Transmitted Energy as a Basic System Resource

Energy is a basic resource in digital transmission links. Physically, radio channels correspond to passive circuits and most of the transmitted energy is lost in the channel. Two alternative approaches are used for performance measurements in terms of energy. Either the average transmitted or received energy per bit is used, both usually normalized by the receiver noise spectral density. This leads to the average transmitted or received signal-to-noise ratio (SNR) per bit, respectively. However, the transmitted energy is the basic system resource. The average energy gain of a channel depends on the transmitted signal. For convenience, the transmitted SNR referred to the receiver is defined to be the product of the transmitted SNR and the representative energy gain, which is defined as the average energy gain of a signal that is uniformly distributed in all dimensions: time, frequency and space. An explicit relationship between the transmitted and received SNR’s using the covariance concept is derived. Limitations of the use of different SNR definitions are summarized

Self-Reported Cognitive Functions Predict the Trajectory of Paranoid Ideation Over a 15-Year Prospective Follow-Up

Background This study investigated whether self-reported cognitive functions (i.e. task orientation, distractibility, persistence, flexibility, and perseverance) predict the trajectory of paranoid ideation over a 15-year prospective follow-up in adulthood. Methods The participants came from the population-based Young Finns study (N = 1210-1213). Paranoid ideation was assessed with the Paranoid Ideation Scale of the Symptom Checklist-90 Revised (SCL-90R) in 1997, 2001, 2007, and 2012. Self-reported cognitive functions were evaluated in 1997 with the Task orientation, Distractibility, Persistence, and Flexibility scales of the DOTS-R (the Revised Dimensions of Temperament Survey) and the Perseverance scale of the FCB-TI (the Formal Characteristics of Behaviour - Temperament Inventory). The data was analyzed using growth curve models that were adjusted for age, sex, and socioeconomic factors in childhood and adulthood. Results Low self-reported task orientation, low persistence, high distractibility, low flexibility, and high perseverance predicted higher level of paranoid ideation over the 15-year follow-up. Conclusions Self-reported cognitive functions seem to predict paranoid ideation over a long-term follow-up. Promoting cognitive functions in early interventions may have long-term protective influences against the development of paranoid ideation in non-clinical populations.Peer reviewe

Paediatric supracondylar humeral fractures: the effect of the surgical specialty on the outcomes

Purpose The effect of surgical specialty on the outcomes of paediatric patients treated for displaced supracondylar humeral fractures remains unclear. The results of residents, paediatric surgeons and orthopaedic surgeons were compared.Methods A retrospective review of 108 children (0 to 16 years) treated for displaced humeral supracondylar fractures (Gartland II or III) requiring closed or open reduction under general anaesthesia were included. The patient charts and radiographs were evaluated to identify type, grade and neurovascular complications. Operative performance (operative time, quality of reduction, need for open reduction, complications) of residents, paediatric surgeons and orthopaedic surgeons were evaluated.Results Residents used a crossed pin configuration for patients in 25/25 (100%), paediatric surgeons in 25/32 (78%) and orthopaedic surgeons in 33/33 (100%) (p = 0.0011). Loss of reduction was present in one patient treated with crossed pins, in two with lateral pins and in two without Kirschner-wires (p = 0.0034). The risk ratio of an unacceptable reduction was 4.0 (95% confidence interval (CI) 0.90 to 18, p = 0.070) for residents and 6.6 (95% CI 1.6 to 27, p = 0.0082) for paediatric surgeons as compared with orthopaedic surgeons. Complications were present in 37% of patients (11/30) for residents, 55% (24/44) for paediatric surgeons and 15% (5/34) for orthopaedic surgeons (p = 0.0013).Conclusion We found statistically significant differences in the incidence of unacceptable reduction, complications and the usage of crossed pin configuration between the surgical specialties. Patients would benefit from the practice of assigning the operative treatment of displaced supracondylar fractures to orthopaedic surgeons.Level of evidence: Level II

The Use of Digital Technologies at School and Cognitive Learning Outcomes : A Population-Based Study in Finland

Recently, the use of information and communications technology (ICT) at school has been extensively increased in Finland. This study investigated whether the use of ICT at school is linked to students 'learning outcomes in Finland. We used the Finnish PISA 2015 data (N=5037). Cognitive learning outcomes (i.e. science, mathematics, reading, collaborative problem-solving) were evaluated with computer-based tests. ICT use at school, ICT availability at school, and students' perceived ICT competence were assessed with self-rating questionnaires. Frequent ICT use at school predicted students' weaker performance in all the cognitive learning outcomes, when adjusted for age, gender, parental socioeconomic status, students' ICT competence, and ICT availability at school. Further, the effect of ICT use on learning outcomes was more negative in students with higher than lower ICT skills. Frequent use of ICT at school appears to be linked to weaker cognitive learning outcomes in Finland. This may be explained by working memory overload and task-switching during the use of digital technologies. This finding also suggests that even though students with ICT skills are good at mechanical use of digital device, they may not have abilities for a goal-oriented and self-directed use of digital technologies that could promote their learning.Peer reviewe

Corticomuscular Coherence Is Tuned to the Spontaneous Rhythmicity of Speech at 2-3 Hz

Human speech features rhythmicity that frames distinctive, fine-grained speech patterns. Speech can thus be counted among rhythmic motor behaviors that generally manifest characteristic spontaneous rates. However, the critical neural evidence for tuning of articulatory control to a spontaneous rate of speech has not been uncovered. The present study examined the spontaneous rhythmicity in speech production and its relationship to cortex–muscle neurocommunication, which is essential for speech control. Our MEG results show that, during articulation, coherent oscillatory coupling between the mouth sensorimotor cortex and the mouth muscles is strongest at the frequency of spontaneous rhythmicity of speech at 2–3 Hz, which is also the typical rate of word production. Corticomuscular coherence, a measure of efficient cortex–muscle neurocommunication, thus reveals behaviorally relevant oscillatory tuning for spoken language.Peer reviewe

Vacancy-Impurity Complexes in Highly Sb-Doped Si Grown by Molecular Beam Epitaxy

Positron annihilation measurements, supported by first-principles electron-structure calculations, identify vacancies and vacancy clusters decorated by 1–2 dopant impurities in highly Sb-doped Si. The concentration of vacancy defects increases with Sb doping and contributes significantly to the electrical compensation. Annealings at low temperatures of 400–500 K convert the defects to larger complexes where the open volume is neighbored by 2–3 Sb atoms. This behavior is attributed to the migration of vacancy-Sb pairs and demonstrates at atomic level the metastability of the material grown by epitaxy at low temperature.Peer reviewe

Flaxseed Ingestion Alters Ratio of Enterolactone Enantiomers in Human Serum

Enterolactone (EL) is an enterolignan found in human subjects. In this pilot study, the enantiomeric ratios of serum EL were determined in serum from healthy adults during consumption of habitual diet, and after an 8-day supplementation with flaxseed (25 g/day). (−)EL dominated in all serum samples collected during habitual diet consumption. However, the ratio of (−)EL and (+)EL enantiomers differed markedly between individuals. Flaxseed ingestion increased significantly the proportion of (+)EL in all subjects. Moreover, a small but significant increase in serum (−)EL concentration was measured. After flaxseed ingestion, (−)EL concentrations correlated with those of (+)EL suggesting that the stereochemistry of the parent plant lignan in flaxseed is not a major determinant of EL formation in human subjects. Comparison of EL concentrations obtained with the validated chromatographic methods (HPLC-MS/MS, HPLC-CEAD, and GC-MS) and the time-resolved fluoroimmunoassay (TR-FIA) revealed that the immunoassay method underestimates human serum EL concentrations after the flaxseed ingestion