bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the genetic contribution to mental illness: a timely end for the psychiatric rodent?
Authors: Davis Brittany A. , Isles Anthony R.
Published: May 2014

Rodent models are a key factor in the process of translating psychiatric genetics and genomics findings, allowing us to shed light on how risk‐genes confer changes in neurobiology by merging different types of data across fields, from behavioural neuroscience to the burgeoning omics (e.g. genomics, epigenomics, proteomics, etc.). Moreover, they also provide an indispensable first step for drug discovery. However, recent evidence from both clinical and genetic studies highlights possible limitations in the current methods for classifying psychiatric illness, as both symptomology and underlying genetic risk are found to increasingly overlap across disorder diagnoses. Meanwhile, integration of data from animal models across disorders is currently limited. Here, we argue that behavioural neuroscience is in danger of missing informative data because of the practice of trying to ‘diagnose’ an animal model with a psychiatric illness. What is needed is a shift in emphasis, from seeking to ally an animal model to a specific disorder, to one focused on a more systematic assessment of the neurobiological and behavioural outcomes of any given genetic or environmental manipulation.
Estradiol regulates responsiveness of the dorsal premammillary nucleus of the hypothalamus and affects fear‐ and anxiety‐like behaviors in female rats
Authors: Litvin Yoav , Cataldo Giuseppe , Pfaff Donald W. , Kow Lee‐Ming
Published: May 2014

Research suggests a causal link between estrogens and mood. Here, we began by examining the effects of estradiol (E2) on rat innate and conditioned defensive behaviors in response to cat odor. Second, we utilized whole‐cell patch clamp electrophysiological techniques to assess noradrenergic effects on neurons within the dorsal premammillary nucleus of the hypothalamus (PMd), a nucleus implicated in fear reactivity, and their regulation by E2. Our results show that E2 increased general arousal and modified innate defensive reactivity to cat odor. When ovariectomized females treated with E2 as opposed to oil were exposed to cat odor, they showed elevations in risk assessment and reductions in freezing, indicating a shift from passive to active coping. In addition, animals previously exposed to cat odor showed clear cue + context conditioning 24 h later. However, although E2 persisted in its effects on general arousal in the conditioning task, its effects on fear disappeared. In the patch clamp experiments noradrenergic compounds that typically induce fear clearly excited PMd neurons, producing depolarizations and action potentials. E2 treatment shifted some excitatory effects of noradrenergic agonists to inhibitory, possibly by differentially affecting α‐ and β‐adrenoreceptors. In summary, our results implicate E2 in general arousal and fear reactivity, and suggest these may be governed by changes in noradrenergic responsivity in the PMd. These effects of E2 may have ethological relevance, serving to promote mate seeking even in contexts of ambiguous threat and shed light on the involvement of estrogen in mood and its associated disorders.
Distinguishing informational from value‐related encoding of rewarding and punishing outcomes in the human brain
Authors: Jessup Ryan K. , O'Doherty John P.
Published: May 2014

There is accumulating evidence implicating a set of key brain regions in encoding rewarding and punishing outcomes, including the orbitofrontal cortex, medial prefrontal cortex, ventral striatum, anterior insula, and anterior cingulate. However, it has proved challenging to reach consensus concerning the extent to which different brain areas are involved in differentially encoding rewarding and punishing outcomes. Here, we show that many of the brain areas involved in outcome processing represent multiple outcome components: encoding the value of outcomes (whether rewarding or punishing) and informational coding, i.e. signaling whether a given outcome is rewarding or punishing, ignoring magnitude or experienced utility. In particular, we report informational signals in the lateral orbitofrontal cortex and anterior insular cortex that respond to both rewarding and punishing feedback, even though value‐related signals in these areas appear to be selectively driven by punishing feedback. These findings highlight the importance of taking into account features of outcomes other than value when characterising the contributions of different brain regions in outcome processing.
Asymmetric Assortative Mating Behaviour Reflects Incomplete Pre‐zygotic Isolation in the Nasonia Species Complex
Authors: Buellesbach Jan , Greim Christopher , Raychoudhury Rhitoban , Schmitt Thomas
Published: May 2014

Preference of con‐ over heterospecific mates leading to assortative mating can substantially contribute to pre‐zygotic reproductive isolation and prevent fitness losses if post‐zygotic hybridization barriers already exist. The jewel wasp genus Nasonia displays quite strong and well‐studied post‐zygotic reproductive isolation due to a ubiquitous Wolbachia infection causing cytoplasmic incompatibility between different species. Pre‐zygotic isolation, however, has received far less research attention in this model organism, especially concerning the mechanisms and criteria of mate choice. In the present study, we analysed mate rejection and mate acceptance rates in cross‐comparisons between all four Nasonia species. We put emphasis on observing which sex is more likely to interrupt interspecific matings and how discriminatory behaviour varies across the different species in all possible combinations. We found an asymmetric distribution of assortative mating among the four Nasonia species that appears to be highly influenced by the respective combinations of sex and species. Females appeared to be the main discriminators against heterospecific mating partners, but interestingly, we could also detect mate discrimination and rejection behaviour in males, a widely neglected factor in research on mating behaviour in general and on Nasonia in particular. Moreover, the asymmetry in the assortative mating behaviour was partially reflective of sym‐ or allopatric distributions of natural Nasonia populations.
Conformational modulation and hydrodynamic radii of CP12 protein and its complexes probed by fluorescence correlation spectroscopy
Authors: Moparthi Satish Babu , Thieulin‐Pardo Gabriel , Mansuelle Pascal , Rigneault Hervé , Gontero Brigitte , Wenger Jérôme
Published: May 2014

Light/dark regulation of the Calvin cycle in oxygenic photosynthetic organisms involves the formation and dissociation of supramolecular complexes between CP12, a nuclear‐encoded chloroplast protein, and the two enzymes glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) (EC 1.2.1.13) and phosphoribulokinase (PRK) (EC 2.7.1.19). Despite the high importance of understanding the structural basis of the interaction of CP12 with GAPDH and PRK to investigate the regulation of the Calvin cycle, information is still lacking about the structural remodulation of CP12 and its complex formation. Here, we characterize the diffusion dynamics and hydrodynamic radii of CP12 from Chlamydomonas reinhardtii upon binding to GAPDH and PRK using fluorescence correlation spectroscopy experiments. We quantify a hydrodynamic radius of 3.4 ± 0.2 nm for the CP12 protein with an increase up to 5.2 ± 0.3 nm upon complex formation with GAPDH and PRK. In addition, unfolding experiments reveal a 1.6‐ and 2.0‐fold increase respectively of the hydrodynamic radii for the N‐terminal and C‐terminal cysteine CP12 mutant proteins compared with their native folded structures. The different behavior of the CP12 mutant proteins during hydrophobic collapse transition is a direct clue to different structural orientations of the CP12 mutant proteins. These different structures are expected to facilitate the binding of either GAPDH or PRK during binary complex and ternary complex formation.

Structured digital abstract

GAPDH, CP12 and PRK physically interact by fluorescence correlation spectroscopy (View interaction)

CP12 and PRK bind by fluorescence correlation spectroscopy (View interaction)

GAPDH and CP12 bind by fluorescence correlation spectroscopy(View interaction)
Application of the AquaCrop model to simulate the biomass of Miscanthus x giganteus under different nutrient supply conditions
Authors: Stričević Ruzica , Dželetović Zeljko , Djurović Nevenka , Cosić Marija
Published: May 2014

There are conflicting opinions about the need to fertilize Miscanthus and, also, the question has been raised whether Miscanthus should be irrigated, especially if water resources are limited. Crop growth modeling can help answer such questions. In this article the FAO AquaCrop water‐driven model was selected to simulate Miscanthus biomass under different nutrient and water supply conditions. The article reports the outcomes of 6‐year experiments with Miscanthus on two locations in Serbia: Zemun, where three fertilizer treatments were applied (Nl – 100 kg ha−1, Nopt 50 kg ha−1 and Nf nonfertilized), and Ralja, where only Nl 100 kg ha−1 was applied. Model calibration focused on the measured data (root depth, crop phenology, and the above‐ground biomass by year of growth. Calibration results showed a very good match between measured and simulated values. The largest and only significant difference was noted in 2008, when the crop was establishing and exhibited uneven radication. The simulation results for the next 5 years showed a variance from −4 to 5.7%, believed to be a very good match. A high coefficient of determination (R2 = 0.995) and high Willmott index of agreement (0.998) were also indicative of a good match between simulated and recorded biomass yields. The measured and simulated results for validated datasets at both locations were good. The average RMSE was 2.89 Mg ha−1; when compared to the deviations noted at the test site itself, it was apparent that they were smaller in all the years of research except the first year. The index of agreement was 0.97 and the coefficient of determination R2 0.947. The AquaCrop model can be used with a high degree of reliability in strategic planning of Miscanthus cultivation in new areas, under different nutrient and water supply and local weather and soil conditions.
Effect of home bleaching on the mechanical properties of resin luting cements using Hertzian indentation test
Authors: Bagheri Rafat , Vojdani Mahroo , Mogharabi Sara , Burrow Michael F.
Published: May 2014

Aim

The aim of the present study was to determine the effects of immersion time and 10% carbamide peroxide treatment using a Hertzian indentation test after placing resin‐based cements into 37°C distilled water, with and without 10% carbamide peroxide.

Methods

Disc‐shaped specimens (10‐mm diameter × 1‐mm thick), were prepared from five resin‐based cements; seT PP, Maxcem Elite, RelyX Unicem, Panavia F, and G‐Cem. The specimens of each material were randomly divided into three groups of six. The study groups were bleached with 10% carbamide peroxide on one surface for 21 days for 2 h per day. Two control groups were kept in distilled water for either 24 h or 21 days. A load was applied to the center of the disc using a hard, steel ball. The load at the first crack was recorded.

Results

Significant differences were observed between the cements. seT PP showed the highest strength, and G‐Cem the lowest. Differences between the treatment and control groups were statistically significant for all cements, except Panavia F.

Conclusions

The effect of 10% carbamide peroxide treatment reduces cement strength, which could be important for patients undergoing bleaching who have crowns.
A seascape genetic analysis reveals strong biogeographical structuring driven by contrasting processes in the polyploid saltmarsh species Puccinellia maritima and Triglochin maritima
Authors: Rouger R. , Jump A. S.
Published: May 2014

Little is known about the processes shaping population structure in saltmarshes. It is expected that the sea should act as a powerful agent of dispersal. Yet, in contrast, import of external propagules into a saltmarsh is thought to be small. To determine the level of connectivity between saltmarsh ecosystems at a macro‐geographical scale, we characterized and compared the population structure of two polyploid saltmarsh species, Puccinellia maritima and Triglochin maritima based on a seascape genetics approach. A discriminant analysis of principal components highlighted a genetic structure for both species arranged according to a regional pattern. Subsequent analysis based on isolation‐by‐distance and isolation‐by‐resistance frameworks indicated a strong role of coastal sediment transport processes in delimiting regional structure in P. maritima, while additional overland propagule dispersal was indicated for T. maritima. The identification and comparison of regional genetic structure and likely determining factors presented here allows us to understand the biogeographical units along the UK coast, between which barriers to connectivity occur not only at the species level but at the ecosystem scale. This information is valuable in plant conservation and community ecology and in the management and restoration of saltmarsh ecosystems.
Identification of the type of exercise therapy that affects functioning in patients with early‐stage amyotrophic lateral sclerosis: A multicenter, collaborative study
Authors: Kamide Naoto , Asakawa Takashi , Shibasaki Nobuhiko , Kasahara Yoshio , Tamada Yoshiki , Kitano Kosuke , Kikuchi Yutaka , Yorimoto Keisuke , Kobayashi Yoko , Komori Testuo
Published: May 2014

Background

The types of exercise therapy that have an effect on functioning in early‐stage amyotrophic lateral sclerosis patients are not well‐known.

Aim

To investigate the types of exercise therapy that have an effect on functioning in early‐stage amyotrophic lateral sclerosis patients.

Methods

The participants were consecutive amyotrophic lateral sclerosis patients who were prescribed exercise therapy at six institutions in Japan. All data (age, sex, site of onset and disease duration) were collected retrospectively from the patients' medical records. The amyotrophic lateral sclerosis functional rating scale‐revised scores were collected to assess patients' functioning at two time‐points, at baseline and during exercise therapy. Furthermore, details of the types of exercise therapy were investigated. The change in the amyotrophic lateral sclerosis functional rating scale‐revised score was calculated using the score at two time‐points. A multiple regression analysis was used to determine the effect of type of exercise therapy on the change in amyotrophic lateral sclerosis functional rating scale‐revised scores.

Results

The analysis included 156 participants. The interaction term of performance factor (walking training, standing training, and activities of daily living task training) was significantly associated with the change in the amyotrophic lateral sclerosis functional rating scale‐revised score, but the interaction term of the muscle function factor (resistance training and cycle ergometer training) was not.

Conclusion

The combination of performance task training appears to alleviate functional decline in early‐stage amyotrophic lateral sclerosis patients.
Determining the frequency, kinds and cues of violence displayed by patients in an acute older person ward environment: findings from an observational study
Authors: Jackson Debra , Wilkes Lesley , Waine Melissa , Luck Lauretta
Published: May 2014

Background

Workplace violence is one of the most complex and significant occupational hazards experienced by nurses in healthcare settings. Verbal abuse and physical violence are particularly prevalent in older person assessment wards, owing to the prevalence of illnesses involving cognitive dysfunction; the high frequency and nature of contact with staff; and the frustration caused by high levels of disability.

Aim

To determine the frequency, kinds and cues of violence displayed by patients towards nurses in an acute older person assessment ward environment using a structured observational tool – the Violence Assessment Tool (VAT).

Design

Observational study.

Method

Non‐participant structured observations of behavioural cues for violence towards nurses in an acute older person hospital ward were gathered and analysed.

Results

One hundred and twelve hours of observations were undertaken, resulting in 95 behavioural cues for violence in 19 patients. Four of these patients subsequently escalated to physical violence. Pacing around the bed was the only commonality in the behavioural cues of patients who became violent. All patients who became violent had previously demonstrated shoving.

Conclusions

To date, the assessment of potentially violent older patients has not been adequately addressed. The VAT may be one way of addressing this challenge through early identification of the more subtle behavioural cues that could indicate potential for violence. Further research on the VAT using a larger data set could determine its predictability for physically violent acts displayed by older people.

Implications for practice

The VAT will allow early identification, early de‐escalation and ultimately a reduction in violence against nurses in acute older person wards.
Competence in advanced older people nursing: development of ‘Nursing older people – Competence evaluation tool’
Authors: Bing‐Jonsson Pia Cecilie , Bjørk Ida Torunn , Hofoss Dag , Kirkevold Marit , Foss Christina
Published: May 2014

Background

Community care is characterised by a move from institutionalised to home‐based care, a large patient population with comorbidities including cognitive failure, and nurses who struggle to keep up with their many competence demands. No study has examined the competence of nurses based on present demands, and an instrument for this purpose is lacking.

Aim and objective

We conducted a Delphi study based in Norway to develop the substantial content of a new competence measurement instrument. We sought to reach consensus regarding which nursing staff competence is most relevant to meet the current needs of older patients.

Design and method

A total of 42 experts participated in three consecutive panel investigations. Snowball sampling was used. The experts were clinicians, leaders, teachers, researchers and relatives of older people who required nursing. In Round 1, all experts were interviewed individually. These data were analysed using meaning coding and categorisation. In Rounds 2 and 3, the data were collected using electronic questionnaires and analysed quantitatively with SPSS.

Results

The experts agreed that health promotion as well as disease prevention, treatment, palliative care, ethics and regulation, assessment and taking action, covering basic needs, communication and documentation, responsibility and activeness, cooperation, and attitudes towards older people were the most relevant categories of competence.

Conclusions

The experts showed clear consensus regarding the most relevant and current competence for nurses of older people. Assuming that older people in need of health care have the same requirements across cultures, this study's findings could be used as a basis for international studies.

Implications for practice

Those who nurse older people require competence that is complex and comprehensive. One way to evaluate nursing competence is through evaluation tools such as the Nursing Older People – Competence Evaluation tool.
Effects of crop‐straw biochar on crop growth and soil fertility over a wheat‐millet rotation in soils of China
Authors: Zhao X. , Wang J. W. , Xu H. J. , Zhou C. J. , Wang S. Q. , Xing G. X.
Published: May 2014

We conducted a pot experiment using a wheat‐millet rotation to examine the effects of two successive rice‐straw biochar applications on crop growth and soil properties in acidic oxisols and alkaline cambosols from China. Biochar was incorporated into soil at rates of 0, 2.25 or 22.5 Mg/ha at the beginning of each crop season with identical applications of NPK fertilizer. In the oxisols, the largest biochar treatment enhanced soil pH and cation exchange capacity, decreased soil bulk density, improved soil P, K, Ca and Mg availability and enhanced their uptake, and increased wheat and millet yields by 157 and 150% for wheat grain and straw, respectively, and 72.6% for millet straw. In the cambosols, biochar treatment decreased soil bulk density, improved P and K availability, increased N, P and K uptake by crops and increased wheat and millet straw yields by 19.6 and 60.6%, respectively. Total soil organic carbon increased in response to successive biochar applications over the rotation. No difference in water‐soluble organic carbon was recorded between biochar‐treated and control soils. Converting straw to biochar and treating soils with successive applications may be a viable option for improving soil quality, sequestering carbon and utilizing straw resources in China.
The effective neural drive to muscles is the common synaptic input to motor neurons
Authors: Farina Dario , Negro Francesco , Dideriksen Jakob Lund
Published: May 2014

Key points

Despite the non‐linear property of individual motor neurons, the pool of motor neurons linearizes the relation between their common synaptic input and the neural drive to the muscle, i.e. the ensemble of axonal action potentials reaching the muscle from the spinal cord.

In the frequency bandwidth relevant for force generation, the motor neuron pool attenuates the input signals sent independently to each motor neuron and transfers only the common signal components with a pure scaling.

The effective neural drive to the muscle tends to exactly replicate, without phase distortion, the common synaptic input to motor neurons for increasing number of active motor neurons.

The classic definition and functional meaning of motor unit synchronization are discussed in relation to the role of common input in determining the neural drive to muscle.

We analysed the transformation of synaptic input to the pool of motor neurons into the neural drive to the muscle. The aim was to explain the relations between common oscillatory signals sent to motor neurons and the effective component of the neural signal sent to muscles as output of the spinal cord circuitries. The approach is based on theoretical derivations, computer simulations, and experiments. It is shown theoretically that for frequencies smaller than the average discharge rates of the motor neurons, the pool of motor neurons determines a pure amplification of the frequency components common to all motor neurons, so that the common input is transmitted almost undistorted and the non‐common components are strongly attenuated. The effective neural drive to the muscle thus mirrors the common synaptic input to motor neurons. The simulations with three models of motor neuron confirmed the theoretical results by showing that the coherence function between common input components and the neural drive to the muscle tends to 1 when increasing the number of active motor neurons. This result, which was relatively insensitive to the type of model used, was also supported experimentally by observing that, in the low‐pass signal bandwidth, the peak in coherence between groups of motor units of the abductor digiti minimi muscle of five healthy subjects tended to 1 when increasing the number of motor units. These results have implications for our understanding of the neural control of muscles as well as for methods used for estimating the strength of common input to populations of motor neurons.
Exercise training modulates functional sympatholysis and α‐adrenergic vasoconstrictor responsiveness in hypertensive and normotensive individuals
Authors: Mortensen Stefan P. , Nyberg Michael , Gliemann Lasse , Thaning Pia , Saltin Bengt , Hellsten Ylva
Published: May 2014

Key points

Essential hypertension is linked to an increased sympathetic vasoconstrictor activity and reduced tissue perfusion.

Exercise training can improve the ability to override sympathetic vasoconstrictor activity.

Here we show that 8 weeks of exercise training reduces the vasoconstrictor response to sympathetic nerve activity (induced by tyramine) and improves the ability to override sympathetic vasoconstrictor activity.

We found no difference in the ability to override sympathetic vasoconstrictor activity during exercise, the reduction in blood flow in response to increases in sympathetic nerve activity or the hyperaemic response to infused ATP between normo‐ and hypertensive subjects.

These results help us to better understand how exercise training can reduce blood pressure and improve tissue perfusion.

Essential hypertension is linked to an increased sympathetic vasoconstrictor activity and reduced tissue perfusion. We investigated the role of exercise training on functional sympatholysis and postjunctional α‐adrenergic responsiveness in individuals with essential hypertension. Leg haemodynamics were measured before and after 8 weeks of aerobic training (3–4 times per week) in eight hypertensive (47 ± 2 years) and eight normotensive untrained individuals (46 ± 1 years) during arterial tyramine infusion, arterial ATP infusion and/or one‐legged knee extensions. Before training, exercise hyperaemia and leg vascular conductance (LVC) were lower in the hypertensive individuals (P < 0.05) and tyramine lowered exercise hyperaemia and LVC in both groups (P < 0.05). Training lowered blood pressure in the hypertensive individuals (P < 0.05) and exercise hyperaemia was similar to the normotensive individuals in the trained state. After training, tyramine did not reduce exercise hyperaemia or LVC in either group. When tyramine was infused at rest, the reduction in blood flow and LVC was similar between groups, but exercise training lowered the magnitude of the reduction in blood flow and LVC (P < 0.05). There was no difference in the vasodilatory response to infused ATP or in muscle P2Y2receptor content between the groups before and after training. However, training lowered the vasodilatory response to ATP and increased skeletal muscle P2Y2receptor content in both groups (P < 0.05). These results demonstrate that exercise training improves functional sympatholysis and reduces postjunctional α‐adrenergic responsiveness in both normo‐ and hypertensive individuals. The ability for functional sympatholysis and the vasodilator and sympatholytic effect of intravascular ATP appear not to be altered in essential hypertension.
Nicotinic ACh receptors in the hippocampal circuit; functional expression and role in synaptic plasticity
Authors: Yakel Jerrel L.
Published: May 2014

Acetylcholine (ACh) can regulate neuronal excitability in the hippocampus, an important area in the brain for learning and memory, by acting on both nicotinic (nAChRs) and muscarinic ACh receptors. The primary cholinergic input to the hippocampus arises from the medial septum and diagonal band of Broca (MS‐DBB), and we investigated how their activation regulated hippocampal synaptic plasticity. We found that activation of these endogenous cholinergic inputs can directly induce different forms of hippocampal synaptic plasticity with a timing precision in the millisecond range. Furthermore, we observed a prolonged enhancement of excitability both pre‐ and postsynaptically. Lastly we found that the presence of the α7 nAChR subtype to both pre‐ and postsynaptic sites appeared to be required to induce this plasticity. We propose that α7 nAChRs coordinate pre‐ and postsynaptic activities to induce glutamatergic synaptic plasticity, and thus provide a novel mechanism underlying physiological neuronal communication that could lead to timing‐dependent synaptic plasticity in the hippocampus.
Native store‐operated calcium channels are functionally expressed in mouse spinal cord dorsal horn neurons and regulate resting calcium homeostasis
Authors: Xia Jingsheng , Pan Rong , Gao Xinghua , Meucci Olimpia , Hu Huijuan
Published: May 2014

Key points

A previous study indicates that store‐operated calcium channels (SOCs) play a role in pain hypersensitivity. Here we report for the first time that SOCs are expressed and functional in spinal cord dorsal horn neurons.

Using the small inhibitory RNA knockdown approach, we have demonstrated that Orai1 is necessary, and both STIM1 and STIM2 are important for SOC entry and SOC current in dorsal horn neurons.

Our findings demonstrate that STIM1, STIM2 and Orai1 play an important role in resting Ca2+homeostasis.

Our results also indicate that SOCs are involved in the function of neurokinin 1 receptors and activation of SOCs produces an excitatory action in dorsal horn neurons.

The present study reveals that a novel calcium signal mediated by SOCs is present in dorsal horn neurons and provides a potential mechanism for SOC inhibition‐induced central analgesia.

Store‐operated calcium channels (SOCs) are calcium‐selective cation channels that mediate calcium entry in many different cell types. Store‐operated calcium entry (SOCE) is involved in various cellular functions. Increasing evidence suggests that impairment of SOCE is responsible for numerous disorders. A previous study demonstrated that YM‐58483, a potent SOC inhibitor, strongly attenuates chronic pain by systemic or intrathecal injection and completely blocks the second phase of formalin‐induced spontaneous nocifensive behaviour, suggesting a potential role of SOCs in central sensitization. However, the expression of SOCs, their molecular identity and function in spinal cord dorsal horn neurons remain elusive. Here, we demonstrate that SOCs are expressed in dorsal horn neurons. Depletion of calcium stores from the endoplasmic reticulum (ER) induced large sustained calcium entry, which was blocked by SOC inhibitors, but not by voltage‐gated calcium channel blockers. Depletion of ER calcium stores activated inward calcium‐selective currents, which was reduced by replacing Ca2+with Ba2+and reversed by SOC inhibitors. Using the small inhibitory RNA knockdown approach, we identified both STIM1 and STIM2 as important mediators of SOCE and SOC current, and Orai1 as a key component of the Ca2+release‐activated Ca2+channels in dorsal horn neurons. Knockdown of STIM1, STIM2 or Orai1 decreased resting Ca2+levels. We also found that activation of neurokinin 1 receptors led to SOCE and activation of SOCs produced an excitatory action in dorsal horn neurons. Our findings reveal that a novel SOC signal is present in dorsal horn neurons and may play an important role in pain transmission.
Method for Predicting Unsteady Vibration of Gas Turbine Compressor Blades Under Subsonic Near-Stall Conditions
Authors: Yamaguchi Kazuyuki , Takahashi Yasuo
Published: May 2014

Wind tunnel tests and numerical calculations using computational fluid dynamics (CFD) analysis and structural finite element analysis were conducted to clarify the vibration characteristics of gas turbine compressor blades under subsonic near-stall conditions. The results show that discrete low-frequency components of pressure are created by variation of the separation region and that discrete high-frequency components are created by vortex shedding when the compressor blade incidence angle is in the stall region. The natural frequency component resonated by the random fluid force is dominant in blade vibration. The numerically calculated phenomena agree well with the measured phenomena. The vibration amplitude increases with the incidence angle and the Mach number, and it increases rapidly at higher angles. A simple method for predicting the vibration stress using static calculations is reasonably accurate.
Traveling Wave Excitation: A Method to Produce Consistent Experimental Results
Authors: Cox Geofrey S. , Palazotto Anthony N. , Brown Jeffrey M. , George Tommy J.
Published: May 2014

This paper describes the experimental framework to establish consistent, repeatable results associated with a traveling wave excitation system. The experiment is employed to ascertain the forced response and mistuning patterns for rotors. Several items attributing to existing experimental inconsistencies were identified and their effects were realized during this research. These experimental items were signal input locations, response measurement locations, and rotor alignment position. Accounting for these experimental variables, this paper develops a process which enables consistent rotor forced response results, independent of its orientation on the test stand.
Effects of Mechanical Preloads on the Rotordynamic Performance of a Rotor Supported on Three-Pad Gas Foil Journal Bearings
Authors: Sim Kyuho , Koo Bonjin , Sung Lee Jong , Ho Kim Tae
Published: May 2014

This paper presents the rotordynamic performance measurements and model predictions of a rotor supported on three-pad gas foil journal bearings (GFJBs) with various mechanical preloads. The rotor with its length of 240 mm, diameter of 40 mm, and weight of 19.6 N is supported on two GFJBs and one pair of gas foil thrust bearings (GFTBs), being a permanent magnet rotor of a high speed electric motor. Each bearing pad consisting of a top foil and a bump-strip layer is installed on a lobed bearing housing surface over the arc length of 120 deg along the circumference. Test three-pad GFJBs have four different mechanical preloads, i.e., 0 μm, 50 μm, 70 μm, 100 μm with a common radial nominal clearance of 150 μm. A series of speed-up tests are conducted up to 93 krpm to evaluate the effects of increasing mechanical preloads on the rotordynamic performance. Two sets of orthogonally positioned displacement sensors record the rotor horizontal and vertical motions at the thrust collar and the other end. Test results show that the filtered synchronous amplitudes change little, but the onset speed of subsynchronous motions (OSS) increases dramatically for the increasing mechanical preloads. In addition, test bearings with the 100 μm preload show a higher OSS in load-on-pad (LOP) condition than that in load-between-pads (LBP) condition. A comparison with test results for a one-pad GFJB with a single top foil and bump-strip layer reveals that three-pad GFJB has superior rotordynamic performance to the one-pad one. Finally, the test data benchmark against linear rotordynamic predictions to validate a rotor-GFJB model. In general, predicted natural frequencies of the rotor-bearing system and synchronous rotor motions agree well with test data. However, stability analyses underestimate OSSs recorded during the experimental tests.
Leakage current and structural analysis of annealed HfO2/La2O3 and CeO2/La2O3 dielectric stacks: A nanoscopic study
Authors: Shubhakar Kalya , Pey Kin Leong , Bosman Michel , Kushvaha Sunil Singh , O'Shea Sean Joseph , Kouda Miyuki , Kakushima Kuniyuki , Iwai Hiroshi
Published: May 2014

Grain boundaries in the polycrystalline microstructure of post-annealed high-κ (HK) dielectrics are a major limitation in the reliability of HK dielectrics used for advanced CMOS technologies. Another challenge in the field of HK dielectrics is to ensure higher drain drive current in CMOS, while maintaining low leakage current. In this work, the authors demonstrate enhanced performance of HfO2 and CeO2 dielectrics by incorporating lanthanum. The resulting stacks show promising dielectric characteristics with reduced leakage current and uniform (amorphous) crystal structure. The improved HK characteristics were shown to occur even over nanometer-length scales using scanning probe microscopy and transmission electron microscopy, in agreement with previous studies based on micron-scale device-level measurement.
Comparative assessment of the stability of nonfouling poly(2-methyl-2-oxazoline) and poly(ethylene glycol) surface films: An in vitro cell culture study
Authors: Chen Yin , Pidhatika Bidhari , von Erlach Thomas , Konradi Rupert , Textor Marcus , Hall Heike , Lühmann Tessa
Published: May 2014

Poly(ethylene glycol) (PEG) has been the most frequently reported and commercially used polymer for surface coatings to convey nonfouling properties. PEGylated surfaces are known to exhibit limited chemical stability, particularly due to oxidative degradation, which limits long-term applications. In view of excellent anti-adhesive properties in the brush conformation and resistance to oxidative degradation, poly(2-methyl-2-oxazoline) (PMOXA) has been proposed recently as an alternative to PEG. In this study, the authors systematically compare the (bio)chemical stability of PEG- and PMOXA-based polymer brush monolayer thin films when exposed to cultures of human umbilical vein endothelial cells (HUVECs) and human foreskin fibroblasts (HFFs). To this end, the authors used cell-adhesive protein micropatterns in a background of the nonfouling PEG and PMOXA brushes, respectively, and monitored the outgrowth of HUVECs and HFFs for up to 21 days and 1.5 months. Our results demonstrate that cellular micropatterns spaced by PMOXA brushes are significantly more stable under serum containing cell culture conditions in terms of confinement of cells to the adhesive patterns, when compared to corresponding micropatterns generated by PEG brushes. Moreover, homogeneous PEG and PMOXA-based brush monolayers on Nb2O5 surfaces were investigated after immersion in endothelial cell medium using ellipsometry and x-ray photoelectron spectroscopy.
Attenuation of wall disturbances in an electron cyclotron resonance oxygen–argon plasma using real time control
Authors: Keville Bernard , Gaman Cezar , Zhang Yang , Holohan Anthony M. , Turner Miles M. , Daniels Stephen
Published: May 2014

Present practice in plasma-assisted semiconductor manufacturing specifies recipes in terms of inputs such as gas flow rates, power and pressure. However, ostensibly identical chambers running identical recipes may produce very different results. Extensive chamber matching, i.e., initial iterative, empirical tuning of the process recipe, which entails time-consuming, ex situ statistical analysis of process metrics such as etch depth, uniformity, anisotropy and selectivity, is required to ensure acceptable results. Once matched, chambers are run open loop and are thus sensitive to disturbances such as actuator drift, wall seasoning and substrate loading, which may impact negatively on process reproducibility. An alternative approach, which may obviate the need for chamber matching and reduce the sensitivity of process metrics to exogenous disturbances, would be to specify a recipe in terms of quantities such as active species densities, and to regulate these in real time by adjusting the inputs with a suitable control algorithm. In this work, real time control of an electron cyclotron resonance O2/Ar plasma used for photoresist ashing has been implemented. The design of elementary, model-based algorithms for the control of the argon 750 and oxygen 844 line intensities measured by optical emission spectroscopy is described. Fluorination of the chamber walls by means of an SF6 plasma prior to ashing inhibits wall recombination of oxygen radicals resulting in an approximately 20% increase in ash rate in the open loop case. However, closed loop control almost completely attenuates the effect of fluorination, thus demonstrating the efficacy of the control algorithms in ensuring a reproducible ash rate in the face of a wall disturbance.
Simultaneous Fermentation of Glucose and Xylose to Butanol by Clostridium sp. Strain BOH3
Authors: Xin Fengxue , Wu Yi-Rui , He Jianzhong
Published: May 2014

Cellulose and hemicellulose constitute the major components in sustainable feedstocks which could be used as substrates for biofuel generation. However, following hydrolysis to monomer sugars, the solventogenic
Clostridium
will preferentially consume glucose due to transcriptional repression of xylose utilization genes. This is one of the major barriers in optimizing lignocellulosic hydrolysates that produce butanol. Unlike studies on existing bacteria, this study demonstrates that newly reported
Clostridium
sp. strain BOH3 is capable of fermenting 60 g/liter of xylose to 14.9 g/liter butanol, which is similar to the 14.5 g/liter butanol produced from 60 g/liter of glucose. More importantly, strain BOH3 consumes glucose and xylose simultaneously, which is shown by its capability for generating 11.7 g/liter butanol from a horticultural waste cellulosic hydrolysate containing 39.8 g/liter glucose and 20.5 g/liter xylose, as well as producing 11.9 g/liter butanol from another horticultural waste hemicellulosic hydrolysate containing 58.3 g/liter xylose and 5.9 g/liter glucose. The high-xylose-utilization capability of strain BOH3 is attributed to its high xylose-isomerase (0.97 U/mg protein) and xylulokinase (1.16 U/mg protein) activities compared to the low-xylose-utilizing solventogenic strains, such as
Clostridium
sp. strain G117. Interestingly, strain BOH3 was also found to produce riboflavin at 110.5 mg/liter from xylose and 76.8 mg/liter from glucose during the fermentation process. In summary,
Clostridium
sp. strain BOH3 is an attractive candidate for application in efficiently converting lignocellulosic hydrolysates to biofuels and other value-added products, such as riboflavin.
The Temperature Gradient-Forming Device, an Accessory Unit for Normal Light Microscopes To Study the Biology of Hyperthermophilic Microorganisms
Authors: Mora Maximilian , Bellack Annett , Ugele Matthias , Hopf Johann , Wirth Reinhard
Published: May 2014

To date, the behavior of hyperthermophilic microorganisms in their biotope has been studied only to a limited degree; this is especially true for motility. One reason for this lack of knowledge is the requirement for high-temperature microscopy—combined, in most cases, with the need for observations under strictly anaerobic conditions—for such studies. We have developed a custom-made, low-budget device that, for the first time, allows analyses in temperature gradients up to 40°C over a distance of just 2 cm (a biotope-relevant distance) with heating rates up to ∼5°C/s. Our temperature gradient-forming device can convert any upright light microscope into one that works at temperatures as high as 110°C. Data obtained by use of this apparatus show how very well hyperthermophiles are adapted to their biotope: they can react within seconds to elevated temperatures by starting motility—even after 9 months of storage in the cold. Using the temperature gradient-forming device, we determined the temperature ranges for swimming, and the swimming speeds, of 15 selected species of the genus
Thermococcus
within a few months, related these findings to the presence of cell surface appendages, and obtained the first evidence for thermotaxis in
Archaea
.
Genetic Diversity and Virulence Potential of Shiga Toxin-Producing Escherichia coli O113:H21 Strains Isolated from Clinical, Environmental, and Food Sources
Authors: Feng Peter C. H. , Delannoy Sabine , Lacher David W. , dos Santos Luis Fernando , Beutin Lothar , Fach Patrick , Rivas Marta , Hartland Elizabeth L. , Paton Adrienne W. , Guth Beatriz E. C.
Published: May 2014

Shiga toxin-producing
Escherichia coli
strains of serotype O113:H21 have caused severe human diseases, but they are unusual in that they do not produce adherence factors coded by the locus of enterocyte effacement. Here, a PCR microarray was used to characterize 65 O113:H21 strains isolated from the environment, food, and clinical infections from various countries. In comparison to the pathogenic strains that were implicated in hemolytic-uremic syndrome in Australia, there were no clear differences between the pathogens and the environmental strains with respect to the 41 genetic markers tested. Furthermore, all of the strains carried only Shiga toxin subtypes associated with human infections, suggesting that the environmental strains have the potential to cause disease. Most of the O113:H21 strains were closely related and belonged in the same clonal group (ST-223), but CRISPR analysis showed a great degree of genetic diversity among the O113:H21 strains.
Identification and Characterization of a Novel Secreted Glycosidase with Multiple Glycosidase Activities in Streptococcus intermedius
Authors: Imaki Hidenori , Tomoyasu Toshifumi , Yamamoto Naoki , Taue Chiharu , Masuda Sachiko , Takao Ayuko , Maeda Nobuko , Tabata Atsushi , Whiley Robert A. , Nagamune Hideaki
Published: May 2014

Streptococcus intermedius
is a known human pathogen and belongs to the anginosus group (
S. anginosus
,
S. intermedius
, and
S. constellatus
) of streptococci (AGS). We found a large open reading frame (6,708 bp) in the
lac
operon, and bioinformatic analysis suggested that this gene encodes a novel glycosidase that can exhibit β-
d
-galactosidase and
N
-acetyl-β-
d
-hexosaminidase activities. We, therefore, named this protein “multisubstrate glycosidase A” (MsgA). To test whether MsgA has these glycosidase activities, the
msgA
gene was disrupted in
S. intermedius
. The
msgA
-deficient mutant no longer showed cell- and supernatant-associated β-
d
-galactosidase, β-
d
-fucosidase,
N
-acetyl-β-
d
-glucosaminidase, and
N
-acetyl-β-
d
-galactosaminidase activities, and all phenotypes were complemented in
trans
with a recombinant plasmid carrying
msgA
. Purified MsgA had all four of these glycosidase activities and exhibited the lowest

K
m

with 4-methylumbelliferyl-linked
N
-acetyl-β-
d
-glucosaminide and the highest
k
cat
with 4-methylumbelliferyl-linked β-
d
-galactopyranoside. In addition, the purified LacZ domain of MsgA had β-
d
-galactosidase and β-
d
-fucosidase activities, and the GH20 domain exhibited both
N
-acetyl-β-
d
-glucosaminidase and
N
-acetyl-β-
d
-galactosaminidase activities. The β-
d
-galactosidase and β-
d
-fucosidase activities of MsgA are thermolabile, and the optimal temperature of the reaction was 40°C, whereas almost all enzymatic activities disappeared at 49°C. The optimal temperatures for the
N
-acetyl-β-
d
-glucosaminidase and
N
-acetyl-β-
d
-galactosaminidase activities were 58 and 55°C, respectively. The requirement of sialidase treatment to remove sialic acid residues of the glycan branch end for glycan degradation by MsgA on human α
1
-antitrypsin indicates that MsgA has exoglycosidase activities. MsgA and sialidase might have an important function in the production and utilization of monosaccharides from oligosaccharides, such as glycans for survival in a normal habitat and for pathogenicity of
S. intermedius
.