bluuebunny/crossref_metadata_2025_split huggingface dataset:
ON THE BUREAUCRACY OF BUREAUCRACIES: ANALYSING THE SIZE AND ORGANIZATION OF OVERHEAD IN PUBLIC ORGANIZATIONS
Authors: BOON JAN , WYNEN JAN 
Published: January 2017

AbstractGovernments across the globe try to rebalance their budgets by rationalizing overhead operations. When overhead‐reducing policies are adopted, it is important to understand why some central government organizations have a higher overhead than others, and why organizational models to produce overhead efficiencies are used to different degrees. This study focuses on the Flemish context to analyse differences between central government organizations in the size and organization of two overhead processes: human resources management (HRM) and finance and control (FIN). Significant effects are found for autonomy, organizational size, spatial dispersion and budgetary stress, yet effects vary according to whether HRM or FIN is considered and whether the focus is on the size or the organization of HRM or FIN. Our findings have practical implications to get a process‐sensitive understanding of the size and organization of overhead, and theoretical implications as they cast light on factors that shape decision‐making in public organizations.
Simulated microgravity decreases circulating iron in rats: role of inflammation‐induced hepcidin upregulation
Authors: Cavey Thibault , Pierre Nicolas , Nay Kévin , Allain Coralie , Ropert Martine , Loréal Olivier , Derbré Frédéric 
Published: January 2017

New Findings
What is the central question of this study?
Although microgravity is well known to reduce circulating iron in astronauts, the underlying mechanism is still unknown. We investigated whether hepcidin, a key hormone regulating iron metabolism, could be involved in this deleterious effect.

What is the main finding and its importance?
We show that hindlimb suspension, a model of microgravity, stimulates the production of hepcidin in liver of rats. In agreement with the biological role of hepcidin, we found a decrease of circulating iron and an increase of spleen iron content in hindlimb‐unloaded rats. Consequently, our study supports the idea that hepcidin could play a role in the alteration of iron metabolism parameters observed during spaceflight.

During spaceflight, humans exposed to microgravity exhibit an increase of iron storage and a reduction of circulating iron. Such perturbations could promote oxidative stress and anaemia in astronauts. The mechanism by which microgravity modulates iron metabolism is still unknown. Herein, we hypothesized that microgravity upregulates hepcidin, a hormone produced by the liver that is the main controller of iron homeostasis. To test this hypothesis, rats were submitted to hindlimb unloading (HU), the reference model to mimic the effects of microgravity in rodents. After 7 days, the mRNA level of hepcidin was increased in the liver of HU rats (+74%, P = 0.001). In agreement with the biological role of hepcidin, we found an increase of spleen iron content (+78%, P = 0.030) and a decrease of serum iron concentration (−35%, P = 0.002) and transferrin saturation (−25%, P = 0.011) in HU rats. These findings support a role of hepcidin in microgravity‐induced iron metabolism alteration. Furthermore, among the signalling pathways inducing hepcidin mRNA expression, we found that only the interleukin‐6/signal transducer and activator of transcription 3 (IL‐6/STAT3) axis was activated by HU, as shown by the increase of phospho‐STAT3 (+193%, P < 0.001) and of the hepatic mRNA level of haptoglobin (+167%, P < 0.001), a STAT3‐inducible gene, in HU rats. Taken together, these data support the idea that microgravity may alter iron metabolism through an inflammatory process upregulating hepcidin.
Role of STIM2 in cell function and physiopathology
Authors: Berna‐Erro Alejandro , Jardin Isaac , Salido Gines M. , Rosado Juan A. 
Published: January 2017

AbstractAn endoplasmic reticulum (ER)‐resident protein that regulates cytosolic and ER free‐Ca2+ concentration by induction of store‐operated calcium entry: that is the original definition of STIM2 and its function. While its activity strongly depends on the amount of calcium stored in the ER, its function goes further, to intracellular signalling and gene expression. Initially under‐studied owing to the prominent function of STIM1, STIM2 came to be regarded as vital in mice, gradually emerging as an important player in the nervous system, and cooperating with STIM1 in the immune system. STIM2 has also been proposed as a relevant player in pathological conditions related to ageing, Alzheimer's and Huntington's diseases, autoimmune disorders and cancer. The discovery of additional functions, together with new splicing forms with opposite roles, has clarified existing controversies about STIM2 function in SOCE. With STIM2 being essential for life, but apparently not for development, newly available data demonstrate a complex and still intriguing behaviour that this review summarizes, updating current knowledge of STIM2 function.
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Efficient Low-pH Iron Removal by a Microbial Iron Oxide Mound Ecosystem at Scalp Level Run
Authors: Grettenberger Christen L. , Pearce Alexandra R. , Bibby Kyle J. , Jones Daniel S. , Burgos William D. , Macalady Jennifer L. 
Published: January 2017

ABSTRACT

Acid mine drainage (AMD) is a major environmental problem affecting tens of thousands of kilometers of waterways worldwide. Passive bioremediation of AMD relies on microbial communities to oxidize and remove iron from the system; however, iron oxidation rates in AMD environments are highly variable among sites. At Scalp Level Run (Cambria County, PA), first-order iron oxidation rates are 10 times greater than at other coal-associated iron mounds in the Appalachians. We examined the bacterial community at Scalp Level Run to determine whether a unique community is responsible for the rapid iron oxidation rate. Despite strong geochemical gradients, including a >10-fold change in the concentration of ferrous iron from 57.3 mg/liter at the emergence to 2.5 mg/liter at the base of the coal tailings pile, the bacterial community composition was nearly constant with distance from the spring outflow. Scalp Level Run contains many of the same taxa present in other AMD sites, but the community is dominated by two strains of
Ferrovum myxofaciens
, a species that is associated with high rates of Fe(II) oxidation in laboratory studies.

IMPORTANCE
Acid mine drainage pollutes more than 19,300 km of rivers and streams and 72,000 ha of lakes worldwide. Remediation is frequently ineffective and costly, upwards of $100 billion globally and nearly $5 billion in Pennsylvania alone. Microbial Fe(II) oxidation is more efficient than abiotic Fe(II) oxidation at low pH (P. C. Singer and W. Stumm, Science 167:1121–1123, 1970,
https://doi.org/10.1126/science.167.3921.1121
). Therefore, AMD bioremediation could harness microbial Fe(II) oxidation to fuel more-cost-effective treatments. Advances will require a deeper understanding of the ecology of Fe(II)-oxidizing microbial communities and the factors that control their distribution and rates of Fe(II) oxidation. We investigated bacterial communities that inhabit an AMD site with rapid Fe(II) oxidation and found that they were dominated by two operational taxonomic units (OTUs) of
Ferrovum myxofaciens
, a taxon associated with high laboratory rates of iron oxidation. This research represents a step forward in identifying taxa that can be used to enhance cost-effective AMD bioremediation.
Engineering Mycobacteria for the Production of Self-Assembling Biopolyesters Displaying Mycobacterial Antigens for Use as a Tuberculosis Vaccine
Authors: Lee Jason W. , Parlane Natalie A. , Rehm Bernd H. A. , Buddle Bryce M. , Heiser Axel 
Published: January 2017

ABSTRACT

Tuberculosis (TB) is a disease caused by
Mycobacterium tuberculosis
or
Mycobacterium bovis
and still remains one of the world's biggest global health burdens. Recently, engineered polyhydroxyalkanoate (PHA) biobeads that were produced in both
Escherichia coli
and
Lactococcus lactis
and displayed mycobacterial antigens were found to induce significant cell-mediated immune responses in mice. We observed that such PHA beads contained host cell proteins as impurities, which we hypothesized to have the potential to induce immunity. In this study, we aimed to develop PHA beads produced in mycobacteria (mycobacterial PHA biobeads [MBB]) and test their potential as a TB vaccine in a mouse model. As a model organism, nonpathogenic
Mycobacterium smegmatis
was engineered to produce MBB or MBB with immobilized mycobacterial antigens Ag85A and ESAT-6 on their surface (A:E-MBB). Three key enzymes involved in the poly(3-hydroxybutyric acid) pathway, namely, β-ketothiolase (PhaA), acetoacetyl-coenzyme A reductase (PhaB), and PHA synthase (PhaC), were engineered into
E. coli
-
Mycobacterium
shuttle plasmids and expressed in
trans
. Immobilization of specific antigens to the surface of the MBB was achieved by creating a fusion with the PHA synthase which remains covalently attached to the polyester core, resulting in PHA biobeads displaying covalently immobilized antigens. MBB, A:E-MBB, and an
M. smegmatis
vector control (MVC) were used in a mouse immunology trial, with comparison to phosphate-buffered saline (PBS)-vaccinated and
Mycobacterium bovis
BCG-vaccinated groups. We successfully produced MBB and A:E-MBB and used them as vaccines to induce a cellular immune response to mycobacterial antigens.

IMPORTANCE
Tuberculosis (TB) is a disease caused by
Mycobacterium tuberculosis
or
Mycobacterium bovis
and still remains one of the world's biggest global health burdens. In this study, we produced polyhydroxyalkanoate (PHA) biobeads in mycobacteria and used them as vaccines to induce a cellular immune response to mycobacterial antigens.
Establishment and Validation of RNA-Based Predictive Models for Understanding Survival of Vibrio parahaemolyticus in Oysters Stored at Low Temperatures
Authors: Liao Chao , Zhao Yong , Wang Luxin 
Published: January 2017

ABSTRACT

This study developed RNA-based predictive models describing the survival of
Vibrio parahaemolyticus
in Eastern oysters (
Crassostrea virginica
) during storage at 0, 4, and 10°C. Postharvested oysters were inoculated with a cocktail of five
V. parahaemolyticus
strains and were then stored at 0, 4, and 10°C for 21 or 11 days. A real-time reverse transcription-PCR (RT-PCR) assay targeting expression of the
tlh
gene was used to evaluate the number of surviving
V. parahaemolyticus
cells, which was then used to establish primary molecular models (MMs). Before construction of the MMs, consistent expression levels of the
tlh
gene at 0, 4, and 10°C were confirmed, and this gene was used to monitor the survival of the total
V. parahaemolyticus
cells. In addition, the
tdh
and
trh
genes were used for monitoring the survival of virulent
V. parahaemolyticus
. Traditional models (TMs) were built based on data collected using a plate counting method. From the MMs,
V. parahaemolyticus
populations had decreased 0.493, 0.362, and 0.238 log
10
CFU/g by the end of storage at 0, 4, and 10°C, respectively. Rates of reduction of
V. parahaemolyticus
shown in the TMs were 2.109, 1.579, and 0.894 log
10
CFU/g for storage at 0, 4, and 10°C, respectively. Bacterial inactivation rates (IRs) estimated with the TMs (−0.245, −0.152, and −0.121 log
10
CFU/day, respectively) were higher than those estimated with the MMs (−0.134, −0.0887, and −0.0732 log
10
CFU/day, respectively) for storage at 0, 4, and 10°C. Higher viable
V. parahaemolyticus
numbers were predicted using the MMs than using the TMs. On the basis of this study, RNA-based predictive MMs are the more accurate and reliable models and can prevent false-negative results compared to TMs.

IMPORTANCE
One important method for validating postharvest techniques and for monitoring the behavior of
V. parahaemolyticus
is to establish predictive models. Unfortunately, previous predictive models established based on plate counting methods or on DNA-based PCR can underestimate or overestimate the number of surviving cells. This study developed and validated RNA-based molecular predictive models to describe the survival of
V. parahaemolyticus
in oysters during low-temperature storage (0, 4, and 10°C). The RNA-based predictive models show the advantage of being able to count all of the culturable, nonculturable, and stressed cells. By using primers targeting the
tlh
gene and pathogenesis-associated genes (
tdh
and
trh
), real-time RT-PCR can evaluate the total surviving
V. parahaemolyticus
population as well as differentiate the pathogenic ones from the total population. Reliable and accurate predictive models are very important for conducting risk assessment and management of pathogens in food.
Rapid Enrichment of Dehalococcoides-Like Bacteria by Partial Hydrophobic Separation
Authors: Temme Hanna R. , Sande Kipp , Yan Tao , Novak Paige J. 
Published: January 2017

ABSTRACT

Organohalide-respiring bacteria can be difficult to enrich and isolate, which can limit research on these important organisms. The goal of this research was to develop a method to rapidly (minutes to days) enrich these organisms from a mixed community. The method presented is based on the hypothesis that organohalide-respiring bacteria would be more hydrophobic than other bacteria as they dehalogenate hydrophobic compounds. The method developed tests this hypothesis by separating a portion of putative organohalide-respiring bacteria, those phylogenetically related to
Dehalococcoides mccartyi
, at the interface between a hydrophobic organic solvent and an aqueous medium. This novel partial separation technique was tested with a polychlorinated biphenyl-enriched sediment-free culture, a tetrachloroethene-enriched digester sludge culture, and uncontaminated lake sediment. Significantly higher fractions, up to 20.4 times higher, of putative organohalide-respiring bacteria were enriched at the interface between the medium and either hexadecane or trichloroethene. The selective partial separation of these putative organohalide-respiring bacteria occurred after 20 min, strongly suggesting that the separation was a result of physical-chemical interactions between the cell surface and hydrophobic solvent. Dechlorination activity postseparation was verified by the production of
cis
-dichloroethene when amended with tetrachloroethene. A longer incubation time of 6 days prior to separation with trichloroethene increased the total number of putative organohalide-respiring bacteria. This method provides a way to quickly separate some of the putative organohalide-respiring bacteria from other bacteria, thereby improving our ability to study multiple and different bacteria of potential interest and improving knowledge of these bacteria.

IMPORTANCE
Organohalide-respiring bacteria, bacteria capable of respiring chlorinated contaminants, can be difficult to enrich, which can limit their predictable use for the bioremediation of contaminated sites. This paper describes a method to quickly separate
Dehalococcoides
-like bacteria, a group of organisms containing organohalide-respiring bacteria, from other bacteria in a mixed community. From this work,
Dehalococcoides
-like bacteria appear to have a hydrophobic cell surface, facilitating a rapid (20 min) partial separation from a mixed culture at the surface of a hydrophobic liquid. This method was verified in a polychlorinated biphenyl-enriched sediment-free culture, an anaerobic digester sludge, and uncontaminated sediment. The method described can drastically reduce the amount of time required to partially separate
Dehalococcoides
-like bacteria from a complex mixed culture, improving researchers' ability to study these important bacteria.
Polysaccharide Degradation Capability of Actinomycetales Soil Isolates from a Semiarid Grassland of the Colorado Plateau
Authors: Yeager Chris M. , Gallegos-Graves La Verne , Dunbar John , Hesse Cedar N. , Daligault Hajnalka , Kuske Cheryl R. 
Published: January 2017

ABSTRACT

Among the bacteria, members of the order
Actinomycetales
are considered quintessential degraders of complex polysaccharides in soils. However, studies examining complex polysaccharide degradation by
Actinomycetales
(other than
Streptomyces
spp.) in soils are limited. Here, we examine the lignocellulolytic and chitinolytic potential of 112
Actinomycetales
strains, encompassing 13 families, isolated from a semiarid grassland of the Colorado Plateau in Utah. Members of the
Streptomycetaceae
,
Pseudonocardiaceae
,
Micromonosporaceae
, and
Promicromonosporaceae
families exhibited robust activity against carboxymethyl cellulose, xylan, chitin, and pectin substrates (except for low/no pectinase activity by the
Micromonosporaceae
). When incubated in a hydrated mixture of blended
Stipa
and
Hilaria
grass biomass over a 5-week period,
Streptomyces
and
Saccharothrix
(a member of the
Pseudonocardiaceae
) isolates produced high levels of extracellular enzyme activity, such as endo- and exocellulase, glucosidase, endo- and exoxylosidase, and arabinofuranosidase. These characteristics make them well suited to degrade the cellulose and hemicellulose components of grass cell walls. On the basis of the polysaccharide degradation profiles of the isolates, relative abundance of
Actinomycetales
sequences in 16S rRNA gene surveys of Colorado Plateau soils, and analysis of genes coding for polysaccharide-degrading enzymes among 237
Actinomycetales
genomes in the CAZy database and 5 genomes from our isolates, we posit that
Streptomyces
spp. and select members of the
Pseudonocardiaceae
and
Micromonosporaceae
likely play an important role in the degradation of hemicellulose, cellulose, and chitin substances in dryland soils.

IMPORTANCE
Shifts in the relative abundance of
Actinomycetales
taxa have been observed in soil microbial community surveys during large, manipulated climate change field studies. However, our limited understanding of the ecophysiology of diverse
Actinomycetales
taxa in soil systems undermines attempts to determine the underlying causes of the population shifts or their impact on carbon cycling in soil. This study combines a systematic analysis of the polysaccharide degradation potential of a diverse collection of
Actinomycetales
isolates from surface soils of a semiarid grassland with analysis of genomes from five of these isolates and publicly available
Actinomycetales
genomes for genes encoding polysaccharide-active enzymes. The results address an important gap in knowledge of
Actinomycetales
ecophysiology—identification of key taxa capable of facilitating lignocellulose degradation in dryland soils. Information from this study will benefit future metagenomic studies related to carbon cycling in dryland soils by providing a baseline linkage of
Actinomycetales
phylogeny with lignocellulolytic functional potential.
Lysobacter PilR, the Regulator of Type IV Pilus Synthesis, Controls Antifungal Antibiotic Production via a Cyclic di-GMP Pathway
Authors: Chen Yuan , Xia Jing , Su Zhenhe , Xu Gaoge , Gomelsky Mark , Qian Guoliang , Liu Fengquan 
Published: January 2017

ABSTRACT

Lysobacter enzymogenes
is a ubiquitous soil gammaproteobacterium that produces a broad-spectrum antifungal antibiotic, known as heat-stable antifungal factor (HSAF). To increase HSAF production for use against fungal crop diseases, it is important to understand how HSAF synthesis is regulated. To gain insights into transcriptional regulation of the HSAF synthesis gene cluster, we generated a library with deletion mutations in the genes predicted to encode response regulators of the two-component signaling systems in
L. enzymogenes
strain OH11. By quantifying HSAF production levels in the 45 constructed mutants, we identified two strains that produced significantly smaller amounts of HSAF. One of the mutations affected a gene encoding a conserved bacterial response regulator, PilR, which is commonly associated with type IV pilus synthesis. We determined that
L. enzymogenes
PilR regulates pilus synthesis and twitching motility via a traditional pathway, by binding to the
pilA
promoter and upregulating
pilA
expression. Regulation of HSAF production by PilR was found to be independent of pilus formation. We discovered that the
pilR
mutant contained significantly higher intracellular levels of the second messenger cyclic di-GMP (c-di-GMP) and that this was the inhibitory signal for HSAF production. Therefore, the type IV pilus regulator PilR in
L. enzymogenes
activates twitching motility while downregulating antibiotic HSAF production by increasing intracellular c-di-GMP levels. This study identifies a new role of a common pilus regulator in proteobacteria and provides guidance for increasing antifungal antibiotic production in
L. enzymogenes
.

IMPORTANCE
PilR is a widespread response regulator of the two-component system known for regulating type IV pilus synthesis in proteobacteria. Here we report that, in the soil bacterium
Lysobacter enzymogenes
, PilR regulates pilus synthesis and twitching motility, as expected. Unexpectedly, PilR was also found to control intracellular levels of the second messenger c-di-GMP, which in turn inhibits production of the antifungal antibiotic HSAF. The coordinated production of type IV pili and antifungal antibiotics has not been observed previously.
Mechanisms of Horizontal Cell-to-Cell Transfer of Wolbachia spp. in Drosophila melanogaster
Authors: White Pamela M. , Pietri Jose E. , Debec Alain , Russell Shelbi , Patel Bhavin , Sullivan William 
Published: January 2017

ABSTRACT

Wolbachia
is an intracellular endosymbiont present in most arthropod and filarial nematode species. Transmission between hosts is primarily vertical, taking place exclusively through the female germ line, although horizontal transmission has also been documented. The results of several studies indicate that
Wolbachia
spp. can undergo transfer between somatic and germ line cells during nematode development and in adult flies. However, the mechanisms underlying horizontal cell-to-cell transfer remain largely unexplored. Here, we establish a tractable system for probing horizontal transfer of
Wolbachia
cells between
Drosophila melanogaster
cells in culture using fluorescence
in situ
hybridization (FISH). First, we show that horizontal transfer is independent of cell-to-cell contact and can efficiently take place through the culture medium within hours. Further, we demonstrate that efficient transfer utilizes host cell phagocytic and clathrin/dynamin-dependent endocytic machinery. Lastly, we provide evidence that this process is conserved between species, showing that horizontal transfer from mosquito to
Drosophila
cells takes place in a similar fashion. Altogether, our results indicate that
Wolbachia
utilizes host internalization machinery during infection, and this mechanism is conserved across insect species.

IMPORTANCE
Our work has broad implications for the control and treatment of tropical diseases.
Wolbachia
can confer resistance against a variety of human pathogens in mosquito vectors. Elucidating the mechanisms of horizontal transfer will be useful for efforts to more efficiently infect nonnatural insect hosts with
Wolbachia
as a biological control agent. Further, as
Wolbachia
is essential for the survival of filarial nematodes, understanding horizontal transfer might provide new approaches to treating human infections by targeting
Wolbachia
. Finally, this work provides a key first step toward the genetic manipulation of
Wolbachia
.