A Laurasian origin for a pantropical bird radiation is supported by genomic and fossil data (Aves: Coraciiformes).

The evolution of pantropically distributed clades has puzzled palaeo- and neontologists for decades regarding the different hypotheses about where they originated. In this study, we explored how a pantropical distribution arose in a diverse clade with a rich fossil history: the avian order Coraciiformes. This group has played a central role in the debate of the biogeographical history of Neoaves. However, the order lacked a coherent species tree to inform study of its evolutionary dynamics. Here, we present the first complete species tree of Coraciiformes, produced with 4858 ultraconserved elements, which supports two clades: (1) Old World-restricted bee-eaters, rollers and ground-rollers; and (2) New World todies and motmots, and cosmopolitan kingfishers. Our results indicated two pulses of diversification: (1) major lineages of Coraciiformes arose in Laurasia approximately 57 Ma, followed by independent dispersals into equatorial regions, possibly due to tracking tropical habitat into the lower latitudes-the Coracii (Coraciidae + Brachypteraciidae) into the Afrotropics, bee-eaters throughout the Old World tropics, and kingfishers into the Australasian tropics; and (2) diversification of genera in the tropics during the Miocene and Pliocene. Our study supports the important role of Laurasia as the geographical origin of a major pantropical lineage and provides a new framework for comparative analyses in this charismatic bird radiation.

Population Health Management: Is There Any Role for Orthopaedics?: An AOA Critical Issues Symposium.

The next phase of health-care reform will accelerate the formation of integrated delivery systems and the creation of value and savings through population health management. Accomplishing this goal requires 3 key factors, including (1) enabling groups of physicians and hospitals to legally work together to cover a broad geographic area, (2) the formation of integrated delivery systems that cover the low to high-acuity and post-acute care spectrums, and (3) identifying mechanisms through which a subspecialty can impact the health of a population of patients.At first glance, it would be easy to assume that this is largely a primary care initiative and that orthopaedic surgeons cannot influence population health since they often just repair things after they have broken or worn out. This symposium will challenge that assumption and demonstrate the potential for orthopaedic surgeons to play a major role in population health management. Some of the mechanisms include implementing shared decision-making for elective procedures, reducing premature/unnecessary imaging and subspecialty referrals, improving bone health (osteoporosis prevention and fall risk assessment), and developing payment methodologies to reward population-based, rather than individual-based, positive musculoskeletal outcomes.

Aging and effort expenditure: The impact of subjective perceptions of task demands.

Engagement in cognitively demanding activities has a positive impact on cognitive health in older adults. Previous work, however, has suggested that the costs associated with engagement increase in later life and influence motivation. We examined how subjective perceptions of these costs varied with age and influenced task engagement. The following questions were of specific interest: (a) Are there age differences in subjective perceptions of cognitive costs? (b) What is the impact of these perceptions on engagement? We tested 39 older (ages 65-84) and 37 younger (20-42) adults on a working memory task. Systolic blood pressure responsivity (SBP-R; reflective of effort) and subjective perceptions of task difficulty were assessed. We found that age was associated with an increase in the perceptions of cognitive costs, and that these subjective perceptions had a stronger impact on older adults' engagement than on that of younger adults. More important, this impact was specific to subjective perceptions of cognitive costs. The results provide further support for the hypothesis that increased costs associated with cognitive engagement influence older adults' willingness to engage cognitive resources, and that these costs in part reflect subjective perceptions that are independent of objective task demands. (PsycINFO Database Record

Temperature-dependent phagotrophy and phototrophy in a mixotrophic chrysophyte.

The roles of temperature and light on grazing and photosynthesis were examined for Dinobryon sociale, a common freshwater mixotrophic alga. Photosynthetic rate was determined for D. sociale adapted to temperatures of 8, 12, 16, and 20°C under photosynthetically active radiation light irradiances of 25, 66, and 130 µmol photons · m(-2)  · s(-1) , with concurrent measurement of bacterial ingestion at all temperatures under medium and high light (66 and 130 µmol photons · m(-2)  · s(-1) ). Rates of ingestion and photosynthesis increased with temperature to a maximum at 16°C under the two higher light regimes, and declined at 20°C. Although both light and temperature had a marked effect on photosynthesis, there was no significant difference in bacterivory at medium and high irradiances at any given temperature. At the lowest light condition (25 µmol photons · m(-2)  · s(-1) ), photosynthesis remained low and relatively stable at all temperatures. D. sociale acquired the majority of carbon from photosynthesis, although the low photosynthetic rate without a concurrent decline in feeding rate at 8°C suggested 20%-30% of the carbon budget could be attributed to bacterivory at low temperatures. Grazing experiments in nutrient-modified media revealed that this mixotroph had increased ingestion rates when either dissolved nitrogen or phosphorus was decreased. This work increases our understanding of environmental effects on mixotrophic nutrition. Although the influence of abiotic factors on phagotrophy and phototrophy in pure heterotrophs and phototrophs has been well studied, much less is known for mixotrophic organisms.

The Relationship Between Work Relative Value Unit Awareness and Work Relative Value Unit Accumulation Among Physicians.

This was a retrospective, cross-sectional study to determine whether a relationship exists between work relative value unit(wRVU) awareness and wRVU accumulation among faculty physicians. Physician wRVU awareness was obtained by a distributed survey to faculty physicians in early 2016. wRVU accumulation was pulled from a faculty productivity database. Productivity data from FY14-FY15 was used to determine wRVU accumulation relative to each respondent's specialty-specific benchmark. Data were analyzed to investigate the nature, of the relationship between awareness and accumulation. The analysis showed that physicians with above-average awareness were significantly more likely to surpass their wRVU benchmark when compared to physicians with below-average awareness. Additionally, wRVU awareness accounted for a significant percentage of the variation in wRVU output. Considering the financial importance of wRVU generation for healthcare organizations, there is a need to devote more time and resources to developing physician awareness of wRVUs.

The Impact of Motivation and Task Difficulty on Resource Engagement: Differential Influences on Cardiovascular Responses of Young and Older Adults.

This study examined whether the level of cognitive engagement older adults were willing to invest is disproportionately influenced by the personal implications of the task, as suggested by Selective Engagement Theory. We experimentally altered the personal implications of the task by manipulating participants accountability for their performance. Young (N = 50) and older (N = 50) adults performed a memory-search task of moderate difficulty but within the capabilities of both age groups. Both physiological (systolic blood pressure responsivity; SBP-R) and subjective (NASA-TLX) measures of cognitive effort were assessed across all difficulty levels. The results replicated findings from previous research that indicated older adults must exert more effort than younger adults to achieve the same level of objective performance. Most importantly, our results showed that older adults were especially sensitive to our accountability manipulation, with the difference in SBP-R between accountability conditions being greater for older than for young adults. Finally, we found that there was little relation between subjective measures of workload and our physiological measures of task engagement. Together, the results of this study provide continued support for the Selective Engagement Theory.

Aging and the impact of irrelevant information on social judgments.

We conducted 2 experiments to specifically examine whether older adults are more susceptible to the negative impact of irrelevant evaluative information when making social judgments. Young (ages 20-44), middle-aged (ages 45-63), and older (ages 65-85) adults were presented with descriptions of people consisting of positive and negative traits that varied in relevance to specific occupations. They were asked to either form a general impression based on these traits or to evaluate the person's fitness for the specified occupation. In both studies, evaluative content of the descriptions (i.e., the number of positive minus number of negative traits) was a significant predictor of subjective evaluations. Of prime importance, adults of all ages were similarly able to selectively process relevant versus irrelevant information when occupational fitness evaluations required them to focus on a subset of information in the descriptions. Participants also adjusted the specific types of information used in making judgments, with the relative importance of agentic traits and negative information being greater when making occupation evaluations than when forming impressions. The results suggest that age differences in the processing evaluative information are minimal, and that the availability of well-established knowledge structures can help older adults effectively control the impact of irrelevant evaluative information when making social inferences.

Cubilin maintains blood levels of HDL and albumin.

Cubilin is an endocytic receptor highly expressed in renal proximal tubules, where it mediates uptake of albumin and filtered forms of apoA-I/HDL. Cubilin deficiency leads to urinary loss of albumin and apoA-I; however, the consequences of cubilin loss on the homeostasis of blood albumin and apoA-I/HDL have not been studied. Using mice heterozygous for cubilin gene deletion (cubilin HT mice), we show that cubilin haploinsufficiency leads to reduced renal proximal tubular uptake of albumin and apoA-I and significantly increased urinary loss of albumin and apoA-I. Moreover, cubilin HT mice displayed significantly decreased blood levels of albumin, apoA-I, and HDL. The levels of albumin and apoA-I protein or mRNA expressed in the liver, kidney, or intestine of cubilin HT mice did not change significantly. The clearance rate of small HDL3 particles (density>1.13 g/ml) from the blood increased significantly in cubilin HT mice. In contrast, the rate of clearance of larger HDL2 particles from the blood did not change significantly, indicating a decreased half-life for HDL particles capable of filtering through the glomerulus. On the basis of these findings, we conclude that cubilin deficiency reduces renal salvage and delivery back to the blood of albumin and apoA-I, which decreases blood levels of albumin and apoA-I/HDL. These findings raise the possibility that therapeutic increase of renal cubilin expression might reduce proteinuria and increase blood levels of albumin and HDL.

Cubilin expression is monoallelic and epigenetically augmented via PPARs.

BACKGROUND: Cubilin is an endocytic receptor that is necessary for renal and intestinal absorption of a range of ligands. Endocytosis mediated by cubilin and its co-receptor megalin is the principal mechanism for proximal tubule reabsorption of proteins from the glomerular filtrate. Cubilin is also required for intestinal endocytosis of intrinsic factor-vitamin B12 complex. Despite its importance, little is known about the regulation of cubilin expression. RESULTS: Here we show that cubilin expression is under epigenetic regulation by at least two processes. The first process involves inactivation of expression of one of the cubilin alleles. This monoallelic expression state could not be transformed to biallelic by inhibiting DNA methylation or histone deacetylation. The second process involves transcriptional regulation of cubilin by peroxisome proliferator-activated receptor (PPAR) transcription factors that are themselves regulated by DNA methylation and histone deacetylation. This is supported by findings that inhibitors of DNA methylation and histone deacetylation, 5Aza and TSA, increase cubilin mRNA and protein in renal and intestinal cell lines. Not only was the expression of PPARα and γ inducible by 5Aza and TSA, but the positive effects of TSA and 5Aza on cubilin expression were also dependent on both increased PPAR transcription and activation. Additionally, 5Aza and TSA had similar effects on the expression of the cubilin co-receptor, megalin. CONCLUSIONS: Together, these findings reveal that cubilin and megalin mRNA expression is under epigenetic control and thus point to new avenues for overcoming pathological suppression of these genes through targeting of epigenetic regulatory processes.

The impact of age and motivation on cognitive effort: implications for cognitive engagement in older adulthood.

We examined age differences in the effort required to perform the basic cognitive operations needed to achieve a specified objective outcome, and how hypothesized increases in effort requirements in later life are related to intrinsic motivation associated with enjoyment of and participation in effortful cognitive activities. Young (N = 59; 20-40 years) and older (N = 57; 64-85 years) adults performed a memory-search task varying in difficulty across trials, with systolic blood pressure responsivity-calculated as the increase over baseline during task performance-used as a measure of effort expenditure and task engagement. Consistent with expectations, older adults exhibited greater levels of responsivity (i.e., effort) at all levels of objective task difficulty, and this increase was reflected in subjective perceptions of difficulty. Older adults also exhibited greater levels of disengagement (i.e., effort withdrawal) than younger adults at higher levels of task difficulty, conceivably reflecting the disproportionately greater effort required for successful performance in the former group. We also found that, relative to younger adults, older adults' engagement was more sensitive to the importance attached to the task (i.e., motivation to do well). Finally, we also obtained evidence that increased costs associated with cognitive engagement in later life were negatively associated with intrinsic levels of motivation to engage in effortful cognitive activity. The results support the general conclusion that the costs of cognitive activity increase with age in adulthood, and that these costs influence individuals' willingness to engage resources in support of demanding cognitive activities.

Changes in nitric oxide, cGMP, and nitrotyrosine concentrations over skin along the meridians in obese subjects.

The purposes of these studies were to quantify the concentrations of total nitrate and nitrite (NO(x)(-)) cyclic guanosine monophosphate (cGMP), and nitrotyrosine over skin surface in normal weight healthy volunteers (n = 64) compared to overweight/obese subjects (n = 54). A semi-circular plastic tube was taped to the skin along acupuncture points (acupoints), meridian line without acupoint (MWOP), and nonmeridian control and filled with a 2-Phenyl-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl solution for 20 min. The concentrations of NO(x)(-), cGMP, and nitrotyrosine in the samples were quantified in a blinded fashion using chemiluminescence and enzyme-linked immunosorbent assay, respectively. In normal weight healthy volunteers, NO(x)(-) and cGMP concentrations were consistently increased over the pericardium meridian (PC) 4-7 compared with nonmeridian areas. NO(x)(-) concentration is enhanced over the bladder meridian (BL) 56-57, but cGMP level is similar between the regions. In overweight/obese subjects, NO(x)(-) contents were increased or tended to be elevated over PC and BL regions. cGMP is paradoxically decreased over PC acupoints and nonmeridian control on the forearm but the decreases were blunted along BL regions on the leg. Nitrotyrosine concentrations are markedly elevated (five- to sixfold) over both PC and BL in all areas of overweight/obese subjects. This is the first evidence showing that nitrotyrosine level is tremendously elevated over skin accompanied by paradoxical changes in nitric oxide (NO)-cGMP concentrations over PC skin region in overweight/obese subject. The results suggest that NO-related oxidant inflammation is systemically enhanced while cGMP generation is impaired over PC skin region but not over BL region in obesity.

A randomized controlled trial on the effects of cycling with and without electrical stimulation on cardiorespiratory and vascular health in children with spinal cord injury.

OBJECTIVE: To examine the cardiorespiratory/vascular effects of cycling with and without functional electrical stimulation (FES) in children with spinal cord injury (SCI). DESIGN: Randomized controlled trial. SETTING: Pediatric referral hospital. PARTICIPANTS: Children with SCI (N=30), ages 5 to 13 years, with injury levels from C4 to T11, and American Spinal Injury Association grades A, B, or C. INTERVENTIONS: Children were randomly assigned to 1 of 3 groups: FES leg cycling exercise, passive leg cycling, or noncycling control group receiving electrical stimulation therapy. After receiving instruction on the use of the equipment, children exercised for 1 hour 3 times per week for 6 months at home with parental supervision. MAIN OUTCOME MEASURES: Oxygen uptake (Vo(2)) during an incremental arm ergometry test, resting heart rate, forced vital capacity, and a fasting lipid profile. RESULTS: There were no differences (P>.05) between groups after 6 months of exercise when comparing pre- and postvalues. However, there were differences between groups for some variables when examining percent change. The FES cycling group showed an improvement (P=.035) in Vo(2) (16.2%+/-25.0%) as compared with the passive cycling group (-28.7%+/-29.1%). For lipid levels, the electrical stimulation-only group showed declines (P=.032) in cholesterol levels (-17.1%+/-8.5%) as compared with the FES cycling group (4.4%+/-20.4%). CONCLUSIONS: Cycling with FES led to gains in Vo(2), whereas electrical stimulation alone led to improvements in cholesterol.

ATP-binding cassette transporters ABCA1, ABCA7, and ABCG1 in mouse spermatozoa.

Mammalian spermatozoa lose plasma membrane cholesterol during their maturation in the epididymis and during their capacitation in the female reproductive tract. While acceptors such as high-density lipoproteins (HDL) and apolipoproteins A-I (apoA-I) and J have been found in male and female reproductive tracts, transporters that mediate cholesterol efflux from plasma membranes of spermatozoa to such acceptors have not yet been defined. Candidate transporters are members of the ATP-binding cassette (ABC) transporter superfamily including ABCA1, ABCA7, ABCG1 and ABCG4, which have all been implicated in the transport of sterols and phospholipids to apolipoproteins and HDL. Here we show that mouse spermatozoa in the seminiferous tubules and epididymis express ABCA1, ABCA7 and ABCG1, but not ABCG4. Moreover, we show that ABCA1, ABCA7, and ABCG1 antibodies decrease cholesterol efflux from spermatozoa to lipid acceptors apoA-I and albumin and inhibit in vitro fertilization.

Outcomes of a home cycling program using functional electrical stimulation or passive motion for children with spinal cord injury: a case series.

BACKGROUND/OBJECTIVE: Children with spinal cord injury (SCI) are at risk for musculoskeletal and cardiovascular complications. Stationary cycling using functional electrical stimulation (FES) or passive motion has been suggested to address these complications. The purpose of this case series is to report the outcomes of a 6-month at-home cycling program for 4 children with SCI. METHODS: Two children cycled with FES and 2 cycled passively at home for 1 hour, 3 times per week. OUTCOME MEASURES: Data collected included bone mineral density of the left femoral neck, distal femur, and proximal tibia; quadriceps and hamstring muscle volume; stimulated quadriceps and hamstring muscle strength; a fasting lipid profile; and heart rate and oxygen consumption during incremental upper extremity ergometry testing. RESULTS: The 2 children cycling with FES and 1 child cycling passively exhibited improved bone mineral density, muscle volume, stimulated quadriceps strength, and lower resting heart rate. For the second child cycling passively, few changes were realized. Overall, the lipid results were inconsistent, with some positive and some negative changes seen. CONCLUSIONS: This case series suggests that cycling with or without FES may have positive health benefits and was a practical home exercise option for these children with SCI.

Exercise testing using upper extremity ergometry in pediatric spinal cord injury.

PURPOSE: To describe an upper extremity ergometer test for children with spinal cord injury (SCI) and examine differences based on injury level for peak heart rate (HR peak), oxygen uptake (VO 2 peak/kg), and peak power output per kilogram (W peak/kg). METHODS: Twenty-nine children with motor complete SCI participated. Nine had low cervical (C7, C8), 9 had upper thoracic (T1-T4), and 11 had mid/low thoracic (T5-T11) SCI. HR peak, VO2 peak/kg, and W peak/kg were compared based on these 3 injury level groupings. RESULTS: HR peak (p = 0.013), VO 2 peak/kg (p = 0.041), and W peak/kg (p = 0.001) differed between groups. The mid/low thoracic group had the highest values for each variable. CONCLUSIONS: The differences in HR peak, VO 2 peak/kg, and W peak/kg were consistent with exercise effects reported for adults with SCI. Further research is needed to develop an appropriate standardized ergometric test for children with SCI.

Lower extremity muscle activity during cycling in adolescents with and without cerebral palsy.

BACKGROUND: In individuals with cerebral palsy, adaptation and plasticity in the neuromuscular system can lead to detrimental changes affecting gait. Cycling may be an effective method to improve mobility. The biomechanics of cycling in adolescents with cerebral palsy have been studied, but further analysis of the frequency and amplitude characteristics of the electromyographic signals can assist with interpretation of the cycling kinematics. METHODS: Data were analyzed from 10 adolescents with typical development (mean=14.9, SD=1.4 years) and 10 adolescents with cerebral palsy (mean=15.6, SD=1.8 years) as they cycled at two different cadences. Analyses of the lower extremity electromyographic signals involved frequency and amplitude analysis across the cycling revolution. FINDINGS: Examination of cycling cadence revealed that adolescents with cerebral palsy had altered electromyographic characteristics in comparison to adolescents with typical development across the entire crank revolution for all muscles. Analyses of individual muscles indicated both inappropriate muscle activation and weakness. INTERPRETATION: A more comprehensive analysis of electromyographic activity has the potential to provide insight into how a task is accomplished. In this study, the control of the several muscles, especially the rectus femoris, was significantly different in adolescents with cerebral palsy. This, combined with muscle weakness, may have contributed to the observed deviations in joint kinematics. Interventions that increase muscle strength with feedback to the nervous system about appropriate activation timing may be beneficial to allow individuals with cerebral palsy to cycle more efficiently.

Quality of life in children with spinal cord injury.

PURPOSE: To compare reports of the child's quality of life (QOL) between children with spinal cord injury (SCI) and their parents using the Pediatric Quality of Life 4.0 Generic Scales (PedsQL), and assess agreement between parent and child responses. To examine the influence of level of injury on QOL and internal consistency reliability of the PedsQL in pediatric SCI. METHODS: Twenty-eight children (17 male children and 11 female children) between five and 13 years and their parents completed the PedsQL. RESULTS: Children rated their QOL better than their parents; however, there was good to excellent parent-child agreement. No differences were noted between children with tetraplegia and paraplegia. Low internal consistency reliability was obtained for various domains. CONCLUSIONS: In addition to using summary scores, specific ratings may raise important points for clinical decision-making. Results on internal consistency reliability suggest the need for condition-specific questionnaires for children with SCI.

Bone mineral density of the hip and knee in children with spinal cord injury.

BACKGROUND/OBJECTIVE: To report on the bone mineral density (BMD) of the hip, distal femur, and proximal tibia in children with spinal cord injury (SCI) of at least 1-year duration and before skeletal maturity. METHODS: BMD values were measured in 28 children (age, 9.6 +/- 2.5 years; range, 5-13 years) using dual-energy x-ray absorptiometry (DEXA) and were analyzed based on sex, injury, and time since injury. The hip values were compared with reported age- and sex-matched values in children without disability. No comparison was made at the knee because normative data were not available. RESULTS: Average BMD values were 0.48 +/- 0.17 g/cm2 for the total hip, 0.48 +/- 0.17 g/cm2 at the femoral neck, 0.41 +/- 0.17 g/cm2 at the greater trochanter, 0.47 +/- 0.17 g/cm2 at Ward's triangle, 0.38 +/- 0.10 g/ cm2 at the distal femur, and 0.37 +/- 0.07 g/cm2 at the proximal tibia. Trends were observed with respect to sex, level of injury, and time since injury. Z-scores for the femoral neck, greater trochanter, and Ward's triangle were -1.65 +/- 1.02, -1.83 +/- 1.30, and -1.78 +/- 0.78, respectively, representing a 40% lower BMD in comparison with children without disability. CONCLUSIONS: Children with a SCI seem to have a substantially lower BMD at the hip and knee in comparison with children without disability, placing them at the same risk for lower extremity fractures as adults with SCI, with potentially higher risks as they age given the lack of activity in a period of their life where exercise is essential for optimal bone health.