bluuebunny/crossref_metadata_2025 huggingface dataset:
Two one-dimensional coordination polymers generated from a new benzimidazole bridging ligand and CdX2(X= Br and I)
Authors: Zhang Yue-Feng , Ma Jian-Ping , Liu Qi-Kui , Dong Yu-Bin
Published: April 2013

The novel asymmetric bridging ligand 1-[(pyridin-3-yl)methyl]-2-[4-(pyridin-3-yl)phenyl]-1H-benzimidazole (L) has been used to construct the coordination polymerscatena-poly[[[dibromidocadmium(II)]-μ3-1-[(pyridin-3-yl)methyl]-2-[4-(pyridin-3-yl)phenyl]-1H-benzimidazole] monohydrate], {[CdBr2(C24H18N4)]·H2O}n, (I), andcatena-poly[[diiodidocadmium(II)]-μ3-1-[(pyridin-3-yl)methyl]-2-[4-(pyridin-3-yl)phenyl]-1H-benzimidazole], [CdI2(C24H18N4)]n, (II). Compounds (I) and (II) are closely related one-dimensional polymers based on 16- and 20-membered macrocycles along the chains, but they are not isomorphous. The chains are crosslinked into a two-dimensional networkviahydrogen bonds and π–π interactions in (I), and into a three-dimensional framework through π–π interactions in (II). One well-ordered solvent water molecule per asymmetric unit is included in (I) and forms O...Br hydrogen bonds.
The correct assignment of stereochemistry in di-μ-dichlorido-bis{bis[2-(5-benzylsulfonyl)-3-fluoro-2-(pyridin-2-yl)phenyl-κ2N,C1]iridium(III)} toluene monosolvate
Authors: Mesto Ernesto , Scordari Fernando , Lacalamita Maria , De Cola Luisa , Ragni Roberta , Farinola Gianluca Maria
Published: April 2013

The title complex, [Ir2(C18H13FNO2S)4Cl2]·C7H8, was crystallized from dichloromethane solution under a toluene atmosphere. It is a dimeric complex in which each of the two IrIIIcentres is octahedrally coordinated by two bridging chloride ligands and by two chelating cyclometalated 2-(4-benzylsulfonyl-2-fluorophenyl)pyridine ligands. The crystal structure analysis unequivocally establishes thetransdisposition of the two cyclometalated ligands bound to each IrIIIcentre, contrary to our previous hypothesis of acisdisposition. The latter was based on the1H NMR spectra of a series of dimeric benzylsulfonyl-functionalized dichloride-bridged iridium complexes, including the compound described in the present work [Ragniet al.(2009).Chem. Eur. J.15, 136–148]. The toluene solvent molecules, embedded in cavities in the crystal structure, are highly disordered and could not be modelled successfully; their contribution was removed from the refinement using the SQUEEZE routine in the programPLATON[Spek (2009).Acta Cryst.D65, 148–155].
A one-dimensional zinc(II) coordination polymer incorporating [1,1′-biphenyl]-4,4′-dicarboxylate andN,N′-bis(pyridin-3-ylmethyl)-[1,1′-biphenyl]-4,4′-dicarboxamide ligands
Authors: Zhou Wen , Wang Jian
Published: April 2013

In the title compound,catena-poly[[[N,N′-bis(pyridin-3-ylmethyl)-[1,1′-biphenyl]-4,4′-dicarboxamide]chloridozinc(II)]-μ-[1,1′-biphenyl]-4,4′-dicarboxylato-[[N,N′-bis(pyridin-3-ylmethyl)-[1,1′-biphenyl]-4,4′-dicarboxamide]chloridozinc(II)]-μ-[N,N′-bis(pyridin-3-ylmethyl)-[1,1′-biphenyl]-4,4′-dicarboxamide]], [Zn2(C14H8O4)Cl2(C26H22N4O2)3]n, the ZnIIcentre is four-coordinate and approximately tetrahedral, bonding to one carboxylate O atom from a bidentate bridging dianionic [1,1′-biphenyl]-4,4′-dicarboxylate ligand, to two pyridine N atoms from twoN,N′-bis(pyridin-3-ylmethyl)-[1,1′-biphenyl]-4,4′-dicarboxamide ligands and to one chloride ligand. The pyridyl ligands exhibit bidentate bridging and monodentate terminal coordination modes. The bidentate bridging pyridyl ligand and the bridging [1,1′-biphenyl]-4,4′-dicarboxylate ligand both lie on special positions, with inversion centres at the mid-points of their central C—C bonds. These bridging groups link the ZnIIcentres into a one-dimensional tape structure that propagates along the crystallographicbdirection. The tapes are interlinked into a two-dimensional layer in theabplane through N—H...O hydrogen bonds between the monodentate ligands. In addition, the thermal stability and solid-state photoluminescence properties of the title compound are reported.
A three-dimensional manganese(II) metal–organic framework based on 5-methoxybenzene-1,3-dicarboxylic acid and exhibiting a pts net
Authors: Huang Xiao-Hui
Published: April 2013

The solvothermal reaction of MnCl2·H2O and 5-methoxybenzene-1,3-dicarboxylic acid (MeO-m-H2BDC) led to a three-dimensional MnIImetal–organic framework, namely poly[(dimethylformamide-κO)(μ4-5-methoxybenzene-1,3-dicarboxylato-κ4O1:O1′:O3,O3′:O3)manganese(II)], [Mn(C9H6O5)(C3H7NO)]nor [Mn(MeO-m-BDC)(DMF)]n(DMF is dimethylformamide). The MnIIatom is six-coordinated and exhibits a distorted octahedral geometry formed by five carboxylate O atoms from four different MeO-m-BDC2−anionic ligands and by one DMF O atom. The three-dimensional framework of (I) formed by the bridging MeO-m-BDC2−ligands and the MnIIatoms exhibits aptstopological network when MeO-m-BDC2−and MnIIare viewed as four-connected nodes.
Seed harvesting is influenced by associational effects in mixed seed neighbourhoods, not just by seed density
Authors: Ostoja Steven M. , Schupp Eugene W. , Durham Susan , Klinger Rob
Published: April 2013

Rodents frequently forage in a density‐dependent manner, increasing harvesting in patches with greater seed densities. Although seldom considered, seed harvesting may also depend on the species identities of other individuals in the seed neighbourhood. When the seed harvest of a focal species increases in association with another seed species, the focal species suffers from Associational Susceptibility. In contrast, if seeds of the focal species are harvested less when in association with a second species, the focal species benefits from Associational Resistance.

To evaluate density dependence and associational effects among seeds in mixtures, we conducted seed removal experiments using a completely additive design patterned after a two‐species competition experiment using seeds of either Achnatherum hymenoides (Indian ricegrass), Leymus cinereus (basin wildrye) or Pseudoroegneria spicata (bluebunch wheatgrass), all native perennial grasses, combined with seeds of Bromus tectorum (cheatgrass), a non‐native annual grass. The experiment involved placing five fixed quantities of the native seeds mixed with five fixed quantities of B. tectorum seeds in a factorial design, resulting in 35 seed mixture combinations. The seed‐eating rodent community at our study sites, in order of abundance, is composed of Peromyscus maniculatus (North American deer mouse), Dipodomys ordii (Ord's kangaroo rat) and Perognathus parvus (Great Basin pocket mouse).

Native seed harvesting was density dependent, with a greater proportion of seeds being harvested as density increased. In the mixed density model, the presence of B. tectorum did not affect harvest of any of the native species' seeds when analysed individually. However, when all three native species were analysed together, increasing quantities of B. tectorum resulted in reduced harvest of native seeds, demonstrating weak but significant Associational Resistance. In contrast, harvest of B. tectorum seeds increased when in combination with any of the native seed species individually, indicating relatively strong Associational Susceptibility.

These results demonstrate that seed harvest is determined not just by seed density, but also by the local seed neighbourhood and suggest that associational effects between native seeds and B. tectorum can occur in field conditions. The ecological implications of seed selection and associational effects on plant populations in natural and managed systems are also discussed.
Trophic complexity enhances ecosystem functioning in an aquatic detritus‐based model system
Authors: Jabiol Jérémy , McKie Brendan G. , Bruder Andreas , Bernadet Caroline , Gessner Mark O. , Chauvet Eric
Published: April 2013

Understanding the functional significance of species interactions in ecosystems has become a major challenge as biodiversity declines rapidly worldwide. Ecosystem consequences arising from the loss of diversity either within trophic levels (horizontal diversity) or across trophic levels (vertical diversity) are well documented. However, simultaneous losses of species at different trophic levels may also result in interactive effects, with potentially complex outcomes for ecosystem functioning.

Because of logistical constraints, the outcomes of such interactions have been difficult to assess in experiments involving large metazoan species. Here, we take advantage of a detritus–based model system to experimentally assess the consequences of biodiversity change within both horizontal and vertical food‐web components on leaf‐litter decomposition, a fundamental process in a wide range of ecosystems.

Our concurrent manipulation of fungal decomposer diversity (0, 1 or 5 species), detritivore diversity (0, 1 or 3 species), and the presence of predatory fish scent showed that trophic complexity is key to eliciting diversity effects on ecosystem functioning. Specifically, although fungi and detritivores tended to promote decomposition individually, rates were highest in the most complete community where all trophic levels were represented at the highest possible species richness. In part, the effects were trait‐mediated, reflected in the contrasting foraging responses of the detritivore species to predator scent.

Our results thus highlight the importance of interactive effects of simultaneous species loss within multiple trophic levels on ecosystem functioning. If a common phenomenon, this outcome suggests that functional ecosystem impairment resulting from widespread biodiversity loss could be more severe than inferred from previous experiments confined to varying diversity within single trophic levels.
Reconciling resource utilization and resource selection functions
Authors: Hooten Mevin B. , Hanks Ephraim M. , Johnson Devin S. , Alldredge Mat W.
Published: April 2013

Analyses based on utilization distributions (UDs) have been ubiquitous in animal space use studies, largely because they are computationally straightforward and relatively easy to employ. Conventional applications of resource utilization functions (RUFs) suggest that estimates of UDs can be used as response variables in a regression involving spatial covariates of interest.

It has been claimed that contemporary implementations of RUFs can yield inference about resource selection, although to our knowledge, an explicit connection has not been described.

We explore the relationships between RUFs and resource selection functions from a hueristic and simulation perspective. We investigate several sources of potential bias in the estimation of resource selection coefficients using RUFs (e.g. the spatial covariance modelling that is often used in RUF analyses).

Our findings illustrate that RUFs can, in fact, serve as approximations to RSFs and are capable of providing inference about resource selection, but only with some modification and under specific circumstances.

Using real telemetry data as an example, we provide guidance on which methods for estimating resource selection may be more appropriate and in which situations. In general, if telemetry data are assumed to arise as a point process, then RSF methods may be preferable to RUFs; however, modified RUFs may provide less biased parameter estimates when the data are subject to location error.
Antimicrobial use in aquaculture re‐examined: its relevance to antimicrobial resistance and to animal and human health
Authors: Cabello Felipe C. , Godfrey Henry P. , Tomova Alexandra , Ivanova Larisa , Dölz Humberto , Millanao Ana , Buschmann Alejandro H.
Published: April 2013

The worldwide growth of aquaculture has been accompanied by a rapid increase in therapeutic and prophylactic usage of antimicrobials including those important in human therapeutics. Approximately 80% of antimicrobials used in aquaculture enter the environment with their activity intact where they select for bacteria whose resistance arises from mutations or more importantly, from mobile genetic elements containing multiple resistance determinants transmissible to other bacteria. Such selection alters biodiversity in aquatic environments and the normal flora of fish and shellfish. The commonality of the mobilome (the total of all mobile genetic elements in a genome) between aquatic and terrestrial bacteria together with the presence of residual antimicrobials, biofilms, and high concentrations of bacteriophages where the aquatic environment may also be contaminated with pathogens of human and animal origin can stimulate exchange of genetic information between aquatic and terrestrial bacteria. Several recently found genetic elements and resistance determinants for quinolones, tetracyclines, and β‐lactamases are shared between aquatic bacteria, fish pathogens, and human pathogens, and appear to have originated in aquatic bacteria. Excessive use of antimicrobials in aquaculture can thus potentially negatively impact animal and human health as well as the aquatic environment and should be better assessed and regulated.
In situ activity of a dominant Prochlorococcus ecotype (eHL‐II) from rRNA content and cell size
Authors: Lin Yajuan , Gazsi Katrina , Lance Veronica P. , Larkin Alyse A. , Chandler Jeremy W. , Zinser Erik R. , Johnson Zackary I.
Published: April 2013

In the open ocean genetically diverse clades of the unicellular cyanobacteria Prochlorococcus are biogeographically structured along environmental gradients, yet little is known about their in situ activity. To address this gap, here we use the numerically dominant Prochlorococcus clade eHL‐II (eMIT9312) as a model organism to develop and apply a method to examine their in situ activity using rRNA content and cell size as metrics of cellular physiology. For two representative isolates (MIT9312 and MIT9215) rRNA cell−1 increases linearly with specific growth rate but is anticorrelated with cell size indicated by flow cytometrically measured (SSC). Although each strain has a unique relationship between cellular rRNA (or cell size) and growth rate, both strains have the same strong positive correlation between rRNA cell−1 SSC−1 and growth rate. We field test this approach and observe distinct patterns of eHL‐II clade specific activity (rRNA cell−1 SSC−1) with depth that are consistent with patterns of photosynthetic rates. This molecular technique provides unique insight into the ecology of Prochlorococcus and could potentially be expanded to include other microbes to unravel the ecological and biogeochemical contributions of genetically distinct marine side scatter microbes.
WHEN THE TIES THAT BIND UNWIND: EXAMINING THE ENDURING AND SITUATIONAL PROCESSES OF CHANGE BEHIND THE MARRIAGE EFFECT
Authors: BERSANI BIANCA E. , DOHERTY ELAINE EGGLESTON
Published: April 2013

Despite the continued growth of research demonstrating that marriage promotes desistance from crime, efforts aimed at understanding the mechanisms driving this effect are limited. Several theories propose to explain why we observe a reduction in offending after marriage including identity changes, strengthened attachments, reduced opportunities, and changes to routine activities. Although mechanisms are hard to measure, we argue that each proposed mechanism implies a specific change process, that is, whether the change that ensues after marriage is enduring (stable) or situational (temporary). Drawing on a medical model framework, we cast the role of marriage as a treatment condition and observe whether the effect of marriage is conditional on staying married or whether the effect persists when the “treatment” is taken away (i.e., divorce). We use 13 years of monthly level data from the National Longitudinal Survey of Youth (NLSY97), a nationally representative sample containing close to 3,000 individuals with an arrest history, to examine changes in relationship status and arrest from adolescence into young adulthood. Estimates from multilevel within‐individual models reveal greater support for situational mechanisms in that divorce is detrimental particularly for those in longer marriages; yet they also reveal important caveats that suggest a closer examination of the marriage effect. This research adds to the growing body of knowledge regarding the marriage effect by redirecting desistance research away from asking if marriage matters to asking how marriage affects desistance. A better understanding of this change process has important implications for criminal justice policy.
A MULTILEVEL FRAMEWORK FOR UNDERSTANDING POLICE CULTURE: THE ROLE OF THE WORKGROUP
Authors: INGRAM JASON R. , PAOLINE EUGENE A. , TERRILL WILLIAM
Published: April 2013

Relying on a well‐established theoretical paradigm from organizational psychology, the aim of the current inquiry is to apply a multilevel approach to the study of police culture that identifies workgroups as important entities that influence officers’ occupational outlooks. More specifically, we propose that police culture be assessed in a way similar to concepts in criminology, such as collective efficacy and street culture, whereby the shared features of individuals’ environments are considered. Within this framework, we draw on survey data from five municipal police agencies to examine how strongly officers within 187 separate workgroups share culture, as well as the extent to which culture differs across these workgroups. Collectively, the findings suggest that the workgroup serves as a viable context that patterns culture in police organizations. As such, the study provides a way to move beyond conceptualizations of police culture as either a purely monolithic or an individual‐level phenomenon.
A DUAL‐SYSTEMS APPROACH FOR UNDERSTANDING DIFFERENTIAL SUSCEPTIBILITY TO PROCESSES OF PEER INFLUENCE
Authors: THOMAS KYLE J. , MARIE MCGLOIN JEAN
Published: April 2013

The distinct peer‐based perspectives of deviant normative influence and unstructured/unsupervised socializing with friends contend that adolescents rely on different information when deciding to offend, with the former positing that individuals offend after considering the longer term consequences of behavior, and the latter positing that decisions to offend derive from situational stimuli. We argue that these processes can be organized under a dual‐systems framework of decision making, which leads to the hypothesis that individuals at the edges of impulsivity should be differentially vulnerable to these peer influence processes because of their tendency to rely on only one system of decision making. We use two large data sets to test this hypothesis: a nationally representative sample of adolescents from the AddHealth study (N = ∼9,000) and a pooled panel data set of adolescents from the Gang Resistance Education and Training (G.R.E.A.T.) evaluation (N = 1,172). The results of longitudinal negative binomial analyses indicate that normative influence by deviant peers has a stronger effect on delinquency for adolescents with low impulsivity than it does for individuals with high impulsivity. Differences in the informal socializing with peers coefficients are less clear and offer minimal support for our predictions.
Inulin and Erythritol As Sucrose Replacers in Short‐dough Cookies: Sensory, Fracture, and Acoustic Properties
Authors: Laguna Laura , Primo‐Martín Cristina , Salvador Ana , Sanz Teresa
Published: April 2013

The effect of sucrose replacement by erythritol and inulin was studied in short‐dough cookies using instrumental and sensory analysis. Two levels of replacement were used (25% and 50% of total sucrose content). Descriptive sensory analysis showed that the sucrose replacement affects visual and texture cookies characteristics, being the differences perceived by mouth greater than by hand. In general, sucrose substitutes produced a less crispy cookie and lower consumer acceptability, with the exception of 25% sucrose replacement by inulin. Matrix aeration attributes such as open and crumbly obtained by trained panel were important properties, and correlated positively with consumer acceptance and negatively with maximum force at break (hardness). Inulin cookies sensory properties were more similar to the control than the erythritol cookies. Also, consumer overall acceptance decreased significantly with sucrose replacement by erythritol. The analysis of texture and sound revealed that inulin cookies were softer whereas erythritol cookies were harder in comparison with control cookies; despite this difference, inulin cookies had similar sound characteristics to erythritol cookies.

Practical Application Erythritol and inulin were evaluated as partial sucrose replacer in cookies. Changes in sensory and instrumental data were observed but a replacement of 25% sucrose was achieved without having a detrimental effect on consumer perception.
Impaired liver regeneration by β‐glucosylceramide is associated with decreased fat accumulation
Authors: Ben Ya'acov Ami , Lalazar Gadi , Zolotaryova Lydia , Steinhardt Yair , Lichtentein Yoav , Ilan Yaron , Shteyer Eyal
Published: April 2013

Objective

To investigate the effect of β‐glucosylceramide (GC), a natural glycolipid, on hepatic fat accumulation and regenerative response after partial hepatectomy (PH).

Methods

Male C57Bl/6 mice were assigned to either 70% PH or sham surgery after receiving daily intraperitoneal injection of GC or vehicle for 3 days. Hepatic fat accumulation, cytokines, cell cycle proteins and adipogenic genes expression were assessed at various time points after PH.

Results

The administration of GC delayed hepatic triglyceride accumulation during hepatic regeneration. This observation was closely correlated with alterations in the expression of four major adipogenic genes during the course of liver regeneration, with reduced expression 3 h after PH and increased expression 48 h post‐surgery. GC significantly reduced hepatocellular proliferation 48 h after PH. In GC‐treated mice, both tumor necrosis factor‐α and interleukin‐6 levels were lower 3, 48 and 72 h after PH compared with the control group.

Conclusions

Administration of GC delayed hepatic triglyceride accumulation and suppressed early adipogenic gene expression during the hepatic regenerative response. These changes are closely associated with early inhibition of liver regeneration and temporal alteration of cytokine secretion.
Role of NF‐κβ and Oxidative Pathways in Atherosclerosis: Cross‐Talk Between Dyslipidemia and Candesartan
Authors: Hadi Najah R. , Yousif Nasser Ghaly , Abdulzahra Mohammed S. , Mohammad Bassim I. , al‐amran Fadhil G. , Majeed Murooge L. , Yousif Maitham G.
Published: April 2013

Purpose

The objective of this study is to assess the effect of the candesartan on the progression of atherosclerosis through the downregulation of NF‐κβ and interference with oxidative pathway.

Methods

Twenty‐four rabbits were assigned to three groups: control group fed normal diet; induced untreated group fed 1% cholesterol diet; and treated candesartan group also fed 1% cholesterol diet. Plasma lipid profiles were measured, and ELISA for plasma cytokines and chemokine was performed. Analyses of NF‐κβ and VCAM‐1 were performed using Western blotting with RT‐PCR for NF‐κB activity at mRNA. Doppler ultrasound was used to evaluate aortic intima‐media thickness, and atheroma was detected by H&E staining. Immunofluorescent staining was performed to confirm accumulation of monocytes and PMNs.

Results

Candesartan markedly reduced the levels of the plasma lipid profile including total cholesterol [TC], triglycerides [TG], and LDL‐C, while significantly elevating levels in the plasma HDL‐C, in addition to reducing cytokine (TNF‐α, IL‐6, IL‐1β) and chemokine levels (MCP‐1). Also, it decreased the aortic malondialdehyde (MDA) concentration and elevated the aortic glutathione (GSH) level compared with untreated animals (P < 0.05). The triplex Doppler ultrasound study confirmed that the candesartan attenuated intima‐media thickness at 6 months of study. All candesartan‐treated rabbits showed significantly attenuated atherosclerosis lesions with reduced accumulation of monocytes and had significantly reduced VCAM‐1 expression and NF‐κβ activity.

Conclusion

Candesartan retards the progression of atherosclerosis via interference with NF‐κβ and oxidative pathways.
Congruence between mcy based genetic type and microcystin composition within the populations of toxic Microcystis in a plateau lake, China
Authors: Jiang Yongguang , Yu Gongliang , Chai Wenbo , Song Gaofei , Li Renhui
Published: April 2013

Genetic diversity and differential microcystin contributions within the populations of toxic Microcystis in freshwater ecosystems have not been fully discussed. To illustrate this issue, we sequenced clone libraries of the first adenylation domain of mcyB (mcyBA1) from Microcystis populations in a plateau lake. Phylogenetic analysis revealed two divergent groups of McyBA1 with two closely related subgroups within Group I. While neutral evolution was indicated on the whole McyBA1 domain, 1–5 recombination breakpoints and several codons under positive or negative selections were found. Significant seasonal changes of McyBA1 diversity were observed. Group I composed the major proportion of the McyBA1 pool throughout the growing season in the whole lake. Group IA and Group II denominated Microcystis strains isolated from this lake were characterized by preference production of microcystin‐RR (62–85%) and microcystin‐LR (> 98%) respectively. We detected the intracellular microcystins in lake water and microcystin‐RR was a main variant (mostly > 50%). In summary, McyBA1 subgroups were dominant within the population of toxic Microcystis and contributed the predominance of microcystin‐RR in the lake. The differences of substrate preference in microcystin biosynthesis among groups were caused by neutral evolution and homologous recombination.
Microbial community composition and endolith colonization at an Arctic thermal spring are driven by calcite precipitation
Authors: Starke Verena , Kirshtein Julie , Fogel Marilyn L. , Steele Andrew
Published: April 2013

Environmental conditions shape community composition. Arctic thermal springs provide an opportunity to study how environmental gradients can impose strong selective pressures on microbial communities and provide a continuum of niche opportunities. We use microscopic and molecular methods to conduct a survey of microbial community composition at Troll Springs on Svalbard, Norway, in the high Arctic. Microorganisms there exist under a wide range of environmental conditions: in warm water as periphyton, in moist granular materials, and in cold, dry rock as endoliths. Troll Springs has two distinct ecosystems, aquatic and terrestrial, together in close proximity, with different underlying environmental factors shaping each microbial community. Periphyton are entrapped during precipitation of calcium carbonate from the spring's waters, providing microbial populations that serve as precursors for the development of endolithic communities. This process differs from most endolith colonization, in which the rock predates the communities that colonize it. Community composition is modulated as environmental conditions change within the springs. At Troll, the aquatic environments show a small number of dominant operational taxonomic units (OTUs) that are specific to each sample. The terrestrial environments show a more even distribution of OTUs common to multiple samples.
Low hydrogen peroxide production in mitochondria of the long‐lived Arctica islandica: underlying mechanisms for slow aging
Authors: Munro Daniel , Pichaud Nicolas , Paquin Frédérique , Kemeid Vincent , Blier Pierre U.
Published: April 2013

The observation of an inverse relationship between lifespan and mitochondrial H2O2 production rate would represent strong evidence for the disputed oxidative stress theory of aging. Studies on this subject using invertebrates are surprisingly lacking, despite their significance in both taxonomic richness and biomass. Bivalve mollusks represent an interesting taxonomic group to challenge this relationship. They are exposed to environmental constraints such as microbial H2S, anoxia/reoxygenation, and temperature variations known to elicit oxidative stress. Their mitochondrial electron transport system is also connected to an alternative oxidase that might improve their ability to modulate reactive oxygen species (ROS) yield. Here, we compared H2O2 production rates in isolated mantle mitochondria between the longest‐living metazoan—the bivalve Arctica islandica—and two taxonomically related species of comparable size. In an attempt to test mechanisms previously proposed to account for a reduction of ROS production in long‐lived species, we compared oxygen consumption of isolated mitochondria and enzymatic activity of different complexes of the electron transport system in the two species with the greatest difference in longevity. We found that A. islandica mitochondria produced significantly less H2O2 than those of the two short‐lived species in nearly all conditions of mitochondrial respiration tested, including forward, reverse, and convergent electron flow. Alternative oxidase activity does not seem to explain these differences. However, our data suggest that reduced complex I and III activity can contribute to the lower ROS production of A. islandica mitochondria, in accordance with previous studies. We further propose that a lower complex II activity could also be involved.
Periorbital allergic contact dermatitis resulting from topical retinoic acid use
Authors: Anderson Austen , Gebauer Kurt
Published: April 2013

Contact dermatitis to topical tretinoin or retinoic acid is rarely described. We outline the case of a 20‐year‐old woman presenting with bilateral periorbital dermatitis against the background of longstanding use of retinoic acid for the ocular complications of toxic epidermal necrolysis. Patch testing confirmed a contact allergy to retinoic acid and the symptoms of the dermatitis resolved after the cessation of retinoic acid.
Decellularized Porcine Saphenous Artery for Small‐Diameter Tissue‐Engineered Conduit Graft
Authors: Xiong Yun , Chan Wing Yue , Chua Alvin W.C. , Feng Jiajun , Gopal Pamela , Ong Yee Siang , Song Colin
Published: April 2013

Decellularized xenografts have been identified as potential scaffolds for small‐diameter vascular substitutes. This study aimed to develop and investigate a biomechanically functional and biocompatible acellular conduit using decellularized porcine saphenous arteries (DPSAs), through a modified decellularization process using Triton X‐100/NH4OH solution and serum‐containing medium. Histological and biochemical analysis indicated a high degree of cellular removal and preservation of the extracellular matrix. Bursting pressure tests showed that the DPSAs could withstand a pressure of 1854 ± 164 mm Hg. Assessment of in vitro cell adhesion and biocompatibility showed that porcine pulmonary artery endothelial cells were able to adhere and proliferate on DPSAs in static and rotational culture. After interposition into rabbit carotid arteries in vivo, DPSAs showed patency rates of 60% at 1 month and 50% at 3 months. No aneurysm and intimal hyperplasia were observed in any DPSAs. All patent grafts showed regeneration of vascular elements, and thrombotic occlusion was found to be the main cause of graft failure, probably due to remaining xenoantigens. In conclusion, this study showed the development and evaluation of a decellularization process with the potential to be used as small‐diameter grafts.
Juvenile eye growth, when completed? An evaluation based on IOL‐Master axial length data, cross‐sectional and longitudinal
Authors: Fledelius Hans C. , Christensen Anders S. , Fledelius Christian
Published: April 2013

Purpose:  To test Sorsby’s classical statement of axial eye growth as completed at the age of 13 years, with a view also to differentiating between basic eye growth and juvenile elongation associated with eventual refractive change towards myopia.

Methods:  (i) A total of 160 healthy eyes close to emmetropia were included in a cross‐sectional set‐up (age 4–20 years, 91 males, 69 females), and (ii) 78 longitudinal data sets (67 male and 11 female annual repeat exams over 2–7 years, n = 30; age span 4–19 years) were available for evaluating individual axial elongation. The IOL‐Master equipment was preferred for conventional ultrasound oculometry due to its extreme repeatability of measuring values, thus making it well fitted for evaluating very small differences. In particular, this had bearing for the decelerating end phase of growth in the longitudinal investigation.

Results:  Sorby’s statement about age 13 as general limit found support from the cross‐sectional data, which suggested stable emmetropic eye size from about 11–12 years, with an average apparently outgrown male emmetropic value of 23.5 mm versus females’ 22.9 mm. The longitudinal data, however, showed emmetropic growth also beyond this age, with individual data to establish continued axial elongation also at age 13–18 years. The final basic teenage growth is however minute and without practical implications.

Conclusions:  Individual ocular growth curves have indicated axial elongation to occur also after the age of 13 years. With regard to the – mainly academic – discrepancy between cross‐sectional and longitudinal results, bigger samples are needed, and the juvenile myopic trend has to be acknowledged.
Co‐evolution of mobile language learning: Going global with games consoles in higher education
Authors: Hemmi Akiko , Narumi‐Munro Fumiko , Alexander Wilma , Parker Helen , Yamauchi Yoko
Published: April 2013

Game consoles have been adopted as a learning platform in school education. However, there is a scarcity of studies examining the utility of games consoles with built‐in WiFi as affordable learning platforms in universities. This paper contributes to knowledge about the capacity of the Nintendo DSi to create new learning spaces mediated and supported by DSi consoles, free Flipnote Studio software for DS and a dedicated course website. An application of the DSi is described for remote supplemental language tutorial activities linking a dispersed body of students on a year‐abroad programme. It was found that the use of DSi as a mobile learning platform has great potential if it is used in combination with shared webspace, such as Hatena, by increasing students' learning motivation and eliminating fears/uncertainty about their progress.
A framework of combining case‐based reasoning with a work breakdown structure for estimating the cost of online course production projects
Authors: He Wu
Published: April 2013

Currently, a work breakdown structure (WBS) approach is used as the most common cost estimation approach for online course production projects. To improve the practice of cost estimation, this paper proposes a novel framework to estimate the cost for online course production projects using a case‐based reasoning (CBR) technique and a WBS. A prototype was developed to illustrate the effectiveness of the framework. Preliminary results suggest that the combined approach of using CBR and WBS is preferred and enables project managers to generate reasonable estimates for online course production projects more efficiently.
Effects of mitochondrial ferritin overexpression in normal and sideroblastic erythroid progenitors
Authors: Invernizzi Rosangela , Travaglino Erica , Della Porta Matteo G. , Gallì Anna , Malcovati Luca , Rosti Vittorio , Bergamaschi Gaetano , Erba Benedetta G. , Bellistri Francesca , Bastia Raffaella , Santambrogio Paolo , Levi Sonia , Cazzola Mario
Published: April 2013

In myelodysplastic syndromes with ring sideroblasts (MDS‐RS), the iron deposited in the mitochondria of RS is present in the form of mitochondrial ferritin (FTMT), but it is unknown whether FTMT overexpression is the cause or the result of mitochondrial iron deposition. Lentivirus FTMT‐transduced CD34+ bone marrow cells from seven healthy donors and CD34+ cells from 24 patients with MDS‐RS were cultured according to a procedure that allowed the expansion of high numbers of erythroid progenitors. These cells were used to investigate the possible influence of experimentally‐induced FTMT overexpression on normal erythropoiesis and the functional effects of FTMT in sideroblastic erythropoiesis. In MDS‐RS progenitors, FTMT overexpression was associated with reduced cytosolic ferritin levels, increased surface transferrin receptor expression and reduced cell proliferation; FTMT effects were independent of SF3B1 mutation status. Similarly, FTMT overexpressing normal erythroid progenitors were characterized by reduced cytosolic ferritin content and increased CD71 expression, and also by higher apoptotic rate in comparison with the FTMT‐ controls. Significantly lower levels of STAT5 phosphorylation following erythropoietin stimulation were found in both sideroblastic and normal FTMT+ erythroid cells compared to the FTMT‐ cells. In conclusion, experimental overexpression of FTMT may modify mitochondrial iron availability and lead to ineffective erythropoiesis.
A cost‐minimisation analysis comparing photoselective vaporisation (PVP) and transurethral resection of the prostate (TURP) for the management of symptomatic benign prostatic hyperplasia (BPH) in Queensland, Australia
Authors: Whitty Jennifer A. , Crosland Paul , Hewson Kaye , Narula Rajan , Nathan Timothy R. , Campbell Peter A. , Keller Andrew , Scuffham Paul A.
Published: April 2013

Objectives

To compare the costs of photoselective vaporisation (PVP) and transurethral resection of the prostate (TURP) for management of symptomatic benign prostatic hyperplasia (BPH) from the perspective of a Queensland public hospital provider.

Patients and Methods

A decision‐analytic model was used to compare the costs of PVP and TURP.

Cost inputs were sourced from an audit of patients undergoing PVP or TURP across three hospitals.

The probability of re‐intervention was obtained from secondary literature sources.

Probabilistic and multi‐way sensitivity analyses were used to account for uncertainty and test the impact of varying key assumptions.

Results

In the base case analysis, which included equipment, training and re‐intervention costs, PVP was AU$ 739 (95% credible interval [CrI] –12 187 to 14 516) more costly per patient than TURP.

The estimate was most sensitive to changes in procedural costs, fibre costs and the probability of re‐intervention.

Sensitivity analyses based on data from the most favourable site or excluding equipment and training costs reduced the point estimate to favour PVP (incremental cost AU$ –684, 95% CrI –8319 to 5796 and AU$ –100, 95% CrI –13 026 to 13 678, respectively). However, CrIs were wide for all analyses.

Conclusions

In this cost minimisation analysis, there was no significant cost difference between PVP and TURP, after accounting for equipment, training and re‐intervention costs.

However, PVP was associated with a shorter length of stay and lower procedural costs during audit, indicating PVP potentially provides comparatively good value for money once the technology is established.
Children's Naive Theories of Intelligence Influence Their Metacognitive Judgments
Authors: Miele David B. , Son Lisa K. , Metcalfe Janet
Published: April 2013

Recent studies have shown that the metacognitive judgments adults infer from their experiences of encoding effort vary in accordance with their naive theories of intelligence. To determine whether this finding extends to elementary schoolchildren, a study was conducted in which 27 third graders (Mage = 8.27) and 24 fifth graders (Mage = 10.39) read texts presented in easy‐ or difficult‐to‐encode fonts. The more children in both grades viewed intelligence as fixed, the less likely they were to interpret effortful or difficult encoding as a sign of increasing mastery and the more likely they were to report lower levels of comprehension as their perceived effort increased. This suggests that children may use naive theories of intelligence to make motivationally relevant inferences earlier than previously thought.
The development and validation of a questionnaire to measure the clinical learning environment for undergraduate dental students (DECLEI)
Authors: Kossioni A. E. , Lyrakos G. , Ntinalexi I. , Varela R. , Economu I.
Published: April 2013

Aim

The aim of this study was to develop and validate according to psychometric standards a self‐administered instrument to measure the students' self‐perceptions of the undergraduate clinical dental environment (DECLEI).

Materials and methods

The initial questionnaire was developed using feedback from dental students, experts' opinion and an extensive literature review. Critical incident technique (CIT) analysis was used to generate items and identify domains. Thirty clinical dental students participated in a pilot validation that generated a 67‐item questionnaire. To develop a shorter and more practical version of the instrument, DECLEI‐67 was distributed to 153 clinical students at the University of Athens and its English version to 51 students from various dental schools, attending the 2012 European Dental Students Association meeting. This final procedure aimed to select items, identify subscales and measure internal consistency and discriminant validity.

Results

A total of 202 students returned the questionnaires (response rate 99%). The final instrument included 24 items divided into three subscales: (i) organisation and learning opportunities, (ii) professionalism and communication and (iii) satisfaction and commitment to the dental studies. Cronbach's α for the total questionnaire was 0.89. The interscale correlations ranged from 0.39 to 0.48. The instrument identified differences related to school of origin, age and duration of clinical experience. An interpretation of the scores (range 0–100) has been proposed.

Conclusions

The 24‐item DECLEI seemed to be a practical and valid instrument to measure a dental school's undergraduate clinical learning environment.
Mice lacking the Parkinson's related GPR37/PAEL receptor show non‐motor behavioral phenotypes: age and gender effect
Authors: Mandillo S. , Golini E. , Marazziti D. , Di Pietro C. , Matteoni R. , Tocchini‐Valentini G. P.
Published: April 2013

Non-motor symptoms in Parkinson's disease (PD) have been often described at different stages of the disease but they are poorly understood. We observed specific phenotypes related to these symptoms in mice lacking the PD‐associated GPR37/PAEL receptor. GPR37 is an orphan G‐protein‐coupled receptor highly expressed in the mammalian central nervous system. It is a substrate of parkin and it is involved in the pathogenesis of PD. GPR37 interacts with the dopamine transporter (DAT), modulating nigro‐striatal dopaminergic signaling and behavioral responses to amphetamine and cocaine. GPR37 knockout (KO) mice are resistant to MPTP and exhibit several motor behavioral abnormalities related to altered dopaminergic system function. To evaluate non-motor behavioral domains, adult and aged, male and female GPR37 KO mice and their wild‐type (WT) littermates were analyzed in a series of cross‐sectional studies. Aged GPR37 KO female mice showed mild improvements in olfactory function, while anxiety and depression‐like behaviors appeared to be significantly increased. A reduction of the startle response to acoustic stimuli was observed only in adult GPR37 KO mice of both genders. Furthermore, HPLC analysis of major neurotransmitter levels revealed gender differences in the striatum, hippocampus and olfactory bulb of mutant mice. The absence of GPR37 receptor could have a neuroprotective effect in an age and gender‐dependent manner, and the study of this receptor could be valuable in the search for novel therapeutic targets.
The impact of haemarthropathy on the QoL of Korean severe haemophilia A patients: the critical level of haemarthropathy for the QoL
Authors: You C. W.
Published: April 2013

The minimum goal of secondary prophylaxis may be to delay the progression of haemarthropathy below a critical level over which it has a great impact on the QoL of haemophilia patients. However, the critical level of haemarthropathy may be different across countries. For these reasons, the impact of haemarthropathy on the QoL in Korean haemophilia A patients was investigated. Depending on observed Pettersson scores of 27 severe haemophilia A patients, they were divided into three groups, P (Pettersson score) ≤10, P11~19 and P ≥ 20 groups. The QoL of each patient, assessed by the SF36, was compared between the groups. In addition, the changes in the QoL of the patients were observed according to the changes of Pettersson scores to find out the critical level of arthropathy. None of the scores of the SF36 scales were different between the P ≤ 10 and P11~19 groups. In contrast, the scores of PF and MH scales were significantly different between the P11~19 and P ≥ 20 groups. When changes in the scores of each scale in the SF36 were observed according to changes in Pettersson scores, the average P score of 13.0 ± 2.7 was thought to be the critical level of haemarthropathy because above that level, haemarthropathy and physical and mental health of the patients rapidly deteriorated. The progression of haemarthropathy to the critical level should be delayed as long as possible to prevent or to delay a rapid deterioration of the QoL of Korean patients with haemophilia.
Epicrania Fugax: 19 Cases of an Emerging Headache
Authors: Cuadrado María Luz , Ordás Carlos M. , Sánchez‐Lizcano María , Casas‐Limón Javier , Matías‐Guiu Jordi A. , García‐García María Eugenia , Fernández‐Matarrubia Marta , Barahona‐Hernando Raúl , Porta‐Etessam Jesús
Published: April 2013

Objective

Epicrania fugax (EF) is a primary headache of recent description. We aimed to report 19 new cases of EF, and thus contribute to the characterization of this emerging headache.

Background

EF is characterized by painful paroxysms starting in a particular area of the head, and rapidly radiating forwards or backwards through the territories of different nerves. The pain is felt in quick motion along a lineal or zigzag trajectory. To date, 47 cases have been published, 34 with forward EF and 13 with backward EF.

Methods

We performed a descriptive study of all EF cases attending our Headache Unit from April 2010 to December 2012. Demographic and clinical data were recorded with a structured questionnaire.

Results

Overall, there were 12 women and 7 men. Mean age at onset was 51.7 ± 16.2. Fourteen patients had forward EF, while 5 patients had backward EF. Painful paroxysms lasted 1‐4 seconds. Pain intensity was usually moderate or severe, and pain quality was mostly electric. Four patients had ocular autonomic accompaniments. Pain frequency was extremely variable, and 7 patients identified some triggers. Between attacks, 13 patients had some pain or tenderness in the stemming area. Thirteen patients required therapy for their pain. Neuromodulators, indomethacin, anesthetic blockades, and steroid injections were used in different cases, with partial or complete response.

Conclusion

EF appears as a distinct headache syndrome and could be eventually included in future editions of the International Classification of Headache Disorders.