title: Performance at the cost of well-being? Testing the multi-level effects of HR practices on organisational performance via employee experiences and well-being

authors: Sutton, Anna

abstract: Purpose
While the potential for HR practices (HRPs) to improve organisational performance is well-established, the mechanisms by which this occurs are complex. Individual HRPs may affect organisational performance either by mutual gains (improving both organisational performance and employee well-being) or by conflicting outcomes (organisational performance is improved at the expense of employee well-being). Models which combine HRPs may mask these differences and this study therefore tests pathways for four individual HRPs.
Design/methodology/approach 
HRPs (employee involvement, pay, performance management and training) were hypothesised to influence organisational performance directly and indirectly via employee experiences of work (communication, autonomy) and employee well-being. The study used a large secondary dataset, the UK Workplace Employee Relations Survey 2011, to test these relationships in a multi-level model.
Findings
Employee experiences of work strongly predicted well-being. In addition, three different pathways from HRP to organisational performance were identified. Pay showed indirect negative effects, involvement had direct positive effects and performance management had a mixture of both positive direct and negative indirect effects on performance.
Originality/value
Using a disaggregated analysis of HRP and demonstrating their differing effects, this study questions the feasibility of a universal model of HRP effects. By using multi-level modelling (MLM), the study develops understanding of employee perspectives and integrates these into organisational-level models, demonstrating that performance effects are partially mediated by both employee experiences of work and employee well-being. Finally, the study highlights the complexity of performance effects achieved via both employee benefits and an intensification of employee experiences.

text: Performance at the cost of well-being? Testing the multi-level effects of HR practices on organisational performance via employee experiences and well-being Purpose
While the potential for HR practices (HRPs) to improve organisational performance is well-established, the mechanisms by which this occurs are complex. Individual HRPs may affect organisational performance either by mutual gains (improving both organisational performance and employee well-being) or by conflicting outcomes (organisational performance is improved at the expense of employee well-being). Models which combine HRPs may mask these differences and this study therefore tests pathways for four individual HRPs.
Design/methodology/approach 
HRPs (employee involvement, pay, performance management and training) were hypothesised to influence organisational performance directly and indirectly via employee experiences of work (communication, autonomy) and employee well-being. The study used a large secondary dataset, the UK Workplace Employee Relations Survey 2011, to test these relationships in a multi-level model.
Findings
Employee experiences of work strongly predicted well-being. In addition, three different pathways from HRP to organisational performance were identified. Pay showed indirect negative effects, involvement had direct positive effects and performance management had a mixture of both positive direct and negative indirect effects on performance.
Originality/value
Using a disaggregated analysis of HRP and demonstrating their differing effects, this study questions the feasibility of a universal model of HRP effects. By using multi-level modelling (MLM), the study develops understanding of employee perspectives and integrates these into organisational-level models, demonstrating that performance effects are partially mediated by both employee experiences of work and employee well-being. Finally, the study highlights the complexity of performance effects achieved via both employee benefits and an intensification of employee experiences.

year: 2023-02-14

title: An examination of novel archaeal stress response genes

authors: Dinger, Marcel Eduard

abstract: The regulation of gene expression is the fundamental system employed by cells and organisms to respond to changes in their surroundings. To further understand the origins and nature of the processes underlying gene regulatory systems, the stress response in the thermophilic archaeon, Thermococcus zilligii, was examined. Microorganisms respond to stress by triggering physiological and morphological changes, which are largely brought about by adaptive changes in gene expression. The use of a thermophilic archaeon in this research is significant, since this group of organisms is widely regarded to resemble ancient life more closely than other extant life on Earth. Moreover, since the informational processing systems in archaea are thought to be closely related to those of the eukaryal nucleus, the study of the archaeal stress-response may further the understanding of the evolutionary relationship between the Archaea and the Eucarya. The stress response of T. zilligii was examined by analysing the total cytoplasmic protein complements from cultures ranging from mid-log to late stationary phase. Using N-terminal sequencing and BLASTP searches, homologues of four low molecular weight proteins that varied in level were identified in the genome sequences of members of the closely related genus, Pyrococcus. The genes originated from four distinct families, which were named srb, src, srd and sre. 
The srb family represents an essentially undescribed group of genes (COGI433), that occurs primarily amongst members of the Euryarchaeota. Due to the sporadic distribution of srb genes amongst extant life, the srb genes are suggested to have undergone horizontal transfer across large phylogenetic distances on several occasions. A sequence homologous to srb family members was identified as part of a hypothetical ORF in Clostridium perfringens, which encodes a protein that consists of a fusion of a transcriptional regulator belonging to the ArsR family and an SRB homologue. Several srb genes were found to occur as part of putative operons, the majority of which included genes homologous to the MinD family of P-loop ATPases. 
The src family encodes the highly conserved SaclOb family of DNA-binding proteins (COG1581). src genes occur exclusively amongst archaeal genomes, but were absent in Halobacterium sp. NRC-1, Methanopyrus kandleri, Methanosarcina mazei and M. acetivorans. The consensus secondary structure of the SRC proteins consists of a relatively long α-helix flanked by two small β-strands, followed by a second α-helix, and then three further β-strands. 
The srd family encodes proteins that are homologous to the C-terminal half of members of the Lrp/AsnC family of transcriptional regulators (COG1522). It is suggested here that the SRD family forms a logical subgroup that is structurally, and presumably functionally, distinct to the other members of the Lrp/AsnC family. srd genes occur in all nonmethanogenic archaea and in some bacteria. It is suggested that the srd family originated in the archaeal lineage and was later transferred to members of the Bacteria. The srd genes often appear as part of operon-like arrangements, which seem to be unrelated to one another, and consequently it is suggested that the SRD proteins are involved in a relatively generic function, such as transcriptional regulation. 
The sre family represents an undescribed group of highly conserved genes (COG1698) that occur exclusively amongst archaeal genomes. One sre gene was found in every archaeal genome sequenced to date, except for Pyrobaculum aerophilum and Halobacterium sp. NRC-1. Comparison of the SRE and 16S rRNA distance trees suggests that the sre genes were not prone to horizontal transfer. The secondary structure predicted from the SRE sequences consists of four large helical regions separated by short coiled regions. 
Recombinant proteins encoded by the srbPab1, srbPab2, srdPab2 and srePab genes cloned from Pyrococcus abyssi were produced in Escherichia coli and purified. An examination of the predicted quaternary associations of the recombinant proteins revealed that each of the proteins, with the exception rSRBPab2, formed multimeric structures. rSRBPabl formed dimer-sized multimers that occurred at 80°C, but not at room temperature. rSRDPab2 formed dimer-sized molecules that occurred preferentially at 80°C and in the presence of DNA. rSREPab formed structures that were consistent in size with those predicted for dimers and tetramers. Neither rSRBPabl, rSRDPab2 or rSREPab bound to DNA in the conditions examined.

text: An examination of novel archaeal stress response genes The regulation of gene expression is the fundamental system employed by cells and organisms to respond to changes in their surroundings. To further understand the origins and nature of the processes underlying gene regulatory systems, the stress response in the thermophilic archaeon, Thermococcus zilligii, was examined. Microorganisms respond to stress by triggering physiological and morphological changes, which are largely brought about by adaptive changes in gene expression. The use of a thermophilic archaeon in this research is significant, since this group of organisms is widely regarded to resemble ancient life more closely than other extant life on Earth. Moreover, since the informational processing systems in archaea are thought to be closely related to those of the eukaryal nucleus, the study of the archaeal stress-response may further the understanding of the evolutionary relationship between the Archaea and the Eucarya. The stress response of T. zilligii was examined by analysing the total cytoplasmic protein complements from cultures ranging from mid-log to late stationary phase. Using N-terminal sequencing and BLASTP searches, homologues of four low molecular weight proteins that varied in level were identified in the genome sequences of members of the closely related genus, Pyrococcus. The genes originated from four distinct families, which were named srb, src, srd and sre. 
The srb family represents an essentially undescribed group of genes (COGI433), that occurs primarily amongst members of the Euryarchaeota. Due to the sporadic distribution of srb genes amongst extant life, the srb genes are suggested to have undergone horizontal transfer across large phylogenetic distances on several occasions. A sequence homologous to srb family members was identified as part of a hypothetical ORF in Clostridium perfringens, which encodes a protein that consists of a fusion of a transcriptional regulator belonging to the ArsR family and an SRB homologue. Several srb genes were found to occur as part of putative operons, the majority of which included genes homologous to the MinD family of P-loop ATPases. 
The src family encodes the highly conserved SaclOb family of DNA-binding proteins (COG1581). src genes occur exclusively amongst archaeal genomes, but were absent in Halobacterium sp. NRC-1, Methanopyrus kandleri, Methanosarcina mazei and M. acetivorans. The consensus secondary structure of the SRC proteins consists of a relatively long α-helix flanked by two small β-strands, followed by a second α-helix, and then three further β-strands. 
The srd family encodes proteins that are homologous to the C-terminal half of members of the Lrp/AsnC family of transcriptional regulators (COG1522). It is suggested here that the SRD family forms a logical subgroup that is structurally, and presumably functionally, distinct to the other members of the Lrp/AsnC family. srd genes occur in all nonmethanogenic archaea and in some bacteria. It is suggested that the srd family originated in the archaeal lineage and was later transferred to members of the Bacteria. The srd genes often appear as part of operon-like arrangements, which seem to be unrelated to one another, and consequently it is suggested that the SRD proteins are involved in a relatively generic function, such as transcriptional regulation. 
The sre family represents an undescribed group of highly conserved genes (COG1698) that occur exclusively amongst archaeal genomes. One sre gene was found in every archaeal genome sequenced to date, except for Pyrobaculum aerophilum and Halobacterium sp. NRC-1. Comparison of the SRE and 16S rRNA distance trees suggests that the sre genes were not prone to horizontal transfer. The secondary structure predicted from the SRE sequences consists of four large helical regions separated by short coiled regions. 
Recombinant proteins encoded by the srbPab1, srbPab2, srdPab2 and srePab genes cloned from Pyrococcus abyssi were produced in Escherichia coli and purified. An examination of the predicted quaternary associations of the recombinant proteins revealed that each of the proteins, with the exception rSRBPab2, formed multimeric structures. rSRBPabl formed dimer-sized multimers that occurred at 80°C, but not at room temperature. rSRDPab2 formed dimer-sized molecules that occurred preferentially at 80°C and in the presence of DNA. rSREPab formed structures that were consistent in size with those predicted for dimers and tetramers. Neither rSRBPabl, rSRDPab2 or rSREPab bound to DNA in the conditions examined.

year: 2003

title: Time to Diagnosis and Persistence: The Two Major Determinants of Effective Tuberculosis Control

authors: Ruthe, Alaine Tess

subjects: tuberculosis

abstract: The greatest challenge confronting effective tuberculosis (TB) eradication is the time to diagnosis, and duration of treatment of chronically infected individuals which represent a pool of infection. In an attempt to help limit the spread of TB in New Zealand, a fast SNP based diagnostic test was developed, to quickly identify the highly transmissible and virulent endemic Rangipo strain. The role of VapBC toxin-antitoxin systems in M. tuberculosis has been the subject of great interest recently, due to their expanded number in the genome and links with virulence and the regulation of cell growth in response to environmental stress. Their ability to regulate growth under adverse conditions for presumed survival advantages possibly leading to dormancy or persistence, make them ideal candidates for the development of new M. tuberculosis treatments. To establish differential expression of vapC, and therefore identify possible pathways and functions of the VapBC proteins, RT-qPCR was used to assess the expression levels of vapB and vapC in M. smegmatis under conditions of stress. No consistant changes in vapC mRNA levels were observed, resulting in the hypothesis that it is not the transcriptional differences which are important in the regulation of VapC, but post-transcriptional factors. In order to investigate the function(s) of M. tuberculosis VapBCs, these VapBC proteins were expressed and purified in M. smegmatis, and the VapC toxin tested for RNase activity. The purification, expression, RNase testing and bioinformatic analysis of M. tuberculosis VapCs suggested that VapCRv2530c, VapCRv0065 and VapCRv0617 may all target the same recognition sequence, UA*GG. Bioinformatic analysis revealed an abundance of this target sequence in horizontal gene transfer and TA genes, raising the possibility that VapC toxins could be functioning as selfish elements, or initiating transcriptional regulation cascades when a rapid change in the proteomic response and metabolic state of the cell is required. It is intriguing that the three M. tuberculosis VapC proteins tested thus far appear to target the same recognition sequence, possibly suggesting that all 47 VapCs are RNases and are targeting the same sequence. Alternatively; VapCs may belong to sub-groups targeting different sequences, allowing M. tuberculosis to exude both gross and fine metabolic control; or, they may share the same target, but are regulated by different activators triggered in response to different environmental stimuli.

text: Time to Diagnosis and Persistence: The Two Major Determinants of Effective Tuberculosis Control The greatest challenge confronting effective tuberculosis (TB) eradication is the time to diagnosis, and duration of treatment of chronically infected individuals which represent a pool of infection. In an attempt to help limit the spread of TB in New Zealand, a fast SNP based diagnostic test was developed, to quickly identify the highly transmissible and virulent endemic Rangipo strain. The role of VapBC toxin-antitoxin systems in M. tuberculosis has been the subject of great interest recently, due to their expanded number in the genome and links with virulence and the regulation of cell growth in response to environmental stress. Their ability to regulate growth under adverse conditions for presumed survival advantages possibly leading to dormancy or persistence, make them ideal candidates for the development of new M. tuberculosis treatments. To establish differential expression of vapC, and therefore identify possible pathways and functions of the VapBC proteins, RT-qPCR was used to assess the expression levels of vapB and vapC in M. smegmatis under conditions of stress. No consistant changes in vapC mRNA levels were observed, resulting in the hypothesis that it is not the transcriptional differences which are important in the regulation of VapC, but post-transcriptional factors. In order to investigate the function(s) of M. tuberculosis VapBCs, these VapBC proteins were expressed and purified in M. smegmatis, and the VapC toxin tested for RNase activity. The purification, expression, RNase testing and bioinformatic analysis of M. tuberculosis VapCs suggested that VapCRv2530c, VapCRv0065 and VapCRv0617 may all target the same recognition sequence, UA*GG. Bioinformatic analysis revealed an abundance of this target sequence in horizontal gene transfer and TA genes, raising the possibility that VapC toxins could be functioning as selfish elements, or initiating transcriptional regulation cascades when a rapid change in the proteomic response and metabolic state of the cell is required. It is intriguing that the three M. tuberculosis VapC proteins tested thus far appear to target the same recognition sequence, possibly suggesting that all 47 VapCs are RNases and are targeting the same sequence. Alternatively; VapCs may belong to sub-groups targeting different sequences, allowing M. tuberculosis to exude both gross and fine metabolic control; or, they may share the same target, but are regulated by different activators triggered in response to different environmental stimuli.

year: 2015