bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of structural, architectural and mechanical aspects of cellular and acellular bone in two teleost fish
Authors: Cohen Liat , Dean Mason , Shipov Anna , Atkins Ayelet , Monsonego-Ornan Efrat , Shahar Ron 
Published: May 2012

SUMMARY
The histological diversity of the skeletal tissues of fishes is impressive compared with that of other vertebrate groups, yet our understanding of the functional consequences of this diversity is limited. In particular, although it has been known since the mid-1800s that a large number of fish species possess acellular bones, the mechanical advantages and consequences of this structural characteristic – and therefore the nature of the evolution of this feature – remain unclear. Although several studies have examined the material properties of fish bone, these have used a variety of techniques and there have been no direct contrasts of acellular and cellular bone. We report on a comparison of the structural and mechanical properties of the ribs and opercula between two freshwater fish – the common carp Cyprinus carpio (a fish with cellular bone) and the tilapia Oreochromis aureus (a fish with acellular bone). We used light microscopy to show that the bones in both fish species exhibit poor blood supply and possess discrete tissue zones, with visible layering suggesting differences in the underlying collagen architecture. We performed identical micromechanical testing protocols on samples of the two bone types to determine the mechanical properties of the bone material of opercula and ribs. Our data support the consensus of literature values, indicating that Young’s moduli of cellular and acellular bones are in the same range, and lower than Young’s moduli of the bones of mammals and birds. Despite these similarities in mechanical properties between the bone tissues of the fish species tested here, cellular bone had significantly lower mineral content than acellular bone; furthermore, the percentage ash content and bone mineral density values (derived from micro-CT scans) show that the bone of these fishes is less mineralized than amniote bone. Although we cannot generalize from our data to the numerous remaining teleost species, the results presented here suggest that while cellular and acellular fish bone may perform similarly from a mechanical standpoint, there are previously unappreciated differences in the structure and composition of these bone types.
Molt–breeding overlap alters molt dynamics and behavior in zebra finches,Taeniopygia guttata castanotis
Authors: Echeverry-Galvis Maria A. , Hau Michaela 
Published: May 2012

SUMMARYCostly events in the life history cycle of organisms such as reproduction, migration and pelage/plumage replacement are typically separated in time to maximize their outcome. Such temporal separation is thought to be necessitated by energetical trade-offs, and mediated through physiological processes. However, certain species, such as tropical birds, are able to overlap two costly life history stages: reproduction and feather replacement. It has remained unclear how both events progress when they co-occur over extended periods of time. Here we determined the consequences and potential costs of such overlap by comparing molt and behavioral patterns in both sexes of captive zebra finches (Taeniopygia guttata castanotis) that were solely molting or were overlapping breeding and molt. Individuals overlapping the early stages of breeding with molt showed a roughly 40% decrease in the growth rate of individual feathers compared with birds that were molting but not breeding. Further, individuals that overlapped breeding and molt tended to molt fewer feathers simultaneously and exhibited longer intervals between shedding consecutive feathers on the tail or the same wing as well as delays in shedding corresponding flight feathers on opposite sides. Overlapping individuals also altered their time budgets: they devoted more than twice the time to feeding while halving the time spent for feather care in comparison to molt-only individuals. These data provide experimental support for the previously untested hypothesis that when molt and reproduction overlap in time, feather replacement will occur at a slower and less intense rate. There were no sex differences in any of the variables assessed, except for a tendency in females to decline body condition more strongly over time during the overlap than males. Our data indicate the existence of major consequences of overlapping breeding and molt, manifested in changes in both molt dynamics and time budgets of both sexes. It is likely that under harsher conditions in natural environments such consequences will be more severe and may result in fitness consequences.
Growth and development of house sparrows (Passer domesticus) in response to chronic food restriction throughout the nestling period
Authors: Killpack Tess L. , Karasov William H. 
Published: May 2012

SUMMARYBirds have evolved phenotypic plasticity in growth and developmental patterns in order to respond to fluctuating environmental conditions and to mitigate the impact of poor feeding on fitness. Chronic food shortage can occur during chick development in the wild, and the responses of altricial birds have not been thoroughly studied. House sparrow (Passer domesticus) nestlings were raised in the laboratory on age-specific meal sizes (controls) or meal sizes 25% less than age-specific amounts (food-restricted) and analyzed at 6, 9 and 12 days post-hatch for differences in growth and development. Food-restricted birds had significantly reduced body mass and body temperature, but skeletal growth was maintained with respect to controls. Muscle mass was significantly reduced and muscle water content was slightly, though not significantly, higher in food-restricted birds, which may reflect slight developmental immaturity. Assimilation organ masses, summed enzymatic capacity of the intestine and lipid content of the liver were significantly reduced in food-restricted birds. Findings from this study indicate that altricial birds experiencing chronic, moderate food restriction throughout the nestling period may allocate resources to structural growth through energy-saving reductions in mass of assimilation organs and body temperature.
Proprioceptive feedback reinforces centrally generated stepping patterns in the cockroach
Authors: Fuchs Einat , Holmes Philip , David Izhak , Ayali Amir 
Published: May 2012

SUMMARYThe relative importance of sensory input for the production of centrally generated motor patterns is crucial to our understanding of how animals coordinate their body segments to locomote. In legged locomotion, where terrain heterogeneity may require stride-by-stride changes in leg placement, evidence suggests that sensory information is essential for the timing of leg movement. In a previous study we showed that in cockroaches, renowned for rapid and stable running, a coordinated pattern can be elicited from the motor centres driving the different legs in the absence of sensory feedback. In the present paper, we assess the role of movement-related sensory inputs in modifying this central pattern. We studied the effect of spontaneous steps as well as imposed transient and periodic movements of a single intact leg, and demonstrate that, depending on the movement properties, the resulting proprioceptive feedback can significantly modify phase relationships among segmental oscillators of other legs. Our analysis suggests that feedback from front legs is weaker but more phasically precise than from hind legs, selectively transferring movement-related information in a manner that strengthens the inherent rhythmic pattern and modulates local perturbations.
Simulating transoceanic migrations of young loggerhead sea turtles: merging magnetic navigation behavior with an ocean circulation model
Authors: Putman Nathan F. , Verley Philippe , Shay Thomas J. , Lohmann Kenneth J. 
Published: May 2012

SUMMARYYoung loggerhead sea turtles (Caretta caretta) from eastern Florida, USA, undertake a transoceanic migration in which they gradually circle the Sargasso Sea before returning to the North American coast. Loggerheads possess a ‘magnetic map’ in which regional magnetic fields elicit changes in swimming direction along the migratory pathway. In some geographic areas, however, ocean currents move more rapidly than young turtles can swim. Thus, the degree to which turtles can control their migratory movements has remained unclear. In this study, the movements of young turtles were simulated within a high-resolution ocean circulation model using several different behavioral scenarios, including one in which turtles drifted passively and others in which turtles swam briefly in accordance with experimentally derived data on magnetic navigation. Results revealed that small amounts of oriented swimming in response to regional magnetic fields profoundly affected migratory routes and endpoints. Turtles that engaged in directed swimming for as little as 1–3 h per day were 43–187% more likely than passive drifters to reach the Azores, a productive foraging area frequented by Florida loggerheads. They were also more likely to remain within warm-water currents favorable for growth and survival, avoid areas on the perimeter of the migratory route where predation risk and thermal conditions pose threats, and successfully return to the open-sea migratory route if carried into coastal areas. These findings imply that even weakly swimming marine animals may be able to exert strong effects on their migratory trajectories and open-sea distributions through simple navigation responses and minimal swimming.
Challenging zebrafish escape responses by increasing water viscosity
Authors: Danos Nicole , Lauder George V. 
Published: May 2012

SUMMARYEscape responses of fishes have long been studied as a model locomotor behavior in which hypothesized maximal or near-maximal muscle power output is used to generate rapid body bending. In this paper we present the results of experiments that challenged zebrafish (Danio rerio) to perform escape responses in water of altered viscosity, to better understand the effects that the fluid mechanical environment exerts on kinematics. We quantified escape kinematics using 1000 frames s–1 high-speed video, and compared escape response kinematics of fish in three media that differed in viscosity: 1 mPa s (normal water), 10 mPa s and 20 mPa s (20 times normal water viscosity). We hypothesized that because viscosity is increased but not density there will be a different effect on kinematic variables resulting from unsteady (acceleration-dependent) hydrodynamic forces and steady (velocity-dependent) ones. Similarly, we hypothesized that the kinematics of stage 1 will be less affected by viscosity than those of stage 2, as higher angular velocities are reached during stage 1 resulting in higher Reynolds numbers. Our results showed a significant overall effect of viscosity on escape response kinematics but the effect was not in accordance with our predictions. Statistical tests showed that increasing viscosity significantly decreased displacement of the center of mass during stage 1 and after 30 ms, and decreased maximum velocity of the center of mass, maximum angular velocity and acceleration during stage 1, but increased time to maximum angular acceleration and time to maximum linear velocity of the center of mass. Remarkably, increasing water viscosity 20 times did not significantly affect the duration of stage 1 or stage 2.
Changes in extreme cold tolerance, membrane composition and cardiac transcriptome during the first day of thermal acclimation in the porcelain crabPetrolisthes cinctipes
Authors: Ronges Daria , Walsh Jillian P. , Sinclair Brent J. , Stillman Jonathon H. 
Published: May 2012

SUMMARYIntertidal zone organisms can experience transient freezing temperatures during winter low tides, but their extreme cold tolerance mechanisms are not known. Petrolisthes cinctipes is a temperate mid–high intertidal zone crab species that can experience wintertime habitat temperatures below the freezing point of seawater. We examined how cold tolerance changed during the initial phase of thermal acclimation to cold and warm temperatures, as well as the persistence of cold tolerance during long-term thermal acclimation. Thermal acclimation for as little as 6 h at 8°C enhanced cold tolerance during a 1 h exposure to –2°C relative to crabs acclimated to 18°C. Potential mechanisms for this enhanced tolerance were elucidated using cDNA microarrays to probe for differences in gene expression in cardiac tissue of warm- and cold-acclimated crabs during the first day of thermal acclimation. No changes in gene expression were detected until 12 h of thermal acclimation. Genes strongly upregulated in warm-acclimated crabs represented immune response and extracellular/intercellular processes, suggesting that warm-acclimated crabs had a generalized stress response and may have been remodelling tissues or altering intercellular processes. Genes strongly upregulated in cold-acclimated crabs included many that are involved in glucose production, suggesting that cold acclimation involves increasing intracellular glucose as a cryoprotectant. Structural cytoskeletal proteins were also strongly represented among the genes upregulated in only cold-acclimated crabs. There were no consistent changes in composition or the level of unsaturation of membrane phospholipid fatty acids with cold acclimation, which suggests that neither short- nor long-term changes in cold tolerance are mediated by changes in membrane fatty acid composition. Overall, our study demonstrates that initial changes in cold tolerance are likely not regulated by transcriptomic responses, but that gene-expression-related changes in homeostasis begin within 12 h, the length of a tidal cycle.
The impact of gender on urine C-peptide creatinine ratio interpretation
Authors: Thomas Nicholas J , Shields Beverley M , Besser Rachel E J , Jones Angus G , Rawlingson Andrew , Goodchild Emily , Leighton Christopher , Bowman Pamela , Shepherd Maggie , Knight Bridget A , McDonald Timothy J , Hattersley Andrew T 
Published: May 2012

Background Urinary C-peptide creatinine ratio (UCPCR) is a non-invasive and convenient way of assessing endogenous insulin production. Adjusting for urine creatinine levels allows for differences in urine concentration. Creatinine excretion is known to be higher in men due to gender differences in muscle mass. We investigated the impact of gender on UCPCR. Methods One hundred and seventy-six subjects underwent a mixed meal tolerance test (MMTT). We looked at the relationship between UCPCR on urine C-peptide and creatinine excretion rates using timed post-meal urine samples. A further 415 subjects had two-hour post-meal UCPCR measurements in order to derive gender-specific percentiles for different diabetes subgroups and controls. Results UCPCR was 1.48-fold higher in women ( n= 78) than men ( n= 98), median (interquartile range [IQR]): 1.88 (0.49–3.49) men versus 2.88 (1.58–4.91) nmol mmol−1 women, P= 0.01. This reflects a gender difference in creatinine excretion rates (11.5 [8.3–13.7] men versus 8.2 [5.6–9.1] women μmol min−1 P < 0.001). C-peptide excretion rate was similar in men and women (19.8 [5.2–37.0] versus 22.1 [7.4–40.5] pmol min−1, P = 0.7). UCPCR was higher in women in all subgroups defined by diabetes classification and treatment, except long-term type 1 diabetes in whom C-peptide secretion was minimal. Conclusions Gender affects UCPCR, with higher values found in women. This results from lower urine creatinine reflecting gender differences in muscle mass. This necessitates gender-specific ranges for accurate interpretation of UCPCR results.
The Social Care Component of Multidisciplinary Mental Health Teams: A Review and National Survey
Authors: Evans Sherrill , Huxley Peter , Baker Christine , White Jo , Madge Sally , Onyett Steve , Gould Nick 
Published: May 2012

Background The study reviewed the disciplinary composition of community mental health teams (CMHTs) and conducted a national survey of mental health providers in England and Wales to explore the determinants of the social care component of CMHTs. Methods A comprehensive literature review and a national survey of NHS mental health Trusts in England and Wales. Results The literature review showed that team composition was rarely well justified with regard to effectiveness, despite some evidence that greater professional diversity (i.e. inclusion of social workers) was associated with higher effectiveness. Forty-two mental health Trusts responded (53.2%) to the survey. There were no staffing differences between responding and non-responding Trusts. Social workers accounted for 19.3% of the staffing total. Nurses formed a third of the workforce and social support workers made up a further 10%. We found that there continues to be a shortage (compared to policy targets and previous research) of psychiatrists, psychologists and occupational therapists, whereas the numbers of nurses employed far exceeds their target numbers. Total staffing numbers appeared to be slightly higher in Trusts citing ‘financial resources’ as a determining factor of team composition. Despite being statistically non-significant, the ‘financial resource’ effect was of medium magnitude. Similarly, there was a non-significant but approaching medium-sized effect of higher numbers of social care support staff when guidance was cited as a rationale for CMHT composition. There was a non-significant (P = 0.076) medium magnitude (η2p 5 0.067) trend towards higher staff numbers in more integrated trusts that did not cite financial resources as a driver of team composition. Conclusions If service recipients are to gain equal access to appropriately staffed services, further attention needs to be paid to supporting an adequately skilled multidisciplinary workforce. The workforce needs to be organised in a way that best provides for local needs rather than a service based largely on the existing supply of different professionals and disjointed workforce planning.
Assessing the Potential Adverse Consequences of Supplemental Calcium on Cardiovascular Outcomes: Should We Change Our Approach to Bone Health?
Authors: Rojas-Fernandez Carlos H , MacLaughlin Eric J , Dore Naomi L , Ebsary Sally 
Published: May 2012

Objective: To assess cardiovascular risks associated with supplemental calcium use to assist clinicians with evidence-based recommendations for patients who have, or who are at risk for, osteoporosis or osteopenia. Data Sources: Literature was accessed through December 2011 using MEDLINE, Cochrane Library, and International Pharmaceutical Abstracts using the terms calcium compounds and cardiovascular disease. In addition, reference citations from the publications identified were reviewed. Study Selection And Data Extraction:: All English-language articles were evaluated. Randomized controlled trials, observational studies, and metaanalyses were included. Data Synthesis: While supplemental calcium and vitamin D have been demonstrated to improve bone mineral density and decrease the risk of fractures, there have been recent reports that calcium supplements may increase the risk for cardiovascular events. Nine clinical trials and/or meta-analyses were reviewed; 3 documented increases in cardiovascular risk associated with calcium supplements, and 6 did not. No studies were designed to assess cardiovascular outcomes as primary end points. Balancing the evidence from these analyses with the results of randomized controlled trials assessing the effect of calcium on fracture prevention suggests that the benefits of calcium outweigh the cardiovascular risk. Conclusions: At this time, there is no cause to change routine practice surrounding supplemental calcium use in patients who have, or are at risk for, osteoporosis or osteopenia.
Contribution of Renal Impairment to Potentially Preventable Medication-Related Hospital Admissions
Authors: Leendertse Anne J , van Dijk Elisabeth A , De Smet Peter AGM , Egberts Toine CG , van den Bemt Patricia MLA 
Published: May 2012

Background: Medication errors and renal impairment contribute to severe adverse drug events, which may lead to hospital admission. Objective: To determine whether medication errors and renal impairment contribute to hospital admission and examine these errors for strategies to prevent admissions. Methods: The 714 medication-related hospital admissions reported in the prospective multicenter study HARM (Hospital Admissions Related to Medication) were analyzed. The patients were divided into 3 groups based on the availability of creatinine levels: group A, the home-monitored group (n = 227); group B, the hospital-monitored group (n = 420); and group C, the unmonitored group (n = 67). Results: After assessment, 70 admissions (10%) were considered to be related to a medication error and renal impairment (A, 29; B, 41; C, none). In these 70 patients, 85 errors occurred in group A, 66 errors in group B, and none in group C. Dosing errors were identified in 46 patients (A, 14; B. 32), a drug-drug interaction in 22 patients (A. 13; B, 9), and a drug-disease interaction in 17 patients (A, 10; B, 7). Conclusions: Renal impairment and medication errors may lead to medication-related hospital admissions. Monitoring renal function and adjusting pharmacotherapy according to renal function might help to prevent hospital admissions. This can be a strategy for research on how to decrease the number of medication-related hospital admissions.
Generic Immunosuppression: Deciphering the Message Our Patients are Receiving
Authors: Hulbert Amanda L , Pilch Nicole A , Taber David J , Chavin Kenneth D , Baliga Prabhakar K 
Published: May 2012

Background: The introduction of generic immunosuppressants elicited controversy within the transplant community and it is unknown whether patient attitudes mirror the ambiguity of provider perceptions. With the current health care economic crisis, it is necessary to consider generic immunosuppression as an option. A greater understanding of patient perceptions would enhance vital communication between providers and patients to facilitate education and appropriate monitoring. Objective: To evaluate transplant recipients’ perceptions of generic versus brand immunosuppressants based on experience with these agents and the willingness of patients to convert treatment from brand to generic formulations based on socioeconomic variables and baseline demographics. Methods: Key informant interviews were conducted to inform the development of the survey instrument. The survey was distributed to solid organ transplant recipients at a large, academic medical center from October to December 2010. RESULTS: Nine patients participated in key informant interviews. Financial considerations and provider recommendations were the most commonly identified factors to influence perceptions of generic immunosuppressants. A total of 255 patients completed the survey; treatment in 81 (32%) participants had been converted to a generic immunosuppressant. Those currently receiving a generic immunosuppressant expressed higher beliefs of generic and brand equivalency (75% vs 54%, p = 0.006) and an increased willingness to convert treatment to a generic given equivalent cost (51 % vs 32%, p = 0.024). African American participants were found to have a decreased belief of generic and brand equivalency compared to other ethnicities (60% vs 75%, p = 0.013). Participants with an annual income of less than $30,000 had higher beliefs of generic and brand equivalency (60% vs 40%, p = 0.0001). Education level and age did not impact beliefs of generic efficacy or willingness to convert therapy. Conclusions: Patient ethnicity, income, and experience with generic immunosuppressants appear to contribute to perceptions of generic immunosuppressants. The prevalence of generic immunosuppressant use supports the importance of communication of this issue between providers and patients.