bluuebunny/crossref_metadata_2025 huggingface dataset:
Virus infection triggers widespread silencing of host genes by a distinct class of endogenous siRNAs in
Arabidopsis
Authors: Cao Mengji , Du Peng , Wang Xianbing , Yu Yun-Qi , Qiu Yan-Hong , Li Wanxiang , Gal-On Amit , Zhou Changyong , Li Yi , Ding Shou-Wei
Published: September 2014

Significance

RNAi-mediated antiviral immunity directs specific virus resistance by virus-derived siRNAs in contrast to broad-spectrum resistance triggered in innate immunity by host pattern recognition receptors. Here we show that induction of antiviral RNAi in
Arabidopsis
is associated with production of a genetically distinct class of virus-activated siRNAs (vasiRNAs) by RNA-dependent RNA polymerase-1 to target hundreds of host genes for RNA silencing by Argonaute-2. Production of vasiRNAs is induced by viruses from two different supergroups of RNA virus families, targeted for inhibition by Cucumber mosaic virus, and correlated with virus resistance independently of viral siRNAs. We propose that antiviral RNAi activates broad-spectrum antiviral activity via widespread silencing of host genes directed by vasiRNAs in addition to specific antiviral defense by viral siRNAs.
A family of starch-active polysaccharide monooxygenases
Authors: Vu Van V. , Beeson William T. , Span Elise A. , Farquhar Erik R. , Marletta Michael A.
Published: September 2014

Significance

Polysaccharide monooxygenases (PMOs) are recently discovered extracellular fungal and bacterial enzymes that are able to cleave the recalcitrant polysaccharides cellulose and chitin. We describe the discovery of a new family of fungal PMOs that act on starch based on bioinformatic, biochemical, and spectroscopic studies on NCU8746, a representative starch-active PMO from
Neurospora crassa
. The data support a proposed enzymatic mechanism and show that NCU08746 shares evolutionarily conserved features with previously reported PMOs. This discovery extends the currently known PMO family, suggesting the existence of a PMO superfamily with a much broader range of substrates. Starch-active PMOs provide an expanded perspective on studies of starch metabolism and may have potential in the food and starch-based biofuel industries.
Resistance of the boreal forest to high burn rates
Authors: Héon Jessie , Arseneault Dominique , Parisien Marc-André
Published: September 2014

Significance

Climate change is expected to drastically increase both fire size and the frequency of large-fire years in the North American boreal forest, with consequent effects on forest ecosystems and carbon stocks. However, the influence of fire size and time since previous fire on fire activity is poorly understood because of incomplete records of past fire overlaps. Here we reconstruct the length of overlapping fires during the last 200 years along a 190-km transect and provide direct field evidence that extreme burn rates can be sustained by occasional droughts triggering immense fires. Fire occurrence in the most fire-prone regions of the North American boreal forest is, however, already fuel-limited and will resist further climate change because of overabundant young forest stands.
Structural adaptations to diverse fighting styles in sexually selected weapons
Authors: McCullough Erin L. , Tobalske Bret W. , Emlen Douglas J.
Published: September 2014

Significance

Animal weapons are among nature’s most diverse structures. Intuitively, species have different types of weapons because they fight in different ways, yet no studies have directly tested whether weapons perform better at the animals’ own style of fighting than they do at others. We constructed biomechanical models of the horns of different rhinoceros beetle species to evaluate the functional performance of horns in response to both species-typical and species-atypical fighting loads. We found that horns are both stronger and stiffer in response to species-typical fighting loads, which suggests selection for improved performance under different fighting styles played an important role in the diversification of weapon form.
Reforestation as a novel abatement and compliance measure for ground-level ozone
Authors: Kroeger Timm , Escobedo Francisco J. , Hernandez José L. , Varela Sebastián , Delphin Sonia , Fisher Jonathan R. B. , Waldron Janice
Published: September 2014

Significance

Despite often decadeslong control efforts, in many regions of the world ambient concentrations of ground-level ozone threaten human and ecosystem health. Furthermore, in many places the effects of continuing land use and climate change are expected to counteract ongoing efforts to reduce ozone concentrations. Combined with the rising cost of more stringent conventional technological ozone controls, this creates a need to explore novel approaches to reducing tropospheric ozone pollution. Reforestation of peri-urban areas, which removes ozone and one of its precursors, may be a cost-effective approach to ozone control and can produce important ancillary benefits. We identify key criteria for maximizing the ozone abatement and cost effectiveness of such reforestation and the substantial potential for its application in the United States.
Activation of transcription and retrotransposition of a novel retroelement,
Steamer
, in neoplastic hemocytes of the mollusk
Mya arenaria
Authors: Arriagada Gloria , Metzger Michael J. , Muttray Annette F. , Sherry James , Reinisch Carol , Street Craig , Lipkin W. Ian , Goff Stephen P.
Published: September 2014

Significance

The soft shell clam in many areas of the North Atlantic is afflicted with a fatal leukemia-like disease of unknown origin. Leukemic cells from the diseased animals were found to release reverse transcriptase and to express high RNA levels of a previously unknown member of the gypsy family of retroelements,
Steamer
. The DNA copy number of the element was increased to enormously high levels in diseased cells, mediated by reverse transcription and integration into the host genome. The activation of
Steamer
expression and transposition may initiate or accelerate the course of leukemia and constitutes a potential diagnostic marker of the disease.
Involvement of the host DNA-repair enzyme TDP2 in formation of the covalently closed circular DNA persistence reservoir of hepatitis B viruses
Authors: Königer Christian , Wingert Ida , Marsmann Moritz , Rösler Christine , Beck Jürgen , Nassal Michael
Published: September 2014

Significance

Chronic hepatitis B virus (HBV) infection puts >250 million humans at risk for developing liver cirrhosis and liver cancer. Current therapies are not curative because they do not target HBV´s persistence reservoir, the plasmid-like covalently closed circular DNA (cccDNA). RNA production from cccDNA initiates the generation of progeny virus via protein-primed reverse transcription, yielding viral polymerase-linked relaxed-circular DNA (RC-DNA). Its conversion, upon infection, into cccDNA requires multiple poorly understood steps, including polymerase removal. We found that the host enzyme tyrosyl-DNA-phosphodiesterase 2 (TDP2), important for repair of cellular protein–DNA adducts, performed this step in vitro and that TDP2 depletion impaired the conversion of RC-DNA to cccDNA in cells. These data establish a functional link between HBV and cellular DNA repair and pave the way for targeting HBV persistence.
Role of cavities and hydration in the pressure unfolding of T4lysozyme
Authors: Nucci Nathaniel V. , Fuglestad Brian , Athanasoula Evangelia A. , Wand A. Joshua
Published: September 2014

Significance

Pressure unfolding of proteins is a fundamental aspect of their thermodynamic response, the origins of which remain controversial. Here, we use high-pressure solution NMR to investigate the pressure response of a model protein, T4 lysozyme, under various conditions. Our data resolve longstanding controversies regarding the pressure response of this protein and the hydration of the internal hydrophobic cavity. It is shown that local packing (cavities) and the availability of conformational space have important and nonlocal impacts on the protein pressure response. Overall, the findings presented here reveal a previously unappreciated complexity in the pressure response of protein structure.
Phosphatidylethanolamine deficiency disrupts α-synuclein homeostasis in yeast and worm models of Parkinson disease
Authors: Wang Shaoxiao , Zhang Siyuan , Liou Liang-Chun , Ren Qun , Zhang Zhaojie , Caldwell Guy A. , Caldwell Kim A. , Witt Stephan N.
Published: September 2014

Significance

We tested the hypothesis that a form of mitochondrial dysfunction alters the homeostasis of the cytosolic Parkinson disease (PD)-associated protein α-synuclein (α-syn). Using yeast and worm models of PD, we show that low levels of phosphatidylethanolamine (PE), caused by the depletion of mitochondrial phosphatidylserine decarboxylase (psd), lead to decreased respiration, endoplasmic reticulum (ER) stress, high levels of α-syn and cytoplasmic α-syn foci, and slow growth. Ethanolamine, which replenishes PE through the Kennedy pathway, diminished ER stress, decreased the level of α-syn, eliminated foci, and restored growth of
psd1
Δ cells to near wild-type levels. A low level of mitochondrial PE disrupts the homeostasis of α-syn and leads to the accumulation of cytoplasmic foci of this protein.
Molecular basis for the recognition of methylated adenines in RNA by the eukaryotic YTH domain
Authors: Luo Shukun , Tong Liang
Published: September 2014

Significance

Methylation of the N6 position of selected internal adenines (m
6
A) in mRNAs and noncoding RNAs is widespread in eukaryotes, and the YTH domain in a collection of proteins recognizes this modification. We report the crystal structure of the splicing factor YT521-B homology (YTH) domain of
Zygosaccharomyces rouxii
methylated RNA-binding protein 1 in complex with a heptaribonucleotide with an m
6
A residue in the center. The m
6
A modification is recognized by an aromatic cage, and there are also interactions with other regions of the RNA. Mutations in the RNA binding site can abolish the formation of the complex. Overall, our structural and biochemical studies have defined the molecular basis for how the YTH domain functions as a reader of methylated adenines.
Genetic, anatomic, and clinical determinants of human serum sterol and vitamin D levels
Authors: Stiles Ashlee R. , Kozlitina Julia , Thompson Bonne M. , McDonald Jeffrey G. , King Kevin S. , Russell David W.
Published: September 2014

Significance

Cholesterol is the major sterol in blood and in excess causes cardiovascular disease. In addition to cholesterol, numerous other sterols of unknown function and pathogenicity circulate in the bloodstream. Here, we use chemical methods to screen for over 60 different sterols and sterol derivatives in the sera of 3,230 clinically well-characterized individuals. Twenty-seven sterols and two sterol derivatives (vitamin D
2
and D
3
) were routinely detected in vastly different amounts in a majority of individuals. Genes, ethnicity, gender, age, clinical phenotype, and anatomy were identified as significant sources of interindividual variation in these lipid metabolites.
Substratum-induced differentiation of human pluripotent stem cells reveals the coactivator YAP is a potent regulator of neuronal specification
Authors: Musah Samira , Wrighton Paul J. , Zaltsman Yefim , Zhong Xiaofen , Zorn Stefan , Parlato Matthew B. , Hsiao Cheston , Palecek Sean P. , Chang Qiang , Murphy William L. , Kiessling Laura L.
Published: September 2014

Significance

Human pluripotent stem (hPS) cells can self-renew indefinitely and differentiate into almost any cell type. Thus, hPS cells represent a potentially unlimited supply of cells for regenerative medicine, drug screening, and developmental studies. Realizing the full potential of hPS cells requires efficient protocols to direct their differentiation into desired cell types. Most efforts to control hPS cell differentiation have focused on soluble signaling factors, while the roles of insoluble signals, such as the mechanical properties of the ECM, have been less explored. We show that matrix mechanics alone can robustly induce neuronal differentiation of hPS cells, independent of soluble neurogenic factors. These results can guide the design of materials to influence stem cell fate.
Johan Hjort's impact on fisheries science: a bibliometric analysis
Authors: Aksnes Dag W. , Browman Howard I.
Published: September 2014

We analyse how Johan Hjort's publication, “Fluctuations in the great fisheries of northern Europe, viewed in the light of biological research” (Hjort, 1914), has been cited in the subsequent scientific literature. In the context of this special issue commemorating the 100th anniversary of Hjort's seminal publication, our objective is to provide insights into how his work has penetrated the literature and influenced the development of fishery science. We also tracked Hjort's related article, “Fluctuations in the year classes of important food fishes” (Hjort, 1926). We present the citation life cycles of these articles and analyse various characteristics of the publications that cite them. The importance of Hjort (1914) is reflected in the large number of citations that it has accrued (908), and by the 40–50 citations that it continues to receive every year. This is exceptional for a 100-year-old scientific article, in any field. Hjort (1926) initially received as many cites as Hjort (1914), but the latter subsequently became the paradigmatic article. Hjort (1914) has been cited in 162 different journals and by scientists in 53 countries—Hjort's work has had a broad and global impact on fisheries research. The contextual analysis demonstrated that Hjort (1914) is considered a seminal, novel, and paradigm setting study—the core research questions addressed by Hjort (1914) remain unsolved and several of his hypotheses continue to drive fisheries science to this day.
Evaluating a Posterior Approach for Surgical Treatment of Thoracolumbar Pseudarthrosis in Ankylosing Spondylitis
Authors: Wang Ting , Wang Dechun , Cong Yanan , Yin Chuqiang , Li Shuzhong , Chen Xiaoliang
Published: September 2014

Study Design:

Retrospective study of a posterior approach for surgical treatment of thoracolumbar pseudarthrosis in ankylosing spondylitis (AS).

Objective:

The aim of the current study was to report the surgical results of symptomatic thoracolumbar pseudarthrosis in AS through a posterior approach.

Summary of Background Data:

Spinal pseudarthrosis is a well-known complication in AS. The condition may complicate with mechanical back pain, spinal deformity, and sometimes neurological deficits. Conservative treatment often fails in this situation and surgical treatment is required. However, the optimal surgical procedure for this condition is still controversial.

Methods:

From January 2006 to December 2011, 12 AS patients with spinal pseudarthrosis at the thoracolumbar segment were treated surgically after failure of >3 months conservative treatment. The indications for surgery were persisting back pain in all patients, combined with neurological deficits in 4 patients and spinal deformities in 3 patients. Transforaminal or transpedicular debridement of the pseudarthrosis at the anterior column was performed from a posterior approach. After complete debridement, bone graft at the anterior open wedge defect of the pseudarthrosis was performed from a posterior approach. Posterior pedicle screws were placed for fixation. Clinical and radiographic outcomes were assessed with an average follow-up of 28 months (range, 24–36 mo).

Results:

The persistent back pain obtained significant relief in all cases after surgery. Four patients with neurological deficits showed complete recovery of neurological function at follow-up. The spinal deformities in 3 cases obtained correction. Solid bony fusion was achieved in all cases, and there was no correction loss at follow-up.

Conclusions:

In AS with symptomatic thoracolumbar pseudarthrosis, a posterior transforaminal or transpedicular approach can provide circumferential stability, anterior bone graft, and neurological decompression simultaneously. A supplemental anterior approach may be avoided by this method.
Low n‐3 Long‐Chain Polyunsaturated Fatty Acids in Newly Diagnosed Celiac Disease in Children With Preexisting Type 1 Diabetes Mellitus
Authors: Tárnok András , Marosvölgyi Tamás , Szabó Éva , Györei Eszter , Decsi Tamás
Published: September 2014

Objective:

Fat malabsorption can occur in celiac disease (CD) owing to villus atrophy and inflammation of small intestinal mucosa. Abnormal fatty acid (FA) status of intestinal mucosa in children with CD was reported earlier. Previously we found significantly reduced availability of n‐3 long‐chain polyunsaturated fatty acids (n‐3 LCPUFA) in children and young adults with type 1 diabetes mellitus (DM). The aim of this study was to investigate FAs in plasma lipid classes in children with newly diagnosed CD with or without preexisting DM.

Methods:

FA composition of plasma samples of children with untreated CD only (n = 20) and with preexisting DM (CDDM, n = 8) were compared with those of healthy controls (n = 21). Detailed analysis of phospholipid, triacylglycerol, and sterol ester FAs was performed by high‐resolution capillary gas–liquid chromatography.

Results:

Significantly decreased docosapentaenoic (C22:5n‐3), docosahexaenoic (C22:6n‐3), n‐3 polyunsaturated fatty acids (n‐3 PUFA), and n‐3 LCPUFA values were found in CDDM group compared with controls and patients with CD. When compared with healthy controls, no significant difference was found in plasma FAs of children with newly diagnosed CD only.

Conclusions:

Children with CDDM showed marked signs of reduced availability of n‐3 PUFA and n‐3 LCPUFA in circulating lipids. Although different tissues express membrane FAs differently, our present study suggests that CD on its own does not necessarily lead to detectable disturbances of essential FA metabolism in plasma and supports the concept that DM has significant impact on plasma FA composition in children.
Why is it so easy to underestimate systematic errors when measuring
G
?
Authors: Bartlett D. F.
Published: September 2014

Before this Theo Murphy Meeting, my working hypothesis was that human activity during the measurement of
G
significantly affects the measurement itself. Noise caused by the gravity gradient of humans was indeed the reason why in one experiment the apparatus was raised 3 m above the floor. The meeting convinced me that all experimenters took adequate precautions against gravity gradients caused by human activity. During the meeting, another concern arose: was the cycle time between two states of the experiment so long that the environment changed significantly in the meantime? Once again, it appears that the experimenters were appropriately cautious. After the meeting, it became clear that ageing effects in thin, stressed wires could be an issue. I conclude with a speculation about a future ‘atomic’ value of
G
.
The attracting masses in measurements of
G
: an overview of physical characteristics and performance
Authors: Gillies G. T. , Unnikrishnan C. S.
Published: September 2014

Simple spheres and cylinders have been the geometries employed most frequently, but not uniquely, for the attracting masses used historically in measurements of the Newtonian gravitational constant
G
. We present a brief overview of the range of sizes, materials and configurations of the attracting masses found in several representative experimental arrangements. As one particular case in point, we present details of the large tungsten spheres designed originally by Beams, which have been incorporated into several different apparatuses for measuring
G
over the past 50 years. We also consider the question of possible systematic dependence of the results and their precision on the size of the large masses/mass systems that have been employed to date. We close with some considerations for possible future work.
Measuring the Newtonian constant of gravitation
G
with an atomic interferometer
Authors: Prevedelli M. , Cacciapuoti L. , Rosi G. , Sorrentino F. , Tino G. M.
Published: September 2014

We have recently completed a measurement of the Newtonian constant of gravitation
G
using atomic interferometry. Our result is
G
=6.67191(77)(62)×10
−11
 m
3
 kg
−1
 s
−2
where the numbers in parenthesis are the type A and type B standard uncertainties, respectively. An evaluation of the measurement uncertainty is presented and the perspectives for improvement are discussed. Our result is approaching the precision of experiments based on macroscopic sensing masses showing that the next generation of atomic gradiometers could reach a total relative uncertainty in the 10 parts per million range.
G
measurements with time-of-swing method at HUST
Authors: Li Qing , Liu Jian-Ping , Zhao Hui-Hui , Yang Shan-Qing , Tu Liang-Cheng , Liu Qi , Shao Cheng-Gang , Hu Zhong-Kun , Milyukov Vadim , Luo Jun
Published: September 2014

We review the
G
measurements with time-of-swing method at HUST. Two independent experiments have been completed and an improved experiment is in progress. The first
G
value was determined as 6.6699(7)×10
−11
 m
3
 kg
−1
 s
−2
with a relative standard uncertainty (
u
r
) of 105 ppm by using a long period torsion pendulum and two cylindrical source masses. Later, this result was corrected to be 6.6723(9)×10
−11
 m
3
 kg
−1
 s
−2
with
u
r
=130 ppm after considering the density distribution of the cylinders and the air buoyancy, which was 360 ppm larger than the previous value. In 2009, a new experiment by using a simple block pendulum and spherical source masses with more homogeneous density was carried out. A series of improvements were performed, and the
G
value was determined to be 6.67349(18)×10
−11
 m
3
 kg
−1
 s
−2
with
u
r
=26 ppm. To reduce the anelasticity of the torsion fibre, fused silica fibres with
Q
's of approximately 5×10
4
are used to measure
G
in the ongoing experiment. These fibres are coated with thin layers of germanium and bismuth in turn to reduce the electrostatic effect. Some other improvements include the gravity compensation, reduction of the coating layer effect, etc. The prospective uncertainty of the next
G
value is 20 ppm or lower.
Colwellia aquaemaris sp. nov., isolated from the Cynoglossus semilaevis culture tank in a recirculating mariculture system
Authors: Liu Ying , Liu Liang-Zi , Zhong Zhi-Ping , Zhou Yu-Guang , Liu Ying , Liu Zhi-Pei
Published: September 2014

A Gram-staining-negative, heterotrophic, facultatively anaerobic bacterium, designated S1T, was isolated from the Cynoglossus semilaevis culture pond in a recirculating mariculture system in Tianjin, China. The taxonomy of strain S1T was studied by using a polyphasic approach. Cells of strain S1T were non-spore-forming, curved rods, 0.4–0.6 µm wide and 1.2–2.0 µm long, and motile by means of a single polar flagellum. The strain was positive for oxidase and catalase activities. Strain S1T was able to grow at 4–30 °C (optimum, 25 °C), at pH 5.5–10.0 (optimum, pH 6.5–7.5) and in the presence of 1–5 % (w/v) NaCl (optimum, 2 %). Strain S1T contained Q-8 as the sole respiratory quinone and C16 : 1ω7c/C16 : 1ω6c and C16 : 0 as the predominant cellular fatty acids. The genomic DNA G+C content was 40.1 mol% (T
m). Phylogenetic analysis based on 16S rRNA gene sequences placed strain S1T in the genus

Colwellia

, and it formed a distinct lineage in the phylogenetic tree together with

Colwellia meonggei

MA1-3T,

Colwellia aestuarii

SMK-10T,

Colwellia polaris

537T and

Colwellia chukchiensis

BCw111T, with 97.7, 96.1, 95.9 and 95.0 % 16S rRNA gene sequence similarity to these strains, respectively. DNA–DNA relatedness of strain S1T to

Colwellia meonggei

MA1-3T was 23.5±3.6 %. On the basis of the phylogenetic and phenotypic evidence, strain S1T is considered to represent a novel species of the genus

Colwellia

, for which the name Colwellia aquaemaris sp. nov. is proposed. The type strain is S1T ( = CGMCC 1.12165T = JCM 18479T).
Evolutionary Conserved Function of Barley and Arabidopsis 3-KETOACYL-CoA SYNTHASES in Providing Wax Signals for Germination of Powdery Mildew Fungi
Authors: Weidenbach Denise , Jansen Marcus , Franke Rochus B. , Hensel Goetz , Weissgerber Wiebke , Ulferts Sylvia , Jansen Irina , Schreiber Lukas , Korzun Viktor , Pontzen Rolf , Kumlehn Jochen , Pillen Klaus , Schaffrath Ulrich
Published: September 2014

For plant pathogenic fungi, such as powdery mildews, that survive only on a limited number of host plant species, it is a matter of vital importance that their spores sense that they landed on the right spot to initiate germination as quickly as possible. We investigated a barley (Hordeum vulgare) mutant with reduced epicuticular leaf waxes on which spores of adapted and nonadapted powdery mildew fungi showed reduced germination. The barley gene responsible for the mutant wax phenotype was cloned in a forward genetic screen and identified to encode a 3-KETOACYL-CoA SYNTHASE (HvKCS6), a protein participating in fatty acid elongation and required for synthesis of epicuticular waxes. Gas chromatography-mass spectrometry analysis revealed that the mutant has significantly fewer aliphatic wax constituents with a chain length above C-24. Complementation of the mutant restored wild-type wax and overcame germination penalty, indicating that wax constituents less present on the mutant are a crucial clue for spore germination. Investigation of Arabidopsis (Arabidopsis thaliana) transgenic plants with sense silencing of Arabidopsis REQUIRED FOR CUTICULAR WAX PRODUCTION1, the HvKCS6 ortholog, revealed the same germination phenotype against adapted and nonadapted powdery mildew fungi. Our findings hint to an evolutionary conserved mechanism for sensing of plant surfaces among distantly related powdery mildews that is based on KCS6-derived wax components. Perception of such a signal must have been evolved before the monocot-dicot split took place approximately 150 million years ago.
Crystal structure of 4,4-dibutyl-2-phenyl-3,4-dihydroquinazoline
Authors: El-Hiti Gamal A. , Smith Keith , Hegazy Amany S. , Alshammari Mohammed B. , Kariuki Benson M.
Published: September 2014

In the title compound, C22H28N2, the dihedral angle between the planes of the phenyl ring and the dihydroquinazoline ring system (r.m.s. deviation = 0.030 Å) is 24.95 (7)° and bothn-butane chains assume all-transconformations. In the crystal, N—H...N hydrogen bonds link the molecules intoC(4) chains propagating in the [001] direction.
Heredity of acne in Korean patients
Authors: Cho Eun Byul , Ha Ji Min , Park Eun Joo , Kim Kwang Ho , Kim Kwang Joong
Published: September 2014

Acne is a chronic inflammatory disease of the pilocebaceous unit that presents with various spectrum and severity. Genetic backgrounds and environmental factors are also considered to be relevant, but few studies have focused on Korean patients. A cross‐sectional epidemiologic study on family history of Korean acne patients was performed to analyze family history of acne, and to compare the severity and characteristics of acne in association with family history. A total of 221 patients were enrolled, 98 male (44.3%) and 123 female (55.7%). Patients were grouped as patients with (A+) or without (A‐) family history of acne. In a second analysis, patients with any experience of acne treatment were evaluated. Severity of acne was measured with Burton's grading system and Korean Acne Grading System (KAGS). Female patients had a higher tendency to have family history than males (P = 0.002). Group A+ had statistically significant earlier onset of acne (P = 0.002). In inexperienced patients, patients with family history showed a relatively earlier onset (P = 0.084). This study confirmed the role of heredity in acne. Family history of acne is associated with earlier onset of the disease, and more non‐inflammatory lesions.
Using multivariate statistics to explore trade‐offs among spatial planning scenarios
Authors: Harris Linda R. , Watts Matthew E. , Nel Ronel , Schoeman David S. , Possingham Hugh P.
Published: September 2014

Scenario planning can be useful to guide decision‐making under uncertainty. While systematic conservation planning can create protected‐area networks for multiple and complex reserve–design scenarios, planners rarely compare different reserve networks explicitly, or quantify trade‐offs among scenarios.

We demonstrate the use of multivariate statistics traditionally applied in community ecology to compare reserves designed under different scenarios, using conservation planning for beaches in South Africa as an example. Twelve reserve–design scenarios were run in Marxan in a hierarchical experimental design with three levels: including/excluding the probability of site destruction; two different cost types; and three different configurations of existing terrestrial and marine reserves.

Multivariate statistics proved to be useful tools in the conservation planning context. In our case study, they showed that the trade‐off associated with including the probability of site destruction during coastal reserve design depended on the cost type: if the cost is related to the site‐destruction probability then reserves are significantly larger; if not, then reserves are significantly more costly. In both cases, the configuration of existing reserves lockeda prioriinto the solutions was more important and resulted in significantly larger and more costly reserves.

Synthesis and applications. This study demonstrates a novel application of multivariate statistical tools to robustly quantify potential trade‐offs among diverse sets of reserve–design scenarios. These statistics can be applied: to support negotiations with stakeholders and decision‐makers regarding reserve configurations in the face of uncertainty; in reserve–design sensitivity analyses; and in priority setting for future research and data collection to improve conservation plans.
Further validation of the Health Promoting Activities Scale with mothers of typically developing children
Authors: Bourke‐Taylor Helen , Lalor Aislinn , Farnworth Louise , Pallant Julie F.
Published: September 2014

Background/aim

The Health Promoting Activities Scale (HPAS) measures the frequency that mothers participate in self‐selected leisure activities that promote health and wellbeing. The scale was originally validated on mothers of school‐aged children with disabilities, and the current article extends this research using a comparative sample of mothers of typically developing school‐aged children.

Method

Australian mothers (N = 263) completed a questionnaire containing the HPAS, a measure of depression, anxiety and stress (DASS‐21) and questions concerning their weight, height, sleep quality and demographics. Statistical analysis assessed the underlying structure, internal consistency and construct validity of the HPAS. Inferential statistics were utilised to investigate the construct validity.

Results

Exploratory factor analysis supported the unidimensionality of the HPAS. It showed good internal consistency (Cronbach's alpha = 0.78). Significantly lower HPAS scores were recorded for women who were obese; had elevated levels of depression, anxiety and stress; had poor quality sleep or had heavy caring commitments. The mean HPAS score in this sample (M = 32.2) was significantly higher than was previously reported for women of children with a disability (M = 21.6: P < 0.001).

Conclusions

Further psychometric evaluation of the HPAS continues to support the HPAS as a sound instrument that measures the frequency that women participate in meaningful occupation that is associated with differences in mental health and wellbeing and other health indicators.
The Dynamics of Community Health Care Consolidation: Acquisition of Physician Practices
Authors: CHRISTIANSON JON B. , CARLIN CAROLINE S. , WARRICK LOUISE H.
Published: September 2014

Policy Points:

In order to develop effective policies on the consolidation of community health systems, policymakers must understand both the motivations and processes for consolidation.

We found that physician practice consolidation is often a strategic response by providers to public and private cost containment efforts; therefore, it will be difficult to reverse using traditional policy options.

Many current health care cost containment policies incentivize continued provider consolidation, which presents a direct challenge to health care reform models that rely on competition among providers to accomplish cost control and quality improvement.

Context

Health care delivery systems are becoming increasingly consolidated in urban areas of the United States. While this consolidation could increase efficiency and improve quality, it also could raise the cost of health care for payers. This article traces the consolidation trajectory in a single community, focusing on factors influencing recent acquisitions of physician practices by integrated delivery systems.

Methods

We used key informant interviews, supplemented by document analysis.

Findings

The acquisition of physician practices is a process that will be difficult to reverse in the current health care environment. Provider revenue uncertainty is a key factor driving consolidation, with public and private attempts to control health care costs contributing to that uncertainty. As these efforts will likely continue, and possibly intensify, community health care systems now are less consolidated than they will be in the future. Acquisitions of multispecialty and primary care practices by integrated delivery systems follow a common process, with relatively predictable issues relating to purchase agreements, employment contracts, and compensation. Acquisitions of single‐specialty practices are less common, with motivations for acquisitions likely to vary by specialty type, group size, and market structure. Total cost of care contracting could be an important catalyst for practice acquisitions in the future.

Conclusions

In the past, market and regulatory forces aimed at controlling costs have both encouraged and rewarded the consolidation of providers, with important new developments likely to create momentum for further consolidation, including acquisitions of physician practices.
Habitat fragmentation and genetic variability of tetrapod populations
Authors: Rivera‐Ortíz F. A. , Aguilar R. , Arizmendi M. D. C. , Quesada M. , Oyama K.
Published: September 2014

In the last two centuries, the development of human civilization has transformed large natural areas into anthropogenic landscapes, making habitat fragmentation a pervasive feature of modern landscapes. In animal populations, habitat fragmentation may alter their genetic diversity and structure due to limited gene flow and dispersion and reduced effective population sizes, potentially leading to genetic drift in small habitat patches. We tested the hypothesis that habitat fragmentation affects genetic diversity of tetrapod populations through a meta‐analysis. We also examined certain life history traits of species and particular external landscape factors that may determine the magnitude of genetic erosion observed in fragmented habitats. Our results showed that habitat fragmentation reduces overall genetic diversity of tetrapod populations. Stronger negative fragmentation effects were detected for amphibians, birds and mammals. Within each taxonomic group, species with large body size were more strongly affected by fragmentation. Particularly within mammals, we found that less vagile species with short generation times represent the most susceptible tetrapod group to lose genetic diversity in fragmented habitats. As external drivers, we found a nonsignificant trend of lower fragmentation effects in study systems of less than 50 years and stronger effects in older (>100 years) fragmented systems. As expected, the extent of habitat loss was also important in determining the magnitude of genetic erosion in tetrapods. Extreme habitat loss showed stronger negative effects on genetic diversity irrespective of taxonomic groups. The information gathered in this review also highlights research bias and gaps in the literature.
Ongoing impact of HIV infection on mortality among people who inject drugs despite free antiretroviral therapy
Authors: Lappalainen Leslie , Hayashi Kanna , Dong Huiru , Milloy M. J. , Kerr Thomas , Wood Evan
Published: September 2014

Aims

To determine the impact of HIV infection on mortality over time among people who inject drugs (PWID) in settings with free HIV/AIDS care.

Design and Setting

Prospective cohort study of PWID in Vancouver, Canada, recruited between May 1996 and December 2011. We ascertained morality rates and causes of death through a confidential linkage with the provincial vital statistics registry.

Participants

A total of 2283 individuals were followed for a median of 60.9 months (interquartile range: 34.4–113.1), among whom 622 (27.2%) individuals were HIV‐positive at baseline, and 179 (7.8%) seroconverted during follow‐up.

Measurements

The primary and secondary outcomes of interests were all‐cause mortality and cause of death, respectively. The main independent variable of interest was HIV serostatus (positive versus negative). We used Cox proportional hazards regression to determine factors associated with mortality, including socio‐demographic variables, drug use behaviors and other risk behaviors.

Findings

During the study period, 491 (21.5%) individuals died. In multivariate analyses, HIV infection remained associated independently with all‐cause mortality (adjusted hazard ratio = 3.15; 95% CI: 2.59–3.82). While all‐cause mortality rates declined markedly during the study period (P < 0.001), the independent effect of HIV infection on mortality remained unchanged over time (P = 0.640). Among HIV‐positive individuals, significant changes in causes of death from infectious and AIDS‐related causes to non‐AIDS‐related etiologies were observed.

Conclusions

HIV infection continues to have a persistent impact on mortality rates among people who inject drugs in settings with free HIV/AIDS care, although causes of death have shifted markedly from infectious and AIDS‐related causes to non‐AIDS‐related etiologies.
Foundations for the future: A long‐term plan for Australian ecosystem science
Authors: Andersen Alan , Beringer Jason , Bull C. Michael , Byrne Margaret , Cleugh Helen , Christensen Rebekah , French Kris , Harch Bronwyn , Hoffmann Ary , Lowe Andrew J. , Moltmann Tim , Nicotra Adrienne , Pitman Andy , Phinn Stuart , Wardle Glenda , Westoby Mark
Published: September 2014

Australia's ecosystems are the basis of our current and future prosperity, and our national well‐being. A strong and sustainable Australian ecosystem science enterprise is vital for understanding and securing these ecosystems in the face of current and future challenges. This Plan defines the vision and key directions for a national ecosystem science capability that will enable Australia to understand and effectively manage its ecosystems for decades to come. The Plan's underlying theme is that excellent science supports a range of activities, including public engagement, that enable us to understand and maintain healthy ecosystems. Those healthy ecosystems are the cornerstone of our social and economic well‐being. The vision guiding the development of this Plan is that in 20 years' time the status of Australian ecosystems and how they change will be widely reported and understood, and the prosperity and well‐being they provide will be secure. To enable this, Australia's national ecosystem science capability will be coordinated, collaborative and connected. The Plan is based on an extensive set of collaboratively generated proposals from national town hall meetings that also form the basis for its implementation. Some directions within the Plan are for the Australian ecosystem science community itself to implement, others will involve the users of ecosystem science and the groups that fund ecosystem science. We identify six equal priority areas for action to achieve our vision: (i) delivering maximum impact for Australia: enhancing relationships between scientists and end‐users; (ii) supporting long‐term research; (iii) enabling ecosystem surveillance; (iv) making the most of data resources; (v) inspiring a generation: empowering the public with knowledge and opportunities; (vi) facilitating coordination, collaboration and leadership. This shared vision will enable us to consolidate our current successes, overcome remaining barriers and establish the foundations to ensure Australian ecosystem science delivers for the future needs of Australia.
Political Reinforcement: How Rising Inequality Curbs Manifested Welfare Generosity
Authors: Barth Erling , Finseraas Henning , Moene Karl O.
Published: September 2014

We propose a political reinforcement hypothesis, suggesting that rising inequality moves party politics on welfare state issues to the right, strengthening rather than modifying the impact of inequality. We model policy platforms by incorporating ideology and opportunism of party members and interests and sympathies of voters. If welfare spending is a normal good within income classes, a majority of voters moves rightward when inequality increases. As a response, the left, in particular, shift their welfare policy platform toward less generosity. We find support for our arguments using data on the welfare policy platforms of political parties in 22 OECD countries.
Dissolution Threats and Legislative Bargaining
Authors: Becher Michael , Christiansen Flemming Juul
Published: September 2014

Chief executives in many parliamentary democracies have the power to dissolve the legislature. Despite a well‐developed literature on the endogenous timing of parliamentary elections, political scientists know remarkably little about the strategic use of dissolution power to influence policymaking. To address this gap, we propose and empirically evaluate a theoretical model of legislative bargaining in the shadow of executive dissolution power. The model implies that the chief executive's public support and legislative strength, as well as the time until the next constitutionally mandated election, are important determinants of the use and effectiveness of dissolution threats in policymaking. Analyzing an original time‐series data set from a multiparty parliamentary democracy, we find evidence in line with key empirical implications of the model.
The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: protocol, methods and analysis of data
Authors: Pandit J. J. , Andrade J. , Bogod D. G. , Hitchman J. M. , Jonker W. R. , Lucas N. , Mackay J. H. , Nimmo A. F. , O'Connor K. , O'Sullivan E. P. , Paul R. G. , Palmer J. H. MacG. , Plaat F. , Radcliffe J. J. , Sury M. R. J. , Torevell H. E. , Wang M. , Cook T. M. ,   the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland
Published: September 2014

Accidental awareness during general anaesthesia with recall is a potentially distressing complication of general anaesthesia that can lead to psychological harm. The 5th National Audit Project was designed to investigate the reported incidence, predisposing factors, causality and impact of accidental awareness. A nationwide network of local co‐ordinators across all UK and Irish public hospitals reported all new patient reports of accidental awareness to a central database, using a system of monthly anonymised reporting over a calendar year. The database collected the details of the reported event, anaesthetic and surgical technique, and any sequelae. These reports were categorised into main types by a multidisciplinary panel, using a formalised process of analysis. The main categories of accidental awareness were: certain or probable; possible; during sedation; on or from the intensive care unit; could not be determined; unlikely; drug errors; and statement only. The degree of evidence to support the categorisation was also defined for each report. Patient experience and sequelae were categorised using current tools or modifications of such. The 5th National Audit Project methodology may be used to assess new reports of accidental awareness during general anaesthesia in a standardised manner, especially for the development of an ongoing database of case reporting. This paper is a shortened version describing the protocols, methods and data analysis from 5th National Audit Project – the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home#pt.
QT Correction Methods in Infants and Children: Effects of Age and Gender
Authors: Benatar Abraham , Feenstra Arjen
Published: September 2014

Background

Accurate determination of the QTc interval in children is important especially when using drugs which can prolong cardiac repolarization. Previous work suggests the most appropriate correction formula to be QTc = QT/RR0.38. We set out to compute the best population‐derived age and gender‐related QT correction formula factor in normal children.

Methods

We evaluated a cohort of 1400 healthy children. From a resting 12‐lead electrocardiogram, QT and RR intervals were measured. Subjects were divided into four age and gender groups: 0–1 years (n = 540); 1–5 years (n = 281); 5–10 years (n = 277), and > 10 years (n = 302). QT/RR intervals were plotted and fitted with two regression analyses, linear regression obtaining constant α (QTc = QT + α x (1‐RR)), and log‐linear analysis deriving constant β (QTc = QT/RRβ). Furthermore, regression analysis of QTc/RR for the two formulas was performed obtaining slope and R2.

Results

Correction constant α decreased steadily with increasing age, genders remained on par until 10 years of age followed by more pronounced decrease in females (range 0.24–0.18). The β constant showed a similar trend however with more pronounced decline (range 0.45–0.31). Regression slopes of QTc/RR plots (all ages and both genders) were close to zero (both formulas).

Conclusion

For the full range of pediatric subjects, the optimum population‐based correction factors α and β decreased with increasing age and gender, digressing more so in adolescent girls. More specific correction factors, based on age and gender, are necessary in QT correction.
Use of ECG Restitution (Beat‐to‐Beat QT‐TQ Interval Analysis) to Assess Arrhythmogenic Risk of QTc Prolongation with Guanfacine
Authors: Fossa Anthony A. , Zhou Meijian , Robinson Antoine , Purkayastha Jaideep , Martin Patrick
Published: September 2014

Background

Guanfacine (Intuniv) is a centrally active alpha‐2A adrenergic agonist for the new indication of attention‐deficit/hyperactivity disorder. QTc (QTcF and QTcNi) was prolonged at both therapeutic (4 mg) and supratherapeutic (8 mg) doses of a thorough QT study even though guanfacine has had a safe clinical history of over 3 million prescriptions for the treatment of hypertension. In an attempt to understand this disparity, retrospective evaluation of the continuous ECG data utilized dynamic beat‐to‐beat and ECG restitution analyses was performed.

Methods

Sixty healthy subjects using 24‐hour Holters were examined in a 3‐arm, placebo‐ and positive‐controlled, double‐blind crossover study for effects on beat‐to‐beat QT, TQ, and RR intervals.

Results

ECG restitution analyses indicated that, at all time points, a disproportionate effect to increase the TQ interval (rest) occurred more in relationship to each QT interval lengthening resulting in a placebo‐adjusted reduced QT/TQ ratio of 21% after 4 mg and 31% after 8 mg (both antiarrhythmic responses). Additionally, the percentage of time and magnitude of stress on the heart, as measured by the upper limits of the QT/TQ ratio, were reduced with guanfacine by 22% to 24%. In contrast to guanfacine, moxifloxacin did not show a significant improvement in any restitution parameters but reflected a trend toward proarrhythmia with an increase in the QT/TQ ratio of up to 11%.

Conclusion

These results indicate that guanfacine causes a stabilizing effect on cardiac restitution that helps reconcile the clinical evidence for a lack of arrhythmia liability despite apparent increases in typical QT/QTc prolongation measures.