The uncommon is common: Structural similarities of symptom heterogeneity across mental disorders

The heterogeneity of symptoms among individuals diagnosed with the same mental disorder complicates the identification of biomarkers and the development of targeted treatments. Yet, the characteristics of this heterogeneity remain largely unknown. We investigated the frequency of disorder-specific symptom combinations, a marker of symptom heterogeneity, in five samples, each assessed for symptoms of a specific disorder (posttraumatic stress disorder, depression, anxiety, schizophrenia and burnout). The frequency of symptom combinations was heavily skewed in all samples, with most symptom combinations being reported only by few individuals. Moreover, the distribution of the symptom combination frequency could be approximated by a power-law and a log-normal distribution. This demonstrates similarities in the structure of symptom heterogeneity among mental disorders. Furthermore, we show that studies with sample sizes typical for research in mental health preclude many rare symptom combinations, limiting the validity of the obtained evidence by such studies for individuals with rare symptom combinations.

Dynamic Characteristics Analysis of a Seal-Rotor System with Rub-Impact Fault

Labyrinth seals are widely used to prevent fluid leakage in high-low pressure areas of the rotating machinery. However, the rub-impact fault easily occurs in labyrinth seals. Considering the influence of gyroscopic effect, a finite element model of seal-rubbing rotor system is established in this study based on the Muszynska seal force model, the rolling bearing force model and the nonlinear rubbing force model. The vibration characteristics under the coupling faults of airflow excitation and rub-impact are analyzed. Firstly, the response of the system without rub-impact fault is numerically simulated and verified by experiments. Subsequently, the dynamic characteristics of the rotor under the conditions of slight rub-impact and severe rub-impact faults are analyzed. Finally, the influence of the rub-impact parameters is further studied. The results indicate that when the rub-impact fault is absent, airflow excitation occurs at a certain speed, which exhibits the characteristics of frequency locking and combination frequency. The coupling dynamic responses of airflow-induced vibration and rub-impact fault show a rich spectrum of nonlinear phenomena, which is closely related to the degree of rub-impact. This study may provide a theoretical basis for the detection and diagnosis of fluid-induced rub-impact fault in labyrinth seal-rotor systems.

The Value of Statistics Contributing to Scoring in the NBA: A Quantitative Approach

We model three years of National Basketball Association (NBA) data to calculate the number of points generated from assists, offensive rebounds, and steals. We partition the data into eight groups based on the combinations of occurrences (or not) of these three statistics in a made basket. A linear programming model solves for the coefficients of each of the three statistics in each combination, and the weighted average of the coefficients by combination frequency produces a final value for the points generated by each statistic. A fraction of these points is assigned to the player that made the assist, offensive rebound, or steal, with the remaining portion of the points scored assigned to the scorer. A scale for total points accounted for by a player from points scored, assists, offensive rebounds, and steals is developed and used to compare the offensive production of a sample of NBA players from the 2018–2019 season. JEL Classifications: C1, C3,C6, Z2

An Experimental Approach on Beating in Vibration Due to Rotational Unbalance

This paper proposes a study in theoretical and experimental terms focused on the vibration beating phenomenon produced in particular circumstances: the addition of vibrations generated by two rotating unbalanced shafts placed inside a lathe headstock, with a flat friction belt transmission between the shafts. The study was done on a simple computer-assisted experimental setup for absolute vibration velocity signal acquisition, signal processing and simulation. The input signal is generated by a horizontal geophone as the sensor, placed on a headstock. By numerical integration (using an original antiderivative calculus and signal correction method) a vibration velocity signal was converted into a vibration displacement signal. In this way, an absolute velocity vibration sensor was transformed into an absolute displacement vibration sensor. An important accomplishment in the evolution of the resultant vibration frequency (or combination frequency as well) of the beating vibration displacement signal was revealed by numerical simulation, which was fully confirmed by experiments. In opposition to some previously reported research results, it was discovered that the combination frequency is slightly variable (tens of millihertz variation over the full frequency range) and it has a periodic pattern. This pattern has negative or positive peaks (depending on the relationship of amplitudes and frequencies of vibrations involved in the beating) placed systematically in the nodes of the beating phenomena. Some other achievements on issues involved in the beating phenomenon description were also accomplished. A study on a simulated signal proves the high theoretical accuracy of the method used for combination frequency measurement, with less than 3 microhertz full frequency range error. Furthermore, a study on the experimental determination of the dynamic amplification factor of the combination vibration (5.824) due to the resonant behaviour of the headstock and lathe on its foundation was performed, based on computer-aided analysis (curve fitting) of the free damped response. These achievements ensure a better approach on vibration beating phenomenon and dynamic balancing conditions and requirements.

Hydration Chemistry of Cement Studied by Near Infrared Spectroscopy

Cement is a complex mixture of inorganic compounds which mainly composed of calcium silicates and calcium aluminates. Cement is mixed with water to form concrete. During the mixing calcium silicate hydrate (CSH) and calcium hydroxide are formed. The ratio of water/cement (w/c ratio) is important to obtain a mixture that gives optimum strength to the concrete. In this work, three different cement samples were mixed with water in four different ratios, including 0.35, 0.40, 0.45 and 0.55, respectively. The hydration process of cement was investigated by using near infrared (NIR) spectroscopy over a period of 28 days. The combination frequency of OH stretching and bending of water molecules gives rise to an absorption around 5200 cm-1. This peak contains contributions of overtones from several types of water molecules in the cement. Fourth derivatives spectra of all cement samples showed three peaks in the combination band region of 5300-5100 cm-1. These peaks indicated the presence of three distinct types of water molecules in the system. First, the characteristic peak at 5260-5240 cm-1 represented the hydrogen bond between water molecules and silinol group of calcium silicates. This peak indicated the formation of CSH from hydration of cement. Furthermore, this peak experienced a slight red shift after a period of seven days indicating stronger hydrogen bonding of water molecules with silinol groups. The peak at 5130 cm-1 corresponded to hydrogen bonding between water molecules and the peak at 5165 cm-1 corresponded to hydrogen bonding between free water and bound water. The suitable w/c ratio for cement-1 is at 0.35-0.45, cement-2, and cement-3 are 0.45. In addition, real concrete sample showed two characteristic peaks at 5250 cm-1 and 5165 cm-1, demonstrating the presence of CSH and free water within concrete, respectively. Near infrared spectroscopy in combination with fourth derivative technique can be used to investigate the hydration chemistry of cement and concrete.

Water Structure in Proteins in Solid State Studied by Near Infrared Spectroscopy

Water adsorption in proteins is the crucial process of protein folding and structure stabilizing. Adsorption of water on proteins can be evaluated by near-infrared spectroscopy, a useful technique for observing combination frequency of a water molecule. In this work, albumin, lysozyme, and silk, were used as models for α-helix and β-pleated sheet proteins. Their NIR spectra during water adsorption process were measured by using an NIR spectrometer equipped with a transflectance accessory. Moreover, the quantitative adsorption of water was determined by gravimetric technique. The results indicate that, there are five different NIR absorptions arise from the OH combination frequencies of water adsorbed by albumin in the 5300-5100 cm-1 region. But there are only four absorptions for lysozyme and silk. The OH combination frequencies arising from water molecules in albumin indicate that it acquires free water molecules (5280 cm-1) and adsorbed water molecules through carbonyl-water interactions (5248 and 5160 cm-1) and amino-water interactions (5200 and 5120 cm-1). Interestingly, there is no indication for the presence of free water molecules in lysozyme and silk. Furthermore, the gravimetric results indicate that the rate of water adsorbed follows the order RW.Alb<RW.Lys<RW.Sil and total mass of water adsorbed per gram solid follows the order WAlb<WLys=WSil.

HIGHER CTX-M, TEM, AND SHV EXTENDED-SPECTRUM BETA-LACTAMASE PLASMID GENE COMBINATION FREQUENCY IN ESBL PRODUCING KLEBSIELLA PNEUMONIAE COMPARED WITH ESBL PRODUCING ESCHERICHIA COLI

Introduction:Extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae confer antibiotic resistance to broad-spectrum penicillins, cephalosporins, using ESBL genes CTX-M, TEM, SHV, which are encoded in bacterial plasmid genome. Methods: We compared plasmid CTX-M, TEM, and SHV ESBL gene combinations in ESBL producing Escherichia coliand Klebsiella pneumoniae. Altogether, 136 ESBL producing Enterobacteriaceae isolation cases were analyzed. Results:The ESBL producing Enterobacteriaceae, mostly K. pneumoniae (n = 66; 48.53%), E. coli (n = 36; 26.47%), were isolated from 52 (38.2%) female and 84 (61.8%) male patients from Riga East Clinical University Hospital. Overall,132 isolates (97.06%) registered positive for the plasmid CTX-M gene, 97 isolates (71.32%) for the plasmid TEM gene, and 87 isolates (63.97%) for the plasmid SHV gene.Patients with the three ESBL plasmid gene (CTX-M+ TEM+ SHV+) combination were significantly older (67.11 ± 14.16 years) than patients with other gene combinations (59.63 ± 18.14 years; p = 0.047). Plasmid SHV gene frequency was higher in K. pneumoniae (p < 0.001). The K. pneumoniae mostly presented with the three plasmid ESBL gene (CTX-M+ TEM+ SHV+) combination, whereas E. coli presented with other gene combinations (p = 0.014). Conclusions: Klebsiella Pneumoniae, more often, presented with the plasmid SHV ESBL gene and the three ESBL gene (CTX-M+ TEM+ SHV+) combination, compared to E. coli. Older patients with ESBL producing Enterobacteriaceae infection, more often, presented with the three ESBL gene (CTX-M+ TEM+ SHV+) combination, compared to younger patients with the infection.

Are Chinese Correlative Conjunctions Psychologically Real? An Investigation of the Combination Frequency Effect

The present study used an online grammaticality judgment task to examine whether Chinese discontinuous correlative conjunctions are psychologically real in mental lexicon. High- and low-frequency discontinuous correlative conjunctions were compared with random combinations differing in combination frequencies but matched for constituent word frequency. Forty graduate students participated in the study. Results showed that responses were faster and more accurate for high-frequency correlative conjunctions than low-frequency ones, but the effects were absent for random combinations. The results indicate that Chinese discontinuous correlative conjunctions have psychological reality in mental lexicon in addition to the representation of their constituent words, and that grammatical functions of correlative conjunctions may be a critical factor for the formation of such holistic representations.