaganju, kao što su primjerice uške ili repovi drugih životinja. Grizenje repova izrazito je raširena pojava u uzgoju svinja koja stvara velike ekonomske gubitke i utječe na dobrobit životinja. Ovaj poremećaj ponašanja svinja ima najmanje tri različita polazišta na osnovi kojih se dijeli na tri osnovna oblika. Prvi je oblik ‘dvofazno ili dvo-stupanjsko grizenje’, a kako mu i samo ime govori, sastoji se od dvije odvojene faze. U prvoj fazi svinja nježno drži rep druge u ustima bez da izazove bilo kakvo vidljivo oštećenje tkiva. Tada proces prelazi u drugu fazu, pri čemu ozljeda na repu i posljedično krvarenje privlači i druge životinje iz skupine te naglo dolazi da eskalacije poremećaja ponašanja. Drugi oblik naziva se ‘iznenadno-snažno grizenje’, i kod njega dolazi do naglog i snažnog napada jedne svinje na rep druge svinje. Kod ovog oblika poremećaja odmah dolazi do većih ozljeda, s mogućim djelomičnim ili potpunim gubitkom repa te se ovaj oblik grizenja vrlo često determinira kao kanibalizam. Treći se oblik ovog poremećaja u ponašanju naziva „opsesivno grizenje“. On podrazumijeva snažno i stalno grizenje repova od strane jedne ili nekoliko životinja u skupini. Životinje koje pokazuju ovaj oblik ponašanja stalno su u potrazi za žrtvom te iz tog razloga ovaj oblik grizenja rezultira vrlo brzo do većeg broja ozljeda. Kao mogući uzroci ovog poremećaja spominju se zdravstveno stanje, neodgovarajući uvjeti držanja i nedostatna, odnosno nepravilna hranidba, a kao ne manje važni čimbenici spominju se spol, stres, dosada i genetska predispozicija. Usporedba podataka iz različitih do sad provedenih istraživanja otežana je zbog neujednačene terminologije i različitih načina definiranja ovog poremećaja ponašanja. Ovaj pregledni rad predstavlja aktualni pregled literaturnih saznanja o grizenju repova u svinja, i razmatra različite čimbenike okoliša i uzgoja koji mogu utjecati na njegovo izražavanje i složenost.Tail biting is a multi-causal behavioural disorder in pigs. It is considered that the motivation behind it comes from the pig’s inability to express its species-specific behaviour, such as rooting or chewing. Therefore, animals redirect their behaviour onto other objects available to them, such as the ears or tails of other animals. Tail biting is a widespread phenomenon in breeding pigs, causing great economic losses and affecting the welfare of animals. This behavioural disorder has at least three different starting points, based on which it can be divided into three basic forms. The first is called ‘two-stage biting’, where in the first stage the pig gently holds the tail in the mouth and manipulates it without causing any visible tissue damage. This process proceeds to the second stage, where tail injury and consequent bleeding attracts other animals from the group, when the disorder suddenly escalates. The second form is called ‘sudden-strong biting’, and it is manifested as a sudden and strong attack of one pig against the tail of another. This form of the disorder results in immediate injuries, with possible partial or complete loss of the tail. This form of biting is often determined as cannibalism. The third form of this behavioural disorder is called ‘obsessive biting’. It implies strong and consistent biting of tails by one or several animals in the group. Animals that show this form of behaviour are constantly in search of a victim, and for this reason, this form of tail biting quickly results in a great number of injuries. Possible causes for the development of this disorder include a range of factors, such as health status, inadequate housing, boredom, gender, stress, genetics and insufficient or improper nutrition, as outlined in the literature. Comparison of data from different studies has been hampered by the lack of uniform terminology and the many different definitions of this disorder. This review presents the current findings on the tail-biting phenomena in pigs, and consider the various factors of the environment and husbandry that can affect its expression and complexity
Effects of molecular structure on the physical, chemical, and electrical properties of ester‐based transformer insulating liquids
This article presents the experimental studies carried out on the environmental friendly polyol ester insulating liquids to investigate the effect of molecular structure on the physical, chemical, and electrical properties. Six different polyol esters that can be produced from the transesterification of various methyl esters with neopentylglycol/trimethylolpropane alcohols were synthesized and compared with those of refined, bleached, and deodorized palm oil (RBDPO) and mineral transformer oil. The finding suggests that the physical properties like fire point, pour point, and viscosity are very much affected by the molecular weight and molecular composition of the polyol esters. The electrical properties are also highly influenced by the molecular structure‐related characteristics, such as the polarity, dipole polarization, carbon chain length, and degree of branching. The results confirm the findings of previous studies that the polyol esters and RBDPO have more polarity and dipole polarization compared to mineral oil. The experimental evidence showed that the newly synthesized insulating liquids have favorable thermal and electrical properties, thus suggesting that the insulating liquids have the potential to replace conventional insulating liquids to provide a more sustainable power system in the future
A nanomolecular approach to decrease adhesion of biofouling-producing bacteria to graphene-coated material
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