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Brain-derived neurotrophic factor (BDNF) gene variants may potentially influence behaviour. In order to test this hypothesis, we investigated the relationship between BDNF Val66Met polymorphism and aggressive behaviour in a population of schizophrenic patients. Our results showed that increased number of BDNF Met alleles was associated with increased aggressive behaviour.
Abnormal brain connectivity has recently been reported in obsessive compulsive disorder (OCD). However, structural differences in the corpus callosum (CC), the primary structure connecting the two hemispheres, have not been extensively studied. In this case-control study, we recruited 30 patients with OCD and 30 healthy control subjects carefully matched for age, sex and handedness. Combining surface-based mesh-modeling and voxel-based morphometry (VBM), we compared callosal thickness and white matter (WM) density in patients and controls. We investigated associations between callosal structure and cortical gray matter (GM) density, and we related CC measures to neuropsychological performance in OCD. OCD patients showed small anterior and posterior callosal regions compared to healthy control subjects. In the OCD group, anterior callosal thickness was positively correlated with GM density of the right mid-dorso-lateral prefrontal (BA 9/46) area, while posterior callosal thickness was positively correlated with GM density in the left supramarginal gyrus (BA 40). Moreover, posterior callosal WM density was positively correlated with verbal memory, visuo-spatial memory, verbal fluency, and visuo-spatial reasoning performances. Callosal attributes were related to GM density in cortical areas innervated by the CC, and were also related to performance in cognitive domains impaired in the disorder. The CC may therefore be integrally involved in OCD.
Marfan syndrome is an autosomal dominant disorder of the connective tissue, whose cardinal features affect eyes, musculoskeletal, and cardiovascular system. Despite prevalence and natural history of cardiovascular manifestation are well known in adults, little is known about children and young adult patients. The aim of this study was to describe a well-characterised cohort of consecutive children and young patients with marfan syndrome, looking at the impact of family history and presence of bicuspid aortic valve on disease severity.
A total of 30 consecutive children and young patients with Marfan syndrome were evaluated. All patients underwent a comprehensive clinical–instrumental–genetic evaluation. Particular attention was posed to identify differences in prevalence of cardiovascular abnormalities between patients with and without family history of Marfan syndrome or bicuspid aortic valve.
Of these 30 patients, family history of Marfan syndrome and bicuspid aortic valve were present in 76 and 13%, respectively. Compared to patients with family history of Marfan syndrome, those without showed higher prevalence of aortic sinus dilation (87 versus 32%, p-value = 0.009), greater aortic sinus diameters (4.2 ± 2.1 versus 1.9 ± 1.1 z score, p-value = 0.002), and higher rate of aortic surgery during follow-up (37 versus 0%, p-value = 0.002). Compared to patients with tricuspid aortic valve, those with bicuspid aortic valve were younger (3.2 ± 4.3 versus 10.7 ± 6.8 years old, p-value = 0.043), showed greater aortic sinus diameters (4.2 ± 0.9 versus 2.2 ± 1.6 z score, p-value = 0.033), and underwent more frequently aortic root replacement (50 versus 4%, p-value = 0.004).
In our cohort of patients with Marfan syndrome, the absence of family history and the presence of bicuspid aortic valve were associated to severe aortic phenotype and worse prognosis.
To develop a risk score for deep sternal wound infection (DSWI) after isolated coronary artery bypass grafting (CABG).
Multicenter, prospective study.
Tertiary-care referral hospitals.
The study included 7,352 patients from the European multicenter coronary artery bypass grafting (E-CABG) registry.
An additive risk score (the E-CABG DSWI score) was estimated from the derivation data set (66.7% of patients), and its performance was assessed in the validation data set (33.3% of patients).
DSWI occurred in 181 (2.5%) patients and increased 1-year mortality (adjusted hazard ratio, 4.275; 95% confidence interval [CI], 2.804–6.517). Female gender (odds ratio [OR], 1.804; 95% CI, 1.161–2.802), body mass index ≥30 kg/m2 (OR, 1.729; 95% CI, 1.166–2.562), glomerular filtration rate <45 mL/min/1.73 m2 (OR, 2.410; 95% CI, 1.413–4.111), diabetes (OR, 1.741; 95% CI, 1.178–2.573), pulmonary disease (OR, 1.935; 95% CI, 1.178–3.180), atrial fibrillation (OR, 1.854; 95% CI, 1.096–3.138), critical preoperative state (OR, 2.196; 95% CI, 1.209–3.891), and bilateral internal mammary artery grafting (OR, 2.088; 95% CI, 1.422–3.066) were predictors of DSWI (derivation data set). An additive risk score was calculated by assigning 1 point to each of these independent risk factors for DSWI. In the validation data set, the rate of DSWI increased along with the E-CABG DSWI scores (score of 0, 1.0%; score of 1, 1.8%; score of 2, 2.2%; score of 3, 6.9%; score ≥4: 12.1%; P < .0001). Net reclassification improvement, integrated discrimination improvement, and decision curve analysis showed that the E-CABG DSWI score performed better than other risk scores.
DSWI is associated with poor outcome after CABG, and its risk can be stratified using the E-CABG DSWI score.
The presence of counter-rotating (CR) components in galaxies is not that rare but their origin is still unclear. Important clues to the formation and evolution of CR galaxies are provided by galaxy kinematics, such as the mass distribution and the shape of the gravitational potential. In order to better understand the origin and incidence of CR galaxies, we aim at modeling CR stellar disks, as they would be observed with Integral Field Units (IFU) instruments, and measuring the kinematics of these peculiar astrophysical objects to reveal the CR signatures. In the bi-dimensional maps of analysed models, the double sigma signature is the best diagnostic to spot the presence of a CR disk component.
Is it true that innovation occurs only in abundant environments? Baumard defends that increased standards of living are a necessary condition for a change in life history strategy to help understand the Industrial Revolution. Here, we argue that many examples of innovations occur in scarce environments when there is near-zero opportunity cost. We suggest potential psychological pathways to explain this dual-cognitive process.
South Africa's private sector is vital to rhino conservation yet there is a lack of research into the attitudes of current and potential rhino owners towards rhino conservation and horn trade. We surveyed 169 members of the South African private wildlife ranching industry to examine these matters. We sought to understand: (1) ranchers’ motivations for owning or not owning rhinos, (2) how rhino ownership affects ranchers’ income and operations, and (3) the attitudes of wildlife industry members towards legalization of global rhino horn trade. Our findings indicate that all respondents recognize the risks of rhino ownership and tend to distrust national and provincial environmental departments. In addition to these concerns, rhino owners have substantial monthly security and management expenditures. We found positive attitudes overall towards global rhino horn trade. Rhino owners strongly agreed that legalization would benefit rhino owners and rhino conservation. Documenting the realities of private rhino ownership and the opinions of the wildlife industry is important for policy design and for informed debate about the legalization of the rhino horn trade.
Since baseline executive dysfunction predicts worsening Instrumental Activities of Daily Living (i-ADL) over time and progression to Alzheimer's Disease (AD), we aimed to analyze the role of neuropsychological variables to outline which factors can contribute to functional impairment. Specific attention to executive functions (EFs) has been given.
A total of 144 subjects complaining of different cognitive deficits – ranging from “MCI likely due to AD” to “mild AD patients” – underwent an overall neuropsychological assessment. The Behavioral Assessment of the Dysexecutive Syndrome was used to analyze EFs. We conducted multiple linear regression analyses to study whether the level of independent living skills – assessed with the Lawton-scale – could be associated with cognitive and behavioral measurements.
We found a significant association between i-ADL and specific EFs measured by Rule Shift Cards (p = 0.04) and Modified Six Elements (p = 0.02). Moreover, considering i-ADL scores, we observed an involvement of mood changes and a reduced awareness of deficits in terms of Hamilton Depression Rating Scale (p = 0.02) and Awareness of Deficit Questionnaire – Dementia scale (p < 0.0001), respectively.
Our results suggest the importance of considering the association between a reduction in i-ADL and executive dysfunction in patients who have AD etiopathology, for which the ability to inhibit a response, self-monitoring, set-shifting and mood deflection play a key role. Besides, no straightforward associations between i-ADL scores and global cognition, memory, language comprehension, attention, and perspective taking abilities were found.
This paper deals with two ideas appeared during the last developing phase in Artificial Intelligence: Reservoir Computing (RC) and Random Neural Networks. Both have been very successful in many applications. We propose a new model belonging to the first class, taking the structure of the second for its dynamics. The new model is called Echo State Queuing Network. The paper positions the model in the global Machine Learning area, and provides examples of its use and performances. We show on largely used benchmarks that it is a very accurate tool, and we illustrate how it compares with standard RC models.
We present a simple, fast method for thickness characterization of suspended graphene/graphite flakes that is based on transmission electron microscopy (TEM). We derive an analytical expression for the intensity of the transmitted electron beam I0(t), as a function of the specimen thickness t (t<<λ; where λ is the absorption constant for graphite). We show that in thin graphite crystals the transmitted intensity is a linear function of t. Furthermore, high-resolution (HR) TEM simulations are performed to obtain λ for a 001 zone axis orientation, in a two-beam case and in a low symmetry orientation. Subsequently, HR (used to determine t) and bright-field (to measure I0(0) and I0(t)) images were acquired to experimentally determine λ. The experimental value measured in low symmetry orientation matches the calculated value (i.e., λ=225±9 nm). The simulations also show that the linear approximation is valid up to a sample thickness of 3–4 nm regardless of the orientation and up to several ten nanometers for a low symmetry orientation. When compared with standard techniques for thickness determination of graphene/graphite, the method we propose has the advantage of being simple and fast, requiring only the acquisition of bright-field images.
As recognized in a large number of studies, the quantitative evaluation of fault-tolerant computer systems needs to deal simultaneously with aspects of both performance and dependability. For this purpose, Meyer  developed the concept of performability, which may be interpreted as the cumulative performance over a finite mission time. The increasing need to evaluate cumulative measures comes from the fact that in highly available systems, steady-state measures can be very poor, even if the mission time is not small. Considering, for instance, critical applications, it is crucial for the user to ensure that the probability that the system will achieve a given performance level is high enough.
Formally, the system fault-repair behavior is assumed to be modeled by a homogeneous Markov chain. Its state space is divided into disjoint subsets, which represent the different configurations of the system. A performance level or reward rate is associated with each of these configurations. This reward rate quantifies the ability of the system to perform in the corresponding configuration. Performability is then the accumulated reward over the mission time.
Simulating a Markov model is the method of choice when analytic or numerical approaches are not possible. Basically, the former happens when the model is not regular enough, meaning that it does not have enough structure, the latter when its size precludes the use of numerical procedures. We also use the term Monte Carlo to refer to these simulation methods, using the term in its most common meaning, i.e. the use of randomness to solve deterministic problems. There are many important subfields in this wide area that have been the object of concerted research efforts, for instance the MCMC ,  or the perfect simulation  approaches, and many procedures designed for specific application areas, such as queuing , , , financial problems , physics , and many more , , . Monte Carlo techniques are extremely powerful, and they can deal, in principle, with any kind of model. They are not limited by the lack of structure in the model, nor by the model's size. However, they have their own difficulties, the main one being the case of rare events. If you want to analyze a specific metric quantifying some aspect of this rarity, the fact that the focused event appears with very small probability means that it will also be hard to observe in the simulation.