Effect of modification of histidine residues on organization of the pigment--protein complexes of chromatium minutissimum

The effect of diethyl pyrocarbonate on chromatophores and isolated pigment--protein complexes of Chromatium minutissimum was studied. It is shown that modification of histidine residues results in the destruction of the core antenna LHI (B880) and in a spectral shift from 850 to 830 nm in the peripheral antenna LHII (B800-850). In the purple sulfur bacterium Chromatium minutissimum the pigment--protein complexes B800-B850 (peripheral antenna, LHII) and B880 (core antenna, LHI) collect and transmit the absorbed light energy to the reaction centers. The composition of pigments and proteins as well as primary structure of the majority of polypeptides in both types of complexes from various photosynthetic bacteria have been determined.     

The role of stress and level of burnout in job performance among nurses

Nurses' empathy for and connection with patients demonstrates core professional values which are essential but, consequently, attract certain factors capable of inducing stress. Studies of the roles and responsibilities associated with nursing have implicated multiple and conflicting demands which might not be without some resultant effects. However, little research has been conducted on these work characteristics in developing economies to determine how these might impact the nurse employees' performance. There is need for evidence-based empirical findings to facilitate improvement in healthcare services. This study examined stress and level of burnout among Nigerian nurses (n = 2245) who were selected using stratified random sampling. The participants were measured using an 'abridged measures booklet' adopted from the Maslach Burnout Inventory-General Survey (MBI-GS), Job Autonomy Questionnaire (JAQ), Questionnaire on Organisational Stress-Doetinchem (VOS-D) and Job Diagnostic Survey (JDS). The roles of work-home interference (WHI) and home-work interference (HWI), with respect to work characteristics and burnout (paying special attention to gender), were examined. Analyses using t-tests and linear regression showed no gender differences in burnout levels among Nigerian nurses, who experience medium to high levels of emotional exhaustion, medium levels of depersonalisation and high levels of personal accomplishment. WHI and HWI were found to mediate the relationship between work characteristics and burnout. The meditational relationship differs between genders. This study calls for further research into gender and burnout among the caring professions, especially in under-developed and developing economies of the world.