bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social interactions influence dopamine and octopamine homeostasis in the brain of the ant Formica japonica
Authors: Wada-Katsumata Ayako , Yamaoka Ryohei , Aonuma Hitoshi 
Published: April 2011

SUMMARY
In ants, including Formica japonica, trophallaxis and grooming are typical social behaviors shared among nestmates. After depriving ants of either food or nestmates and then providing them with either food or nestmates, a behavioral change in type and frequency of social interactions was observed. We hypothesized that starvation and isolation affected levels of brain biogenic amines including dopamine (DA) and octopamine (OA) – neuromediators modifying various insect behaviors – and tested the relationship between brain biogenic amines and social behaviors of stressed ants. Ants starved for 7 days contained lower brain DA levels and they did not perform trophallaxis toward nestmates. Feeding starved ants sucrose solution re-established trophallaxis but not brain DA levels. The performance of trophallaxis induced recovery of brain DA content to the level of untreated ants. Ants that were isolated for 2 days displayed markedly increased OA levels, which following nestmate interactions, returned to levels similar to those of control (non-isolated) ants and ants isolated for 1 h. We conclude that: (1) starvation reduced brain DA level but had no significant effect on brain OA (trophallaxis recovered the brain DA levels), and (2) isolation increased brain OA level but had no effect on brain DA (trophallaxis and grooming events recovered the brain OA levels). We suggest that social interactions with nestmates influenced brain biogenic amine homeostasis in stressed F. japonica.
Activity of the claw retractor muscle in stick insects in wall and ceiling situations
Authors: Bußhardt Philipp , Gorb Stanislav N. , Wolf Harald 
Published: April 2011

SUMMARYThe activity of the middle part of the claw retractor muscle was examined in two species of stick insects (Carausius morosus and Cuniculina impigra). We performed electromyographic recordings while the animals were standing on a smooth or a rough surface of a platform in horizontal, vertical or inverted positions, as well as during rotations of the platform. We recorded tonic and phasic motor units. The tonic units were active all the time without significant differences in spike frequency, regardless of the position of the animals (although there was a tendency for higher discharge frequencies to occur during platform rotations). The phasic units were active almost exclusively during platform movement. In contrast to the tonic units, we detected significant differences in the activities of the phasic units; namely, higher spike frequencies during rotations compared with the stationary phases, especially for rotations into ‘more awkward’ positions. A comparison of the two species revealed no difference in muscle activity, despite differences in the animals' tarsal attachment structures. The same was true when comparing the muscle activity of the two species on both the smooth and the rough surfaces.
High background noise shapes selective auditory filters in a tropical cricket
Authors: Schmidt Arne K. D. , Riede Klaus , Römer Heiner 
Published: April 2011

SUMMARYBecause of call frequency overlap and masking interference, the airborne sound channel represents a limited resource for communication in a species-rich cricket community like the tropical rainforest. Here we studied the frequency tuning of an auditory neuron mediating phonotaxis in the rainforest cricket Paroecanthus podagrosus, suffering from strong competition, in comparison with the same homologous neuron in two species of European field crickets, where such competition does not exist. As predicted, the rainforest species exhibited a more selective tuning compared with the European counterparts. The filter reduced background nocturnal noise levels by 26 dB, compared with only 16 and 10 dB in the two European species. We also quantified the performance of the sensory filter under the different filter regimes by examining the representation of the species-specific amplitude modulation of the male calling song, when embedded in background noise. Again, the filter of the rainforest cricket performed significantly better in terms of representing this important signal parameter. The neuronal representation of the calling song pattern within receivers was maintained for a wide range of signal-to-noise ratios because of the more sharply tuned sensory system and selective attention mechanisms. Finally, the rainforest cricket also showed an almost perfect match between the filter for sensitivity and the peripheral filter for directional hearing, in contrast to its European counterparts. We discuss the consequences of these adaptations for intraspecific acoustic communication and reproductive isolation between species.
Repeatability of standard metabolic rate, active metabolic rate and aerobic scope in young brown trout during a period of moderate food availability
Authors: Norin Tommy , Malte Hans 
Published: April 2011

SUMMARY
Standard metabolic rate (SMR) and active metabolic rate (AMR) are two fundamental physiological parameters providing the floor and ceiling in aerobic energy metabolism. The total amount of energy available within these two parameters confines constitutes the absolute aerobic scope (AAS). Previous studies on fish have found SMR to closely correlate with dominance and position in the social hierarchy, and to be highly repeatable over time when fish were provided an ad libitum diet. In this study we tested the temporal repeatability of individual SMR, AMR and AAS, as well as repeatability of body mass, in young brown trout (Salmo trutta L.) fed a moderately restricted diet (0.5–0.7% fish mass day–1). Metabolism was estimated from measurements of oxygen consumption rate () and repeatability was evaluated four times across a 15-week period. Individual body mass was highly repeatable across the entire 15 week experimental period whereas residual body-mass-corrected SMR, AMR and AAS showed a gradual loss of repeatability over time. Individual residual SMR, AMR and AAS were significantly repeatable in the short term (5 weeks), gradually declined across the medium term (10 weeks) and completely disappeared in the long term (15 weeks). We suggest that this gradual decline in repeatability was due to the slightly restricted feeding regime. This is discussed in the context of phenotypic plasticity, natural selection and ecology.
Effects of fore–aft body mass distribution on acceleration in dogs
Authors: Walter Rebecca M. , Carrier David R. 
Published: April 2011

SUMMARY
The ability of a quadruped to apply propulsive ground reaction forces (GRF) during rapid acceleration may be limited by muscle power, foot traction or the ability to counteract the nose-up pitching moment due to acceleration. Because the biomechanics of acceleration change, both throughout the stride cycle and over subsequent strides as velocity increases, the factors limiting propulsive force production may also change. Depending on which factors are limiting during each step, alterations in fore–aft body mass distribution may either increase or decrease the maximum propulsive GRF produced. We analyzed the effects of experimental alterations in the fore–aft body mass distribution of dogs as they performed rapid accelerations. We measured the changes in trunk kinematics and GRF as dogs accelerated while carrying 10% body mass in saddlebags positioned just in front of the shoulder girdle or directly over the pelvic girdle. We found that dogs applied greater propulsive forces in the initial hindlimb push-off and first step by the lead forelimb in both weighted conditions. During these steps dogs appear to have been limited by foot traction. For the trailing forelimb, propulsive forces and impulses were reduced when dogs wore caudally placed weights and increased when dogs wore cranially placed weights. This is consistent with nose-up pitching or avoidance thereof having limited propulsive force production by the trailing forelimb. By the second stride, the hindlimbs appear to have been limited by muscle power in their ability to apply propulsive force. Adding weights decreased the propulsive force they applied most in the beginning of stance, when limb retractor muscles were active in supporting body weight. These results suggest that all three factors: foot traction, pitching of the body, and muscle power play roles in limiting quadrupedal acceleration. Digging in to the substrate with claws or hooves appears to be necessary for maximizing propulsion in the initial hindlimb push-off and first forelimb step. Shifting the center of mass forward, as occurred with the loss of the large and heavy tail in the evolution of mammals, is likely to increase the contribution of the forelimbs to acceleration. Hindlimb muscle power appears to play a greater role in limiting acceleration than does forelimb muscle power. As such, we might expect animals built for rapid acceleration to have an increased ratio of hindlimb to forelimb muscle mass.
Chronic social stress impairs thermal tolerance in the rainbow trout (Oncorhynchus mykiss)
Authors: LeBlanc Sacha , Middleton Stephen , Gilmour Kathleen M. , Currie Suzanne 
Published: April 2011

SUMMARYWhen faced with limited resources, juvenile salmonid fish form dominance hierarchies that result in social stress for socially subordinate individuals. Social stress, in turn, can have consequences for the ability of the fish to respond to additional stressors such as pathogens or exposure to pollutants. In the present study, the possibility that social stress affects the ability of rainbow trout (Oncorhynchus mykiss) to tolerate acute increases in water temperature was investigated. To this end, we first evaluated physiological and cellular stress responses following a 1 h heat shock in juvenile fish in dominance hierarchies. We measured stress hormone (cortisol and catecholamines) concentrations and blood, brain and liver tissue levels of three heat shock proteins (HSPs), the stress inducible HSP70, the constitutive HSC70 and HSP90, in dominant and subordinate trout. No effects of social status on the hormonal response to the heat stress were detected, but the cellular heat shock response in the brain and liver of dominant and subordinate individuals was inhibited. We then assessed thermal tolerance in dominant and subordinate fish through critical thermal maximum temperature (CTmax) trials and measured HSPs following the heat shock. Subordinate fish were less thermally tolerant than their dominant counterparts. We conclude that social stress impacts the ability of fish to respond, on a cellular scale and in a tissue-specific manner, to increases in water temperature, with likely consequences for overall fitness.
Treatment of Alternaria Keratitis with Intrastromal and Topical Caspofungin in Combination with Intrastromal, Topical, and Oral Voriconazole
Authors: Neoh Chin Fen , Leung Lok , Vajpayee Rasik B , Stewart Kay , Kong David CM 
Published: April 2011

Objective: To report a case of refractory atypical Alternaria keratitis that was treated with intrastromal and topical caspofungin 0.5% in combination with topical, oral, and intrastromal voriconazole. Case Summary: A 67-year-old female with a history of bilateral intraocular lens exchange and left pseudophakic bullous keratopathy was referred to the emergency department of the Royal Victorian Eye and Ear Hospital, Melbourne, Australia. Visual acuity of her left eye was limited to counting fingers. A fine branching pattern was noted throughout the anterior stroma of her left corneal graft. The anterior chamber was deep and quiet. Hourly topical voriconazole 1% was initiated, with limited response. One week later, Alternaria spp. was cultured from the corneal scraping. Subsequently, topical caspofungin 0.5% was added, with concomitant use of topical, oral, and intrastromal voriconazole. Despite gradual symptomatic improvement, topical voriconazole was increased to 2% and intrastromal caspofungin was added. The patient was discharged after almost 5 weeks of treatment. Topical voriconazole 2% and topical caspofungin 0.5% were continued for an additional 3 weeks and 1 week, respectively, in the outpatient setting. The patient underwent left penetrating keratoplasty 3 weeks postdischarge. Visual acuity was stable at 20/150, with no reported adverse event 15 months postoperative. Discussion: Treatment for Alternaria keratitis remains challenging, as it is refractory to existing antifungal agents. To our knowledge, this is the first reported instance of the use of intrastromal caspofungin to treat Alternaria keratitis in a case in which clinical resolution was not fully achieved despite the use of topical caspofungin in addition to extensive use of topical, intrastromal, and oral voriconazole. This case highlights the importance of intensive pharmacologic management and therapeutic penetrating keratoplasty in preventing evisceration of the patient's eye, especially when Alternaria keratitis is involved. Conclusions: Intrastromal and topical caspofungin were employed in combination with voriconazole for the management of refractory Alternaria keratitis, with no observed adverse effects.
Generic Substitution of Levetiracetam Resulting in Increased Incidence of Breakthrough Seizures
Authors: Fitzgerald Christine L , Jacobson Mercedes P 
Published: April 2011

Objective: We report on 4 patients having an increased incidence of seizures when treatment was switched from brand name levetiracetam (Keppra) to generic levetiracetam formulations. Case Summary: Patients reported an increase in seizure activity to their neurologists after treatment was switched from Keppra to generic levetiracetam formulations. To confirm the timeline of increased seizure activity with use of the generic drug and report these adverse events to MedWatch, we made a telephone call to each patient's pharmacy to collect information on dispensing dates and the generic formulations' manufacturers. Subsequent to the increase in seizure frequency with generic levetiracetam, treatment in all 4 patients was switched back to Keppra. Seizure frequency in all patients returned to baseline when Keppra was reinstituted. Discussion: The Food and Drug Administration (FDA) considers generic medications to be therapeutically equivalent to their corresponding brand name formulation when the generic meets bioequivalence criteria. Considering the linear pharmacokinetic profile of levetiracetam, loss of seizure control or fluctuations of serum concentrations are unexpected if the patient remains on a consistent dose. However, there is growing evidence to support the concept that brand name antiepileptic drugs (AEDs) are not clinically equivalent to their generic counterparts. Because the FDA relies on voluntary reporting of adverse events from health-care professionals and consumers to their MedWatch program, underreporting makes it difficult to quantify the significance of brand to generic switches, and, equally important, generic to generic switches. Conclusions: Until the use of generic AEDs can be evaluated in a large randomized blinded controlled study, clinicians must be vigilant in their efforts to report to MedWatch adverse events resulting from the switch from an AED brand to generic formulation of an AED.
An Equivalent Noise Investigation of Saccadic Suppression
Authors: Watson Tamara , Krekelberg Bart 
Published: April 2011

Visual stimuli presented just before or during an eye movement are more difficult to detect than those same visual stimuli presented during fixation. This laboratory phenomenon—behavioral saccadic suppression—is thought to underlie the everyday experience of not perceiving the motion created by our own eye movements—saccadic omission. At the neural level, many cortical and subcortical areas respond differently to perisaccadic visual stimuli than to stimuli presented during fixation. Those neural response changes, however, are complex and the link to the behavioral phenomena of reduced detectability remains tentative. We used a well established model of human visual detection performance to provide a quantitative description of behavioral saccadic suppression and thereby allow a more focused search for its neural mechanisms.We used an equivalent noise method to distinguish between three mechanisms that could underlie saccadic suppression. The first hypothesized mechanism reduces the gain of the visual system, the second increases internal noise levels in a stimulus-dependent manner, and the third increases stimulus uncertainty. All three mechanisms predict that perisaccadic stimuli should be more difficult to detect, but each mechanism predicts a unique pattern of detectability as a function of the amount of external noise.Our experimental finding was that saccades increased detection thresholds at low external noise, but had little influence on thresholds at high levels of external noise. A formal analysis of these data in the equivalent noise analysis framework showed that the most parsimonious mechanism underlying saccadic suppression is a stimulus-independent reduction in response gain.
In To Africa: Teaching Nanoscience to Undergraduates in KwaZulu-Natal, South Africa
Authors: Augustine Brian H. , Munro Orde Q. 
Published: April 2011

ABSTRACTThere has been considerable interest in developing curricular programs and materials for teaching undergraduate courses in nanoscience in the United States and other developed countries in the past decade. Materials science and nanoscience research programs are growing in developing countries in South America, Africa and Asia. However, there still exists a significant disconnect between the research efforts in developing countries and undergraduate coursework. This report will focus on the teaching of an upper-division one semester lecture/laboratory course developed at James Madison University (JMU) called “The Science of the Small: An Introduction to the Nanoworld” taught in the School of Chemistry at the University of KwaZulu-Natal in Pietermaritzburg (UKZN-PMB), South Africa in 2009 through the Fulbright U.S. Scholar program. We report insights into the preparation needed to teach a cutting-edge laboratory course in South Africa. Also addressed will be some of the challenges of teaching an instrument-intensive laboratory course in a developing country, academic preparation of the typical native isiZulu-speaking UKZN undergraduate student compared to a typical U.S. student, and pre and post attitudes and content assessment of students who were enrolled in the course. Further discussed will be observations of post-apartheid science and math education in South Africa, and the beginning of a pilot program bringing South African undergraduate students to the U.S. to gain undergraduate research experience.
Modeling of AlGaAs on Si tandem PV cells for extended spectral conversion
Authors: Emziane Mahieddine , Mokri Alaeddine 
Published: April 2011

ABSTRACTThe primary objective of this modeling investigation is to optimize a two-junction three-terminal device under the AM1.5G spectrum. Based on previous studies, AlGaAs and Si cells, because of their energy bandgaps, can be combined together to achieve high-efficiency double-junction devices. In this study, the top cell is made of Al0.3Ga0.7As (1.817 eV) while the bottom cell is made of Si (1.124 eV). In order to avoid the losses and design constraints observed in two-terminal and four-terminal devices, the tandem cell AlGaAs/Si is designed with three-terminals. In order to determine the optimal structure of the device, the top and bottom junctions were investigated and optimized with regard to the thicknesses and doping level. The optimum configuration of the device shows an efficiency of 26.27% under the AM1.5G spectrum and one sun, which is higher than the efficiency of an optimized single-junction Si cell under the same illumination conditions. We also studied the effect of the optical concentration on the performance of the device and we found that the overall efficiency reaches over 31% under 50 suns.
Thermoresponsive Hydrogel Microvalve Based on Magnetic Nanoheaters for Microfluidics
Authors: Ghosh Santaneel , Neogi Arup , Yang Chao , Cai Tong , GhoshMitra Somesree , Diercks David , Hu Zhibing 
Published: April 2011

AbstractA novel magneto-active gel based nanomaterial system is presented as an externally tunable flow controller inside a microfluidic channel using the thermoresponsive property of the structure. Integration of ferromagnetic nanoparticles (Fe3O4) in the temperature sensitive polymer-poly (N-isopropylacrylamide) (PNIPAM) provides the swelling and de-swelling behavior of magnetic stimuli controlled micro-component by generating the heat due to the hysteresis loss of Fe3o4 under exposure in an alternating magnetic field. The shrinkage rates of the nanomaterial system at the bulk and micro scale are investigated. Size dependent shrinkage rate and actuation efficiency are ideal for various applications like magnetic micro/nano pump, magnetic field controlled drug delivery devices and magnetic switch applications.
Current Status of Src Inhibitors in Solid Tumor Malignancies
Authors: Puls Lauren N. , Eadens Matthew , Messersmith Wells 
Published: April 2011

Abstract

Summary.
Src is believed to play an important role in cancer, and several agents targeting Src are in clinical development.

Design.
We reviewed Src structure and function and preclinical data supporting its role in the development of cancer via a PubMed search. We conducted an extensive review of Src inhibitors by searching abstracts from major oncology meeting databases in the last 3 years and by comprehensively reviewing ongoing clinical trials on ClinicalTrials.gov.

Results.
In this manuscript, we briefly review Src structure and function, mechanisms involving Src that lead to the development of cancer, and Src inhibitors and key preclinical data establishing a rationale for clinical application. We then focus on clinical data supporting their use in solid tumor malignancies, a newer arena than their more well-established hematologic applications. Particularly highlighted are clinical trials investigating new biomarkers as well as ongoing studies assessing Src inhibitor activity in biomarker-selected patient populations. We also review newer investigational Src-targeting agents.

Conclusions.
Src inhibitors have shown little activity in monotherapy trials in unselected solid tumor patient populations. Combination studies and biomarker-driven clinical trials are under way.
Dimensionality and Psychometric Analysis of an Alcohol Protective Behavioral Strategies Scale
Authors: Novik Melinda G. , Boekeloo Bradley O. 
Published: April 2011

Objective: The current study examined the dimensionality of a protective behavioral strategies (PBS) measure among undergraduate, predominantly freshmen (92.5%) college students reporting recent alcohol use ( n = 320). Method: Participants completed a web-based survey assessing 22 PBS items. Factor analyses determined the underlying factor structure of the items. Congruence of the factor structure among gender and racial sub-groups was examined by rotating the sub-groups' matrices via the Procrustes rotation method. Reliability analyses determined internal consistency. Results: A 2-factor solution was retained utilizing 17 of the original items. Both PBS subscales (Limits and Avoidance) had acceptable internal consistency across all samples. Conclusions: This PBS Scale was determined to be bi-dimensional and reliable. The dimensions suggest two underlying foci: ways to limit alcohol intake and ways to avoid alcohol intake while socializing. Practical implications of these findings are discussed.