bluuebunny/crossref_metadata_2025 huggingface dataset:
MuB is an AAA+ ATPase that forms helical filaments to control target selection for DNA transposition
Authors: Mizuno Naoko , Dramićanin Marija , Mizuuchi Michiyo , Adam Julia , Wang Yi , Han Yong-Woon , Yang Wei , Steven Alasdair C. , Mizuuchi Kiyoshi , Ramón-Maiques Santiago
Published: June 2013

Significance

DNA transposons move from one genomic location to another using a transposase. A regulatory protein might assist in target selection and avoiding self-destruction. MuB is the regulatory protein of Mu transposon. Here we report that MuB is an AAA+ (ATPase associated with diverse cellular activities) ATPase and forms right-handed helical filaments around DNA. The helical parameters of MuB and DNA are mismatched and their interactions are nonuniform. We propose that enhanced ATP hydrolysis by MuB, induced by contacts with the MuA-transposon-end complex, leads to DNA deformation and bending at the MuB filament end, thus creating a favored target for transposition.
Single-molecule spectroscopy reveals photosynthetic LH2 complexes switch between emissive states
Authors: Schlau-Cohen Gabriela S. , Wang Quan , Southall June , Cogdell Richard J. , Moerner W. E.
Published: June 2013

Photosynthetic organisms flourish under low light intensities by converting photoenergy to chemical energy with near unity quantum efficiency and under high light intensities by safely dissipating excess photoenergy and deleterious photoproducts. The molecular mechanisms balancing these two functions remain incompletely described. One critical barrier to characterizing the mechanisms responsible for these processes is that they occur within proteins whose excited-state properties vary drastically among individual proteins and even within a single protein over time. In ensemble measurements, these excited-state properties appear only as the average value. To overcome this averaging, we investigate the purple bacterial antenna protein light harvesting complex 2 (LH2) from
Rhodopseudomonas acidophila
at the single-protein level. We use a room-temperature, single-molecule technique, the anti-Brownian electrokinetic trap, to study LH2 in a solution-phase (nonperturbative) environment. By performing simultaneous measurements of fluorescence intensity, lifetime, and spectra of single LH2 complexes, we identify three distinct states and observe transitions occurring among them on a timescale of seconds. Our results reveal that LH2 complexes undergo photoactivated switching to a quenched state, likely by a conformational change, and thermally revert to the ground state. This is a previously unobserved, reversible quenching pathway, and is one mechanism through which photosynthetic organisms can adapt to changes in light intensities.
Shared places, unshared identities: vernacular discourses and spatialised constructions of identity in the linguistic landscape of Trieste
Authors: Tufi Stefania
Published: June 2013

Language as it appears in the public space is at the centre of investigations into linguistic landscapes. Language agents immersed in a given geo-historical context contribute to the construction of spatialised meaning and to the transformation of space into place. The visibility of a language in a linguistic landscape does not just index a reality, i.e. the use of one or more languages within a community, but contributes to the symbolic construction of a given space. The current study aims to investigate the peculiarities of place-making and -marking of the Slovenian-speaking community in the area of Trieste via an analysis of written signs displaying the minority language. The paper will show that the tension resulting from achieved equality in the legal status of Slovenian and the perception of unequal power relations between different ethnic groups is reproduced in the construction of the local linguistic landscape. The final part of the discussion will suggest that public use of the Slovenian language is central to the performance of a material border.
The dynamics of engineered resident proteins in the mammalian Golgi complex relies on cisternal maturation
Authors: Rizzo Riccardo , Parashuraman Seetharaman , Mirabelli Peppino , Puri Claudia , Lucocq John , Luini Alberto
Published: June 2013

After leaving the endoplasmic reticulum, secretory proteins traverse several membranous transport compartments before reaching their destinations. How they move through the Golgi complex, a major secretory station composed of stacks of membranous cisternae, is a central yet unsettled issue in membrane biology. Two classes of mechanisms have been proposed. One is based on cargo-laden carriers hopping across stable cisternae and the other on “maturing” cisternae that carry cargo forward while progressing through the stack. A key difference between the two concerns the behavior of Golgi-resident proteins. Under stable cisternae models, Golgi residents remain in the same cisterna, whereas, according to cisternal maturation, Golgi residents recycle from distal to proximal cisternae via retrograde carriers in synchrony with cisternal progression. Here, we have engineered Golgi-resident constructs that can be polymerized at will to prevent their recycling via Golgi carriers. Maturation models predict the progress of such polymerized residents through the stack along with cargo, but stable cisternae models do not. The results support the cisternal maturation mechanism.
PDGFRα and CD51 mark human Nestin+ sphere-forming mesenchymal stem cells capable of hematopoietic progenitor cell expansion
Authors: Pinho Sandra , Lacombe Julie , Hanoun Maher , Mizoguchi Toshihide , Bruns Ingmar , Kunisaki Yuya , Frenette Paul S.
Published: June 2013

The intermediate filament protein Nestin labels populations of stem/progenitor cells, including self-renewing mesenchymal stem cells (MSCs), a major constituent of the hematopoietic stem cell (HSC) niche. However, the intracellular location of Nestin prevents its use for prospective live cell isolation. Hence it is important to find surface markers specific for Nestin+ cells. In this study, we show that the expression of PDGFRα and CD51 among CD45− Ter119− CD31− mouse bone marrow (BM) stromal cells characterizes a large fraction of Nestin+ cells, containing most fibroblastic CFUs, mesenspheres, and self-renewal capacity after transplantation. The PDGFRα+ CD51+ subset of Nestin+ cells is also enriched in major HSC maintenance genes, supporting the notion that niche activity co-segregates with MSC activity. Furthermore, we show that PDGFRα+ CD51+ cells in the human fetal BM represent a small subset of CD146+ cells expressing Nestin and enriched for MSC and HSC niche activities. Importantly, cultured human PDGFRα+ CD51+ nonadherent mesenspheres can significantly expand multipotent hematopoietic progenitors able to engraft immunodeficient mice. These results thus indicate that the HSC niche is conserved between the murine and human species and suggest that highly purified nonadherent cultures of niche cells may represent a useful novel technology to culture human hematopoietic stem and progenitor cells.
Impact of Postplacement Adjustment of Peripherally Inserted Central Catheters on the Risk of Bloodstream Infection and Venous Thrombus Formation
Authors: Baxi Sanjiv M. , Shuman Emily K. , Scipione Christy A. , Chen Benrong , Sharma Aditi , Rasanathan Jennifer J. K. , Chenoweth Carol E.
Published: June 2013

Objective.

Peripherally inserted central catheter (PICC) tip malposition is potentially associated with complications, and postplacement adjustment of PICCs is widely performed. We sought to characterize the association between central line-associated bloodstream infection (CLABSI) or venous thrombus (VT) and PICC adjustment.

Design.

Retrospective cohort study.

Setting.

University of Michigan Health System, a large referral hospital.

Patients.

Patients who had PICCs placed between February 2007 and August 2007.

Methods.

The primary outcomes were development of CLABSI within 14 days or VT within 60 days of postplacement PICC adjustment, identified by review of patient electronic medical records.

Results.

There were 57 CLABSIs (2.69/1,000 PICC-days) and 47 VTs (1.23/1,000 PICC-days); 609 individuals had 1, 134 had 2, and 33 had 3 or more adjustments. One adjustment was protective against CLABSI (P = .04), whereas 2 or 3 or more adjustments had no association with CLABSI (P = .58 and .47, respectively). One, 2, and 3 or more adjustments had no association with VT formation (P = .59, .85, and .78, respectively). Immunosuppression (P< .01), power-injectable PICCs (P = .05), and 3 PICC lumens compared with 1 lumen (P = .02) were associated with CLABSI. Power-injectable PICCs were also associated with increased VT formation (P = .03).

Conclusions.

Immunosuppression and 3 PICC lumens were associated with increased risk of CLABSI. Power-injectable PICCs were associated with increased risk of CLABSI and VT formation. Postplacement adjustment of PICCs was not associated with increased risk of CLABSI or VT. Infect Control Hosp Epidemiol 2013;34(8):785-792
Influence of State Laws Mandating Reporting of Healthcare-Associated Infections: The Case of Central Line–Associated Bloodstream Infections
Authors: Pakyz Amy L. , Edmond Michael B.
Published: June 2013

Objective.

To evaluate the impact of state laws on reporting of healthcare-associated infections on central line-associated bloodstream infection (CLABSI) rates.

Design.

Retrospective, cross-sectional study.

Methods.

Hospital-level administrative and Hospital Compare data were collected on University HealthSystem Consortium hospitals. An ordered probit regression model assessed the association between state legislation and CLABSI standardized infection ratio (SIR). The main independent variable was a state legislation variable concerning 3 legal requirements (data submission, reporting of data to the public, inclusion of facility identifiers in public reports) and was coded for hospitals accordingly located in a state that did not have CLABSI reporting, located in a state that had CLABSI reporting legislation and met 3 legal requirements, or located in a state that had CLABSI reporting but did not meet the 3 legal requirements. A secondary analysis ascertained whether the mean state SIR values differed among the 3 legislation groups.

Results.

There were 159 hospitals included; 92 were located in states that had CLABSI reporting and met 3 requirements, 33 were located in states that had reporting but did not meet the 3 requirements, and 34 were in states that had no legislation. There was no effect of state legislation group on CLABSI SIR. There were no significant differences in the mean state CLABSI SIRs among the legislation groups.

Conclusions.

In this sample of academic medical centers, there was no evidence of an effect of state HAI laws on CLABSI occurrence. The impact of state legislation may be lessened by other CLABSI prevention initiatives.
Local and global well-posedness for the critical Schrödinger-Debye system
Authors: Corcho Adán , Oliveira Filipe , Silva Jorge
Published: June 2013

We establish local well-posedness results for the Initial Value Problem associated to the Schrödinger-Debye system in dimensions

N
=
2
,
3

N=2, 3

for data in

H
s

×

H

ℓ

H^s\times H^{\ell }

, with

s
s

and

ℓ
\ell

satisfying

max
{
0
,
s
−
1
}
≤
ℓ
≤
min
{
2
s
,
s
+
1
}

\max \{0, s-1\} \le \ell \le \min \{2s, s+1\}

. In particular, these include the energy space

H
1

×

L
2

H^1\times L^2

. Our results improve the previous ones obtained by B. Bidégaray, and by A. J. Corcho and F. Linares. Moreover, in the critical case (

N
=
2

N=2

) and for initial data in

H
1

×

L
2

H^1\times L^2

, we prove that solutions exist for all times, thus providing a negative answer to the open problem mentioned by G. Fibich and G. C. Papanicolau concerning the formation of singularities for these solutions.
Sensitivity of Erwinia amylovora in Illinois Apple Orchards to Streptomycin, Oxytetracyline, Kasugamycin, and Copper
Authors: Jurgens A. G. , Babadoost M.
Published: June 2013

In 2008 and 2009, severe fire blight (Erwinia amylovora) occurred in Illinois apple orchards, leading to speculation that streptomycin-resistant strains of E. amylovora might be present in some orchards. Statewide surveys were conducted in 2010, 2011, and 2012, and 117, 129, and 170, E. amylovora isolates were collected, respectively, from 20 counties. None of the 416 E. amylovora isolates tested were resistant to streptomycin (Agri-Mycin 17WP) at 50 mg/liter. Seven non-E. amylovora bacterial isolates were collected from E. amylovora-infected shoots that contained both a strA-strB streptomycin resistance gene and IS1133 on transposon Tn5393, which could be a potential source of streptomycin resistance for E. amylovora in Illinois in the future. Colony development of all 84 E. amylovora isolates tested was inhibited on Luria-Bertani medium amended with oxytetracycline at 50 mg/liter and kasugamycin (Kasumin 2L) at 100 mg/liter. Similarly, colony development of the 84 E. amylovora isolates was inhibited on casitone-yeast extract medium amended with copper sulfate at 0.16 mM. In 2011 and 2012, field trials were conducted to evaluate the efficacy of oxytetracycline (Mycoshield 17WP), kasugamycin (Kasumin 2L and ARY-4016-06), copper hydroxide (Kocide-3000 41.6DF), Bacillus subtilis (Serenade Max, QST713), and Pseudomonas fluorescens (Blight Ban A506) for management of fire blight in an apple orchard. Only kasugamycin (Kasumin 2L and ARY-4016-06) reduced blossom infection significantly. There was a significant interaction of kasugamycin (Kasumin 2L) with prohexadione calcium (Apogee 27.5DF) in reducing shoot blight incidence in the field in 2012.
Quantitative Molecular Detection ofXanthomonas hortorumpv.carotaein Carrot Seed Before and After Hot-Water Treatment
Authors: Temple Todd N. , du Toit Lindsey J. , Derie Michael L. , Johnson Kenneth B.
Published: June 2013

Molecular assays to detect and quantify DNA from viable cells of the seedborne pathogen Xanthomonas hortorum pv. carotae in carrot seed were developed and evaluated for use on nontreated and hot-water-treated seed lots. Both a TaqMan real-time polymerase chain reaction (PCR) assay and a loop-mediated isothermal amplification (LAMP) dilution endpoint assay detected and quantified DNA from viable pathogen cells after treatment of carrot seed washes with the live-dead discriminating dye propidium monoazide (PMA). The detection limits of the assays were approximately 101CFU for pure cultures of X. hortorum pv. carotae, and 102to 103CFU/g seed from naturally infested carrot seed lots. X. hortorum pv. carotae in and on carrot seed was killed by soaking the seed in hot water (52°C for 25 min), and a subsequent PMA treatment of these hot-water-treated seed washes suppressed detection of the pathogen with both the real-time PCR and LAMP assays. For 36 commercial seed lots treated with PMA but not hot water, regression of colony counts of X. hortorum pv. carotae measured by dilution plating on a semiselective agar medium versus estimates of pathogen CFU determined by the molecular assays resulted in significant (P ≤ 0.05) linear relationships (R2= 0.68 for the real-time PCR assay and 0.79 for the LAMP assay). The molecular assays provided quantitative estimates of X. hortorum pv. carotae infestations in carrot seed lots in <24 h, which is a significant improvement over the 7 to 14 days required to obtain results from the traditional dilution-plating assay.
First Report of Rust Caused by Puccinia nakanishikii on Lemongrass, Cymbopogon citratus, in Florida
Authors: Ploetz R. C. , Palmateer A. J. , Lopez P. , Aime M. C.
Published: June 2013

Lemongrass, Cymbopogon citratus (DC.) Stapf. (Poaceae), is grown widely in the tropics and subtropics as an ornamental, flavoring ingredient in Asian cooking, and for tea and fragrant oil (3). In February 2013, rust symptoms were observed on lemongrass in several gardens in Miami-Dade County, Florida. Symptoms began as small chlorotic flecks on both leaf surfaces that became crimson and enlarged to streaks ~1 cm in length. On the abaxial side of leaves, erumpent streaks ruptured to produce pustules in which urediniospores formed. Eventually, streaks coalesced to produce large patches of tan to purplish necrotic tissue that blighted most of the leaf surface and was often surrounded by chlorotic borders. These symptoms, fungal morphology, and nuclear ribosomal large subunit (28S) DNA analysis were used to identify the pathogen as Puccinia nakanishikii Dietel. Urediniospores were pyriform to globose, orange to crimson, slightly echinulate, and somewhat longer than a previous report (32.1 ± 3.4 (27 to 42) × 23.3 ± 2.4 (21 to 27) μm vs. 22 to 28 × 22 to 25 μm) (2). Uredinia contained clavate paraphyses, but teliospores were not observed. No aecial host is known for this pathogen. A 28S DNA sequence that was generated with the NL1 and LR3 primers (1,4) was deposited in GenBank under accession no. KC990123; it shared 99% identity with GenBank accession GU058002, which came from a specimen of P. nakanishikii in Hawaii. Voucher specimens of affected leaves of lemongrass have been deposited at the Arthur Herbarium, Purdue University. Although this disease has been reported in California, Hawaii, New Zealand, and Thailand, this is believed to be the first report from Florida (2). Based on rainfall and temperature conditions that are conducive to its development in South Florida, it has the potential to significantly reduce the health and production of this plant in area gardens.

References: (1) C. P. Kurtzman and C. J. Robnett. Antonie Van Leeuwenhoek 73:331. 1998. (2) S. Nelson. Rust of Lemongrass. Univ. Hawaii PD-57, 2008. (3) USDA, ARS, GRIN Online Database. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?12797 , accessed 25 April 2013. (4) R. Vilgalys and M. Hester. J Bacteriol. 172:4238, 1990.
Major Emerging Problems with Minor Meloidogyne Species
Authors: Elling Axel A.
Published: June 2013

Root-knot nematodes (Meloidogyne spp.) represent one of the most polyphagous genera of plant-parasitic nematodes. To date, close to 100 valid species are recognized. In contrast to the size of the genus, the majority of past research focused on a small number of species, i.e., the so-called ‘major’ species M. arenaria, M. hapla, M. incognita, and M. javanica. This review highlights recent work aimed at ‘minor’ root-knot nematodes: M. chitwoodi, M. fallax, M. minor, M. enterolobii (=M. mayaguensis), M. exigua, and M. paranaensis. Some of these species have been described only recently. After a brief profile of each species, identification methods and their application in Meloidogyne spp. are summarized. Intraspecific variation and its impact on plant resistance breeding are discussed and interactions between M. enterolobii and Fusarium solani are highlighted as an example of synergistic interactions with other plant pathogens. Future research on Meloidogyne spp. is not only shaped by recent breakthroughs such as completing the genome sequences of M. hapla and M. incognita, but is also influenced by changes in agriculture. Taken together, the aim of this review is to draw attention to previously neglected and newly described Meloidogyne spp. that are developing into major problems for agriculture in tropical and temperate climates.
Effects of light-activated diazido-PtIVcomplexes on cancer cellsin vitro
Authors: Bednarski Patrick J. , Korpis Katharina , Westendorf Aron F. , Perfahl Steffi , Grünert Renate
Published: June 2013

Various PtIVdiazides have been investigated over the years as light-activatable prodrugs that interfere with cell proliferation, accumulate in cancer cells and cause cell death. The potencies of the complexes vary depending on the substituted amines (pyridine=piperidine>ammine) as well as the coordination geometry (transdiazide>cis). Light-activated PtIVdiazides tend to be less specific than cisplatin at inhibiting cancer cell growth, but cells resistant to cisplatin show little cross-resistance to PtIVdiazides. Platinum is accumulated in the cancer cells to a similar level as cisplatin, but only when activated by light, indicating that reactive Pt species form photolytically. Studies show that Pt also becomes attached to cellular DNA upon the light activation of various PtIVdiazides. Structures of some of the photolysis products were elucidated by LC–MS/MS; monoaqua- and diaqua-PtIIcomplexes form that are reactive towards biomolecules such as calf thymus DNA. Platination of calf thymus DNA can be blocked by the addition of nucleophiles such as glutathione and chloride, further evidence that aqua-PtIIspecies form upon irradiation. Evidence is presented that reactive oxygen species may be generated in the first hours following photoactivation. Cell death does not take the usual apoptotic pathways seen with cisplatin, but appears to involve autophagy. Thus, photoactivated diazido-PtIVcomplexes represent an interesting class of potential anti-cancer agents that can be selectively activated by light and kill cells by a mechanism different to the anti-cancer drug cisplatin.
Photochemistry and DNA photocleavage by a new unsupported dirhodium(II,II) complex
Authors: Li Zhanyong , Burya Scott J. , Turro Claudia , Dunbar Kim R.
Published: June 2013

The new complex [Rh
2
(phen)
2
(CH
3
CN)
6
](BF
4
)
4
(
1
) was synthesized and characterized in solution and its crystal structure was determined. Irradiation of
1
with visible light (
λ
irr
>590 nm) in water results in the release of two equatorial CH
3
CN ligands, CH
3
CN
eq
, as well as in the formation of mononuclear radical Rh(II) fragments stemming from the homolytic photocleavage of the metal–metal bond. The photoproducts, identified by electrospray ionization mass spectrometry, include [Rh(phen)(CH
3
CN)(OH)]
+
and [Rh(phen)(CH
3
CN)(H
2
O)
3
(BF
4
)]
+
. The quantum yield for the photochemical transformation of
1
in H
2
O exceeds unity (
Φ
550 nm
=1.38) indicative of dark reactions following the initial photoprocess. DNA photocleavage was observed for
1
(
λ
irr
>590 nm), whereas the complex is unreactive in the dark. This feature makes
1
a promising photodynamic therapy agent that does not operate via the production of singlet oxygen,
1
O
2
.
Synthesis and cell localization of self-assembled dinuclear lanthanide bioprobes
Authors: Chauvin Anne-Sophie , Thomas Frédéric , Song Bo , Vandevyver Caroline D. B. , Bünzli Jean-Claude G.
Published: June 2013

Lanthanide bioprobes and bioconjugates are ideal luminescent stains in view of their low propensity to photobleaching, sharp emission lines and long excited state lifetimes permitting time-resolved detection for enhanced sensitivity. In this paper, we expand our previous work which demonstrated that self-assembled dinuclear triple-stranded helicates [Ln
2
(L
C2X
)
3
] behave as excellent cell and tissue labels in immunocytochemical and immunohistochemical assays. The synthetic strategy of the hexadentate ditopic ligands incorporating dipicolinic acid, benzimidazole units and polyoxyethylene pendants is revisited in order to provide a more straightforward route and to give access to further functionalization of the polyoxyethylene arms by incorporating a terminal function X. Formation of the helicates [Ln
2
(L
C2X
)
3
] (
X
=COOH, CH
2
OH, COEt, NH
2
, phthalimide) is ascertained by several experimental techniques and their stability tested against diethylenetriaminepentaacetate. Their photophysical properties (quantum yield, lifetime, radiative lifetime and sensitization efficiency) are presented and compared with those of the parent helicates [Ln
2
(L
C2
)
3
]. Finally, the cellular uptake of five Eu
III
helicates is monitored by time-resolved luminescence microscopy and their localization in HeLa cells established by co-staining experiments.
The role of contingency awareness in single-cue human eyeblink conditioning
Authors: Weidemann Gabrielle , Best Erin , Lee Jessica C. , Lovibond Peter F.
Published: June 2013

Single-cue delay eyeblink conditioning is presented as a prototypical example of automatic, nonsymbolic learning that is carried out by subcortical circuits. However, it has been difficult to assess the role of cognition in single-cue conditioning because participants become aware of the simple stimulus contingency so quickly. In this experiment (n = 166), we masked the contingency to reduce awareness. We observed a strong relationship between contingency awareness and conditioned responding, with both trace and delay procedures. This finding suggests that explicit associative knowledge and anticipatory behavior are regulated by a coordinated system rather than by functionally and neurally distinct systems.
Relocating to retirement living: An occupational perspective on successful transitions
Authors: Walker Emily , McNamara Beverley
Published: June 2013

Background/aim

Older adults are increasingly relocating to alternative housing options, such as retirement villages. Relocations can be stressful and these environmental transitions can cause significant disruption to the person‐environment and occupational fit, thus influencing health, well‐being and quality of life. There is a lack of literature from an occupational therapy perspective in relation to healthy older adults seeking to relocate. This study aimed to identify issues healthy older adults face when relocating to retirement living, what strategies they used during this process, how they maintained a sense of home, and the potential for occupational therapy involvement.

Methods

Sixteen semi‐structured, in‐depth interviews were conducted with participants recruited from retirement living facilities across three stages of relocation; ‘Decision’, ‘Early Days’, and ‘Established’. A grounded theory approach was used to code and analyse the data.

Results

Having control over the decisions surrounding relocation, being proactive rather than reactive and preparing sufficiently for the move all contributed to a positive post‐location adjustment. Four main themes emerged from the narratives: timing of decision making, new beginnings, continuity, and strategies for change.

Conclusions

This study contributes to literature surrounding how older adults occupy and make meaning of the spaces they call home and also enriches literature regarding environmental transitions. Relocation can be a disruptive process and occupational therapists are uniquely placed to facilitate healthy ageing throughout this transition using preventative and community‐based occupational therapy.
Bacterial social networks: structure and composition of Myxococcus xanthus outer membrane vesicle chains
Authors: Remis Jonathan P. , Wei Dongguang , Gorur Amita , Zemla Marcin , Haraga Jessica , Allen Simon , Witkowska H. Ewa , Costerton J. William , Berleman James E. , Auer Manfred
Published: June 2013

The social soil bacterium, Myxococcus xanthus, displays a variety of complex and highly coordinated behaviours, including social motility, predatory rippling and fruiting body formation. Here we show that M. xanthus cells produce a network of outer membrane extensions in the form of outer membrane vesicle chains and membrane tubes that interconnect cells. We observed peritrichous display of vesicles and vesicle chains, and increased abundance in biofilms compared with planktonic cultures. By applying a range of imaging techniques, including three‐dimensional (3D) focused ion beam scanning electron microscopy, we determined these structures to range between 30 and 60 nm in width and up to 5 μm in length. Purified vesicle chains consist of typical M. xanthus lipids, fucose, mannose, N‐acetylglucosamine and N‐acetylgalactoseamine carbohydrates and a small set of cargo protein. The protein content includes CglB and Tgl outer membrane proteins known to be transferable between cells in a contact‐dependent manner. Most significantly, the 3D organization of cells within biofilms indicates that cells are connected via an extensive network of membrane extensions that may connect cells at the level of the periplasmic space. Such a network would allow the transfer of membrane proteins and other molecules between cells, and therefore could provide a mechanism for the coordination of social activities.
Identification of an osmo‐dependent and an osmo‐independent choline transporter in Acinetobacter baylyi: implications in osmostress protection and metabolic adaptation
Authors: Sand Miriam , Stahl Julia , Waclawska Izabela , Ziegler Christine , Averhoff Beate
Published: June 2013

Members of the genus Acinetobacter are well known for their metabolic versatility that allows them to adapt to different ecological niches. In previous studies, we have demonstrated that Acinetobacter baylyi ADP1 can cope with high salinities by uptake and accumulation of the well‐known compatible solute glycine betaine. Here, we demonstrate that addition of choline restores growth at high salinities. We further show that choline was actively taken up by the cells and converted to glycine betaine. Uptake of choline was induced by high salinity and the presence of choline in the growth medium. At high salinities, glycine betaine was accumulated in the cells whereas in the absence of osmotic stress it was exported. Inspection of the genome sequence followed by mutant studies led to the identification of two genes encoding secondary transporters (BetT1 and BetT2) of the betaine‐choline‐carnitine transporter (BCCT) family. The BetT1 transporter lacks an extended C‐terminal domain usually found in osmoregulated choline BCCTs. BetT1 was found to facilitate osmolarity‐independent choline transport most likely by a uniport mechanism. We propose that BetT1 does not primarily function in osmoadaptation but might play a role in metabolic adaptation to choline‐rich environments.
Rural and Regional Policy: A Case of Punctuated Incrementalism?
Authors: Cockfield Geoff , Botterill Linda Courtenay
Published: June 2013

The rural policy environment has many of the conditions that might suggest a tendency towards punctuated equilibrium. The Commonwealth has little direct power over rural space and industries, there has been a long tradition of state support for agriculture and decision‐making has generally been kept within a tight policy community, dominated by rural interests. In our review of the PAP data and policy history, we find instead an underlying movement across time and governments towards an expectation of self‐reliance for rural businesses and communities. On top of the long‐term incremental movement towards this expectation, issue attention has shifted according to political, climatological and market conditions, rather than necessarily in line with changes in policy content.
Foreign and Defence Policy on Australia's Political Agenda, 1962–2012
Authors: McDonald Matt
Published: June 2013

This paper explores the content of the Australian foreign and defence policy agenda over the past 50 years, finding evidence of both continuity and change. Australian political leaders have generally committed to cooperation with international institutions, wealth creation through engagement with Asian economies in particular, and security through the American alliance. In this period, changes in foreign policy approach either concerned marginal issues or were driven significantly by exogenous factors: by changes in the international environment or by global events that propelled a reconsideration of Australian foreign and defence policy interests. However, periods of policy change and significant public attention in – particular around the Vietnam and Iraq wars – illustrate the continued relevance of political choices and agency. Both conflicts and debates around them ushered in changing foreign and defence policy considerations, and both raised fundamental questions about Australian security and independence in the context of the American alliance.
Factors that Determine the Decline in University Student Enrolments in Economics in Australia: An Empirical Investigation
Authors: Marangos John , Fourmouzi Vasiliki , Koukouritakis Minoas
Published: June 2013

This study attempts to determine empirically the factors that influence enrolments in economics and business based on data from a panel of Australian universities. Using a two‐equation dynamic reduced‐form system, our results indicate the following: past year enrolments in a certain field of study have the highest impact on that field of study; in periods of recession enrolments favour economics; female enrolments favour business studies over economics; an increase in total enrolments has a small negative effect on economics enrolments; and finally, there is a positive impact of the eight leading Australian universities (‘Group of Eight’) on economics enrolments.
Estimating network economies in retail chains: a revealed preference approach
Authors: Ellickson Paul B. , Houghton Stephanie , Timmins Christopher
Published: June 2013

We measure the effects of chain economies, business stealing, and heterogeneous firms’ comparative advantages in the discount retail industry. Traditional entry models are ill suited for this high‐dimensional problem of strategic interaction. Building upon recently developed profit inequality techniques, our model admits any number of potential rivals and stores per location, an endogenous distribution network, and unobserved (to the econometrician) location attributes that may cause firms to cluster their stores. In an application, we find that Wal‐Mart benefits most from local chain economies, whereas Target shows a greater ability to respond to rival competition. Kmart exhibits neither of these strengths. We explore these results with counterfactual simulations highlighting these offsetting effects and find that local chain economies play an important role in securing Wal‐Mart's industry leader status.
Patent quality and incentives at the patent office
Authors: Schuett Florian
Published: June 2013

Patent examination is a problem of moral hazard followed by adverse selection: examiners must have incentives to exert effort, but also to truthfully reveal the evidence they find. I develop a theoretical model to study the design of incentives for examiners. The model can explain the puzzling compensation scheme in use at the U.S. patent office, where examiners are essentially rewarded for granting patents, as well as the variation in compensation schemes and patent quality across patent offices. It also has implications for the retention of examiners and for administrative patent review.
Multidimensional heterogeneity and the economic importance of risk and matching: evidence from contractual data and field experiments
Authors: Bellemare Charles , Shearer Bruce
Published: June 2013

We measure the cost of risk and the benefits of matching heterogeneous workers to risk levels within a firm that pays its workers piece rates. The workers of this firm are heterogeneous in two dimensions: risk preferences and ability. Our results suggest that workers’ willingness to pay to avoid risk is heterogeneous. It can attain 40% of their expected net earnings but averages to only 1%. Moreover, the benefits to the firm of matching are relatively small: profits are predicted to increase by only 2.3%, 4% if we restrict attention to cases where matching is possible. Although labor‐market sorting contributes to this result (the workers in this firm are relatively risk tolerant), it is not the primary cause. More important is the relative homogeneity of risk conditions in this firm that give rise to limited opportunities for matching.
Changes in richness and abundance of rodents and native predators in response to extreme rainfall in arid Australia
Authors: Pavey Chris R. , Nano Catherine E. M.
Published: June 2013

The dramatic spatial and temporal variation in rainfall and the resource pulses which these trigger provide a challenge for predicting consumer‐primary productivity dynamics especially in arid systems. In particular, understanding is needed of the degree to which boom‐bust dynamics drive arid systems. Here, we assess the response of birds (diurnal raptors, nocturnal rodent‐specialist raptors) and rodents to a resource pulse in the western Simpson Desert across a 43‐month study period that finished in May 2011. Three rainfall pulses in rapid succession from February 2010 to March 2011 underpinned a ‘big rain’ event. Rodent populations irrupted within 6–9 months of the first of the three rainfall pulses (in February 2010). Two rodent‐specialist raptors; the letter‐winged kite, Elanus scriptus, and eastern barn owl, Tyto javanica, appeared in the area within 6–9 months of the start of the rodent irruption. By comparison with the rodents, barn owl and letter‐winged kite, diurnal raptors responded rapidly to the February 2010 rainfall event. When comparing surveys carried out the week prior to the February rainfall event with May 2010, raptor richness increased from two to six species and the index of abundance, measured as mean sightings per km, increased from 0.07 to 1.34. These findings emphasize that the 2010–2011 resource pulse was an ecologically significant event. Our results confirmed the link between big rains and rodent irruptions but they also highlighted the occurrence of finer‐scale temporal fluctuations that are less easily accounted for by rainfall patterning.
Cutaneous Crohn's disease treated with infliximab and 4 years of follow up
Authors: Yoong Corinne , Schofield Clare , Rodins Karl , Faulkner Catherine
Published: June 2013

Metastatic Crohn's disease (MCD) is a rare, non‐contiguous cutaneous manifestation of Crohn's disease. To date, there have been only four reports in the literature of an effective treatment of this condition with infliximab and there are no long‐term follow‐up studies on adult MCD patients treated with infliximab. We present a case of MCD treated with infliximab with 4.5 years of follow up.
Evaluation of pattern ERG as a visual prognosticator in chiasmatic tumours
Authors: Goyal Jawahar L , Thangkhiew Lanalyn , Yadava Usha , Arora Ritu , Jain Parul
Published: June 2013

Background

Tumours compressing the optic pathway may lead to irreversible loss of vision that can be detected by pattern electroretinogram owing to its relation to ganglion cell function. This study aims to assess whether pattern electroretinogram is a useful tool to predict visual outcome following decompressive surgery for sellar and parasellar tumours.

Design

Prospective, non‐randomized study.

Participants

Forty eyes of 20 patients with radiologically confirmed tumours in and around the sellar region.

Methods

Patients were followed for 6 weeks following surgical intervention (transphenoidal or transfrontal approach).

Main Outcome Measures

Best‐corrected visual acuity, visual fields (Humphrey 30‐2 standard automated perimetry) and pattern electroretinogram. The ratio N95/P50 (N2/P1) was calculated for each recording.

Results

There was improvement in visual fields in 35.4% eyes with normal n2/p1 ratio (>1.1) as compared to 22.2% with abnormal ratio. Also, 9.6% eyes with normal ratio and 11.1% with an abnormal ratio deteriorated postoperatively. No association was found between pattern electroretinogram and visual fields preoperatively and postoperatively (P = 0.093).

Conclusions

Pattern electroretinogram may not be a useful prognostic indicator in the preoperative assessment of tumours causing chiasmal compression. An abnormal N2/P1 ratio is not necessarily associated with lesser or no clinical improvement following surgery as compared to an eye with a normal pattern electroretinogram.
Uveitis in human immunodeficiency virus‐infected persons with CD4+ T‐lymphocyte count over 200 cells/mL
Authors: Rose‐Nussbaumer Jennifer , Goldstein Debra A , Thorne Jennifer E , Arantes Tiago E , Acharya Nisha R , Shakoor Akbar , Jeng Bennie H , Yeh Steven , Rahman Hassan , Vemulakonda G Atma , Flaxel Christina J , West Sarah K , Holland Gary N , Smith Justine R
Published: June 2013

Background

Introduction of highly active antiretroviral therapy has altered the course of disease for persons infected with human immunodeficiency virus by elevating CD4+ T‐lymphocyte levels. Changes in the spectrum of systemic diseases encountered in human immunodeficiency virus‐positive individuals are reported in the general medical literature.

Design

Retrospective case series.

Participants

Sixty‐one individuals infected with human immunodeficiency virus, who presented with uveitis when the peripheral CD4+ T‐lymphocyte count was over 200 cells/μL.

Methods

Standardized data collection at seven tertiary‐referral inflammatory eye disease clinics.

Main Outcome Measures

Standardization of Uveitis Nomenclature anatomic classification and descriptors, cause of uveitis, and visual acuity

Results

Peripheral CD4+ T cell counts varied between 207 and 1777 (median = 421) cells/μL at the time of diagnosis of uveitis. Uveitis was classified anatomically as anterior (47.5%), intermediate (6.6%), anterior/intermediate (16.4%), posterior (14.8%) and pan (14.8%). Specific causes of uveitis included infections (34.4%), with syphilis responsible for 16.4% of all cases, and defined immunological disorders (27.0%); no cause for the inflammation was identified in 34.4% of persons. Visual acuity was better than 6/15 in 66.7% and 6/60 or worse in 11.8% of 93 eyes at presentation, and better than 6/15 in 82.4% and 6/60 or worse in 8.8% of 34 eyes at 1 year of follow‐up.

Conclusions

Both infectious and non‐infectious forms of uveitis occur in individuals who are infected with human immunodeficiency virus and have preserved or restored peripheral CD4+ T cell levels. Individuals who are human immunodeficiency virus‐positive and present with uveitis should be evaluated in the same way all patients with uveitis are assessed.
Correlation between decreased choroidal blood flow velocity and the pathogenesis of acute zonal occult outer retinopathy
Authors: Saito Michiyuki , Saito Wataru , Hashimoto Yuki , Yoshizawa Chikako , Shinmei Yasuhiro , Noda Kousuke , Ishida Susumu
Published: June 2013

Background

To evaluate changes of choroidal circulation quantitatively using laser speckle flowgraphy in patients with acute zonal occult outer retinopathy.

Design

Retrospective observational case series.

Participants

Sixteen eyes of 11 acute zonal occult outer retinopathy patients: seven non‐treated eyes with good visual acuity and nine systemic corticosteroid‐treated eyes with progressive visual acuity loss. Six eyes with thyroid‐associated ophthalmopathy receiving systemic corticosteroid therapy served as controls.

Methods

The mean blur rate, an index of quantitative relative blood flow velocity, in the affected area was measured by laser speckle flowgraphy. The changes of mean blur rate, best‐corrected visual acuity and the average threshold at the affected area on Humphrey perimetry during 24‐week follow up were analysed.

Main Outcome Measures

Mean blur rate, best‐corrected visual acuity, and the average threshold.

Results

In non‐treated eyes, the average mean blur rate significantly increased at 24 weeks, with a significant increase of the average threshold. In corticosteroid‐treated eyes, the mean blur rates at 1, 4, 12 and 24 weeks were significantly higher than the pretreatment value, with significant improvement of best‐corrected visual acuity and the average threshold. The increase in mean blur rate at 4 weeks in corticosteroid‐treated acute zonal occult outer retinopathy eyes was significantly higher than that in corticosteroid‐treated control eyes.

Conclusions

In eyes with acute zonal occult outer retinopathy, the mean blur rate at the affected area significantly increases along with improvement of visual functions. These results suggest that impaired choroidal circulation is involved in the pathogenesis of acute zonal occult outer retinopathy.
Neighborhood Access to Transit by Race, Ethnicity, and Poverty in Portland, OR
Authors: McKenzie Brian S.
Published: June 2013

Scholarly discussions of accessibility and spatial mismatch largely ignore transit's role in linking vulnerable populations to opportunity. Yet as the nation's low–income population has become more suburban in recent decades, transit access may become an increasingly valuable, yet scarcer link to opportunity for those with the fewest resources and housing options. This study explores differences in transit access for neighborhoods with high concentrations of heavy transit users. Using data from the 2000 Census and the 5–year 2005–2009 ACS, it compares changes in transit access levels across neighborhoods with high concentrations of blacks, Latinos, and the poor in Portland, OR. Results show that Portland's neighborhoods of Latino concentration had the poorest relative access to transit. Further, levels of transit access declined for neighborhoods of black and Latino concentration during the study period.
Primary esophageal mucosa‐associated lymphoid tissue lymphoma treated by endoscopic submucosal dissection
Authors: Kudo Kenji , Ota Masaho , Narumiya Kosuke , Shirai Yuji , Ohki Takeshi , Yamamoto Masakazu
Published: June 2013

Primary esophageal mucosa‐associated lymphoid tissue (MALT) lymphoma is rare. There have been few reports about early primary esophageal MALT lymphoma being treated endoscopically. The clinical profile of primary esophageal MALT lymphoma is currently unclear, so it is important to accumulate more information about early esophageal MALT lymphoma. To achieve early detection of esophageal MALT lymphoma, we need more accurate knowledge and information about the macroscopic and morphological features of this tumor. Endoscopic resection is one of the most effective treatments. With respect to the lateral andvertical margins of the resected specimen, endoscopic submucosal dissection (ESD) may be superior to endoscopic mucosal resection for treating early esophageal MALT lymphoma. Here we report the macroscopic appearance of the tumor which is the first successful case of ESD for early esophageal MALT lymphoma.
Emergence, dispersal, and mate finding via a substrate‐borne sex pheromone in the parasitoid Metaphycus luteolus
Authors: Kapranas Apostolos , Giudice Daniela Lo , Peri Ezio , Millar Jocelyn G. , Colazza Stefano
Published: June 2013

Metaphycus luteolus Timberlake (Hymenoptera: Encyrtidae) is a facultatively gregarious parasitoid of soft scale insects. We conducted behavioral experiments to better understand the mating structure of this species. Emergence of male and female offspring is synchronized, beginning at the onset of photoperiod. Both sexes are able to disperse, although dispersal of males from natal patches appears to take longer than dispersal of females. We demonstrated the presence of a female‐produced contact pheromone using open arena bioassays and motion tracking software, testing residues deposited by walking females, and extracts of females. Males responded to the females' ‘chemical footprints’ and to acetone and hexane extracts of females by searching and arrestment on the chemical residues. Responses of males were dose dependent and diminished with time since the stimulus was deposited. Our findings support the hypothesis that non‐local mating among wasps emerging from different hosts may be quite common in these parasitoids. The implications of our results for the mating structure and previously documented sex ratio patterns of these parasitoids are described.