LLukas22/scidocs huggingface dataset:
Discussion of “Momentum and Autocorrelation in Stock Returns”

Jegadeesh and Titman (1993) document individual stock momentum: strategies that buy stocks that have performed relatively well in the past and sell stocks that have performed relatively poorly in the past generate significant positive returns over the 3to 12-month horizon. This finding, obtained using data from the U.S. market, also holds for a number of international markets [e.g., Haugen and Baker (1996), Rouwenhorst (1998)]. What are the economic mechanisms behind individual stock momentum? One approach to answering this question is to relate momentum to other factors driving the cross section of expected stock returns. A number of findings have emerged. Adjustments for factors such as the Fama and French three-factor model tend to strengthen, rather than explain, momentum [e.g., Fama and French (1996), Grundy and Martin (2001)]. Contrary to the finding of Conrad and Kaul (1998), cross-sectional differences in expected returns is not an important cause of momentum [e.g., Jegadeesh and Titman (1993), Grundy and Martin (2001)]. And contrary to the finding of Moskowitz and Grinblatt (1999), a number of subsequent articles find that industries (or industry effects) do not explain momentum [e.g., Asness, Porter, and Stevens (2000), Lee and Swaminathan (2000), Grundy and Martin (2001)]. Stock price momentum is partially related to earnings momentum, but both past returns and public earnings surprises (in a multiple regression) help to predict subsequent returns at horizons of six months to a year [e.g., Chan, Jegadeesh, and Lakonishok (1996)].
Effects of induced hypertension on intracranial pressure and flow velocities of the middle cerebral arteries in patients with large hemispheric stroke.

BACKGROUND AND PURPOSE
Our aim was to prospectively evaluate the effects of induced arterial hypertension in patients with large ischemic stroke.


METHODS
A total of 47 monitoring sessions in 19 patients with acute, complete, or subtotal middle cerebral artery (MCA) territory stroke were performed. Intracranial pressure (ICP) was monitored using a parenchymal catheter. Mean arterial blood pressure (MAP), ICP, and peak mean flow velocity of the middle cerebral arteries (V(m)MCA) were continuously recorded. Patients with acute ICP crises were excluded. After obtaining baseline values, MAP was raised by an infusion of norepinephrine to reach an MAP increase of at least 10 mm Hg. After MAP had reached a peak plateau level, the norepinephrine infusion was stopped.


RESULTS
Baseline MAP was 83.6+/-1.6 mm Hg and rose to 108.9+/-2.0 mm Hg after infusion of norepinephrine. ICP slightly increased from 11.6+/-0.9 mm Hg to 11.8+/-0.9 mm Hg (P<0.05). Cerebral perfusion pressure rose from baseline 72.2+/-2 mm Hg to 97+/-1 mm Hg (P<0.0001). V(m)MCA was already higher on the affected side during baseline measurements. At maximum MAP levels, V(m)MCA rose by 25.5+/-5.5 cm/s on the affected side and by 8.6+/-1.6 cm/s on the contralateral side.


CONCLUSIONS
In patients with large hemispheric stroke without an acute ICP crisis, induced hypertension enhances cerebral perfusion pressure and augments the V(m)MCA(s), more so on the affected side. The ICP slightly increases; however, this is probably not clinically significant.
The complement of research and theory in practice: contact theory at work in nonfamilial intergenerational programs.

PURPOSE OF THE STUDY
We assessed whether a shared site intergenerational care program informed by contact theory contributed to more desirable social behaviors of elders and children during intergenerational programming than a center with a more traditional programming approach that lacks some or all of the contact theory tenets.


DESIGN AND METHODS
We observed 59 elder and child participants from the two sites during intergenerational activities. Using the Intergenerational Observation Scale, we coded participants' predominant behavior in 15-s intervals through each activity's duration. We then calculated for each individual the percentage of time frames each behavior code was predominant.


RESULTS
Participants at the theory-based program demonstrated higher rates of intergenerational interaction, higher rates of solitary behavior, and lower rates of watching than at the traditional program.


IMPLICATIONS
Contact theory tenets were optimized when coupled with evidence-based practices. Intergenerational programs with stakeholder support that promotes equal group status, cooperation toward a common goal, and mechanisms of friendship among participants can achieve important objectives for elder and child participants in care settings.
Percutaneous collagen induction: an effective and safe treatment for post-acne scarring in different skin phototypes.

BACKGROUND
Atrophic scars can complicate moderate and severe acne. There are, at present, several modalities of treatment with different results. Percutaneous collagen induction (PCI) has recently been proposed as a simple and effective therapeutic option for the management of atrophic scars.


OBJECTIVE
The aim of our study was to analyze the efficacy and safety of percutaneous collagen induction for the treatment of acne scarring in different skin phototypes.


METHODS & MATERIALS
A total of 60 patients of skin types phototype I to VI were included in the study. They were divided into three groups before beginning treatment: Group A (phototypes I to II), Group B (phototypes III to V), and Group C (phototypes VI). Each patient had three treatments at monthly intervals. The aesthetic improvement was evaluated by using a Global Aesthetic Improvement Scale (GAIS), and analyzed statistically by computerized image analysis of the patients' photographs. The differences in the GAIS scores in the different time-points of each group were found using the Wilcoxon's test for nonparametric-dependent continuous variables. Computerized image analysis of silicone replicas was used to quantify the irregularity of the surface micro-relief with Fast Fourier Transformation (FFT); average values of gray were obtained along the x- and y-axes. The calculated indexes were the integrals of areas arising from the distribution of pixels along the axes.


RESULTS
All patients completed the study. The Wilcoxon's test for nonparametric-dependent continuous variables showed a statistically significant (p < 0.05) reduction in severity grade of acne scars at T5 compared to baseline (T1). The analysis of the surface micro-relief performed on skin replicas showed a decrease in the degree of irregularity of skin texture in all three groups of patients, with an average reduction of 31% in both axes after three sessions. No short- or long-term dyschromia was observed.


CONCLUSION
PCI offers a simple and safe modality to improve the appearance of acne scars without risk of dyspigmentation in patient of all skin types.
Sensitive skin: an overview.

Sensitive skin is a condition of subjective cutaneous hyper-reactivity to environmental factors. Subjects experiencing this condition report exaggerated reactions when their skin is in contact with cosmetics, soaps and sun screens, and they often report worsening after exposure to dry and cold climate. Although no sign of irritation is commonly detected, itching, burning, stinging and a tight sensation are constantly present. Generally substances that are not commonly considered irritants are involved in this abnormal response.Sensitive skin and subjective irritation are widespread but still far from being completely defined and understood. A correlation between sensitive skin and constitutional anomalies and/or other triggering factors such as occupational skin diseases or chronic exposure to irritants has been hypothesized. Recent findings suggest that higher sensitivity can be due to different mechanisms. Hyper-reactors may have a thinner stratum corneum with a reduced corneocyte area causing a higher transcutaneous penetration of water-soluble chemicals. Alterations in vanilloid receptors and changes in neuronal transmission have been described. Monitoring skin parameters such as barrier function, proclivity to irritation, corneocyte size and sensorial transmission can also be useful to identify regional differences in skin sensitivity.
Effect of telmisartan on selected adipokines, insulin sensitivity, and substrate utilization during insulin-stimulated conditions in patients with metabolic syndrome and impaired fasting glucose.

OBJECTIVE
Telmisartan improves glucose and lipid metabolism in rodents. This study evaluated the effect of telmisartan on insulin sensitivity, substrate utilization, selected plasma adipokines and their expressions in subcutaneous adipose tissue (SAT) in metabolic syndrome.


DESIGN AND METHODS
Twelve patients with impaired fasting glucose completed the double-blind, randomized, crossover trial. Patients received telmisartan (160 mg/day) or placebo for 3 weeks and vice versa with a 2-week washout period. At the end of each period, a hyperinsulinemic euglycemic clamp (HEC) combined with indirect calorimetry was performed. During HEC (0, 30, and 120 min), plasma levels of adipokines were measured and a needle biopsy (0 and 30 min) of SAT was performed.


RESULTS
Fasting plasma glucose was lower after telmisartan compared with placebo (P<0.05). There were no differences in insulin sensitivity and substrate utilization. We found no differences in basal plasma adiponectin, resistin and tumour necrosis factor α (TNFα), but an increase was found in basal leptin, after telmisartan treatment. Insulin-stimulated plasma adiponectin (P<0.05), leptin and resistin (P<0.001) were increased, whereas TNFα was decreased (P<0.05) after telmisartan treatment. Expression of resistin, but not adiponectin, TNFα and leptin was increased after telmisartan treatment.


CONCLUSIONS
Despite the decrease in fasting plasma glucose, telmisartan does not improve insulin sensitivity and substrate utilization. Telmisartan increases plasma leptin as well as insulin-stimulated plasma adiponectin, leptin and resistin, and decreases plasma TNFα during HEC. Changes in plasma adipokines cannot be explained by their expressions in SAT. The changes in plasma adipokines might be involved in the metabolic effects of telmisartan in metabolic syndrome.
The Decision-making Model for the Stock Market under Uncertainty

Received Mar 21, 2017 Revised May 26, 2017 Accepted Aug 11, 2017 The main purpose of this research is developing methods and models of decision-making to assess the stock market state, and predict the possible changes in the RTS index value. This article shows that the analytical models for assessing the stock market state do not give reliable results. The absence of the reliable estimates associated with the high degree of uncertainty, random, nonlinear and non-stationary process with a significant degree of aftereffect. In this paper, to formalize the securities market parameters it’s proposed the fuzzy sets method. To assess the stock market current state and make decisions the fuzzy situational analysis model (situational model) is applied. The analytical prediction results of the stock market and graph of the RTS index expected return changes in 2014-2016 are showed. The model of calculating the fuzzy inference rules truth degree to predict the RTS index is developed. The market parameters linguistic definition is given and the expert’s rules construction to predict the RTS index growth is shown. The program in Matlab environment is designed to perform research. The study result showed that the model allows for the RTS index prediction in the condition of incomplete initial data with a confidence level about 90%.
Histomorphometric evaluation of bioceramic molecular impregnated and dual acid-etched implant surfaces in the human posterior maxilla.

BACKGROUND
Physical and bioceramic incorporation surface treatments at the nanometer scale showed higher means of bone-to-implant contact (BIC) and torque values compared with surface topography at the micrometer scale; however, the literature concerning the effect of nanometer scale parameters is sparse.


PURPOSE
The aim of this study was to evaluate the influence of two different implant surfaces on the percentage bone-to-implant contact (BIC%) and bone osteocyte density in the human posterior maxilla after 2 months of unloaded healing.


MATERIALS AND METHODS
The implants utilized presented dual acid-etched (DAE) surface and a bioceramic molecular impregnated treatment (Ossean®, Intra-Lock International, Boca Raton, FL, USA) serving as control and test, respectively. Ten subjects (59 ± 9 years of age) received two implants (one of each surface) during conventional implant surgery in the posterior maxilla. After the non-loaded period of 2 months, the implants and the surrounding tissue were removed by means of a trephine and were non-decalcified processed for ground sectioning and analysis of BIC%, bone density in threaded area (BA%), and osteocyte index (Oi).


RESULTS
Two DAE implants were found to be clinically unstable at time of retrieval. Histometric evaluation showed significantly higher BIC% and Oi for the test compared to the control surface (p < .05), and that BA% was not significantly different between groups. Wilcoxon matched pairs test was used to compare the differences of histomorphometric variables between implant surfaces. The significance test was conducted at a 5% level of significance.


CONCLUSION
The histological data suggest that the bioceramic molecular impregnated surface-treated implants positively modulated bone healing at early implantation times compared to the DAE surface.
Leadership Styles in Virtual Team Context: Limitations, Solutions and Propositions

This paper analyzes previous empirical investigations on leadership style in virtual team context. Inconsistencies were found in the prior studies: oversimplified comparison of transformational and transactional leadership and treating the two leadership styles as polar constructs. To overcome these drawbacks, approaching transformational and transactional behavior combinations at behavior component level is suggested. Also, specific propositions are raised about the effects of leadership behavior combinations under three important yet ignored contextual factors: media richness of communication technology, goal-frustrating events and leader-follower gender. This paper provides useful guidance for future virtual team leadership research as well as for organizations interested in developing virtual team leadership.
Secure synchronization of a class of chaotic systems from a nonlinear observer approach

The aim of this note is two-fold. First, it discusses synchronization of chaotic systems from a control theoretic point of view and introduces the concept of secure synchronization, i.e., a communication scheme that resists possible intrusion based on either adaptive or robust control techniques. Second, for a large class of chaotic systems, i.e., the generalized Lorenz system, global exponential synchronization via a scalar communication signal is suggested and its security is analyzed from a control theoretic viewpoint. Both theoretical analysis and numerical simulations are provided, verifying the proposed chaos-synchronization-based secure communication design principle and methodology.
From Virtuality to Reality and Back

There has been a growing research interest in investigating techniques to combine real and virtual spaces. A variety of “reality” concepts such as Virtual Reality and Augmented Reality and their supporting technologies have emerged in the field of design to adopt the task of replacing or merging our physical world with the virtual world. The different realities can be tailored to enhance comprehension for specific design activities along a design life-cycle. This paper presents stateof-the-art applications of these “reality” concepts in design and related areas, and proposes a classification of these realities to address suitability issues for the effective utilization of the concepts and technologies. Their potentials and implications in certain design activities are also discussed.
Mental health inequalities in Slovenian 15-year-old adolescents explained by personal social position and family socioeconomic status

INTRODUCTION
Mental health inequalities are an increasingly important global problem. This study examined the association between mental health status and certain socioeconomic indicators (personal social position and the socioeconomic status of the family) in Slovenian 15-year-old adolescents.


METHODS
Data originate from the WHO-Collaborative cross-national 'Health Behavior in School-aged Children' study conducted in Slovenia in 2010 (1,815 secondary school pupils, aged 15). Mental health status was measured by: KIDSCREEN-10, the Strength and Difficulties questionnaire (SDQ), a life satisfaction scale, and one question about feelings of depression. Socioeconomic position was measured by the socioeconomic status of the family (Family Affluence Scale, perceived material welfare, family type, occupational status of parents) and personal social position (number of friends and the type of school). Logistic regression and a multivariate analysis of variance (MANOVA) were performed.


RESULTS
Girls had 2.5-times higher odds of suffering feelings of depression (p < 0.001), 1.5-times higher odds of low life satisfaction (p = 0.008), and a greater chance of a lower quality of life and a higher SDQ score than boys (p = 0.001). The adolescents who perceived their family's material welfare as worse had 4-times higher odds (p < 0.001) of a low life satisfaction, a greater chance of a low quality of life, and a higher SDQ score than those who perceived it as better (p < 0.001). Adolescents with no friends had lower KIDSCREEN-10 and higher SDQ scores than those who had more than three friends.


CONCLUSIONS
Despite the fact that Slovenia is among the EU members with the lowest rates of social inequalities, it was found that adolescents with a lower socioeconomic position have poorer mental health than those with a higher socioeconomic position. Because of the financial crisis, we can expect an increase in social inequalities and a greater impact on adolescents' mental health status in Slovenia in the future.
Microcirculatory mechanisms in postnatal hypotension affecting premature infants

Background:Hypotension remains a common complication in preterm infants and is associated with high neonatal morbidity and mortality. The underlying mechanisms are still not fully understood. We studied the microcirculation in extremely low birth weight infants to understand the relationship between blood pressure and skin perfusion.Methods:In 21 patients (gestational age <30 wk, birth weight <1,225 g), functional vessel density (FVD) and diameter distribution were obtained prospectively by side stream dark-field imaging at the right arm in the first 48 h after birth. Infants with blood pressure below gestational age and receiving catecholamines were defined as hypotensive as compared with the remaining normotensive control group.Results:In the first 6 h after birth, FVD was significantly higher in the hypotensive group than in the control group. After 12 h, there were no significant differences in either blood pressure or FVD between the two groups. FVD did not change significantly during the observation period in either group.Conclusion:Hypotensive infants have a higher FVD, possibly due to loss of microvascular tone leading to vasodilation and flow redistribution. However, the link between blood pressure and perfusion remains unclear, and no definitive correlation could be found.
Optimal Damping of EMI Filter Input Impedance

Damping of EMI filter input impedance to avoid resonance with the source output impedance is presented. Optimization of the damping resistor to maximize the damping effects for a given damping capacitor or inductor while minimizing the power loss is proposed. Three different damping circuits are studied, and for each, an analytical model defining the optimal damping resistance is presented. Performances of these damping circuits are compared in terms of achievable damping effects and power dissipation, as well as size and volume of damping capacitors and inductors. A case study is also presented to illustrate the application of the proposed design.
Polymeric versus elemental diet as primary treatment in active Crohn's disease: a randomized, double-blind trial

OBJECTIVE:Enteral feeding is now an established primary therapy for active Crohn's disease. This first-double blind randomized trial was designed to compare the therapeutic efficacy of a polymeric diet (PD) with an elemental diet (ED).METHODS:Patients with active Crohn's disease (Crohn's disease activity index [CDAI] > 150, increased bowel uptake of Tc-HMPAO–labeled leukocytes, and abnormal C-reactive protein [CRP]), were randomized to receive either an ED or a PD. The two preparations were identical except for the nitrogen source, which was amino acid based in ED and intact protein in PD. Enteral feeding was considered successful if clinical remission was achieved as defined by a final CDAI of ≤ 150, a reduction in the CDAI by at least 100 points from baseline level, and a normal CRP.RESULTS:Twenty-one patients were enrolled of whom 11 were randomized to PD and 10 to ED. The two groups were comparable at entry. Clinical remission was obtained in eight (80%) patients receiving ED and six (55%) patients receiving PD, p = 0.1. The treatment failed in three and two patients in the PD and ED groups, respectively. Another two patients were intolerant to the feed (PD). Reduction in the CDAI after treatment with ED (359 ± 67 to 112 ± 19) was similar to that seen with PD (303 ± 27 to 97 ± 11). Similar changes in the CRP were also observed (16 ± 5 to 4 ± 1.6) and (62 ± 20 to 9 ± 6), respectively. Overall, enteral feeding was successful in 14 patients (63%).CONCLUSIONS:Enteral nutrition is effective in treatment of active Crohn's disease. Differences in nitrogen sources of enteral feeds are not relevant to their therapeutic efficacy, as polymeric and elemental diets are equally effective.
Direct Flux Field-Oriented Control of IPM Drives With Variable DC Link in the Field-Weakening Region

This paper presents the direct flux control of an interior permanent-magnet (IPM) motor drive in the field-weakening region. The output torque is regulated by the coordinated control of the stator flux amplitude and the current component in quadrature with the flux, and it is implemented in the stator flux reference frame. The control system guarantees maximum torque production taking into account voltage and current limits, in particular in case of large dc-link variations. The field-oriented control does not necessarily require an accurate magnetic model of the IPM motor, and it is able to exploit the full inverter voltage at different dc-link levels with no additional voltage control loop. The feasibility of the proposed control method is investigated in discrete-time simulation, then tested on a laboratory rig, and finally implemented on board of an electric scooter prototype. The motor under test is an IPM permanent-magnet-assisted synchronous reluctance machine, with high-saliency and limited permanent-magnet flux.