Magnetic resonance tumor regression grade (MR-TRG) to assess pathological complete response following neoadjuvant radiochemotherapy in locally advanced rectal cancer

This study aims to evaluate the feasibility of a magnetic resonance (MR) automatic method for quantitative assessment of the percentage of fibrosis developed within locally advanced rectal cancers (LARC) after neoadjuvant radiochemotherapy (RCT). A total of 65 patients were enrolled in the study and MR studies were performed on 3.0 Tesla scanner; patients were followed-up for 30 months. The percentage of fibrosis was quantified on T2-weighted images, using automatic K-Means clustering algorithm. According to the percentage of fibrosis, an optimal cut-off point for separating patients into favorable and unfavorable pathologic response groups was identified by ROC analysis and tumor regression grade (MR-TRG) classes were determined and compared to histopathologic TRG. An optimal cut-off point of 81% of fibrosis was identified to differentiate between favorable and unfavorable pathologic response groups resulting in a sensitivity of 78.26% and a specificity of 97.62% for the identification of complete responders (CRs). Interobserver agreement was good (0.85). The agreement between P-TRG and MR-TRG was excellent (0.923). Significant differences in terms of overall survival (OS) and disease free survival (DFS) were found between favorable and unfavorable pathologic response groups. The automatic quantification of fibrosis determined by MR is feasible and reproducible

The role of geographical distance on the relationship between cultural intelligence and knowledge transfer

Purpose: This paper's purpose is to investigate the ways in which the geographical distance between headquarters and subsidiaries moderates the relationship between cultural intelligence and the knowledge transfer process. Design/methodology/approach: A sample of 103 senior expatriate managers working in Croatia from several European and non-European countries was used to test the hypotheses. Data were collected using questionnaires, while the methodology employed to test the relationship between the variables was Partial least square. Furthermore, interaction-moderation effect was utilised to test the impact of geographical distance and, for testing control variables, Partial least square multigroup analysis was used. Findings: Cultural Intelligence plays a significant role in the knowledge transfer process performance. However, geographical distance has the power to moderate this relationship based on the direction of knowledge transfer. In conventional knowledge transfer, geographical distance has no significant impact. On the contrary, data have shown that, in reverse knowledge transfer, geographical distance has a moderately relevant effect. We supposed that these findings could be connected to the specific location of the knowledge produced by subsidiaries. Practical implications: Multinational companies should take into consideration that the further away a subsidiary is from the headquarters, and the varying difference between cultures, cannot be completely mitigated by the ability of the manager to deal with cultural differences, namely cultural intelligence. Thus, multinational companies need to allocate resources to facilitate the knowledge transfer between subsidiaries. Originality/value: The present study stresses the importance of cultural intelligence in the knowledge transfer process, opening up a new stream of research inside these two areas of research

Poynting-Robertson effect on black-hole-driven winds

Layers of ionized plasma, in the form of winds ejected from the accretion disk of Supermassive Black Holes (SMBHs) are frequently observed in Active Galactic Nuclei (AGNs). Winds with a velocity often exceeding $0.1c$ are called Ultra-Fast-Outflows (UFOs) and thanks to their high power they can play a key role in the co-evolution between the SMBH and the host galaxy. In order to construct a proper model of the properties of these winds, it is necessary to consider special relativistic corrections due to their very high velocities. We present a derivation of the Poynting-Robertson effect (P-R effect) and apply it to the description of the dynamics of UFOs. The P-R effect is a special relativistic correction which breaks the isotropy of the radiation emitted by a moving particle funneling the radiation in the direction of motion. As a result of the conservation of the four-momentum, the emitting particles are subjected to a drag force and decelerate. We provide a derivation of the drag force caused by the P-R effect starting from general Lorentz transformations and assuming isotropic emission in the gas reference frame. Then, we derive the equations to easily implement this drag force in future simulations. Finally, we apply them in a toy model in which the gas particles move radially under the influence of the gravitation force, the radiation pressure and the drag due to the P-R effect. P-R effect plays an important role in determining the velocity profile of the wind. For a wind launched from $r_0=10r_s$ (where $r_S$ stands for the Schwarzschild radius), the asymptotic velocity reached by the wind is between $10$% and $24$% smaller than the one it would possess if we neglect the effect. This shows that the P-R effect should be taken into account when studying the dynamics of high-velocity, photoionized outflows in general.Comment: Accepted for publication on Astronomy & Astrophysics. 7 pages, 4 figure

Acute Ethanol Gavage Attenuates Hemorrhage/Resuscitation-Induced Hepatic Oxidative Stress in Rats

Acute ethanol intoxication increases the production of reactive oxygen species (ROS). Hemorrhagic shock with subsequent resuscitation (H/R) also induces ROS resulting in cellular and hepatic damage in vivo. We examined the role of acute ethanol intoxication upon oxidative stress and subsequent hepatic cell death after H/R. 14 h before H/R, rats were gavaged with single dose of ethanol or saline (5 g/kg, EtOH and ctrl; H/R_EtOH or H/R_ctrl, resp.). Then, rats were hemorrhaged to a mean arterial blood pressure of 30 ± 2 mmHg for 60 min and resuscitated. Two control groups underwent surgical procedures without H/R (sham_ctrl and sham_EtOH, resp.). Liver tissues were harvested at 2, 24, and 72 h after resuscitation. EtOH-gavage induced histological picture of acute fatty liver. Hepatic oxidative (4-hydroxynonenal, 4-HNE) and nitrosative (3-nitrotyrosine, 3-NT) stress were significantly reduced in EtOH-gavaged rats compared to controls after H/R. Proapoptotic caspase-8 and Bax expressions were markedly diminished in EtOH-gavaged animals compared with controls 2 h after resuscitation. EtOH-gavage increased antiapoptotic Bcl-2 gene expression compared with controls 2 h after resuscitation. iNOS protein expression increased following H/R but was attenuated in EtOH-gavaged animals after H/R. Taken together, the data suggest that acute EtOH-gavage may attenuate H/R-induced oxidative stress thereby reducing cellular injury in rat liver

Longitudinal study of the effect of a 5-year exercise intervention on structural brain complexity in older adults. A Generation 100 substudy

Physical inactivity has been identified as an important risk factor for dementia. High levels of cardiorespiratory fitness (CRF) have been shown to reduce the risk of dementia. However, the mechanism by which exercise affects brain health is still debated. Fractal dimension (FD) is an index that quantifies the structural complexity of the brain. The purpose of this study was to investigate the effects of a 5-year exercise intervention on the structural complexity of the brain, measured through the FD, in a subset of 105 healthy older adults participating in the randomized controlled trial Generation 100 Study. The subjects were randomized into control, moderate intensity continuous training, and high intensity interval training groups. Both brain MRI and CRF were acquired at baseline and at 1-, 3- and 5-years follow-ups. Cortical thickness and volume data were extracted with FreeSurfer, and FD of the cortical lobes, cerebral and cerebellar gray and white matter were computed. CRF was measured as peak oxygen uptake (VO2peak) using ergospirometry during graded maximal exercise testing. Linear mixed models were used to investigate exercise group differences and possible CRF effects on the brain's structural complexity. Associations between change over time in CRF and FD were performed if there was a significant association between CRF and FD. There were no effects of group membership on the structural complexity. However, we found a positive association between CRF and the cerebral gray matter FD (p < 0.001) and the temporal lobe gray matter FD (p < 0.001). This effect was not present for cortical thickness, suggesting that FD is a more sensitive index of structural changes. The change over time in CRF was associated with the change in temporal lobe gray matter FD from baseline to 5-year follow-up (p < 0.05). No association of the change was found between CRF and cerebral gray matter FD. These results demonstrated that entering old age with high and preserved CRF levels protected against loss of structural complexity in areas sensitive to aging and age-related pathology

How attitudes, perceived norms and perceived control influence couples' decisions to have a child

While most research on fertility planning is conducted at the individual level, this paper focuses on the couple, the unit into which most children are born in Europe. We focus on the decision to have a second child, the critical decision if fertility rates are to rise to replacement or near-replacement levels, and seek to extend modelling of couples’ fertility intentions by including partners’ social psychological cognitions as well as directly measurable economic and demographic characteristics. The social psychological model used in these studies is the theory of planned behavior (TPB). The countries under study are Bulgaria and Italy

Adsorption of Rhodamine B from Wastewater on the Arsenic- Hyperaccumulator Pteris Vittata Waste Roots

The Pteris vittata fern, which is a perennial plant known for hyper-accumulating Arsenic, can be grown in hydroponic cultures and is often used for phytoremediation of contaminated water. To reduce the cost of disposing As-contaminated biomass, this study examined the potential of using waste roots from Pteris vittata as a new and inexpensive bio-adsorbent for removing Rhodamine B (RB) dye, which is commonly used in industrial applications. Batch tests were performed at 25°C in order to observe both the rate and the equilibrium conditions of the system. The isotherm showed a typical Langmuir behavior exhibiting a maximum adsorption capacity of 42.7 mg/g. Kinetics tests were conducted at different solid-liquid ratios and fitted by a mathematical model. The maximum likelihood method was employed to estimate the effective diffusivity of RB in the solid which resulted 4.48 10-9 cm2/min. This study lays the groundwork for future investigations into the use of this material in continuous systems to determine its feasibility for application in industrial apparatus

Fractal dimension of cerebral white matter : A consistent feature for prediction of the cognitive performance in patients with small vessel disease and mild cognitive impairment

Patients with cerebral small vessel disease (SVD) frequently show decline in cognitive performance. However, neuroimaging in SVD patients discloses a wide range of brain lesions and alterations so that it is often difficult to understand which of these changes are the most relevant for cognitive decline. It has also become evident that visually-rated alterations do not fully explain the neuroimaging correlates of cognitive decline in SVD. Fractal dimension (FD), a unitless feature of structural complexity that can be computed from high-resolution T1-weighted images, has been recently applied to the neuroimaging evaluation of the human brain. Indeed, white matter (WM) and cortical gray matter (GM) exhibit an inherent structural complexity that can be measured through the FD. In our study, we included 64 patients (mean age \ub1 standard deviation, 74.6 \ub1 6.9, education 7.9 \ub1 4.2 years, 53% males) with SVD and mild cognitive impairment (MCI), and a control group of 24 healthy subjects (mean age \ub1 standard deviation, 72.3 \ub1 4.4 years, 50% males). With the aim of assessing whether the FD values of cerebral WM (WM FD) and cortical GM (GM FD) could be valuable structural predictors of cognitive performance in patients with SVD and MCI, we employed a machine learning strategy based on LASSO (least absolute shrinkage and selection operator) regression applied on a set of standard and advanced neuroimaging features in a nested cross-validation (CV) loop. This approach was aimed at 1) choosing the best predictive models, able to reliably predict the individual neuropsychological scores sensitive to attention and executive dysfunctions (prominent features of subcortical vascular cognitive impairment) and 2) identifying a features ranking according to their importance in the model through the assessment of the out-of-sample error. For each neuropsychological test, using 1000 repetitions of LASSO regression and 5000 random permutations, we found that the statistically significant models were those for the Montreal Cognitive Assessment scores (p-value =.039), Symbol Digit Modalities Test scores (p-value =.039), and Trail Making Test Part A scores (p-value =.025). Significant prediction of these scores was obtained using different sets of neuroimaging features in which the WM FD was the most frequently selected feature. In conclusion, we showed that a machine learning approach could be useful in SVD research field using standard and advanced neuroimaging features. Our study results raise the possibility that FD may represent a consistent feature in predicting cognitive decline in SVD that can complement standard imaging