bluuebunny/crossref_metadata_2025 huggingface dataset:
Communicating climate change: challenges ahead and action needed
Authors: Leal Filho Walter
Published: February 2009

Purpose

Even though climate change is a matter of great scientific relevance and of broad general interest, there are some problems related to its communication. The purpose of this paper is to outline some of the problems inherent to the communication of climate change, list some of the challenges ahead and describe some of the action needed in order to allow it to be better and more widely communicated.

Design/methodology/approach

A description of trends related to education and communication on climate change is made and some recent trends are outlined.

Findings

Finding practical, workable and cost‐efficient solutions to the problems posed by climate change is now a world priority and one which links government and non‐government organisations in a way not seen before. In order to yield the expected results, current initiatives need to be complemented by sound education and communication strategies.

Originality/value

The paper describes the barriers seen when one tries to communicate climate change and outlines some of the current misconceptions of what climate change is. It also suggests a set of measures to address the existing deficiencies.
Carbon accounting and carbon footprint – more than just diced results?
Authors: Schmidt Mario
Published: February 2009

Purpose

The purpose of this paper is to discuss the growing public interest in climate protection and the desire for climate‐friendly consumption which has led to a previously unimagined demand for Carbon Labels on products and various approaches to calculating the carbon footprint of firms or individual products.

Design/methodology/approach

A principal problem in calculating the carbon footprint is the input required to genuinely map the emissions from cradle to grave, in other words the product life path as is customary in a life cycle assessment. Small‐ and medium‐sized companies especially encounter major problems in practice when trying to calculate their footprint and take aspects of upstream CO2 emissions from their suppliers into account as well. The different options regarding how to balance and to include these emissions are compared.

Findings

Such analyses are indispensable against the background of decreasing vertical integration in industrialised countries. This is the classic question concerning the boundaries of balancing, but here with far‐reaching consequences, as incorrect selection of the limits will also falsify the results and conclusions.

Originality/value

The paper demonstrates that there are new methods that can be used to determine CO2 emissions in supply chains from stage to stage recursively and simply pass the data on to the next actor in the chain. A company then only needs to take the data from its direct trading partners into account and can dispense with comprehensive life cycle analyses. This would make CO2 calculations easier but it requires a discussion about the question for what kind of decisions the different approaches are really helpful.
Key energy‐related steps in addressing climate change
Authors: Rosen Marc A.
Published: February 2009

Purpose

Efforts to address climate change need to focus on curtailing carbon emissions to the atmosphere, and these efforts need to focus in large part on energy processes and activities, given the significant contributions to carbon emissions of the energy sectors of countries. This paper aims to describe key energy‐related steps needed to address climate change.

Design/methodology/approach

The key energy‐related steps needed to address climate change are identified, discussed and illustrated.

Findings

Several key energy‐related steps are identified that need to be addressed to combat climate change. These include: use non‐carbon‐based energy sources; use non‐carbon‐based energy carriers and/or energy carriers that facilitate the use of non‐carbon‐based energy sources; remove and sequester carbon‐based atmospheric emissions; and increase efficiency.

Originality/value

Given the major contributions of energy processes to climate change, it is anticipated that initiatives to address these steps will allow major advances to be achieved regarding addressing greenhouse gas emissions and climate change. The key energy‐related steps constitute a logical and pragmatic approach that provides a coherent overall structure to guide efforts to address climate change. It is expected that addressing these steps should assist broader efforts to achieve sustainable development.
An assessment of the principle of subsidiarity in urban planning to face climate change
Authors: Minoia Paola , Calzavara Alessandro , Lovo Loris , Zanetto Gabriele
Published: February 2009

Purpose

The purpose of this paper is to present a case study, showing a local government's capacity in addressing energy consumptions and local greenhouse gases (GHG) emissions in its administration areas. This case demonstrates some strengths and weaknesses in the actions of local institutions to complement the national and European efforts in addressing climate change problems.

Design/methodology/approach

The paper starts by considering the need to address global changes by a multi‐level governance system, in line with the subsidiarity principle proposed by the European Commission for the implementation of its policies. According to this principle, different institutional levels should intervene through control and reduction of GHG emissions from their operational scale. In particular, this paper reports an ongoing activity of urban planning carried out by a local municipality of Northern Italy, Martellago (Venice Province), that has focused on the energy and GHG reduction as a priority.

Findings

The analysis identified some topics to be addressed by urban plans; their higher or lower effectiveness in respect to the climate change adaptation and mitigation needs; and some constraints to be addressed by an enforced integration of different administrative levels of governance.

Originality/value

This paper shows the importance of local planning in climate change issues, which is seldom considered, particularly in practice. In fact, while the elaboration of energy and urban plans is not mandatory for small municipalities, some voluntary actions – like for Martellago – show that their wide applications could contribute importantly to the efforts to decrease GHG emissions.
Development of national climate and adaptation policy in Latvia
Authors: Klavins Maris , Bruneniece Ieva , Bisters Valdis
Published: February 2009

Purpose

The purpose of this paper is to analyse the development and character of climate policy in Latvia with a special emphasis on policy instruments.

Design/methodology/approach

In order to implement policies and measures effectively and monitor progress in achieving its mitigation targets, Latvia uses a wide mix of policy instruments, including regulations (e.g. environmental impact assessment procedures, environmental permits and standards, restrictions and prohibitions), economic and fiscal instruments (the natural resources tax, the excise tax for energy resources, user's charges), and voluntary agreements, also raising public awareness.

Findings

The combination of the policy instruments with the economic and fiscal instruments support consideration of the needs to support industrial developments and consider national growth interests, but at the same time keeping in line with the leadership in the climate change mitigation and adaptation leadership.

Practical implications

The approaches used in Latvia for climate policy development supports prioritising of climate change issues and put the development of adaptation measures as key issues, at the same time stressing efforts in mitigation.

Originality/value

The character of development of climate policy combining different policy instruments in line with limited availability of resources is analysed.
The past protecting the future
Authors: Leal Miguel E.
Published: February 2009

Purpose

In answer to the urgent need to adapt conservation strategies and approaches to climate change, the purpose of this paper is to locate the climatically stable forests in West and Central Africa and to assess whether they overlap with the existing network of protected areas and if not, to prioritize them for protection.

Design/methodology/approach

With ongoing global warming, rain forest will survive where locally soil moisture content remains high compensating for the regional drought stress. As a proxy for a soil moisture‐driven model, rainfall >2,000 mm, altitude >500 m and strong relief (standard deviation in elevation data pixels) were overlapped in a GIS analysis to locate the climatically stable forest within the present continuous forest of Central Africa and within the degraded forest of West Africa. As a means of verification, the biodiversity was measured in and outside the identified areas in Gabon and Equatorial Guinea as high levels of biodiversity are related to the survival and stability of the forest in the past. Biodiversity was calculated (measured as Fisher‐α diversity) for all trees (dbh >5 cm) on 66 transects (200 × 5 m).

Findings

The forest areas identified as climatically stable in the GIS analysis showed a higher biodiversity than the forest outside these areas (student T‐test: P<0.000035, stable = 54.7 and unstable = 33.7), supporting the validity of the model. Mapping the results of the GIS query showed that most of the climatically stable forests in West and Central Africa are located outside the park systems, and that it is already too late to protect the climatically stable forest in West Africa as almost nothing is left of it.

Originality/value

Wedged in between large‐scale drought tolerant ecosystems the African rain forest is most vulnerable to global climate change. Knowing which parts are climatically stable and resilient helps to set and focus conservation priorities and efforts. This approach is a powerful tool which has helped to identify areas with a high‐conservation priority in Africa.
Surgical site infection rate is lower in laparoscopic than open colorectal surgery
Authors: Howard D. P. J. , Datta G. , Cunnick G. , Gatzen C. , Huang A.
Published: February 2009

Objective  Few studies have investigated whether surgical site infection (SSI) incidence differs between laparoscopic colorectal surgery (LCS) and open colorectal surgery (OCS). This study investigated the SSI incidence using the validated UK SSI Surveillance Service (SSISS) criteria for diagnosing wound infections.

Method  Prospective data collection recorded patients’ demographics, operative details, antibiotic use, wound evaluation and microbiological wound culture results, for consecutive patients undergoing elective resectional LCS and OCS. Postdischarge surveillance consisted of patient questionnaires sent out at 30 days and the primary care communication.

Results  A total of 122 patients underwent colorectal resections over 1 year (LCS 43; OCS 79). Patients’ demographics and operative case‐mix were similar for both groups, including body mass index (BMI), diabetic and smoking status. Operative duration was longer in the LCS group compared with OCS group (P = 0.012, Mann–Whitney U‐test), but hospital stay was shorter for LCS (P = 0.0001, Mann–Whitney U‐test). The SSI rate was significantly lower in the LCS than OCS group (7%vs 25% respectively; P = 0.015, two‐tailed Fisher’s exact test). BMI > 30 and operation length > 4 h influenced the risk of SSI formation (P < 0.05, chi‐squared test). One LCS patient required conversion to a limited laparotomy.

Conclusions  Surgical site infection incidence is significantly lower following LCS when compared with OCS. Confounding factors in this study include patient selection for LCS and nonrandomization.
Structure and function of AMP‐activated protein kinase
Authors: Oakhill J. S. , Scott J. W. , Kemp B. E.
Published: February 2009

AMP‐activated protein kinase (AMPK) regulates metabolism in response to energy demand and supply. AMPK is activated in response to rises in intracellular AMP or calcium‐mediated signalling and is responsible for phosphorylating a wide variety of substrates. Recent structural studies have revealed the architecture of the αβγ subunit interactions as well as the AMP binding pockets on the γ subunit. The α catalytic domain (1–280) is autoinhibited by a C‐terminal tail (313–335), which is proposed to interact with the small lobe of the catalytic domain by homology modelling with the MARK2 protein structure. Two direct activating drugs have been reported for AMPK, the thienopyridone compound A769662 and PTI, which may activate by distinct mechanisms.
Efficacy of open patch‐grafting under cardiopulmonary bypass for pulmonic stenosis in small dogs
Authors: Tanaka R , Shimizu M , Hoshi K , Soda A , Saida Y , Takashima K , Yamane Y
Published: February 2009

Objective To assess the efficacy of an open patch‐graft technique under cardiopulmonary bypass (CPB) in small dogs.

Design and methods A retrospective analysis of 10 dogs with pulmonic stenosis. Records between 1992 and 2002 were reviewed. The effect of surgical correction was evaluated and perioperative parameters were compared between survivors and non‐survivors.

Results The postoperative pulmonary pressure gradient was reduced in all seven surviving patients. Mean ± SE was 21.5 ± 7.4 mmHg (range 3.0–54.2 mmHg) and 6/7 dogs were < 40 mmHg at 3 months postoperatively. Comparing the data between those patients that survived and those that did not, the preoperative pressure gradient (P = 0.04) and volume of the Glucose‐Insulin‐Kalium solution used (P = 0.001) were significantly higher in those that did not survive.

Conclusion Open patch‐grafting can be performed in small‐breed dogs and decreased the pulmonary pressure gradient in survivors at 3 months postoperatively. However, this technique is more invasive than balloon valvuloplasty and should be used cautiously in severely stenosed patients.
Clinical evaluation of Alfaxan‐CD® as an intravenous anaesthetic in young cats
Authors: Zaki S , Ticehurst KE , Miyaki Y
Published: February 2009

Objective To describe and evaluate the use of Alfaxan‐CD®as an intravenous anaesthetic in young cats.

Design Thirty‐five Domestic Short‐hair cats aged from 3 to 12 months were admitted into the University Veterinary Teaching Hospital‐Sydney for elective surgery. Anaesthesia was induced with Alfaxan‐CD® and maintained with isoflurane: 22 cats received no premedication and 13 cats received acepromazine (0.03 mg/kg) and butorphanol (0.3 mg/kg) subcutaneously 30 min prior to induction.

Qualitative and quantitative data for induction and recovery were recorded. Physiological parameters were recorded at 0, 2 and 5 min post induction, and every 5 min thereafter until the end of the procedure.

Results Intravenous injection of Alfaxan‐CD® resulted in rapid induction of anaesthesia with a mean time to intubation of 122 s. The mean dose of Alfaxan‐CD® used was 4.2 mg/kg in unpremedicated cats and 2.7 mg/kg in premedicated cats. All cats maintained a heart rate above 95 beats/min. No cat developed hypoxaemia. Hypercapnoea was detected in 4 cats and hypotension was observed in 18 cats. Time to extubation ranged from 1 to 9 min. The mean time to sternal recumbency for premedicated cats was 11 min; 77% of premedicated cats and 23% of unpremedicated cats had a recovery score of 1 or 2.

Conclusion Alfaxan‐CD® is an effective anaesthetic agent in young healthy cats, providing a smooth induction and rapid recovery. Cats that were premedicated with acepromazine and butorphanol prior to induction with Alfaxan‐CD® had better recovery scores than those that were not premedicated.
Are ovine fenugreek (Trigonella foenum‐graecum) staggers and kangaroo gait of lactating ewes two clinically and pathologically similar nervous disorders?
Authors: Bourke CA
Published: February 2009

Fenugreek staggers has occurred in sheep in Victoria, as both an acute and a chronic syndrome. Signs included quadraparesis, a high stepping fore limb gait and a ‘bunny‐hopping’ hind limb gait. Changes consistent with acute oedema were found in the brain and spinal cord of acute cases, and Wallerian degeneration in the peripheral nerves of chronic cases. Kangaroo gait occurred in ewes in New South Wales, and the clinical signs and microscopic changes were remarkably similar to those of fenugreek staggers. Although the diet associated with each is different the causal agent may be the same.
Worm infections in high and low bodyweight Merino ewes during winter and spring
Authors: Larsen JWA , Anderson N
Published: February 2009

Objective  To compare infections of gastrointestinal nematodes in 2‐year‐old (‘maiden’) spring‐lambing Merino ewes in the upper and lower 25% of body weights (BW) at joining.

Design  An observational study over two consecutive years on two farms in western Victoria.

Methods  On each farm, ewes were weighed at the end of mating. Ewes within the upper and lower quartile of BW formed two groups that grazed together for the remainder of the year. On each farm, 20 ewes from each group were also treated with controlled release capsules containing ivermectin to minimise the effects of parasitism. Measures of worm infections were worm egg counts, total worm counts and assessment of breech soiling (‘dag score’). Measures of production were BW, numbers of deaths, pregnant ewes and weaned lambs in each group, and response to treatment with a capsule.

Results  No consistent difference was found in mean worm egg counts between ewes in the high and low BW groups and total worm counts of ewes before lambing were not significantly different in either year. Breech soiling of low BW ewes was consistently higher on both farms in both years. Those ewes also reared 7% to 14% fewer lambs. The difference in BW between the low and high groups remained highly significant on both farms throughout both years.

Conclusion  A strategic approach to worm control is appropriate for ewes in both high and low BW categories. Management options for low BW ewes include culling, supplementary feeding to increase BW before mating, or delaying mating for 12 months.
Dogs Are a Reservoir of Ampicillin-Resistant
Enterococcus faecium
Lineages Associated with Human Infections
Authors: Damborg Peter , Top Janetta , Hendrickx Antoni P. A. , Dawson Susan , Willems Rob J. L. , Guardabassi Luca
Published: February 2009

Ampicillin resistance is a marker for hospital-associated
Enterococcus faecium
. Feces from 208 dogs were selectively screened for the occurrence of ampicillin-resistant
E. faecium
(AREF). AREF was detected in 42 (23%) of 183 dogs screened in a cross-sectional study in the United Kingdom and in 19 (76%) of 25 dogs studied longitudinally in Denmark. AREF carriage was intermittent in all dogs studied longitudinally. Multilocus sequence typing of 63 canine AREF isolates revealed the presence of 13 distinct sequence types. Approximately 76% of the isolates belonged to hospital-adapted clonal complex 17 (CC17), including those of sequence types ST-78 and ST-192, which are widespread in European and Asian hospitals. Longitudinal screening of 18 healthy humans living in contact with 13 of the dogs under study resulted in the identification of a single, intermittent CC17 carrier. This person carried one of the sequence types (ST-78) recovered from his dog. Based on PCR and Southern hybridization analyses, the putative virulence gene cluster from
orf903
to
orf907
was widespread in canine AREF isolates (present in 97%), whereas
orf2351
(present in 26% of isolates) and
orf2430
(present in 31%) were strongly associated with CC17-related sequence types (
P
< 0.05). Surprisingly,
esp
and
hyl
were not detected in any of the isolates. The antimicrobial resistance profiles of canine AREF isolates generally differed from those previously described for clinical human isolates. The results indicate that dogs are frequent carriers of CC17-related lineages and may play a role in the spread of this nosocomial pathogen. The distinctive virulence and antimicrobial resistance profiles observed among canine AREF isolates raise interesting questions about the origin and evolution of the strains causing human infections.
Different Patterns of Regulation for the Copper and Cadmium Metallothioneins of the Ectomycorrhizal Fungus
Hebeloma cylindrosporum
Authors: Ramesh G. , Podila G. K. , Gay G. , Marmeisse R. , Reddy M. S.
Published: February 2009

Metallothioneins (MTs) are small cysteine-rich peptides involved in metal homeostasis and detoxification. We have characterized two MT genes, Hc
MT1
and Hc
MT2
, from the ectomycorrhizal fungus
Hebeloma cylindrosporum
in this study. Expression of Hc
MT1
and Hc
MT2
in
H. cylindrosporum
under metal stress conditions was studied by competitive reverse transcription-PCR analysis. The full-length cDNAs were used to perform functional complementation in mutant strains of
Saccharomyces cerevisiae
. As revealed by heterologous complementation assays in yeast, Hc
MT1
and Hc
MT2
each encode a functional polypeptide capable of conferring increased tolerance against Cd and Cu, respectively. The expression levels of Hc
MT1
were observed to be at their maximum at 24 h, and they increased as a function of Cu concentration. Hc
MT2
was also induced by Cu, but the expression levels were lower than those for Hc
MT1
. The mRNA accumulation of Hc
MT1
was not influenced by Cd, whereas Cd induced the transcription of Hc
MT2
. Zn, Pb, and Ni did not affect the transcription of Hc
MT1
or of Hc
MT2
. Southern blot analysis revealed that both of these genes are present as a single copy in
H. cylindrosporum
. While the promoters of both Hc
MT1
and Hc
MT2
contained the standard stress response elements implicated in the metal response, the numbers and varieties of potential regulatory elements were different in these promoters. These results show that ectomycorrhizal fungi encode different MTs and that each of them has a particular pattern of expression, suggesting that they play critical specific roles in improving the survival and growth of ectomycorrhizal trees in ecosystems contaminated by heavy metals.
Use of Calcofluor White for Detection, Identification, and Quantification of Phytoplanktonic Fungal Parasites
Authors: Rasconi Serena , Jobard Marlène , Jouve Lionel , Sime-Ngando Télesphore
Published: February 2009

We propose a routine protocol based on size fractionation of pelagic samples and the use of the fluorochrome calcofluor white (which binds to β-1,3 and β-1,4 polysaccharides) for diagnosing, identifying, and counting chitinaceous fungal parasites (i.e., the sporangia of chytrids) of phytoplankton. The protocol was applied to freshwater samples collected during different seasons (spring and summer/autumn) in two lakes whose trophic statuses varied. Because few samples were collected (i.e., two dates per site), the findings are considered preliminary and mainly a “proof of concept” rather than a valid comparison of sites versus seasons. The results from the proposed protocol indicate higher diversity of infected host and parasite communities than in previous studies. Chytrid epidemics were omnipresent, infecting diverse phytoplankton host communities, primarily diatoms, chlorophytes, and colonial and filamentous cyanobacteria. The diversity and numerical abundance of sporangia and of hosts, and the prevalence of infection (range, <1 to 24% of total host cells) as well, increased from the oligotrophic Lake Pavin to the eutrophic Lake Aydat, while the temporal changes in parasites were apparently more influenced by the host community composition. We conclude that the proposed protocol offers a valid method for the quantitative ecology of chytrid epidemics in aquatic ecosystems and food web dynamics.
Stimulation of Expression of a Silica-Induced Protein (Sip) in
Thermus thermophilus
by Supersaturated Silicic Acid
Authors: Doi Katsumi , Fujino Yasuhiro , Inagaki Fumio , Kawatsu Ryouichi , Tahara Miki , Ohshima Toshihisa , Okaue Yoshihiro , Yokoyama Takushi , Iwai Satoru , Ogata Seiya
Published: February 2009

The effects of silicic acid on the growth of
Thermus thermophilus
TMY, an extreme thermophile isolated from a siliceous deposit formed from geothermal water at a geothermal power plant in Japan, were examined at 75°C. At concentrations higher than the solubility of amorphous silica (400 to 700 ppm SiO
2
), a silica-induced protein (Sip) was isolated from the cell envelope fraction of log-phase TMY cells grown in the presence of supersaturated silicic acid. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the molecular mass and pI of Sip to be about 35 kDa and 9.5, respectively. Induction of Sip expression occurred within 1 h after the addition of a supersaturating concentration of silicic acid to TM broth. Expression of Sip-like proteins was also observed in other thermophiles, including
T. thermophilus
HB8 and
Thermus aquaticus
YT-1. The amino acid sequence of Sip was similar to that of the predicted solute-binding protein of the Fe
3+
ABC transporter in
T. thermophilus
HB8 (locus tag, TTHA1628; GenBank accession no. NC_006461; GeneID, 3169376). The
sip
gene (987-bp) product showed 87% identity with the TTHA1628 product and the presumed Fe
3+
-binding protein of
T. thermophilus
HB27 (locus tag TTC1264; GenBank accession no. NC_005835; GeneID, 2774619). Within the genome,
sip
is situated as a component of the Fbp-type ABC transporter operon, which contains a palindromic structure immediately downstream of
sip
. This structure is conserved in other
T. thermophilus
genomes and may function as a terminator that causes definitive Sip expression in response to silica stress.
Characterization of a β-Glucoside Operon (bgc) Prevalent in Septicemic and UropathogenicEscherichia coliStrains
Authors: Neelakanta Girish , Sankar T. Sabari , Schnetz Karin
Published: February 2009

Escherichia colistrains, in general, do not ferment cellobiose and aryl-β-d-glucosidic sugars, although “cryptic” β-d-glucoside systems have been characterized. Here we describe an additional cryptic operon (bgc) for the utilization of cellobiose and the aryl-β-d-glucosides arbutin and salicin at low temperature. Thebgcoperon was identified by the characterization of β-glucoside-positive mutants of anE. colisepticemia strain (i484) in which the well-studiedbgl(aryl-β-d-glucoside) operon was deleted. Thesebgc* mutants appeared after 5 days of incubation on salicin indicator plates at 28°C. Thebgcoperon codes for proteins homologous to β-glucoside/cellobiose-specific phosphoenolpyruvate-dependent phosphotransfer system permease subunits IIB (BgcE), IIC (BgcF), and IIA (BgcI); a porin (BgcH); and a phospho-β-d-glucosidase (BgcA). Next to thebgcoperon maps the divergentbgcRgene, which encodes a GntR-type transcriptional regulator. Expression of thebgcoperon is dependent on the cyclic-AMP-dependent regulator protein CRP and positively controlled by BgcR. In thebgc* mutants, a single nucleotide exchange enhances the activity of thebgcpromoter, rendering it BgcR independent. Typing of a representative collection ofE. colidemonstrated the prevalence ofbgcin strains of phylogenetic group B2, representing mainly extraintestinal pathogens, while it is rare among commensalE. colistrains. Thebgclocus is also present in the closely related speciesEscherichia albertii. Further, bioinformatic analyses demonstrated that homologs of thebgcgenes exist in the enterobacterialKlebsiella,Enterobacter, andCitrobacterspp. and also in gram-positive bacteria, indicative of horizontal gene transfer events.
Effect of Temperature on the Biotic Potential of Honeybee Microsporidia
Authors: Martín-Hernández Raquel , Meana Aránzazu , García-Palencia Pilar , Marín Pilar , Botías Cristina , Garrido-Bailón Encarna , Barrios Laura , Higes Mariano
Published: February 2009

The biological cycle of
Nosema
spp. in honeybees depends on temperature. When expressed as total spore counts per day after infection, the biotic potentials of
Nosema apis
and
N. ceranae
at 33°C were similar, but a higher proportion of immature stages of
N. ceranae
than of
N. apis
were seen. At 25 and 37°C, the biotic potential of
N. ceranae
was higher than that of
N. apis
. The better adaptation of
N. ceranae
to complete its endogenous cycle at different temperatures clearly supports the observation of the different epidemiological patterns.
Contrasting Roles of Checkpoint Proteins as Recombination Modulators at Fob1-
Ter
Complexes with or without Fork Arrest
Authors: Mohanty Bidyut K. , Bairwa Narendra K. , Bastia Deepak
Published: February 2009

The replication terminator protein Fob1 of
Saccharomyces cerevisiae
specifically interacts with two tandem
Ter
sites (replication fork barriers) located in the nontranscribed spacer of ribosomal DNA (rDNA) to cause polar fork arrest. The Fob1-
Ter
complex is multifunctional and controls other DNA transactions such as recombination by multiple mechanisms. Here, we report on the regulatory roles of the checkpoint proteins in the initiation and progression of recombination at Fob1-
Ter
complexes. The checkpoint adapter proteins Tof1 and Csm3 either positively or negatively controlled recombination depending on whether it was provoked by polar fork arrest or by transcription, respectively. The absolute requirements for these proteins for inducing recombination at an active replication terminus most likely masked their negative modulatory role at a later step of the process. Other checkpoint proteins of the checkpoint adapter/mediator class such as Mrc1 and Rad9, which channel signals from the sensor to the effector kinase, tended to suppress recombination at Fob1-
Ter
complexes regardless of how it was initiated. We have also discovered that the checkpoint sensor kinase Mec1 and the effector Rad53 were positive modulators of recombination initiated by transcription but had little effect on recombination at
Ter
. The work also showed that the two pathways were Rad52 dependent but Rad51 independent. Since
Ter
sites occur in the intergenic spacer of rDNA from yeast to humans, the mechanism is likely to be of widespread occurrence.
LpqM, a Mycobacterial Lipoprotein-Metalloproteinase, Is Required for Conjugal DNA Transfer inMycobacterium smegmatis
Authors: Nguyen Kiet T. , Piastro Kristina , Derbyshire Keith M.
Published: February 2009

We have previously described a novel conjugal DNA transfer process that occurs inMycobacterium smegmatis. To identify donor genes required for transfer, we have performed a transposon mutagenesis screen; we report here that LpqM, a putative lipoprotein-metalloproteinase, is essential for efficient DNA transfer. Bioinformatic analyses predict that LpqM contains a signal peptide necessary for the protein's targeting to the cell envelope and a metal ion binding motif, the likely catalytic site for protease activity. Using targeted mutagenesis, we demonstrate that each of these motifs is necessary for DNA transfer and that LpqM is located in the cell envelope. The requirement for transfer is specific to the donor strain; anlpqMknockout mutant in the recipient is still proficient in transfer assays. The activity of LpqM is conserved among mycobacteria; homologues from bothMycobacterium tuberculosisandMycobacterium aviumcan complementlpqMdonor mutants, suggesting that the homologues recognize and process similar proteins. Lipoproteins constitute a significant proportion of the mycobacterial cell wall, but despite their abundance, very few have been assigned an activity. We discuss the potential role of LpqM in DNA transfer and the implications of the conservation of LpqM activity inM. tuberculosis.
The Tubulin-Like RepX Protein Encoded by the pXO1 Plasmid Forms Polymers In Vivo inBacillus anthracis
Authors: Akhtar Parvez , Anand Syam P. , Watkins Simon C. , Khan Saleem A.
Published: February 2009

Bacillus anthraciscontains two megaplasmids, pXO1 and pXO2, that are critical for its pathogenesis. Stable inheritance of pXO1 inB. anthracisis dependent upon the tubulin/FtsZ-like RepX protein encoded by this plasmid. Previously, we have shown that RepX undergoes GTP-dependent polymerization in vitro. However, the polymerization properties and localization pattern of RepX in vivo are not known. Here, we utilize a RepX-green fluorescent protein (GFP) fusion to show that RepX forms foci and three distinct forms of polymeric structures inB. anthracisin vivo, namely straight, curved, and helical filaments. Polymerization of RepX-GFP as well as the nature of polymers formed were dependent upon concentration of the protein inside theB. anthraciscells. RepX predominantly localized as polymers that were parallel to the length of the cell. RepX also formed polymers inEscherichia coliin the absence of other pXO1-encoded products, showing that in vivo polymerization is an inherent property of the protein and does not require either the pXO1 plasmid or proteins unique toB. anthracis. Overexpression of RepX did not affect the cell morphology ofB. anthraciscells, whereas it drastically distorted the cell morphology ofE. colihost cells. We discuss the significance of our observations in view of the plasmid-specific functions that have been proposed for RepX and related proteins encoded by several megaplasmids found in members of theBacillus cereusgroup of bacteria.
Divisome under Construction: Distinct Domains of the Small Membrane Protein FtsB Are Necessary for Interaction with Multiple Cell Division Proteins
Authors: Gonzalez Mark D. , Beckwith Jon
Published: February 2009

Cell division in bacteria requires the coordinated action of a set of proteins, the divisome, for proper constriction of the cell envelope. Multiple protein-protein interactions are required for assembly of a stable divisome. Within theEscherichia colidivisome is a conserved subcomplex of inner membrane proteins, the FtsB/FtsL/FtsQ complex, which is necessary for linking the upstream division proteins, which are predominantly cytoplasmic, with the downstream division proteins, which are predominantly periplasmic. FtsB and FtsL are small bitopic membrane proteins with predicted coiled-coil motifs, which themselves form a stable subcomplex that can recruit downstream division proteins independently of FtsQ; however, the details of how FtsB and FtsL interact together and with other proteins remain to be characterized. Despite the small size of FtsB, we identified separate interaction domains of FtsB that are required for interaction with FtsL and FtsQ. The N-terminal half of FtsB is necessary for interaction with FtsL and sufficient, when in complex with FtsL, for recruitment of downstream division proteins, while a portion of the FtsB C terminus is necessary for interaction with FtsQ. These properties of FtsB support the proposal that its main function is as part of a molecular scaffold to allow for proper formation of the divisome.
Novel
trans
-Acting
Bacillus subtilis glnA
Mutations That Derepress
glnRA
Expression
Authors: Fisher Susan H. , Wray Lewis V.
Published: February 2009

Bacillus subtilis
contains two nitrogen transcription factors, GlnR and TnrA. The activities of GlnR and TnrA are regulated by direct protein-protein interactions with the feedback-inhibited form of glutamine synthetase (GS). To look for other factors involved in regulating GlnR activity, we isolated mutants with constitutive
glnRA
expression (Gln
C
). The twenty-seven Gln
C
mutants isolated in this mutant screen all contained mutations tightly linked to the
glnRA
operon which encodes GlnR (
glnR
) and GS (
glnA
). Four Gln
C
mutants contained mutations in the
glnR
gene that most likely impair the ability of GlnR to bind DNA. Three other Gln
C
mutants contained novel
glnA
mutations (S55F, V173I, and L174F). GlnR regulation was completely relieved in the three
glnA
mutants, while only modest defects in TnrA regulation were observed. In vitro enzymatic assays showed that the purified S55F mutant enzyme was catalytically defective while the V173I and L174F enzymes were highly resistant to feedback inhibition. The V173I and L174F GS proteins were found to require higher glutamine concentrations than the wild-type GS to regulate the DNA-binding activities of GlnR and TnrA in vitro. These results are consistent with a model where feedback-inhibited GS is the only cellular factor involved in regulating the activity of GlnR in
B. subtilis
.
Modulation of Deoxysugar Transfer by the Elloramycin Glycosyltransferase ElmGT through Site-Directed Mutagenesis
Authors: Ramos Angelina , Olano Carlos , Braña Alfredo F. , Méndez Carmen , Salas José A.
Published: February 2009

The glycosyltransferase ElmGT from
Streptomyces olivaceus
is involved in the biosynthesis of the antitumor drug elloramycin, and it has been shown to possess a broad deoxysugar recognition pattern, being able to transfer different
l
- and
d
-deoxysugars to 8-demethyl-tetracenomycin C, the elloramycin aglycone. Site-directed mutagenesis in residues L309 and N312, located in the α/β/α motif within the nucleoside diphosphate-sugar binding region, can be used to modulate the substrate flexibility of ElmGT, making it more precise for transfer of specific deoxysugars.
Formation and Metabolism of Methylmalonyl Coenzyme A in
Corynebacterium glutamicum
Authors: Botella Laure , Lindley Nic D. , Eggeling Lothar
Published: February 2009

Genome sequence information suggests that B
12
-dependent mutases are present in a number of bacteria, including members of the suborder
Corynebacterineae
like
Mycobacterium tuberculosis
and
Corynebacterium glutamicum
. We here functionally identify a methylmalonyl coenzyme A (CoA) mutase in
C. glutamicum
that is retained in all of the members of the suborder
Corynebacterineae
and is encoded by NCgl1471, NCgl1472, and NCgl1470. In addition, we observe the presence of methylmalonate in
C. glutamicum
, reaching concentrations of up to 757 nmol g (dry weight)
−1
in propionate-grown cells, whereas in
Escherichia coli
no methylmalonate was detectable. As demonstrated with a mutase deletion mutant, the presence of methylmalonate in
C. glutamicum
is independent of mutase activity but possibly due to propionyl-CoA carboxylase activity. During growth on propionate, increased mutase activity has severe cellular consequences, resulting in growth arrest and excretion of succinate. The physiological context of the mutase present in members of the suborder
Corynebacterineae
is discussed.
A Molybdopterin Oxidoreductase Is Involved in H
2
Oxidation in
Desulfovibrio desulfuricans
G20
Authors: Li Xiangzhen , Luo Qingwei , Wofford Neil Q. , Keller Kimberly L. , McInerney Michael J. , Wall Judy D. , Krumholz Lee R.
Published: February 2009

Three mutants deficient in hydrogen/formate uptake were obtained through screening of a transposon mutant library containing 5,760 mutants of
Desulfovibrio desulfuricans
G20. Mutations were in the genes encoding the type I tetraheme cytochrome
c
3
(
cycA
), Fe hydrogenase (
hydB
), and molybdopterin oxidoreductase (
mopB
). Mutations did not decrease the ability of cells to produce H
2
or formate during growth. Complementation of the
cycA
and
mopB
mutants with a plasmid carrying the intact
cycA
and/or
mopB
gene and the putative promoter from the parental strain allowed the recovery of H
2
uptake ability, showing that these specific genes are involved in H
2
oxidation. The
mop
operon encodes a periplasm-facing transmembrane protein complex which may shuttle electrons from periplasmic cytochrome
c
3
to the menaquinone pool. Electrons can then be used for sulfate reduction in the cytoplasm.
Nonkinase activity of MLCK in elongated filopodia formation and chemotaxis of vascular smooth muscle cells toward sphingosylphosphorylcholine
Authors: Wang Hong Hui , Nakamura Akio , Matsumoto Atsushi , Yoshiyama Shinji , Qin Xiaoran , Ye Li-Hong , Xie Ce , Zhang Yue , Gao Ying , Ishikawa Ryoki , Kohama Kazuhiro
Published: February 2009

The actin-myosin interaction of vascular smooth muscle cells (VSMCs) is regulated by myosin light chain kinase (MLCK), which is a fusion protein of the central catalytic domain with the N-terminal actin-binding and C-terminal myosin-binding domains. In addition to the regulatory role of kinase activity mediated by the catalytic domain, nonkinase activity that derives from both terminals is able to exert a regulatory role as reviewed by Nakamura et al. ( 32 ). We previously showed that nonkinase activity mediated the filopodia upon the stimulation by sphingosylphosphorylcholine (SPC) ( 25 ). To explore the regulatory role of nonkinase activity in chemotaxis, we constructed VSMCs where the expression of MLCK was totally abolished by using a lentivirus-mediated RNAi system. We hypothesized that the MLCK-downregulated VSMCs were unable to form filopodia and to migrate upon SPC stimulation and confirmed the hypothesis. We further constructed a kinase-inactive mutant from bovine cDNA coding wild-type (WT) MLCK by mutating the ATP-binding sites located in the catalytic domain, followed by confirming the presence (absence) of the kinase activity of WT (kinase-inactive mutant). We transfected WT and the mutant into MLCK-downregulated VSMCs. We expected that the transfected VSMCs will recover the ability to induce filopodia and chemotaxis toward SPC and found both constructs rescued the ability. Because they share the actin- and myosin-binding domains, we concluded nonkinase activity plays a major role for SPC-induced migration.
Sphingolipid signaling and treatment during remodeling of the uninfarcted ventricular wall after myocardial infarction
Authors: Yeh Che-Chung , Li Hongzhe , Malhotra Deepak , Huang Mei-Chuan , Zhu Bo-Qing , Goetzl Edward J. , Vessey Donald A. , Karliner Joel S. , Mann Michael J.
Published: February 2009

The sphingosine kinase (SphK)/sphingosine 1-phosphate (S1P) pathway, known to determine the fate and growth of various cell types, can enhance cardiac myocyte survival in vitro and provide cardioprotection in acute ex vivo heart preparations. However, the relevance of these findings to chronic cardiac pathology has never been demonstrated. We hypothesized that S1P signaling is impaired during chronic remodeling of the uninfarcted ventricle during the evolution of post-myocardial infarction (MI) cardiomyopathy and that a therapeutic enhancement of S1P signaling would ameliorate ventricular dysfunction. SphK expression and activity were measured in the remote, uninfarcted myocardium (RM) of C57Bl/6 mice subjected to coronary artery ligation. The mRNA expression of S1P receptor isoforms was also measured, as was the activation of the downstream S1P receptor mediators. A cardioprotective role for S1P1receptor agonism was tested via the administration of the S1P1-selective agonist SEW2871 during and after MI. As a result, the expression data suggested that a dramatic reduction in SphK activity in the RM early after MI may reflect a combination of posttranscriptional and posttranslational modulation. SphK activity continued to decline gradually during chronic post-MI remodeling, when S1P1receptor mRNA also fell below baseline. The S1P1-specific agonism with oral SEW2871 during the first 2-wk after MI reduced apoptosis in the RM and resulted in improved myocardial function, as reflected in the echocardiographic measurement of fractional shortening. In conclusion, these results provide the first documentation of alterations in S1P-mediated signaling during the in situ development of cardiomyopathy and suggest a possible therapeutic role for the pharmacological S1P receptor agonism in the post-MI heart.
Both central command and exercise pressor reflex activate cardiac sympathetic nerve activity in decerebrate cats
Authors: Tsuchimochi Hirotsugu , Hayes Shawn G. , McCord Jennifer L. , Kaufman Marc P.
Published: February 2009

Both static and dynamic exercise are known to increase cardiac pump function as well as arterial blood pressure. Feedforward control by central command and feedback control by the exercise pressor reflex are thought to be the neural mechanisms causing these effects during exercise. It remains unknown as to how each mechanism activates cardiac sympathetic nerve activity (CSNA) during exercise, especially at its onset. Thus we examined the response of CSNA to stimulation of the mesencephalic locomotor region (MLR, i.e., central command) and to static muscle contraction of the triceps surae muscles or stretch of the calcaneal tendon in decerebrate cats. We found that MLR stimulation immediately increased CSNA, which was followed by a gradual increase in heart rate, mean arterial pressure, and ventral root activity in a stimulus intensity-dependent manner. The latency of the increase in CSNA from the onset of MLR stimulation ranged from 67 to 387 ms. Both static contraction and tendon stretch also rapidly increased CSNA. Their latency from the development of tension in response to ventral root stimulation ranged from 78 to 670 ms. These findings suggest that both central command and the muscle mechanoreflex play a role in controlling cardiac sympathetic outflow at the onset of exercise.
Lubiprostone stimulates secretion from tracheal submucosal glands of sheep, pigs, and humans
Authors: Joo N. S. , Wine J. J. , Cuthbert A. W.
Published: February 2009

Lubiprostone, a putative ClC-2 chloride channel opener, has been investigated for its effects on airway epithelia (tracheas). Lubiprostone is shown to increase submucosal gland secretion in pigs, sheep, and humans and to increase short-circuit current (SCC) in the surface epithelium of pigs and sheep. Use of appropriate blocking agents and ion-substitution experiments shows anion secretion is the driving force for fluid formation in both glands and surface epithelium. From SCC concentration-response relations, it is shown that for apical lubiprostone Kd = 10.5 nM with a Hill slope of 1.08, suggesting a single type of binding site and, from the speed of the response, close to the apical surface, confirmed the rapid blockade by Cd ions. Responses to lubiprostone were reversible and repeatable, responses being significantly larger with ventral compared with dorsal epithelium. Submucosal gland secretion rates following basolateral lubiprostone were, respectively, 0.2, 0.5, and 0.8 nl gl−1 min−1 in humans, sheep, and pigs. These rates dwarf any contribution surface secretion adds to the accumulation of surface liquid under the influence of lubiprostone. Lubiprostone stimulated gland secretion in two out of four human cystic fibrosis (CF) tissues and in two of three disease controls, chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis (COPD/IPF), but in neither type of tissue was the increase significant. Lubiprostone was able to increase gland secretion rates in normal human tissue in the continuing presence of a high forskolin concentration. Lubiprostone had no spasmogenic activity on trachealis muscle, making it a potential agent for increasing airway secretion that may have therapeutic utility.
Percutaneous Closure of Atrial Septal Defects
Authors: Jategaonkar Smita , Scholtz Werner , Schmidt Henning , Horstkotte Dieter
Published: February 2009

Background—

Percutaneous closure of atrial septal defects is well established in children and adults and has been found to improve symptoms and positively influence right-heart remodeling. The aim of this study was to evaluate the efficacy and long-term outcome in adult patients older than 60 years.

Methods and Results—

The study population comprised 96 patients in the age group of 60 to 84 years. Percutaneous closure was performed effectively in all patients. Functional capacity according to New York Heart Association functional class and peak oxygen uptake (VO
2
max) in the cardiopulmonary exercise testing improved significantly after atrial septal defects closure, especially in patients with a pulmonary-to-systemic flow ratio >2. Echocardiographic measurements of the right ventricular end-diastolic diameter showed a significant decrease. No device-associated complications were observed, but in 16 patients, paroxysmal atrial fibrillation occurred after device implantation.

Conclusions—

Percutaneous atrial septal defects closure can be performed safely and with minimal risk even in elderly patients. They profit in terms of symptom reduction, improvement of exercise capacity, and right-heart remodeling.