Edad, crecimiento y reproducción de Gobio gobio L. (Pisces, Cyprinidae) en un tramo regulado del río Segura (SE de España)

The age, growth and reproduction of Gobio gobio, were studied during a period of two years in a section of the Segura River regulated by the effect of a small upstream hydroelectric power station. A total of 254 specimens were caught monthly by electrofishing. The studied population showed a maximum of six age classes in females (0+–5+) and five in males (1+–5+). All females were mature at 2+ age class, whereas only 62.5% 2+ males showed mature gonads. During the studied period, both sexes showed maximum values of Gonadosomatic Index in May and spawn was different between the two studied periods. Compared with other populations, the studied population from a regulated locality is characterized by a non–seasonal body condition cycle and low captures of juvenile fish (0+, 1+) probably due to the effect of washing produced by drastic and unpredictable flow changes.La edad, crecimiento y reproducción de Gobio gobio, ha sido estudiada a lo largo de dos años en un tramo del río Segura regulado por una pequeña central hidroeléctrica. Mediante pesca eléctrica fueron capturados, mensualmente, un total de 254 ejemplares. Las hembras presentaron seis clases de edad (0+–5+) mientras que los machos presentaron cinco clases (1+–5+). Todas las hembras de clase de edad 2+ resultaron maduras mientras que los machos 2+ resultaron maduros en un 62,5% de los casos. Durante el periodo de estudio, ambos sexos presentaron los máximos valores del Índice Gonadosomático durante los meses de mayo aunque el desove resultó diferente entre los dos periodos estudiados. En comparación con otras poblaciones, la población estudiada en un tramo regulado del río se caracteriza por no presentar un ciclo estacional en la condición somática y bajas capturas de ejemplares juveniles (0+, 1+) debido, probablemente, al efecto de lavado provocado por los drásticos e impredecibles cambios en el caudal

Fitness-related self-conscious emotions and risk for exercise addiction: examining the mediating role of passion

Fitness-related self-conscious emotions (SCEs) have been proposed as antecedents of exercise addiction (EA). However, the potential mechanisms underlying such a relationship remain unexplored. The present study examined the relationship between fitness-related SCEs and risk of EA, as well as the mediating role of passion for exercise. A total of 296 male runners (M = 40.35 years, SD = 10.69) completed a survey assessing weekly exercise frequency/hours, fitness-related SCEs, passion for exercise, and the risk of EA. The relationships between the study variables were examined using structural equation modeling. After controlling for age and weekly exercise frequency/hours, fitness-related SCEs of shame, guilt, and hubristic pride were positively associated with risk of EA. However, while guilt had direct effects on risk of EA, shame and hubristic pride showed indirect effects via obsessive passion. The results of the study are discussed, and some practical implications and future research directions are presented

Symmetric Vlasov-type antenna for High Power Microwave applications

We present a novel Vlasov-type antenna operating at 2.5 GHz and composed of a circular waveguide with a double bevel-cut. Simulation results show that the proposed antenna is capable of providing a wider emission angle if compared to standard Vlasov configurations, while still maintaining an adequate gain level. For this reason, it could be of interest for those High-Power Microwave (HPM) applications in which a larger area need to be covered by the EM field

Edad y crecimiento de Barbus graellsii Steindachner, 1866 y Chondrostoma miegii, Steindachner, 1866 (Pisces, Cyprinidae) en el río Cinca (cuenca hidrográfica del Ebro, NE España)

The age and growth of two endemic cyprinids from the lberian peninsula were studied for one year in a stretch of the Cinca River. There were caught by electrofishing 279 individuals of B. graellsii and 189 individuals of Ch. miegii. lmmature specimens of both species were not caught probably due to their migratory behaviour during the reproductive period. B. graellsii presented a maximum of 11 age classes in both sexes. Female Ch. miegii live for 8 years and males seven years. Growth was allometric in B. graellsii specimens whereas Ch. miegii showed isometric growth. Females were longer than males in both species. B. graellsii females showed higher growth rates than males whereas Ch. miegii showed similar growth rates between sexes. B. graellsii males showed a significant increase in condition before the reproductive period and a decrease in condition during this period, while females only showed a significant decrease in condition in July. Ch. miegii females presented dynamics of condition very similar to B. graellsii males. Key words: Age, Growth, Cyprinidae, Barbus graellsii, Chondrostoma miegii.The age and growth of two endemic cyprinids from the lberian peninsula were studied for one year in a stretch of the Cinca River. There were caught by electrofishing 279 individuals of B. graellsii and 189 individuals of Ch. miegii. lmmature specimens of both species were not caught probably due to their migratory behaviour during the reproductive period. B. graellsii presented a maximum of 11 age classes in both sexes. Female Ch. miegii live for 8 years and males seven years. Growth was allometric in B. graellsii specimens whereas Ch. miegii showed isometric growth. Females were longer than males in both species. B. graellsii females showed higher growth rates than males whereas Ch. miegii showed similar growth rates between sexes. B. graellsii males showed a significant increase in condition before the reproductive period and a decrease in condition during this period, while females only showed a significant decrease in condition in July. Ch. miegii females presented dynamics of condition very similar to B. graellsii males. Key words: Age, Growth, Cyprinidae, Barbus graellsii, Chondrostoma miegii.The age and growth of two endemic cyprinids from the lberian peninsula were studied for one year in a stretch of the Cinca River. There were caught by electrofishing 279 individuals of B. graellsii and 189 individuals of Ch. miegii. lmmature specimens of both species were not caught probably due to their migratory behaviour during the reproductive period. B. graellsii presented a maximum of 11 age classes in both sexes. Female Ch. miegii live for 8 years and males seven years. Growth was allometric in B. graellsii specimens whereas Ch. miegii showed isometric growth. Females were longer than males in both species. B. graellsii females showed higher growth rates than males whereas Ch. miegii showed similar growth rates between sexes. B. graellsii males showed a significant increase in condition before the reproductive period and a decrease in condition during this period, while females only showed a significant decrease in condition in July. Ch. miegii females presented dynamics of condition very similar to B. graellsii males. Key words: Age, Growth, Cyprinidae, Barbus graellsii, Chondrostoma miegii

Effects of pubertal timing and pubertal tempo on social physique anxiety, self-determined motivation, and exercise in early adolescent girls

Purpose: Research has shown that there is a decrease in physical activity levels during early adolescence, especially for girls. Previous studies have shown that the social physique anxiety (SPA) may be a controlling factor influencing exercise motivation and engagement in this behavior; however, the potential role that puberty plays in this decrease has not been considered until now. The objective of the present study was to examine the impact of pubertal timing and pubertal tempo on SPA and exercise motivation and behavior. Methods: Data from 328 early adolescent girls, aged between 9 and 12 at the time of joining the study, were collected in 3 waves over a 2-year period. Using structural equation modeling techniques, different 3-time-point growth models were estimated to examine if earlier maturing and compressed maturing in girls had differential effects on SPA and exercise motivation and behavior. Results: The results from growth analyses suggest that early maturing (according to all the pubertal indicators considered, except menstruation) tends to translate into (1) an increase in SPA levels and (2) a decrease in exercise - in the latter case, by reducing self-determined motivation. However, no differential effects from any of the pubertal indicators were found for compressed maturing in girls. Discussion: These results highlight the need for increased efforts toward developing programs aimed at helping early maturing girls to cope with the challenges of puberty with a particular focus on SPA experiences and exercise motivation and behavior

Early carotid atherosclerosis and cardiac diastolic abnormalities in hypertensive subjects

Despite the fact that it is known that hypertension may be associated to early atherosclerosis manifestations, few data are to date available on the relationship between early carotid abnormalities and left ventricular diastolic dysfunction. To address this issue, 142 hypertensive patients (64 females and 78 males) younger than 55 years, at the first diagnosis of mild-to-moderate essential hypertension (WHO/ISH criteria), were selected from a database consisting of 3541 subjects referred to ultrasound cardiovascular laboratory in the last 5 years. Carotid intima-media thickness (IMT) was detected by high-resolution vascular ultrasound and left ventricular structure and function by the use of Doppler echocardiography. According to carotid IMT values, all patients were subgrouped into two groups consisting of 89 (62.6%) pts with IMT > or = 1 mm (A) and 53 (37.4%) pts with IMT < 1 mm (B). Our results show that isovolumic relaxation time (IVRT), deceleration time of E velocity (EDT) and left ventricular relative wall thickness (LV-RWT) were significantly (P < 0.05) higher in group A (IVRT 112 +/- 8.9 ms; EDT 288 +/- 21.8 ms; LV-RWT 0.40 +/- 0.08) than in group B (IVRT 92.3 +/- 4.6 ms; EDT 203.3 +/- 27.01 ms; LV- RWT 0.37 +/- 0.06). Moreover, the prevalence of left ventricular hypertrophy (LVH) was significantly (P < 0.01) higher in group A (30/89; 33.7%) than in group B (8/53; 15%). A positive correlation (P < 0.001) between IMT, EDT and IVRT was found only in hypertensives without LVH. These results are consistent with the indication that IMT evaluation has to be recommended both in hypertensive patients with LVH and in those without LVH, but with left ventricular diastolic dysfunction. This approach might improve the prognostic stratification of hypertensive subjects and it might be suitable to recognize the subset of patients at a higher risk of cardiovascular disease or events early

A Novel Conical Cut Frequency-Tapered Ring Bar SWS for High-Power and Wide-Bandwidth K-Band TWTs

This article presents a novel frequency-tapered Ring Bar Slow Wave Structure (RBSWS) for high-gain and wide-bandwidth Traveling Wave Tubes (TWTs) operating in the K-band for space applications. Starting from an analytical circuit model of the RBSWS, a conical-cut geometry is introduced to reduce the phase velocity. Our proposed novel RBSWS operates over a frequency range of 18.8 to 20.1 GHz, under a cathodic voltage and current of 19.8 kV and 0.3 A, respectively. Particle-In-Cell (PIC) results, carried out by CST Studio 2023, show a very high output peak power of 840.5 W at a gain of 20.2 dB, for an input power of 8 W, and an electron efficiency of 15.3%. The tapered RBSWS-TWT achieves a wider bandwidth, higher output power, and higher electron efficiency with respect to the untapered RBSWS-TWT, demonstrating the effectiveness of the proposed structure

Exercise addiction: evolution and challenges for its recognition as a clinical disorder

The potential negative effects of exercise addiction (EA) were first reported over 50 years ago, but it has only recently been formally recognized as a disorder in the leading clinical manuals. The inclusion of exercise behaviour as a potentially addictive behaviour will require greater consensus on how to define this disorder, with diagnostic criteria and course descriptions clearly supported by scientific evidence, and on how to categorize it in relation to other mental disorders. This chapter presents an overview of attempts to identify the defining features of EA, the development of instruments to measure it, estimates of its prevalence, and the main strategies for treating it. The diverse terminology used to describe this disorder reflects both the range of perspectives from which it has been examined, and the different manifestations of EA. The chapter concludes by recognizing that the development and validation of specific diagnostic criteria for EA pose many challenges

Psychometric properties of problematic exercise measures: a systematic review

The present study summarized, compared, and critically appraised the methodological quality of the most used self-report measures assessing problematic exercise (PE) (i.e. CES, CET, EAI, EDQ, EDS, OEQ). A pre-registered systematic review was conducted in accordance with the 2018 COSMIN criteria and PRISMA methodology. Six electronic databases were searched for studies developing, validating and/or testing the psychometric properties of the psychometric instruments. Data from 48 studies comprising the six original instruments and their eight modified versions were included. The methodological quality (risk-bias) of the development studies of all 14 instruments was rated as ‘inadequate’. Limited evidence base in support of most of the measurement properties under examination was found, with the most relevant being that concerning content validity. Findings call into question (i) the accuracy and usefulness of the body of evidence obtained by employing these instruments, and (ii) the advisability of persisting with its use, at least until the issues identified in the present study have been adequately addressed. Obtaining further evidence on the measurement properties of existing self-report PE instruments as well as providing them in early stages of development for those to be proposed in the future should be a priority for research in this field

A review of the components of problematic exercise in psychometric assessment instruments

Backgrounds: The range of theoretical conceptualizations of problematic exercise in psychometric assessment instruments makes it difficult to identify the components that define this phenomenon. A better understanding of the underlying components of problematic exercise may contribute to progress toward providing scientific evidence that allows for deciding whether problematic exercise should be considered a substantive mental health disorder. The objective of the present review was to examine and compare, through a content analysis of their items, the components of problematic exercise in psychometric assessment instruments identified in a recent systematic review. Methods: A total of 33 components of problematic exercise were identified in the 17 assessment instruments included in the present review. Results: The results show that, despite the lack of consensus in the operational definition of their factors and the variety of ways of wording their items, the instruments reflect some common components that might indicate core criteria (i.e., salience, withdrawal, and mood modification) or candidate components (i.e., conflict, and continuance despite problems) of problematic exercise. However, other components of different nature were shown to be specific to some of the problematic exercise conceptualizations on which the assessment instruments are based. Conclusion: In the interest of reaching a consensus that allows to advance in this research field, further studies are needed to resolve which components are inherently problematic