Electromyographic investigation of abdominal exercises and the effects of fatigue

Abdominal exercises are widely used to develop the anterior muscles of the trunk. These exercises can be undertaken without the aid of equipment, but increasingly manufacturers are developing equipment which purportedly enhances the training effect for abdominal muscles. As there are many different products and exercises used for abdominal muscle development, it is likely that some are more effective than others. This study aimed to investigate the effectiveness of five commonly performed abdominal exercises. A second aim was to investigate the effects of fatigue on these exercises. Five different types of abdominal exercise [standard crunch (sit-up) with bent knees, gym ball crunch, crunch with 5 kg weight held behind the head, legs raised crunch and a commercially manufactured roller crunch] were examined using integrated surface electromyography (IEMG). The lower rectus abdominis (LRA), upper rectus abdominis (URA) and obliquus externus abdominis (EO) of 15 healthy male participants [age (mean +/- SD) 22.2 +/- 6.8 years; height 1.77 +/- 0.06 m; mass 79.3 +/- 10.7 kg] were monitored using a four-channel special purpose EMG data logger. Three trials of each exercise were performed in random order and normalized to enable comparisons between muscles and exercises. At a later date, ten participants were then re-tested when fresh and after a 30 min whole-body fatigue protocol that specifically targeted the abdominal muscles. Two exercises were evaluated, the abdominal roller crunch and legs raised crunch, which were judged to be the least and most effective, respectively, of the five exercises previously used. The normalized IEMG showed significant (p < 0.001) differences between exercises (gym ball crunch = 86.0 +/- 7.5%; legs raised crunch = 79.9 +/- 5.1%; 5 kg weight crunch = 65.1 +/- 13.4%; standard crunch = 56.2 +/- 3.2%; and roller crunch = 45.0 +/- 11.4%). Post-fatigue, the normalized mean IEMG for both exercises increased significantly (p < 0.05) for LRA and URA muscles but not for the EO (p > 0.05). It was concluded that exercises can be constructed to provide a greater challenge to abdominal muscles, commercially available roller-type equipment appears to be little different from the standard abdominal crunch with bent knees, and fatiguing exercise results in the LRA and URA being more highly activated. These findings provide more detailed knowledge and understanding of the effects of different forms of abdominal exercise.     

Adaptation of composition and biophysical properties of phospholipids to temperature by the crustacean, Gammarus spp.

The compositions of lipid classes as well as the molecular species composition of subclasses (diacyl, alkylacyl, and alkenylacyl forms) of choline and ethanolamine phosphoglycerides in marine amphipod crustaceans, Gammarus spp., collected in the Baltic Sea at 8 and 15°C, were studied in relation to environmental temperature. The structural order of phospholipid multibilayers was also determined. Environmental temperature had little effect on fatty acid composition. The level of some polyunsaturated fatty acids, such as 20:4, even increased in choline and ethanolamine phosphoglycerides at 15°C. Ethanolamine phosphoglycerides were rich in alkenylacyl forms, especially in crustaceans collected at 15°C. The accumulation of sn-1 monoenic, sn-2 polyenic diacyl, alkyl, and alkenylacyl phosphatidylethanolamines and diacyl phosphatidylcholines was observed at 8°C. The phospholipid vesicles of crustaceans collected at 8°C were more disordered than expected compared to those obtained from animals collected at 15°C. It was concluded that, in addition to variations in the levels of sn-1 monoenic and sn-2 polyenic phospholipid molecular species with temperature, ethanolamine plasmalogens may play a role in controlling membrane biophysical properties in marine amphipod crustaceans.     

Electrophysiological and chemical analysis of sex pheromone communication system of the mottled umber,Erannis defoliaria (Lepidoptera: Geometridae)

(Z,Z,Z)-3,6,9-nonadecatriene (Z3,Z6,Z9–19Hy) and (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene (Z3,Z9-cis-6,7-epo-19Hy) were identified in pheromone gland extracts from femaleErannis defoliaria. The two components were found in a 13 ratio, with the main component,Z3,Z9-cis-6,7-epo-19Hy present at an amount of about 1.5 ng per female. The components were identified by means of gas chromatography-mass spectrometry, gas chromatography-electroantennography and gas chromatography-single sensillum recordings. Single sensillum measurements on the male antenna showed two physiological types of sensilla. One type was characterized by a large spike amplitude cell responding toZ3,Z9-cis-6,7-epoxy-19Hy and a small spike amplitude cell responding toZ3,Z6,Z9–19Hy. A second type responded only with a large spike amplitude cell to the epoxide, and this cell was inhibited by the triene. Of the two pheromone components, the epoxide gave the higher response in the EAG tests. Preliminary field tests support the identification of the pheromone components. The epoxide was also found to be present in the extract of the pheromone gland ofColotois pennaria, and males ofC. pennaria andAgriopis marginaria were trapped by the mixture of the identified compounds.     

Photoelektronenspektroskopie — eine Methode zur Lösung anwendungsorientierter Probleme der Katalyse,der Elektronik/Elektrotechnik sowie der Werkstoffentwicklung

Photoelectron-Spectroscopy (XPS) is an analytical method to get quantitative and qualitative informations about element distribution and chemical bonding on solid surfaces and in near surface layers. By means of recent publications about catalysis research, electronics/electrotechnics as well as material development and refinement the performance of XPS will be outlined.     

Family functioning and mood disorders: A comparison between patients with major depressive disorder and bipolar I disorder.

Within a sample of patients with major depressive disorder (MDD; n = 121) and bipolar affective disorder (BPAD; n = 69), the authors examined (a) diagnostic differences in family functioning at acute episode, (b) diagnostic differences in family functioning at episode recovery, (c) within-group changes in family functioning from acute episode to recovery, and (d) whether within-group changes from acute episode to recovery varied by diagnosis. Using a multidimensional model, the authors evaluated interviewer, patient, and family ratings. Overall, patients with MDD and BPAD evidenced similar levels of family impairment at acute episode and recovery. Generally, patients in both groups experienced improvement in family functioning over time, yet mean scores at recovery continued to range from fair to poor. Although certain specific differences emerged, diagnostic groups appeared to be more similar than different in level and pattern of family functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hope: Its nature and measurement.

Hope is a powerful emotion that has been largely neglected by the social sciences. In this paper, we introduce a theory of hope drawn from multiple disciplines, including psychology, philosophy, theology, and medicine. Our integrative approach features four components: the attachment, mastery, and survival motives, as well as spiritual beliefs. In addition, we describe four different empirical analyses aimed at the development and refinement of a comprehensive set of scales for measuring state and trait hope. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Influences of cobalt substitution and size effects on magnetic properties of coprecipitated Co-Fe ferrite nanoparticles

Co-substituted ferrite nanoparticles with narrow size distribution have been prepared by coprecipitation method. X-ray diffraction (XRD) showed that the samples have cubic spinel structure of which the lattice constant slightly decreases upon cobalt substitution. The mean crystallite size of the samples was in the range 9.5-11 nm as deduced from the XRD line broadening. Energy dispersive X-ray spectroscopy (EDX) verified the presence of cobalt in the substituted samples. The morphology and size distribution of the nanoparticles were studied using transmission electron microscopy (TEM). Magnetic properties were determined using a vibrating sample magnetometer (VSM). The samples are characterized by a superparamagnetic transition at blocking temperatures T_B below room temperature. The coercivity H_c at low temperatures follows a simple model of thermal activation of particle's moment over the anisotropy barrier in the temperature range below T_B which is in accordance with Kneller's law for ferromagnetic materials. From the blocking temperature and from the thermal decay of the coercivity, the effective anisotropy constant values were determined to be in order of 10⁶ erg/cm³. The Curie temperature T_C and saturation magnetization M_s at nanoscale are lower than those of the bulk and decrease with the increase of cobalt content.