bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced radiation tolerance in nitride multilayered nanofilms with small period-thicknesses
Authors: Hong Mengqing , Ren Feng , Zhang Hongxiu , Xiao Xiangheng , Yang Bing , Tian Canxin , Fu Dejun , Wang Yongqiang , Jiang Changzhong
Published: October 2012

This paper demonstrates a substantial enhancement in radiation tolerance for small period-thickness of CrN/AlTiN multilayered nanofilms. CrN/AlTiN multilayered nanofilms with period-thicknesses of 3, 5, 7, and 9 nm were irradiated by 190 keV Ar+ ions to fluences ranging from 1 to 5 × 1016 ions/cm2. Nanofilm with 3 nm period-thickness begins to be amorphized under 5 × 1016 ions/cm2, while those with larger period-thicknesses are amorphized under 3 × 1016 ions/cm2. Our results show that multilayered ceramic nanofilms are potential radiation tolerant materials with good properties. The interfaces in the multilayered nanofilms act as good sinks to absorb the radiation-induced defects.
Micromachined switchable metamaterial with dual resonance
Authors: Zhang W. , Liu A. Q. , Zhu W. M. , Li E. P. , Tanoto H. , Wu Q. Y. , Teng J. H. , Zhang X. H. , Tsai M. L. J. , Lo G. Q. , Kwong D. L.
Published: October 2012

We experimentally demonstrate a micromachined switchable metamaterial with dual mode resonance which is induced at THz regime under oblique incidence. Here, we explore, both theoretically and experimentally, the dynamic dual mode switching by reshaping metamaterial elements using micromachined actuators. The mode switching allows robust control over the transmission and the reflection of the metamaterial at 0.76 THz and 1.16 THz. Such switchable dual mode metamaterial promises wide applications in optical switches, tunable filters, and THz detectors.
The cooling effect on structural, electrical, and optical properties of epitaxial a-plane ZnO:Al on r-plane sapphire grown by pulsed laser deposition
Authors: Peng Chun-Yen , Liu Yuan-An , Wang Wei-Lin , Tian Jr-Sheng , Chang Li
Published: October 2012

Here, the unambiguous effect of cooling rate on structural, electrical, and optical properties of a-plane ZnO:Al on r-plane sapphire grown by pulsed laser deposition at 700 °C is reported. A high cooling rate (∼100 °C/min) can result in stripe morphology along m-direction and significant deformation on the epitaxial films of a-plane ZnO:Al with deteriorated crystallinity and significantly lowered resistivity. Also, photoluminescence spectra exhibit high intensities of excess violet and green emissions with low intensity of near band edge luminescence. Comparison with pure a-plane ZnO films is also presented.
The roles of hydrogen in the diamond/amorphous carbon phase transitions of oxygen ion implanted ultrananocrystalline diamond films at different annealing temperatures
Authors: Hu X. J. , Chen X. H. , Ye J. S.
Published: October 2012

We report that the diffusion and desorption of hydrogen (H) play a key role in the diamond/amorphous carbon phase transitions of O+-implanted UNCD films at different annealing temperatures (Ta) by using high resolution transmission electronic microscopy (HRTEM), vis-uv Raman, and Fourier transform infrared (FTIR) spectroscopy measurements. The results of HRTEM and uv Raman spectroscopy measurements show that with Ta increasing from 500 to 900 °C, the amorphous carbon in grain boundaries (GBs) transits to diamond phase. Visible Raman spectroscopy measurements show that the amount of H bonded to trans-polyacetylene (TPA) chains in GBs reduces with Ta increasing to 900 °C, while that of H terminating to the surfaces of diamond grains increases confirmed by FTIR measurements. It reveals that H diffuses from GBs to the surfaces of diamond grains. In this process, the active H extracts H which terminates the diamond surface, leaving a reactive surface site. This gives a chance for the neighbored amorphous carbon clusters to attach to the surface site, so that diamond grains become larger. After 1000 °C annealing, the amount of diamond phase dramatically decreases and diamond transits to amorphous carbon by HRTEM and uv Raman spectroscopy. It is observed that the amount of H bonded to TPA chains in GBs and that of H terminating to the surfaces of diamond grains dramatically decreases from visible Raman spectroscopy and FTIR measurements. It is revealed that H is desorbed from both surfaces of diamond grains and GBs, which forces diamond grains to collapse to amorphous carbon.
Degenerate crystalline silicon films by aluminum-induced crystallization of boron-doped amorphous silicon
Authors: Hwang J. D. , Luo L. C. , Hsueh T. J. , Hwang S. B.
Published: October 2012

Degenerate p-type crystalline silicon film with a hole concentration of 4 × 1021 cm−3 was investigated using aluminum-induced crystallization (AIC) of boron-doped amorphous silicon (a-Si). The AIC mechanism is different from that in the undoped AIC-Si. Boron atoms accumulate at Al layer forming a boron bump and segregate the Al atoms into Si layer, resulting to the formation of AlSi alloy. The degeneracy is not attributed to boron doping but instead to the AlSi alloy. Observations show that Al and Si layer transfer occurs not at original interface of Al and Si, but at the boron bump.
Relative intensity noise of a quantum well transistor laser
Authors: Tan F. , Bambery R. , Feng M. , Holonyak N.
Published: October 2012

A quantum well transistor laser with a base cavity length L = 300 μm has been designed, fabricated, and operated at threshold ITH = 25 mA (0 °C). As a consequence of the inherent advantage of the picosecond base recombination lifetime, the transistor laser is able to achieve nearly a quantum shot-noise limited laser relative intensity noise (RIN) with a peak amplitude of −151 dB/Hz at frequency 8.6 GHz. Compared with a diode laser (a charge storage device) at the same output power, the transistor laser (a charge flow device) has a better than 28 dB (number dependent on the laser device design) peak RIN advantage.
Semitransparent polymer solar cells with one-dimensional (WO3/LiF)N photonic crystals
Authors: Yu Wenjuan , Shen Liang , Long Yongbing , Guo Wenbin , Meng Fanxu , Ruan Shengping , Jia Xu , Ma Hongshi , Chen Weiyou
Published: October 2012

One-dimensional (WO3/LiF)N photonic crystals (1DPCs) are deposited on the Ag cathode of the semitransparent polymer solar cells to improve the efficiency of the device. The 1DPCs with 8 pair of WO3/LiF act as distributed reflectors within the photonic bandgap. Then, power conversion efficiency of 2.58% is achieved and there is an improvement of 26.3% in the efficiency when compared with that of the conventional device without the 1DPCs. The average transmittance of the device with 8 pair of WO3/LiF is almost zero in 400–600 nm wavelength range. It means that the light is absorbed sufficiently in the active layer. The enhanced light absorption results in efficiency improvement remarkably.
Differential expression of the P2X7 receptor in ovarian surface epithelium during the oestrous cycle in the mouse
Authors: Vázquez-Cuevas F. G. , Cruz-Rico A. , Garay E. , García-Carrancá A. , Pérez-Montiel D. , Juárez B. , Arellano R. O.
Published: October 2012

Purinergic signalling has been proposed as an intraovarian regulatory mechanism. Of the receptors responsible for purinergic transmission, the P2X7 receptor is an ATP-gated cationic channel that displays a broad spectrum of cellular functions ranging from apoptosis to cell proliferation and tumourigenesis. In the present study, we investigated the functional expression of P2X7 receptors in ovarian surface epithelium (OSE). P2X7 protein was detected in the OSE layer of the mouse, both in situ and in primary cultures. In cultures, 2′(3′)-O-(4-Benzoylbenzoyl)adenosine-5′-triphosphate (BzATP) activation of P2X7 receptors increased [Ca2+]i and induced apoptosis. The functionality of the P2X7 receptor was investigated in situ by intrabursal injection of BzATP on each day of the oestrous cycle and evaluation of apoptosis 24 h using the terminal deoxyribonucleotidyl transferase-mediated dUTP–fluorescein nick end-labelling (TUNEL) assay. Maximum effects of BzATP were observed during pro-oestrus, with the effects being blocked by A438079, a specific P2X7 receptor antagonist. Immunofluorescence staining for P2X7 protein revealed more robust expression during pro-oestrus and in OSE regions behind the antral follicles, strongly supporting the notion that the differences in apoptosis can be explained by increased receptor expression, which is regulated during the oestrous cycle. Finally, P2X7 receptor expression was detected in the OSE layer of human ovaries, with receptor expression maintained in human ovaries diagnosed with cancer, as well as in the human ovarian carcinoma SKOV3 cell line.
The perception and adaptation of herdsmen to climate change and climate variability in the desert steppe region of northern China
Authors: Hou Xiang-Yang , Han Ying , Li Frank Yonghong
Published: October 2012

The herdsmen in the desert steppe region in Northern China live primarily on the native rangelands. The semiarid climate has a profound impact on the economy and the livelihood of rural communities. Adaptation to the highly variable climate is the norm in pastoral management in the region but the increasing aridity and variability projected by climate change models provides new challenges for sustainable living in the harsh environment. The study surveyed the herdsmen’s perception of climate change and variability in the desert steppe region of Inner Mongolia, and compared it with the observed climatic patterns and the recorded disastrous climatic events. The existing rangeland and livestock management strategies used by local herdsmen to cope with variable climate were also investigated in order to assist in the development of better management adaptation strategies. The herdsman perceived temperature changes over the past 30 years, which matched well with the meteorological observations, while their perceived change in precipitation (decrease) did not agree with the meteorological records (no change). The discrepancy between the observed and perceived precipitation changes may have arisen from the combination of large seasonal and inter-annual fluctuation of precipitation, more recent drought years and a herdsmen’s desire to have a ‘wet year’, and more forage demand from increased livestock numbers. Herdsmen also had a reasonably good perception of strong wind/dust storms and snow storms, and their sensitivity to these extreme disastrous climatic events appeared to be related to the perception of drought. The herdsmen had better perceptions of recent short-term climate change and possibly to use it to assess the long-term changes. The major adaptive management strategies to cope with disastrous climatic events included selling livestock, buying feed, seeking other grazing resources, housing livestock and looking for other alternative jobs to compensate for the economic loss. Grazing other resources, either the reserved winter rangelands in the growing season in current household farm systems or the common winter rangelands in a traditional nomadic system, played a vital role in buffering the effects of extreme climatic events. Setting appropriate stocking rates and growing forage crops in suitable land areas may contribute to increasing the resilience of rangeland systems. Raising the herdsmen’s awareness of long-term climate change and its effects on rangelands is needed to improve their preparedness to adapt to the future climate.
The influence of fuel moisture content on the combustion of Eucalyptus foliage
Authors: Possell Malcolm , Bell Tina L.
Published: October 2012

Leaves from three species of Eucalyptus were combusted in a mass-loss calorimeter to characterise the effect of fuel moisture on energy release and combustion products for this genus. Increasing moisture content reduced peak heat release and the effective heat of combustion in a negative exponential pattern while simultaneously increasing time-to-ignition. Estimates of the probability of ignition, based upon time-to-ignition data, indicated that the critical fuel moisture content for a 50% probability of ignition ranged from 81 to 89% on a dry-weight basis. The modified combustion efficiency of leaves (the ratio of CO2 concentration to the sum of the CO2 and CO concentrations) decreased exponentially as fuel moisture increased. This was because CO2 concentrations during combustion declined exponentially while CO concentrations increased exponentially. However, CO2 mixing ratios were always greater by at least one order of magnitude. Emission factors for CO2 declined exponentially with increasing fuel moisture content while CO emission factors increased exponentially to a maximum. The emission factors for volatile organic compounds increased in a pattern similar to that for CO with increasing fuel moisture content. The empirical relationships identified in this study have implications for fire-behaviour modelling and assessing the effect of fire on air quality and climate.
Synthetic zinc finger repressors reduce mutant huntingtin expression in the brain of R6/2 mice
Authors: Garriga-Canut Mireia , Agustín-Pavón Carmen , Herrmann Frank , Sánchez Aurora , Dierssen Mara , Fillat Cristina , Isalan Mark
Published: October 2012

Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by expanded CAG repeats in the huntingtin (
HTT
) gene. Although several palliative treatments are available, there is currently no cure and patients generally die 10–15 y after diagnosis. Several promising approaches for HD therapy are currently in development, including RNAi and antisense analogs. We developed a complementary strategy to test repression of mutant
HTT
with zinc finger proteins (ZFPs) in an HD model. We tested a “molecular tape measure” approach, using long artificial ZFP chains, designed to bind longer CAG repeats more strongly than shorter repeats. After optimization, stable ZFP expression in a model HD cell line reduced chromosomal expression of the mutant gene at both the protein and mRNA levels (95% and 78% reduction, respectively). This was achieved chromosomally in the context of endogenous mouse
HTT
genes, with variable CAG-repeat lengths. Shorter wild-type alleles, other genomic CAG-repeat genes, and neighboring genes were unaffected. In vivo, striatal adeno-associated virus viral delivery in R6/2 mice was efficient and revealed dose-dependent repression of mutant
HTT
in the brain (up to 60%). Furthermore, zinc finger repression was tested at several levels, resulting in protein aggregate reduction, reduced decline in rotarod performance, and alleviation of clasping in R6/2 mice, establishing a proof-of-principle for synthetic transcription factor repressors in the brain.
Thalamic model of awake alpha oscillations and implications for stimulus processing
Authors: Vijayan Sujith , Kopell Nancy J.
Published: October 2012

We describe a unique conductance-based model of awake thalamic alpha and some of its implications for function. The full model includes a model for a specialized class of high-threshold thalamocortical cells (HTC cells), which burst at the alpha frequency at depolarized membrane potentials (∼−56 mV). Our model generates alpha activity when the actions of either muscarinic acetylcholine receptor (mAChR) or metabotropic glutamate receptor 1 (mGluR1) agonists on thalamic reticular (RE), thalamocortical (TC), and HTC cells are mimicked. In our model of mGluR1-induced alpha, TC cells are equally likely to fire during any phase of alpha, consistent with in vitro experiments. By contrast, in our model of mAChR-induced alpha, TC cells tend to fire either at the peak or the trough of alpha, depending on conditions. Our modeling suggests that low levels of mGluR1 activation on a background of mAChR agonists may be able to initiate alpha activity that biases TC cells to fire at certain phases of alpha, offering a pathway for cortical control. If we introduce a strong stimulus by increasing the frequency of excitatory postsynaptic potentials (EPSPs) to TC cells, an increase in alpha power is needed to mimic the level of phasing of TC cells observed in vivo. This increased alpha power reduces the probability that TC cells spike near the trough of alpha. We suggest that mAChR-induced alpha may contribute to grouping TC activity into discrete perceptual units for processing, whereas mGluR1-induced alpha may serve the purpose of blocking unwanted stimuli from reaching the cortex.
Thermal radiation from Au nanoparticles deposited on patterned Pt microstructures
Authors: Vasile Gabriel , Arikan Mustafa , Ingvarsson Snorri
Published: October 2012

We have investigated the thermal radiation in the infrared regime from resistively heated microfabricated platinum (Pt) wires (heaters), patterned with gold nanoparticles (NPs). The purpose of this work is to enhance the emissivity of the Pt heaters by modifying their surface properties. Gold particles with diameters of 50 nm and 100 nm, respectively, were deposited on the surface of the heaters. Polarization resolved thermal radiation was measured at different temperatures. Measurements show that the intensity of the thermal radiation increases by a factor of 2–3 for heaters with NPs deposited compared with heaters without NPs deposited.
Definable linear orders definably embed into lexicographic orders in o-minimal structures
Authors: Ramakrishnan Janak
Published: October 2012

We classify definable linear orders in o-minimal structures expanding groups. For example, let

(
P
,
≺
)

(P,\prec )

be a linear order definable in the real field. Then

(
P
,
≺
)

(P,\prec )

embeds definably in

(

R

n
+
1

,

>

lex

)

(\mathbb {R}^{n+1},>_{\text {lex}})

, where

>

lex

>_{\text {lex}}

is the lexicographic order and

n
n

is the o-minimal dimension of

P
P

. This improves a result of Onshuus and Steinhorn in the o-minimal group context.
On Zanello’s lower bound for level algebras
Authors: Laksov Dan
Published: October 2012

We consider the proof of Söderberg of Zanello’s lower bound for the Hilbert function of level algebras from the point of view of vector spaces. Our results, when specialised to level algebras, generalise those of Zanello and Söderberg to the case when the modules involved may have nontrivial annihilators. In the process we clarify why the methods of Zanello and Söderberg consist of two distinct parts.

As a contrast we show that for polynomial rings, Zanello’s bound, in the generic case, can be obtained by simple manipulations of numbers without dividing into two separate cases.

We also consider the inclusion-exclusion principle of dimensions of vector spaces used by Zanello in special cases. It turns out that the resulting alternating sums are extremely difficult to handle and have many unexpected properties. This we illustrate by a couple of results and examples. The examples show that the inclusion-exclusion principle does not hold for vector spaces in the way it is used by Zanello.
Witt rings and matroids
Authors: Craven Thomas , Kent Zachary
Published: October 2012

The study of Witt rings of formally real fields in the algebraic theory of quadratic forms has led to a particularly good understanding of the finitely generated torsion free Witt rings. In this paper, we work primarily with a somewhat more general class of rings which can be completely characterized by (binary) matroids. The different types of standard constructions and invariants coming from algebra and from combinatorics lead to previously unstudied problems for both areas; in particular, there are new invariants for Witt rings and new constructions for matroids with many open questions.
Rent‐Seeking and Incentives for Compliance in the Commons
Authors: Holzer Jorge , Lipton Douglas , François Olivier
Published: October 2012

This article studies how rent‐seeking behavior induces an informal leasing market for fishing licenses that leads harvesters in a common pool to circumvent rules set by the manager to conserve the resource, as well as how the vulnerability of the resource to such behavior depends on the management approach adopted. License leasing reduces fleet heterogeneity in terms of catch per unit effort as demonstrated by the outward shift in the stochastic production frontier. While aggregate harvest is invariant to alternative profiles of fleet heterogeneity in quota‐managed fisheries, the productivity of the restricted variable–total effort–increases with the number of leasing contracts in input‐controlled fisheries. If unanticipated by the regulator, the additional pressure on the resource may lead to overfishing and compromise the long‐term viability of the industry.
Health Promotion for Older People
Authors: Simon Chantal
Published: October 2012

In common with other European countries, the UK has an ageing population. Over the past 25 years, the number of people over the age of 65 years increased by 1.5 million. This trend is likely to continue and by 2033, 23% of the population will be over the age of 65 years. An ageing population will bring increased demands on primary care. This article explores the ways that GPs can help this important sector of our practice population remain healthy in old age.
The HC-Pro and P3 Cistrons of an Avirulent Soybean mosaic virus Are Recognized by Different Resistance Genes at the Complex Rsv1 Locus
Authors: Wen R.-H. , Khatabi B. , Ashfield T. , Maroof M. A. Saghai , Hajimorad M. R.
Published: October 2012

The complex Rsv1 locus in soybean plant introduction (PI) ‘PI96983’ confers extreme resistance (ER) against Soybean mosaic virus (SMV) strain N but not SMV-G7 and SMV-G7d. Both the SMV helper-component proteinase (HC-Pro) and P3 cistrons can serve as avirulence factors recognized by Rsv1. To understand the genetics underlying recognition of the two cistrons, we have utilized two soybean lines (L800 and L943) derived from crosses between PI96983 (Rsv1) and Lee68 (rsv1) with distinct recombination events within the Rsv1 locus. L800 contains a single PI96983-derived member (3gG2) of an Rsv1-associated subfamily of nucleotide-binding leucine-rich repeat (NB-LRR) genes. In contrast, although L943 lacks 3gG2, it contains a suite of five other NB-LRR genes belonging to the same family. L800 confers ER against SMV-N whereas L943 allows limited replication at the inoculation site. SMV-N-derived chimeras containing HC-Pro from SMV-G7 or SMV-G7d gained virulence on L943 but not on L800 whereas those with P3 replacement gained virulence on L800 but not on L943. In reciprocal experiments, SMV-G7- and SMV-G7d-derived chimeras with HC-Pro replacement from SMV-N lost virulence on L943 but retained virulence on L800 whereas those with P3 replacement lost virulence on L800 while remaining virulent on L943. These data demonstrate that distinct resistance genes at the Rsv1 locus, likely belonging to the NB-LRR class, mediate recognition of HC-Pro and P3.
Biomechanics of Posterior Dynamic Fusion Systems in the Lumbar Spine
Authors: Yu Alexander K. , Siegfried Catherine M. , Chew Brandon , Hobbs Joseph , Sabersky Abraham , Jho Diana J. , Cook Daniel J. , Bellotte Jonathan Brad , Whiting Donald M. , Cheng Boyle C.
Published: October 2012

Study Design:

A comparative biomechanical human cadaveric spine study of a dynamic fusion rod and a traditional titanium rod.

Objective:

The purpose of this study was to measure and compare the biomechanical metrics associated with a dynamic fusion device, Isobar TTL Evolution, and a rigid rod.

Summary of Background Data:

Dynamic fusion rods may enhance arthrodesis compared with a rigid rod. Wolff’s law implies that bone remodeling and growth may be enhanced through anterior column loading (AL). This is important for dynamic fusion rods because their purpose is to increase AL.

Methods:

Six fresh-frozen lumbar cadaveric specimens were used. Each untreated specimen (Intact) underwent biomechanical testing. Next, each specimen had a unilateral transforaminal lumbar interbody fusion performed at L3–L4 using a cage with an integrated load cell. Pedicle screws were also placed at this time. Subsequently, the Isobar was implanted and tested, and finally, a rigid rod replaced the Isobar in the same pedicle screw arrangement.

Results:

In terms of range of motion, the Isobar performed comparably to the rigid rod and there was no statistical difference found between Isobar and rigid rod. There was a significant difference between the intact and rigid rod and also between intact and Isobar conditions in flexion extension. For interpedicular displacement, there was a significant increase in flexion extension (P=0.017) for the Isobar compared with the rigid rod. Isobar showed increased AL under axial compression compared with the rigid rod (P=0.024).

Conclusions:

Isobar provided comparable stabilization to a rigid rod when using range of motion as the metric, however, AL was increased because of the greater interpedicular displacement of dynamic rod compared with a rigid rod. By increasing interpedicular displacement and AL, it potentially brings clinical benefit to procedures relying on arthrodesis.
Non-standard stochastic averaging of large-amplitude ship rolling in random seas
Authors: Dostal L. , Kreuzer E. , Sri Namachchivaya N.
Published: October 2012

The current intact stability criteria for ships do not account for their dynamic behaviour in irregular waves sufficiently. We provide analytical criteria for ship and sea state parameters that indicate large roll amplitudes or capsizing and determine the mean time for these events. These results can be used to formulate vulnerability criteria for the occurrence of parametric roll. We use reduced order models in order to perform an analytical analysis to this complicated problem. Therefore, we study the dynamics of a ship in random seas as a perturbation of a Hamiltonian system. The random process across the energy levels of the Hamiltonian system is approximated by a Markov process, which is obtained by stochastic averaging. The noise owing to wave excitation is a non-white stationary stochastic process. This is an extension to previous results, where white noise excitation was used.
Genomic Profiling of a Human Leukemic Monocytic Cell-Line (THP-1) Exposed to Alpha Particle Radiation
Authors: Chauhan Vinita , Howland Matthew
Published: October 2012

This study examined alpha (α-) particle radiation effects on global changes in gene expression in human leukemic monocytic cells (THP-1) for the purposes of mining for candidate biomarkers that could be used for the development of a biological assessment tool. THP-1 cells were exposed toα-particle radiation at a dose range of 0 to 1.5 Gy. Twenty-four hours and three days after exposure gene expression was monitored using microarray technology. A total of 16 genes were dose responsive and classified as early onset due to their expression 24 h after exposure. Forty-eight transcripts were dose responsive and classified as late-onset as they were expressed 72 h after exposure. Among these genes, 6 genes were time and dose responsive and validated further using alternate technology. These transcripts were upregulated and associated with biological processes related to immune function, organelle stability and cell signalling/communication. This panel of genes merits further validation to determine if they are strong candidate biomarkers indicative ofα-particle exposure.
Viral infections and molecular mimicry in type 1 diabetes
Authors: Coppieters Ken T. , Wiberg Anna , von Herrath Matthias G.
Published: October 2012

Type 1 diabetes (T1D) is a disease characterized by inflammation of pancreatic islets associated with autoimmunity against insulin‐producing beta cells, leading to their progressive destruction. The condition constitutes a significant and worldwide problem to human health, particularly because of its rapid, but thus far unexplained, increase in incidence. Environmental factors such as viral infections are thought to account for this trend. While there is no lack of reports associating viral infections toT1D, it has proven difficult to establish which immunological processes link viral infections to disease onset or progression. One of the commonly discussed pathways is molecular mimicry, a mechanism that encompasses cross‐reactive immunity against epitopes shared between viruses and beta cells. In this review, we will take a closer look at mechanistic evidence for a potential role of viruses in T1D, with a special focus on molecular mimicry.
PreliminaryTurkish study of psychiatric in‐patients’ competence to make treatment decisions
Authors: Aydin Er Rahime , Sehiralti Mine , Aker Ahmet Tamer
Published: October 2012

Introduction

Competence is a prerequisite for informed consent. Patients who are found to be competent are entitled to accept or refuse the proposed treatment. In recent years, there has been an increased interest in studies examining competence for treatment in psychiatric patients. In this study, we aimed to investigate the decision‐making competencies of inpatients with a range of psychiatric diseases.

Methods

This study was carried out at the psychiatry clinic ofKocaeliUniversityHospital inTurkey fromJune 2007 toFebruary 2008. Decision‐making competence was assessed in 83 patients using theMacArthur CompetenceAssessmentTool‐Treatment (MacCAT‐T).

Results

The study groups consisted of patients with mood (39.8%), psychotic (27.7%) and anxiety disorders (18.1%), and alcohol/substance addiction (14.5%). There was a significant relation between decision‐making competence and demographic and clinical characteristics. Appreciation of the given information was more impaired in psychotic disorder patients than in other patients, but understanding and reasoning of the given information was similar in all groups.

Discussion

These results reveal the importance of evaluating decision‐making competencies of psychiatric patients before any treatment or intervention is carried out to ascertain their ability to give informed consent to treatment. Institutional and national policies need to be determined and put into practice relating to the assessment and management of competence in patients with psychiatric disorders.
Adolescent's preferred modes of delivery for mental health services
Authors: Bradford Sally , Rickwood Debra
Published: October 2012

Background

Mental health interventions for young people are increasingly being delivered online. This is occurring due to an assumption that young people prefer online interventions because they address some of the well‐established help‐seeking barriers.

Method

A self‐report questionnaire investigating preferences for mental health care delivery was administered to a nonclinical sample of 231 young people aged 15–19.

Results

The strongest help‐seeking intention in response to a scenario describing symptoms of depression was for face‐to‐face services, followed by not seeking help at all. Only 16% expressed a preference for online treatment.

Conclusion

The assumption that a majority of young people will prefer online delivery of mental health treatment was not supported, although boys showed a stronger relative preference for online modes.
Stapled transanal rectal resection (STARR) for obstructive defaecation syndrome: patients with previous pelvic floor surgery have poorer long‐term outcome
Authors: Adams K. , Papagrigoriadis S.
Published: October 2012

Aim

Stapled transanal rectal resection (STARR) is used for patients with obstructive defaecation syndrome (ODS) not responding to conservative management. Reports indicate mixed results and there are no studies publishing the long‐term outcome.

Method

Following full investigation, 37 patients with ODS underwent a STARR procedure by one of the authors (SP) between 2005 and 2010.

Results

The median (range) patient age was 53.0 (28–79) years and all were female. Median (range) follow up was 13 (0–57) months, and nine (24.3%) patients were followed for longer than 24 months. Eighteen patients had undergone at least one (and often multiple) previous gynaecological procedures, including hysterectomy (n = 14), colposuspension (n = 3), vaginal rectocele repair (n = 4) and pelvic floor repair (n = 5). Four patients had had at least one previous rectal operation [stapled anopexy (n = 3) and Delorme's procedure (n = 2)]. One patient did not attend for postoperative follow up. Of the remaining 36 patients, 18 had resolution of obstructive symptoms. Of the 18 with residual symptoms, 17 eventually reported the same level of symptoms as before the STARR procedure. There was a significant correlation between the presence of residual symptoms and long‐term ODS recurrence (P < 0.0005). For those with residual symptoms, the mean (95% CI) time to symptom recurrence was 3 (2.86–11.81) months. Twenty (56%) patients were satisfied with the outcome from the STARR procedure.

Conclusion

Residual symptoms are a strong indicator of long‐term failure. STARR was effective for symptom resolution in 50% of patients. Those who had undergone pelvic floor or rectal prolapse surgery were significantly more likely to experience recurrent symptoms.
Prognostic significance of apical lymph node metastasis in patients with node‐positive rectal cancer
Authors: Peng J. , Wu H. , Li X. , Sheng W. , Huang D. , Guan Z. , Wang M. , Cai S.
Published: October 2012

Aim

The aim of this study was to assess the effect of apical lymph node (APN) metastasis in predicting prognosis in curatively treated node‐positive rectal cancer. We also investigated the relationship between APN metastasis and the total number of metastatic lymph nodes.

Method

A retrospective study was performed of 510 curatively treated patients with node‐positive rectal cancer. Clinicopathological variables, including APN status, were assessed in univariate and multivariate analyses. The prognostic significance of APN status in predicting patient outcomes and the relationship between APN status and American Joint Committee on Cancer (AJCC) N stage were analysed.

Results

At a median follow up of 47 months, the 5‐year local recurrence (LR) rate, the disease‐free survival (DFS) rate and the overall survival (OS) rate were 18.3%, 55.5% and 58.8%, respectively. The 5‐year OS rate was 69.6% for patients with no metastasis in APNs (APN(−)) and 40.8% for patients with metastasis in APNs (APN(+)). DFS and OS for patients with undetermined APN status were between those for APN(−) and APN(+). Subgroup analysis gave a 5‐year OS rate of 48.7% in Stage N1 patients with APN(+) and 58.8% for Stage N2 patients with APN(−) (P = 0.0004).

Conclusion

APN metastasis is an important prognostic factor in node‐positive rectal cancer, which provides additional survival‐related prognostic classification irrespective of N stage. As the APN is usually outside the radiation field, in the era of multidisciplinary treatment its assessment should be incorporated into prognostic evaluation of rectal cancer.
BerEP4 is widely expressed in tumors of the sweat apparatus: a source of potential diagnostic error
Authors: Afshar Maryam , Deroide Florence , Robson Alistair
Published: October 2012

Background

A 63‐year‐old man presented with an ulcerated nodule with a rolled pearly edge on his back. A punch biopsy showed diffuse strong BerEP4 expression and retraction artifact. Consequently the tumor was diagnosed as a basal cell carcinoma but on excision the tumor proved to be a porocarcinoma. Although Jimenez et al. reported BerEP4 expression in porocarcinoma, this result is not widely appreciated. This observation prompted us to investigate BerEP4 expression in sweat apparatus tumors.

Methods

Immunocytochemistry was performed using Dako monoclonal mouse BerEP4 with Ventana Benchmark XT immunostainer. Omission of the primary antibody served as a negative control.

Results

Fourteen of 26 porocarcinomas had at least focal BerEP4 expression and two were diffusely and at least focally strongly positive. Seven of seven chondroid syringomas stained diffusely positive, with strong ductal expression; the single chondroid syringocarcinoma was negative. Five of 6 poromas and two of two hidradenomas had focal expression, and staining particularly highlighted the ducts, a co‐localization also apparent in the four spiradenomas and three cylindromas. The single primary mucinous carcinoma had diffuse strong BerEP4 expression.

Discussion

This case and pilot study shows that BerEP4 expression is common in these selected sweat apparatus tumors, and staining may be strongly so. This observation should be borne in mind in clinical practice.
Leaf biomechanical properties as mechanisms of resistance to black cutworm (Agrotis ipsilon) among Poa species
Authors: Hong Seung Cheon , Williamson R. Chris , Held David W.
Published: October 2012

Biomechanical properties can be important parameters in resistance of plants to herbivorous insects. As plants age, however, there can be dramatic changes in physical defenses that can then influence their susceptibility to insect herbivores. We measured changes in leaf biomechanical properties during ontogeny of Poa species and the relationship of these changes to the development of a generalist herbivore, the black cutworm, Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae), was investigated. Larvae were reared on two representative age classes, i.e., young (<60 days after planting) and old (>1 year after planting), of foliage in laboratory assays. Foliage generally reaches a peak fracture force between 80 and 109 days after planting depending on grass type. Foliage from old plants was significantly tougher than that of young plants, and black cutworm larvae reared on foliage from young plants gained significantly (ca. four times) more weight than those fed on foliage from old Poa plants. In addition, fracture force has a negative relationship with black cutworm development. Plant fiber, particularly neutral detergent fiber accounted for 65 and 46% of the variation in fracture force and larval development, respectively. These results provide additional insight into how plant ontogeny influences physical defenses to an insect herbivore in a grass system. Likewise, this is seemingly the first study to suggest a mechanism for host plant resistance to black cutworm. Plant fiber may be a useful trait to explore in plant improvement programs in which black cutworm is a primary pest (e.g., managed turfgrass).
Spatial and temporal variations in fish larvae assemblages ofIlhaGrandeNationalPark,Brazil
Authors: Gogola Tatiane M. , Sanches Paulo V. , Gubiani Éder A. , da Silva Pedro R. L.
Published: October 2012

For understanding the reproductive dynamics of fish assemblages and their relationship with environmental conditions, we need to know more about spawning areas and periods. Studies on temporal and spatial patterns of occurrence of fish eggs and larvae are important for obtaining this kind of information quickly and accurately. In this study, we analysed spatial and temporal patterns of fish larvae in different biotopes in a stretch of the floodplain ofUpperParanaRiver, inIlhaGrandeNationalPark, southernBrazil. We carried out night sampling during six spawning periods, from 2001 to 2008. We selected 18 sampling sites distributed in the mainstream, tributaries and lagoons, encompassing several types of biotopes. We observed significant spatial and temporal differences among biotopes in the composition and structure of the fish larvae assemblages. Lentic environments favoured the development of sedentary and migratory species, whereas tributaries were used as migratory routes and spawning areas. The assemblage in period I differed from the assemblages of other periods, probably because of the presence of dams in theParanaRiver. No association was observed between environmental variables and spatial and temporal patterns of the ichthyoplankton assemblages. Hence, conservation measures are essential to maintain the environmental integrity of spawning (tributaries) and development areas (lagoons) for the maintenance of biodiversity in the floodplain ofUpperParanáRiver.
The frequency of cerebral microbleeds increases with CHADS2 scores in stroke patients with non‐valvular atrial fibrillation
Authors: Song T.‐J. , Kim J. , Lee H. S. , Nam C. M. , Nam H. S. , Heo J. H. , Kim Y. D.
Published: October 2012

Background and purpose

Cerebral microbleeds (CMBs) are extravasations of blood from lipohyalinized or amyloid angiopathic cerebral arterioles, and the presence and numbers of CMBs are significantly associated with the development of oral anticoagulation (OA)‐related intracranial haemorrhage (ICH). The aim of this study was to investigate whether there is a difference in CMBs burden according to CHADS2 scores or CHA2DS2‐VASc scores in non‐valvular atrial fibrillation (NVAF) patients.

Methods

We included 550 ischaemic stroke patients who had NVAF and who had undergone brain magnetic resonance imaging (MRI) with gradient‐recalled echo (GRE) T2 sequences from our prospective stroke registry between January 2005 and November 2011. We calculated CHADS2 scores and CHA2DS2‐VASc scores for all patients based on their underlying cardiovascular diseases. The presence, location and number of CMBs were assessed in each patient. We also investigated whether the CMBs were actually associated with the development of ICH during follow‐up.

Results

The mean patient age was 70.4 ± 10.5 years, and 324 (58.9%) patients were men. One‐hundred and seventy‐three patients (31.5%) had CMBs detected on GRE MRI. Higher CHADS2 scores or CHA2DS2‐VASc scores were strongly associated with the presence and number of CMBs. During follow‐up of median 3.1 ± 1.6 years, the presence of CMBs was independently associated with the development of ICH, whilst the CHADS2 scores or CHA2DS2‐VASc scores were not.

Conclusions

Considering the positive association between the presence of CMBs and OA‐related ICH, our results suggest that the increase in ICH in high‐risk groups during OA may be related to an increased burden of CMBs.
Alternative states and population crashes in a resource‐susceptible‐infected model for planktonic parasites and hosts
Authors: GERLA DAAN J. , GSELL ALENA S. , KOOI BOB W. , IBELINGS BAS W. , VAN DONK ELLEN , MOOIJ WOLF M.
Published: October 2012

1. Despite the strong impact parasites can have, only few models of phytoplankton ecology or aquatic food webs have specifically included parasitism.

2. Here, we provide a susceptible‐infected model for a diatom‐chytrid host–parasite system that explicitly includes nutrients, infected and uninfected hosts, reproduction of the parasite on the hosts and free‐living infective stages.

3. A distinguishing feature of the model is that parasite reproduction on host increases with nutrient availability to the infected host, as has been observed for many parasites and viruses.

4. It follows from this assumption that the parasite’s basic reproduction number, R0, increases with nutrient concentration, because at higher nutrient concentrations, infected hosts consume more nutrients that are used for the reproduction of the parasite.

5. Another important result is that there may be two alternative states to which population densities can converge: one with only the host and one with host and parasite co‐existing. In the latter, the parasite can invade a host population only if it is introduced above a threshold density.

6. Furthermore, the model shows a strong tendency for host–parasite cycles, which may be chaotic. Nutrient enrichment leads to increasing amplitude of these cycles, which may cause host or parasite population extinction caused by stochastic fluctuations during periods of low population density, which is the Paradox of Enrichment.

7. Finally, if alternative states and cycles co‐occur, increased population cycle amplitude may drive the parasite below its threshold density for successful invasion, causing parasite extinction in a ‘deterministic Paradox of Enrichment’. Published results confirm that host–parasite cycles and collapse of host–parasite systems may occur in real plankton communities.

8. Our results underline that ecological detail in host–parasite models may have consequences for disease dynamics that may be overlooked when ecological interactions between environment, host and parasite are not explicitly taken into account.
The distribution and environmental state of vegetated islands within human‐impacted European rivers
Authors: RICAURTE LUISA FERNANDA , BOESCH SARAH , JOKELA JUKKA , TOCKNER KLEMENT
Published: October 2012

1. Vegetated islands within river corridors are pivotal landscape features and are among the first to disappear as a consequence of flow regulation and channelisation. However, how vegetated islands vary along human‐impacted rivers is poorly understood.

2. We carried out a detailed analysis of the contemporary distribution, diversity and environmental state of vegetated islands within 12 human‐impacted European rivers, using 75 Landsat 7 ETM+ satellite images (1999–2002), historical maps, DEM data and landscape metrics. We tested whether channel fragmentation, catchment land use and the environmental state of fringing floodplains determine the spatial patterns of the islands. We also analysed the historical change of islands within selected sections of the Upper Danube, Upper Rhine and Olt rivers.

3. We identified 2771 islands in the contemporary landscape, varying from 0.06 to 9828 ha. Islands covered up to 21% of the active channel area and contributed up to 32% of the total riparian ecotone length. Island density ranged from 0.06 islands per river‐km (River Sava) to 1.6 islands per river‐km (River Tagliamento). River regulation has led to a marked loss of island density: 94% in the Upper Danube, 93% in the Upper Rhine, and 69% in the Olt. The environmental state of the islands was significantly less altered by human activity than of their fringing floodplains; 93.4% of the vegetated islands exhibited a near‐natural state, while 86% of the fringing floodplains were expansively converted to agricultural and urban land uses.

4. Our results highlight the ubiquitous presence of vegetated islands, their sensitivity to river regulation and their pivotal role for the future restoration and management of river corridors.