bluuebunny/crossref_metadata_2025 huggingface dataset:
Six-Month-Old Infants Perceive the Hollow-Face Illusion
Authors: Corrow Sherryse , Granrud Carl E , Mathison Jordan , Yonas Albert
Published: January 2012

In this study we investigated infants' perception of the hollow-face illusion. 6-month-old infants were shown a concave mask under monocular and binocular viewing conditions and the direction of their reaches toward the mask was recorded. Adults typically perceive a concave mask as convex under monocular conditions but as concave under binocular conditions, depending on viewing distance. Based on previous findings that infants reach preferentially toward the parts of a display that are closest to them, we expected that, if infants perceive the hollow-face illusion as adults do, they would reach to the center of the mask when viewing it monocularly and to the edges when viewing it binocularly. The results were consistent with these predictions. Our findings indicated that the infants perceived the mask as convex when viewing it with one eye and concave when viewing it with two eyes. The results show that 6-month-old infants respond to the hollow-face illusion. Our finding suggests that, early in life, the visual system uses the constraint, or assumption, that faces are convex when interpreting visual input.
Damara sheep have higher digestible energy intake than Merino sheep when fed low-quality or high-quality feed
Authors: Wilkes M. J. , Hynd P. I. , Pitchford W. S.
Published: January 2012

The use of animals that are resilient to challenging environments is becoming of increasing importance in animal production systems. Interest in breeds of sheep such as the Damara for sheep meat production is increasing in Australia. Anecdotally this breed outperforms the traditionally grazed Merino in the harsh rangeland environments encountered in the Pastoral Zone of Australia, but little evidence is available to support this claim. A trial was conducted to quantify differences in the efficiency of feed utilisation and growth performance of Damara and Merino sheep under two contrasting dietary regimes. Eighteen castrate males of each breed were offered a ‘low-quality’ diet (L) (7 MJ/kg ME; 8% crude protein, as per manufacturer’s analysis) followed by a ‘high-quality’ diet (H) (11 MJ/kg dry matter and 16% crude protein, as per manufacturer’s analysis). On the L diet, Damaras had similar ad libitum feed intake as Merinos, but the digestibility of feed dry matter and energy was ~10% higher in Damaras than Merinos. Damaras also gained weight (38 g/day) on the L diet, while Merinos lost weight (28 g/day) (P < 0.002). On the H diet the Damaras consumed 14% more feed (P < 0.053) and grew 30% faster than Merinos (P < 0.002), but there was no difference in the apparent dry matter or energy digestibility of the feed. At the conclusion of the trial the Damara carcasses were 22% heavier (28.1 versus 23.1 kg), and had higher dressing percentages (53.2 versus 41.5%) than Merinos, but the proportions of carcass components did not differ. The Damaras achieved higher total digestible energy intakes than the Merinos on both diets. On the low-quality feed this was achieved through higher feed digestibility and on the high-quality feed through greater voluntary feed intake. We speculate that this arises from variation between the breeds in rumen volume, particle flow and the site of digestion, but further studies are required to confirm this contention. The ability of Damara sheep to obtain more nutrients from widely differing feed bases makes them an attractive alternative sheep breed for sheep meat production. Furthermore, the presence of such variation between genotypes offers potential for selective breeding and development of commercial lines of sheep.
Antenatal glucocorticoids reduce growth in appropriately grown and growth-restricted ovine fetuses in a sex-specific manner
Authors: Miller Suzanne L. , Sutherland Amy E. , Supramaniam Veena G. , Walker David W. , Jenkin Graham , Wallace Euan M.
Published: January 2012

Antenatal glucocorticoids are administered to mature the fetal lungs before preterm birth. Glucocorticoids also have non-pulmonary effects, including reducing fetal body and brain growth. The present study examined whether glucocorticoid administration has a sex-specific effect on growth in appropriately grown (control) and intrauterine growth-restricted (IUGR) fetal sheep. IUGR was induced at 0.7 gestation in fetal sheep by single umbilical artery ligation. On Days 5 and 6 after surgery, IUGR or control fetuses were exposed to the synthetic glucocorticoid betamethasone (BM; 11.4 mg) or saline via intramuscular maternal administration. On Day 7, a postmortem was conducted to determine fetal sex and weight. Compared with control fetuses, the birthweight of male and female IUGR fetuses was significantly reduced (by 18.5 ± 4.4% (P = 0.002) and 21.7 ± 6.0% (P = 0.001), respectively). Maternal administration of BM significantly reduced bodyweight in both control and IUGR fetuses (by 11.3 ± 2.8% and 20.5 ± 3.6% in control male and female fetuses, respectively; and by 22.9 ± 3.1% and 38.3 ± 3.4% in IUGR male and female fetuses, respectively; P < 0.001 for all, versus control + saline) fetuses. In control and IUGR animals the degree of growth restriction was greater in females than males (P < 0.05) following administration of BM. These data suggest that antenatal glucocorticoids reduce fetal growth in a sex-specific manner, with females more growth restricted than males.
Requirements of transcription factor Smad-dependent and -independent TGF-β signaling to control discrete T-cell functions
Authors: Gu Ai-Di , Wang Yunqi , Lin Lin , Zhang Song S. , Wan Yisong Y.
Published: January 2012

TGF-β modulates immune response by suppressing non-regulatory T (Treg) function and promoting Treg function. The question of whether TGF-β achieves distinct effects on non-Treg and Treg cells through discrete signaling pathways remains outstanding. In this study, we investigated the requirements of Smad-dependent and -independent TGF-β signaling for T-cell function. Smad2 and Smad3 double deficiency in T cells led to lethal inflammatory disorder in mice. Non-Treg cells were spontaneously activated and produced effector cytokines in vivo on deletion of both Smad2 and Smad3. In addition, TGF-β failed to suppress T helper differentiation efficiently and to promote induced Treg generation of non-Treg cells lacking both Smad2 and Smad3, suggesting that Smad-dependent signaling is obligatory to mediate TGF-β function in non-Treg cells. Unexpectedly, however, the development, homeostasis, and function of Treg cells remained intact in the absence of Smad2 and Smad3, suggesting that the Smad-independent pathway is important for Treg function. Indeed, Treg-specific deletion of TGF-β–activated kinase 1 led to failed Treg homeostasis and lethal immune disorder in mice. Therefore, Smad-dependent and -independent TGF-β signaling discretely controls non-Treg and Treg function to modulate immune tolerance and immune homeostasis.
Structural and mechanistic insight into N-glycan processing by endo-α-mannosidase
Authors: Thompson Andrew J. , Williams Rohan J. , Hakki Zalihe , Alonzi Dominic S. , Wennekes Tom , Gloster Tracey M. , Songsrirote Kriangsak , Thomas-Oates Jane E. , Wrodnigg Tanja M. , Spreitz Josef , Stütz Arnold E. , Butters Terry D. , Williams Spencer J. , Davies Gideon J.
Published: January 2012

N-linked glycans play key roles in protein folding, stability, and function. Biosynthetic modification of N-linked glycans, within the endoplasmic reticulum, features sequential trimming and readornment steps. One unusual enzyme, endo-α-mannosidase, cleaves mannoside linkages internally within an N-linked glycan chain, short circuiting the classical N-glycan biosynthetic pathway. Here, using two bacterial orthologs, we present the first structural and mechanistic dissection of endo-α-mannosidase. Structures solved at resolutions 1.7–2.1 Å reveal a (
β
/
α
)
8
barrel fold in which the catalytic center is present in a long substrate-binding groove, consistent with cleavage within the N-glycan chain. Enzymatic cleavage of authentic Glc
1/3
Man
9
GlcNAc
2
yields Glc
1/3
-Man. Using the bespoke substrate α-Glc-1,3-α-Man fluoride, the enzyme was shown to act with retention of anomeric configuration. Complexes with the established endo-α-mannosidase inhibitor α-Glc-1,3-deoxymannonojirimycin and a newly developed inhibitor, α-Glc-1,3-isofagomine, and with the reducing-end product α-1,2-mannobiose structurally define the -2 to +2 subsites of the enzyme. These structural and mechanistic data provide a foundation upon which to develop new enzyme inhibitors targeting the hijacking of N-glycan synthesis in viral disease and cancer.
C3-dependent mechanism of microglial priming relevant to multiple sclerosis
Authors: Ramaglia Valeria , Hughes Timothy R. , Donev Rossen M. , Ruseva Marieta M. , Wu Xiaobo , Huitinga Inge , Baas Frank , Neal James W. , Morgan B. Paul
Published: January 2012

Microglial priming predisposes the brain to neurodegeneration and affects disease progression. The signal to switch from the quiescent to the primed state is unknown. We show that deleting the C3 convertase regulator complement receptor 1-related protein y (Crry) induces microglial priming. Mice that were double-knockout for Crry and either C3 or factor B did not show priming, demonstrating dependence on alternative pathway activation. Colocalization of C3b/iC3b and CR3 implicated the CR3/iC3b interaction in priming. Systemic lipopolysaccharide challenge overactivated primed microglia with florid expression of proinflammatory molecules, which were blocked by complement inhibition. Relevance for neurodegenerative disease is exemplified by human multiple sclerosis (MS) and by experimental autoimmune encephalomyelitis (EAE), a model of MS. In human MS, microglial priming was evident in perilesional white matter, in close proximity to C3b/iC3b deposits. EAE was accelerated and exacerbated in Crry-deficient mice, and was dependent on C activation. In summary, C3-dependent microglial priming confers susceptibility to other challenges. Our observations are relevant to progression in MS and other neurological diseases exacerbated by acute insults.
Folding energy landscape of the thiamine pyrophosphate riboswitch aptamer
Authors: Anthony Peter C. , Perez Christian F. , García-García Cuauhtémoc , Block Steven M.
Published: January 2012

Riboswitches are motifs in the untranslated regions (UTRs) of RNA transcripts that sense metabolite levels and modulate the expression of the corresponding genes for metabolite import, export, synthesis, or degradation. All riboswitches contain an aptamer: an RNA structure that, upon binding ligand, folds to expose or sequester regulatory elements in the adjacent sequence through alternative nucleotide pairing. The coupling between ligand binding and aptamer folding is central to the regulatory mechanisms of thiamine pyrophosphate (TPP) riboswitches and has not been fully characterized. Here, we show that TPP aptamer folding can be decomposed into ligand-independent and -dependent steps that correspond to the formation of secondary and tertiary structures, respectively. We reconstructed the full energy landscape for folding of the wild-type (WT) aptamer and measured perturbations of this landscape arising from mutations or ligand binding. We show that TPP binding proceeds in two steps, from a weakly to a strongly bound state. Our data imply a hierarchical folding sequence, and provide a framework for understanding molecular mechanism throughout the TPP riboswitch family.
Tissue inhibitor of metalloproteinase-1 (TIMP-1) regulates mesenchymal stem cells through let-7f microRNA and Wnt/β-catenin signaling
Authors: Egea Virginia , Zahler Stefan , Rieth Nicole , Neth Peter , Popp Tanja , Kehe Kai , Jochum Marianne , Ries Christian
Published: January 2012

Tissue inhibitor of metalloproteinases 1 (TIMP-1) is a matrix metalloproteinase (MMP)-independent regulator of growth and apoptosis in various cell types. The receptors and signaling pathways that are involved in the growth factor activities of TIMP-1, however, remain controversial. RNA interference of TIMP-1 has revealed that endogenous TIMP-1 suppresses the proliferation, metabolic activity, and osteogenic differentiation capacity of human mesenchymal stem cells (hMSCs). The knockdown of TIMP-1 in hMSCs activated the Wnt/β-catenin signaling pathway as indicated by the increased stability and nuclear localization of β-catenin in TIMP-1–deficient hMSCs. Moreover, TIMP-1 knockdown cells exhibited enhanced β-catenin transcriptional activity, determined by Wnt/β-catenin target gene expression analysis and a luciferase-based β-catenin–activated reporter assay. An analysis of a mutant form of TIMP-1 that cannot inhibit MMP indicated that the effect of TIMP-1 on β-catenin signaling is MMP independent. Furthermore, the binding of CD63 to TIMP-1 on the surface of hMSCs is essential for the TIMP-1–mediated effects on Wnt/β-catenin signaling. An array analysis of microRNAs (miRNAs) and transfection studies with specific miRNA inhibitors and mimics showed that let-7f miRNA is crucial for the regulation of β-catenin activity and osteogenic differentiation by TIMP-1. Let-7f was up-regulated in TIMP-1–depleted hMSCs and demonstrably reduced axin 2, an antagonist of β-catenin stability. Our results demonstrate that TIMP-1 is a direct regulator of hMSC functions and reveal a regulatory network in which let-7f modulates Wnt/β-catenin activity.
Splash singularity for water waves
Authors: Castro Angel , Córdoba Diego , Fefferman Charles L. , Gancedo Francisco , Gómez-Serrano Javier
Published: January 2012

We exhibit smooth initial data for the two-dimensional (2D) water-wave equation for which we prove that smoothness of the interface breaks down in finite time. Moreover, we show a stability result together with numerical evidence that there exist solutions of the 2D water-wave equation that start from a graph, turn over, and collapse in a splash singularity (self-intersecting curve in one point) in finite time.
Compensatory functions of histone deacetylase 1 (HDAC1) and HDAC2 regulate transcription and apoptosis during mouse oocyte development
Authors: Ma Pengpeng , Pan Hua , Montgomery Rusty L. , Olson Eric N. , Schultz Richard M.
Published: January 2012

Dramatic changes in chromatin structure and histone modification occur during oocyte growth, as well as a global cessation of transcription. The role of histone modifications in these processes is poorly understood. We report the effect of conditionally deleting
Hdac1
and
Hdac2
on oocyte development. Deleting either gene has little or no effect on oocyte development, whereas deleting both genes results in follicle development arrest at the secondary follicle stage. This developmental arrest is accompanied by substantial perturbation of the transcriptome and a global reduction in transcription even though histone acetylation is markedly increased. There is no apparent change in histone repressive marks, but there is a pronounced decrease in histone H3K4 methylation, an activating mark. The decrease in H3K4 methylation is likely a result of increased expression of
Kdm5b
because RNAi-mediated targeting of
Kdm5b
in double-mutant oocytes results in an increase in H3K4 methylation. An increase in TRP53 acetylation also occurs in mutant oocytes and may contribute to the observed increased incidence of apoptosis. Taken together, these results suggest seminal roles of acetylation of histone and nonhistone proteins in oocyte development.
The mystery of missing heritability: Genetic interactions create phantom heritability
Authors: Zuk Or , Hechter Eliana , Sunyaev Shamil R. , Lander Eric S.
Published: January 2012

Human genetics has been haunted by the mystery of “missing heritability” of common traits. Although studies have discovered >1,200 variants associated with common diseases and traits, these variants typically appear to explain only a minority of the heritability. The proportion of heritability explained by a set of variants is the ratio of (
i
) the heritability due to these variants (numerator), estimated directly from their observed effects, to (
ii
) the total heritability (denominator), inferred indirectly from population data. The prevailing view has been that the explanation for missing heritability lies in the numerator—that is, in as-yet undiscovered variants. While many variants surely remain to be found, we show here that a substantial portion of missing heritability could arise from overestimation of the denominator, creating “phantom heritability.” Specifically, (
i
) estimates of total heritability implicitly assume the trait involves no genetic interactions (epistasis) among loci; (
ii
) this assumption is not justified, because models with interactions are also consistent with observable data; and (
iii
) under such models, the total heritability may be much smaller and thus the proportion of heritability explained much larger. For example, 80% of the currently missing heritability for Crohn's disease could be due to genetic interactions, if the disease involves interaction among three pathways. In short, missing heritability need not directly correspond to missing variants, because current estimates of total heritability may be significantly inflated by genetic interactions. Finally, we describe a method for estimating heritability from isolated populations that is not inflated by genetic interactions.
Dispersal, Growth, and Diet of Stocked and Wild Northern Pike Fry in a Shallow Natural Lake, with Implications for the Management of Stocking Programs
Authors: Skov Christian , Koed Anders , Baastrup-Spohr Lars , Arlinghaus Robert
Published: January 2012

Increasing evidence suggests that stocking northern pike Esox lucius has had limited success, especially when age-0 fish are stocked into water bodies where the recruitment of northern pike already occurs. To better understand the ecology of wild and stocked fry, we investigated the dispersal, growth, and food composition of advanced pike fry (∼30 mm) stocked at a high density at a common release site in a shallow natural lake that contained wild young-of-the-year (age-0) pike. The stocked pike fry colonized the entire lake shoreline within just a few days. Dispersal was inversely related to size at stocking, suggesting that smaller fish were displaced by competitively superior larger individuals. While the stocked pike were initially larger than the wild age-0 pike, suboptimal growth was evident among the stocked pike and they were smaller than the wild ones at the end of the growing season. Stomach analyses revealed that the stocked pike ingested less diverse prey items and had higher fractions of empty stomachs throughout the study period. Overall, the fraction of stocked pike in samples rapidly declined over the season, which may have been caused by differential survival or immigration into or emigration out of the study system. Our study adds to the existing literature suggesting that the stocking of age-0 northern pike into waters with naturally reproducing pike populations will result in limited success. We propose two potentially complementary explanations for the apparent low fitness of stocked individuals in competition with wild conspecifics: (1) genetic-based local maladaptation among the stocked fish and (2) carryover effects from the hatchery. The latter may be less likely because the fry stocked were the offspring of wild fish and only spent a few weeks in the hatchery.

Received January 5, 2011; accepted September 12, 2011
The mental representation of the magnitude of symbolic and nonsymbolic ratios in adults
Authors: Meert Gaëlle , Grégoire Jacques , Seron Xavier , Noël Marie-Pascale
Published: January 2012

This study mainly investigated the specificity of the processing of fraction magnitudes. Adults performed a magnitude-estimation task on fractions, the ratios of collections of dots, and the ratios of surface areas. Their performance on fractions was directly compared with that on nonsymbolic ratios. At odds with the hypothesis that the symbolic notation impedes the processing of the ratio magnitudes, the estimates were less variable and more accurate for fractions than for nonsymbolic ratios. This indicates that the symbolic notation activated a more precise mental representation than did the nonsymbolic ratios. This study also showed, for both fractions and the ratios of dot collections, that the larger the components the less precise the mental representation of the magnitude of the ratio. This effect suggests that the mental representation of the magnitude of the ratio was activated from the mental representation of the magnitude of the components and the processing of their numerical relation (indirect access). Finally, because most previous studies of fractions have used a numerical comparison task, we tested whether the mental representation of magnitude activated in the fraction-estimation task could also underlie performance in the fraction-comparison task. The subjective distance between the fractions to be compared was computed from the mean and the variability of the estimates. This distance was the best predictor of the time taken to compare the fractions, suggesting that the same approximate mental representation of the magnitude was activated in both tasks.
A Lot of Data
Authors: Johnson Kent
Published: January 2012

This article encourages the use of explicit methods in linguistics by attempting to estimate the size of a linguistic data set. Such estimations are difficult because redundant data can easily pad the data set. To address this, I offer some explicit operationalizations of the data and their features. For linguistic data, negative associations do not indicate true redundancy, and yet for many measures they can be mathematically impossible to ignore. It is proven that this troublesome phenomenon has positive Lebesgue measure and is monotonically increasing and that these two features hold robustly in four different ways.
A More Fulfilling (and Frustrating) Take on Reflexive Predictions
Authors: Kopec Matthew
Published: January 2012

Even though social scientists continue to discuss the problems posed by self-fulfilling and self-frustrating predictions, philosophers of science have ignored the topic since the 1970s. Back then, the prevailing view was that the methodological problems posed by reflexive predictions are either minor or easily avoided. I believe that this consensus was premature, ultimately relying on an overly narrow understanding of the phenomenon. I present an improved way to understand reflexive predictions (framed in probabilistic terms) and show that, once such predictions are understood this way, the methodological problems they pose may turn out to be neither minor nor easily avoided.
Comparing Probabilistic Measures of Explanatory Power
Authors: Schupbach Jonah N.
Published: January 2012

Recently, in attempting to account for explanatory reasoning in probabilistic terms, Bayesians have proposed several measures of the strength of a potential explanation. These candidate measures of “explanatory power” arguably have interesting normative interpretations and consequences. What has not yet been investigated, however, is whether any of these measures are also descriptive of people's actual explanatory judgments. Here I present my own experimental work investigating this question. I argue that one measure in particular is an accurate descriptor of explanatory judgments. Then I briefly point to some implications of this result for the epistemology and the psychology of explanatory reasoning.
Scientific Realism and the Divide et Impera Strategy: The Ether Saga Revisited
Authors: Cordero Alberto
Published: January 2012

Using the optical ether as a case study, this article advances four lines of consideration to show why synchronic versions of the divide et impera strategy of scientific realism are unlikely to work. The considerations draw from (a) the nineteenth-century theories of light, (b) the rise of surprising implication as an epistemic value from the time of Fresnel on, (c) assessments of the ether in end-of-century reports around 1900, and (d) the roots of ether theorizing in now superseded metaphysical assumptions. The typicality of the case and its impact on diachronic versions of the strategy are briefly discussed.
How to Defeat Wüthrich's Abysmal Embarrassment Argument against Space-Time Structuralism
Authors: Muller F. A.
Published: January 2012

In his award-winning contribution to the biannual PSA conference at Pittsburgh in 2008, Christian Wüthrich mounted an argument against structuralism about space-time in the context of the general theory of relativity (GTR), to the effect that structuralists cannot discern space-time points: an “abysmal embarrassment” for the structuralist, Wüthrich judged. Wüthrich's characterization of space-time structuralism is however incorrect. We demonstrate how, on the basis of a correct characterization of space-time structuralism, it is possible to discern space-time points in the GTR structures under consideration. Thus Wüthrich's argument crumbles.
Performance, Revision, and Extension of the National Nosocomial Infections Surveillance System's Risk Index in Brazilian Hospitals
Authors: Biscione Fernando Martín , Couto Renato Camargos , Pedrosa Tânia M. G.
Published: January 2012

Objective.

To assess the benefit of using procedure-specific alternative cutoff points for National Nosocomial Infections Surveillance (NNIS) risk index variables and of extending surgical site infection (SSI) risk prediction models with a postdischarge surveillance indicator.

Design.

Open, retrospective, validation cohort study.

Setting.

Five private, nonuniversity Brazilian hospitals.

Patients.

Consecutive inpatients operated on between January 1993 and May 2006 (other operations of the genitourinary system [n = 20,723], integumentary system [n = 12,408], or musculoskeletal system [n = 15,714] and abdominal hysterectomy [n = 11,847]).

Methods.

For each procedure category, development and validation samples were defined nonrandomly. In the development samples, alternative SSI prognostic scores were constructed using logistic regression: (i) alternative NNIS scores used NNIS risk index covariates and cutoff points but locally derived SSI risk strata and rates, (ii) revised scores used procedure-specific alternative cutoff points, and (iii) extended scores expanded revised scores with a postdischarge surveillance indicator. Performances were compared in the validation samples using calibration, discrimination, and overall performance measures.

Results.

The NNIS risk index showed low discrimination, inadequate calibration, and predictions with high variability. The most consistent advantage of alternative NNIS scores was regarding calibration (prevalence and dispersion components). Revised scores performed slightly better than the NNIS risk index for most procedures and measures, mainly in calibration. Extended scores clearly performed better than the NNIS risk index, irrespective of the measure or operative procedure.

Conclusions.

Locally derived SSI risk strata and rates improved the NNIS risk index's calibration. Alternative cutoff points further improved the specification of the intrinsic SSI risk component. Controlling for incomplete postdischarge SSI surveillance provided consistently more accurate SSI risk adjustment.

Infect Control Hosp Epidemiol 2012;33(2):124-134
Inclusion of 30-Day Postdischarge Detection Triples the Incidence of Hospital-Onset Methicillin-ResistantStaphylococcus aureus
Authors: Avery Taliser R. , Kleinman Ken P. , Klompas Michael , Aschengrau Ann , Huang Susan S.
Published: January 2012

Background.

Hospitalized patients are at increased risk for acquisition of methicillin-resistantStaphylococcus aureus(MRSA). As hospital length of stay shortens, hospital-acquired MRSA events may be more likely to be detected after discharge.

Objective.

We assessed the impact of attributing MRSA cases discovered within 30 days after discharge to the most recent hospitalization and identified patient characteristics associated with MRSA detection after discharge.

Design.

Retrospective cohort study.

Setting.

Twenty-seven acute care hospitals in Orange County, California.

Participants.

Adult acute care admissions (2002–2007).

Methods.

Using a countywide hospital data set containing diagnostic codes with present-on-admission (POA) indicators, we identified the first admission with a MRSA code for each patient. This incident MRSA admission was defined as predischarge-detected (pre-DD) hospital-onset MRSA (HO-MRSA) when MRSA was not POA. If MRSA was POA and a prior admission occurred within 30 days, this prior admission was assigned postdischarge-detected (post-DD) HO-MRSA. We evaluated the impact of including post-DD HO-MRSA in the calculation of hospital HO-MRSA incidence using signed-rank tests and reviewed changes in hospital rankings. We conducted multivariate comparisons of patient characteristics of pre-DD versus post-DD HO-MRSA patients.

Results.

Among 1,217,253 at-risk hospitalizations, the inclusion of post-DD HO-MRSA tripled the median hospital HO-MRSA incidence, from 12.2 to 35.7 cases per 10,000 at-risk admissions (P<.0001). Hospital ranking changed substantially when including post-DD HO-MRSA. Patients with shorter stays were more likely to have post-DD MRSA.

Conclusions.

On the basis of administrative claims data, the inclusion of post-DD HO-MRSA significantly increased the estimated HO-MRSA incidence and altered hospital rankings. This finding underscores the limitations of single-facility data when deriving HO-MRSA incidence and rank.

Infect Control Hosp Epidemiol2012;33(2):114-121
Performance analysis of AlGaAs/GaAs tunnel junctions for ultra-high concentration photovoltaics
Authors: García I , Rey-Stolle I , Algora C
Published: January 2012

An n++-GaAs/p++-AlGaAs tunnel junction with a peak current density of 10 100 A cm−2 is developed. This device is a tunnel junction for multijunction solar cells, grown lattice-matched on standard GaAs or Ge substrates, with the highest peak current density ever reported. The voltage drop for a current density equivalent to the operation of the multijunction solar cell up to 10 000 suns is below 5 mV. Trap-assisted tunnelling is proposed to be behind this performance, which cannot be justified by simple band-to-band tunnelling. The metal-organic vapour-phase epitaxy growth conditions, which are in the limits of the transport-limited regime, and the heavy tellurium doping levels are the proposed origins of the defects enabling trap-assisted tunnelling. The hypothesis of trap-assisted tunnelling is supported by the observed annealing behaviour of the tunnel junctions, which cannot be explained in terms of dopant diffusion or passivation. For the integration of these tunnel junctions into a triple-junction solar cell, AlGaAs barrier layers are introduced to suppress the formation of parasitic junctions, but this is found to significantly degrade the performance of the tunnel junctions. However, the annealed tunnel junctions with barrier layers still exhibit a peak current density higher than 2500 A cm−2 and a voltage drop at 10 000 suns of around 20 mV, which are excellent properties for tunnel junctions and mean they can serve as low-loss interconnections in multijunction solar cells working at ultra-high concentrations.
Choosing orientation: influence of cargo geometry and ActA polarization on actin comet tails
Authors: Lacayo Catherine I. , Soneral Paula A. G. , Zhu Jie , Tsuchida Mark A. , Footer Matthew J. , Soo Frederick S. , Lu Yu , Xia Younan , Mogilner Alexander , Theriot Julie A.
Published: January 2012

Networks of polymerizing actin filaments can propel intracellular pathogens and drive movement of artificial particles in reconstituted systems. While biochemical mechanisms activating actin network assembly have been well characterized, it remains unclear how particle geometry and large-scale force balance affect emergent properties of movement. We reconstituted actin-based motility using ellipsoidal beads resembling the geometry of Listeria monocytogenes. Beads coated uniformly with the L. monocytogenes ActA protein migrated equally well in either of two distinct orientations, with their long axes parallel or perpendicular to the direction of motion, while intermediate orientations were unstable. When beads were coated with a fluid lipid bilayer rendering ActA laterally mobile, beads predominantly migrated with their long axes parallel to the direction of motion, mimicking the orientation of motile L. monocytogenes. Generating an accurate biophysical model to account for our observations required the combination of elastic-propulsion and tethered-ratchet actin-polymerization theories. Our results indicate that the characteristic orientation of L. monocytogenes must be due to polarized ActA rather than intrinsic actin network forces. Furthermore, viscoelastic stresses, forces, and torques produced by individual actin filaments and lateral movement of molecular complexes must all be incorporated to correctly predict large-scale behavior in the actin-based movement of nonspherical particles.
Risk Aversion: Experimental Evidence from South African Fishing Communities
Authors: Brick Kerri , Visser Martine , Burns Justine
Published: January 2012

We estimate the risk attitudes of a large sample of individuals from various fishing communities along the west coast of South Africa. Female fishers and rights holders are found to be more risk averse than their male counterparts, while rights holders are found to be less risk averse relative to subjects without fishing rights. Risk attitudes are found to be correlated with compliance with fisheries regulations. In particular, a greater degree of risk aversion translates into a reduction in compliance. Furthermore, in the case of gender, female fishers and rights holders are more likely to comply with fisheries regulations.
Latent Thresholds Analysis of Choice Data under Value Uncertainty
Authors: Kobayashi Mimako , Moeltner Klaus , Rollins Kimberly
Published: January 2012

In many non‐market valuation settings stakeholders will be uncertain as to their exact willingness‐to‐pay for a proposed environmental amenity. It then makes sense for the analyst to treat this value as a random variable with distribution only known to the respondent. In stated preference settings, researchers have used elicitation formats with multiple bids and uncertain‐response options to learn about individual value distributions. Past efforts have focused on inference involving the expectation of individual densities. This requires stringent and likely unrealistic assumptions regarding the shape or moments of individual value distributions. We propose a Latent Thresholds Estimator that focuses instead on the range, i.e. minimum and maximum willingness‐to‐pay of individual respondents. The estimator efficiently exploits correlation patterns in individual responses and does not require any restrictive assumptions on underlying values. It also nests some of the existing approaches, which are not statistically supported for our empirical application.
How much Do Decoupled Payments Affect Production? An Instrumental Variable Approach with Panel Data
Authors: Weber Jeremy G. , Key Nigel
Published: January 2012

How much decoupled payments, such as direct payments in the U.S., affect agricultural production remains an open empirical question with implications for policy. Using data from multiple years of the Census of Agriculture, we exploit a provision of the 2002 Farm Act that departed from previous policy by making oilseeds eligible for direct payments, thus increasing payments to areas that historically produced more oilseeds. Our instrumental variable estimates, in contrast to OLS estimates, suggest that changes in payments over the period 2002 to 2007 had little effect on aggregate production at the ZIP‐code level.
A method to infer positive selection from marker dynamics in an asexual population
Authors: Illingworth Christopher J. R. , Mustonen Ville
Published: January 2012

Motivation: The observation of positive selection acting on a mutant indicates that the corresponding mutation has some form of functional relevance. Determining the fitness effects of mutations thus has relevance to many interesting biological questions. One means of identifying beneficial mutations in an asexual population is to observe changes in the frequency of marked subsets of the population. We here describe a method to estimate the establishment times and fitnesses of beneficial mutations from neutral marker frequency data.

Results: The method accurately reproduces complex marker frequency trajectories. In simulations for which positive selection is close to 5% per generation, we obtain correlations upwards of 0.91 between correct and inferred haplotype establishment times. Where mutation selection coefficients are exponentially distributed, the inferred distribution of haplotype fitnesses is close to being correct. Applied to data from a bacterial evolution experiment, our method reproduces an observed correlation between evolvability and initial fitness defect.

Availability: A C++ implementation of the inference tool is available under GNU GPL license (http://www.sanger.ac.uk/resources/software/optimist/).

Contact:  vm5@sanger.ac.uk

Supplementary information:  Supplementary data are available at Bioinformatics online.
The Oral Health Needs of Older People in General Medical Practice: An Overview
Authors: Ray-Chaudhuri Arijit , Olley Ryan C. , Austin Rupert S. , Gallagher Jennifer E.
Published: January 2012

As the UK population ages and older people retain their natural teeth for longer, the complexity of the oral health needs in older people is becoming more challenging. Older patients are often registered with a GP and will increasingly be likely to require dental care. Older people in particular may benefit from dental care but may not have a dentist or perceive any risk of oral disease. This article therefore provides practical insight into the oral health management of older people to assist in addressing their oral health needs.
Impact of Early and High Amino Acid Supplementation on ELBW Infants at 2 Years
Authors: Blanco Cynthia L. , Gong Alice K. , Schoolfield John , Green Belinda K. , Daniels Wanda , Liechty Edward A. , Ramamurthy Rajam
Published: January 2012

Objective:

The aim of the present study was to examine the effects of early and high intravenous (IV) amino acid (AA) supplementation on growth, health, and neurodevelopment of extremely‐low‐birth‐weight (ELBW) infants throughout their first 2 years of life.

Methods:

Infants were prospectively randomized in a double‐masked fashion and treated for 7 days with either IV AA starting at 0.5 g · kg−1 · day−1 and increased by 0.5 g · kg−1 every day to 3 g · kg−1 · day−1 or starting at 2 g · kg−1 · day−1 of IV AA and advanced by 1 g · kg−1 every day to 4 g · kg−1 · day−1. Plasma AA concentrations were determined by reverse‐phase high‐performance liquid chromatography. Survivors were longitudinally assessed with Bayley II Scales of Infant Development and physical, social, and global health.

Results:

Forty‐three of 51 survivors were studied. Mental Developmental Index (MDI) and Psychomotor Developmental Index were similar between groups; however, the early and high AA group had a lower MDI at 18 months. This difference disappeared at 2 years of age. The early and high AA group z score means for weight, length, and head circumferences were significantly lower than the standard AA group at most visits. Cumulative and single plasma AA concentrations correlated negatively with MDI and postnatal growth.

Conclusions:

ELBW infants who received early and high IV AA during the first week of life were associated with poor overall growth at 2 years.
Two polymorphs of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate
Authors: Fábry Jan , Fridrichová Michaela , Dušek Michal , Fejfarová Karla , Krupková Radmila
Published: January 2012

Two polymorphs of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate, 2C2H7N4O+·FO3P2−·2H2O, are presented. Polymorph (I), crystallizing in the space groupPnma, is slightly less densely packed than polymorph (II), which crystallizes inPbca. In (I), the fluorophosphonate anion is situated on a crystallographic mirror plane and the O atom of the water molecule is disordered over two positions, in contrast with its H atoms. The hydrogen-bond patterns in both polymorphs share similar features. There are O—H...O and N—H...O hydrogen bonds in both structures. The water molecules donate their H atoms to the O atoms of the fluorophosphonates exclusively. The water molecules and the fluorophosphonates participate in the formation ofR44(10) graph-set motifs. These motifs extend along theaaxis in each structure. The water molecules are also acceptors of either one [in (I) and (II)] or two [in (II)] N—H...O hydrogen bonds. The water molecules are significant building elements in the formation of a three-dimensional hydrogen-bond network in both structures. Despite these similarities, there are substantial differences between the hydrogen-bond networks of (I) and (II). The N—H...O and O—H...O hydrogen bonds in (I) are stronger and weaker, respectively, than those in (II). Moreover, in (I), the shortest N—H...O hydrogen bonds are shorter than the shortest O—H...O hydrogen bonds, which is an unusual feature. The properties of the hydrogen-bond network in (II) can be related to an unusually long P—O bond length for an unhydrogenated fluorophosphonate anion that is present in this structure. In both structures, the N—H...F interactions are far weaker than the N—H...O hydrogen bonds. It follows from the structure analysis that (II) seems to be thermodynamically more stable than (I).
Cation ordering in the double tungstate LiFe(WO4)2
Authors: Albino Marjorie , Pechev Stanislav , Veber Philippe , Velazquez Matias , Josse Michael
Published: January 2012

Single crystals of lithium iron tungstate, LiFe(WO4)2, were obtained using a high-temperature solution growth method. The analysis was conducted using the monoclinic space groupC2/c, with β = 90.597 (2)°, givingR1 = 0.0177. The Li and Fe atoms lie on twofold axes. The structure can also be refined using the orthorhombic space groupCmcm, giving slightly higher residuals. The experimental value of β and the residuals mitigate in favour of the monoclinic description of the structure. Calculated bond-valence sums for the present results are closer to expected values than those obtained using the results of a previously reported analysis of this structure.
Mixed crystals of 2-carbamoylguanidinium with hydrogen fluorophosphonate and hydrogen phosphite in the ratios 1:0, 0.76 (2):0.24 (2) and 0.115 (7):0.885 (7)
Authors: Fábry Jan , Fridrichová Michaela , Dušek Michal , Fejfarová Karla , Krupková Radmila
Published: January 2012

The title compounds, 2-carbamoylguanidinium hydrogen fluorophosphonate, C2H7N4O+·HFO3P−, (I), 2-carbamoylguanidinium–hydrogen fluorophosphonate–hydrogen phosphite (1/0.76/0.24), C2H7N4O+·0.76HFO3P−·0.24H2O3P−, (II), and 2-carbamoylguanidinium–hydrogen fluorophosphonate–hydrogen phosphite (1/0.115/0.885), C2H7N4O+·0.115HFO3P−·0.885H2O3P−, (III), are isostructural with guanylurea hydrogen phosphite, C2H7N4O+·H2O3P−[Fridrichová, Němec, Císařová & Němec (2010).CrystEngComm,12, 2054–2056]. They constitute structures where the hydrogen phosphite anion has been fully or partially replaced by hydrogen fluorophosphonate. The title structures are the fourth example of isostructural compounds which differ by the presence of hydrogen fluorophosphonate and hydrogen phosphite or fluorophosphonate and phosphite anions. Moreover, the present study reports structures with these mixed anions for the first time. In the reported mixed salts, the P and O atoms of either anion overlap almost exactly, as can be judged by comparison of their equivalent isotropic displacement parameters, while the P—F and P—H directions are almost parallel. There are strong O—H...O hydrogen bonds between the anions, as well as strong N—H...O hydrogen bonds between the 2-carbamoylguanidinium cations in the title structures. Altogether they form a three-dimensional hydrogen-bond pattern. Interestingly, rare N—H...F interactions are also present in the title structures. Another exceptional feature concerns the P—O(H) distances, which are about as long as the P—F distance. The dependence of P—F distances on the longest P—O distances in FO3P2−or HFO3P−is presented. The greater content of hydrogen phosphite in the mixed crystals causes a larger deformation of the cations from planarity.
2-Ammonio-5-chloro-4-methylbenzenesulfonate, its 1-methyl-2-pyrrolidone and dimethyl sulfoxide monosolvates and a corrected structure of 2,2′-(1,4-phenylene)di(4,5-dihydroimidazolium) bis(4-aminobenzenesulfonate) dihydrate
Authors: Bekö Sándor L. , Bats Jan W. , Schmidt Martin U.
Published: January 2012

2-Ammonio-5-chloro-4-methylbenzenesulfonate, C7H8ClNO3S, (Ia), is an intermediate in the synthesis of lake red azo pigments. The present structure determination from single-crystal data confirms the results of a previous powder diffraction determination [Bekö, Thoms, Brüning, Alig, van de Streek, Lakatos, Glaubitz & Schmidt (2010).Z. Kristallogr.225, 382–387]. The zwitterionic tautomeric form is confirmed. During a polymorph screening, two additional pseudopolymorphs were obtained,viz.2-ammonio-5-chloro-4-methylbenzenesulfonate 1-methyl-2-pyrrolidone monosolvate, C7H8ClNO3S·C5H9NO, (Ib), and 2-ammonio-5-chloro-4-methylbenzenesulfonate dimethyl sulfoxide monosolvate, C7H8ClNO3S·C2H6OS, (Ic). The molecules of (Ib) have crystallographicmsymmetry. The 1-methyl-2-pyrrolidone solvent molecule has an envelope conformation and is disordered around the mirror plane. The structure shows hydrogen-bonded ladders of molecules [graph-set notationC22(6)R22(12)] in the [010] direction. The benzene groups of adjacent ladders are also stacked in this direction. A different type of hydrogen-bonded ladder [graph-set notationC(6)R22(4)R44(12)] occurs in (Ic). In (Ia), (Ib) and (Ic), the molecules correspond to the zwitterionic tautomer. The structure of the cocrystal of 4-aminobenzenesulfonic acid with 1,4-bis(4,5-dihydroimidazol-2-yl)benzene [Shang, Ren, Wang, Lu & Yang (2009).Acta Cryst.E65, o2221–o2222] is corrected; it actually contains 4-aminobenzenesulfonate anions and 2,2′-(1,4-phenylene)di(dihydroimidazolium) dications,i.e.2,2′-(1,4-phenylene)di(4,5-dihydroimidazolium) bis(4-aminobenzenesulfonate) dihydrate, C12H16N42+·2C6H6NO3S−·2H2O. Hence, all known structures of aminobenzenesulfonic acid complexes contain ionic or zwitterionic molecules; there is no known structure with a neutral aminobenzenesulfonic acid molecule.
Two polymorphs and the diethylammonium salt of the barbiturate eldoral
Authors: Gelbrich Thomas , Rossi Denise , Griesser Ulrich J.
Published: January 2012

Polymorph (Ia) of eldoral [5-ethyl-5-(piperidin-1-yl)barbituric acid or 5-ethyl-5-(piperidin-1-yl)-1,3-diazinane-2,4,6-trione], C11H17N3O3, displays a hydrogen-bonded layer structure parallel to (100). The piperidine N atom and the barbiturate carbonyl group in the 2-position are utilized in N—H...N and N—H...O=C hydrogen bonds, respectively. The structure of polymorph (Ib) contains pseudosymmetry elements. The two independent molecules of (Ib) are connectedviaN—H...O=C(4/6-position) and N—H...N(piperidine) hydrogen bonds to give a chain structure in the [100] direction. The hydrogen-bonded layers, parallel to (010), formed in the salt diethylammonium 5-ethyl-5-(piperidin-1-yl)barbiturate [or diethylammonium 5-ethyl-2,4,6-trioxo-5-(piperidin-1-yl)-1,3-diazinan-1-ide], C4H12N+·C11H16N3O3−, (II), closely resemble the corresponding hydrogen-bonded structure in polymorph (Ia). Like many other 5,5-disubstituted derivatives of barbituric acid, polymorphs (Ia) and (Ib) contain theR22(8) N—H...O=C hydrogen-bond motif. However, the overall hydrogen-bonded chain and layer structures of (Ia) and (Ib) are unique because of the involvement of the hydrogen-bond acceptor function in the piperidine group.