Evidence of parallel evolution in the dental elements of Sweetognathus conodonts.

The repeated emergence of similar morphologies in the dental elements of Permian Sweetognathus conodonts has been a hypothesized example of parallel evolution. To test if morphological parallelisms occur between isolated Sweetognathus lineages, this study uses two-dimensional-based geometric morphometrics combined with a revised and expanded phylogeny of Permian Sweetognathus conodonts to quantify dental element trait distributions and compare the phenotypic trajectories between lineages. A hierarchical clustering method was used to identify recurrent species pairs based on principal component scores describing their morphological variation, with the further incorporation of widely used ecological metrics such as limiting similarity and morphological overlap. Our research implies that a major contributor to conodont diversity in Palaeozoic marine trophic networks is the emergence of recurrent parallel morphologies via disruptive and directional selection. This study illustrates the mechanisms through which conodonts achieved their status as hyper-diverse predators and scavengers, contributing substantially to the complexity of Palaeozoic marine communities.

Synthesis and properties of titanomagnetite (Fe(3-x)Ti(x)O4) nanoparticles: a tunable solid-state Fe(II/III) redox system.

Titanomagnetite (Fe(3-x)Ti(x)O(4)) nanoparticles were synthesized by room temperature aqueous precipitation, in which Ti(IV) replaces Fe(III) and is charge compensated by conversion of Fe(III) to Fe(II) in the unit cell. A comprehensive suite of tools was used to probe composition, structure, and magnetic properties down to site-occupancy level, emphasizing distribution and accessibility of Fe(II) as a function of x. Synthesis of nanoparticles in the range 0≤x≤0.6 was attempted; Ti, total Fe and Fe(II) content were verified by chemical analysis. TEM indicated homogeneous spherical 9-12 nm particles. µ-XRD and Mössbauer spectroscopy on anoxic aqueous suspensions verified the inverse spinel structure and Ti(IV) incorporation in the unit cell up to x≤0.38, based on Fe(II)/Fe(III) ratio deduced from the unit cell edge and Mössbauer spectra. Nanoparticles with a higher value of x possessed a minor amorphous secondary Fe(II)/Ti(IV) phase. XANES/EXAFS indicated Ti(IV) incorporation in the octahedral sublattice (B-site) and proportional increases in Fe(II)/Fe(III) ratio. XA/XMCD indicated that increases arise from increasing B-site Fe(II), and that these charge-balancing equivalents segregate to those B-sites near particle surfaces. Dissolution studies showed that this segregation persists after release of Fe(II) into solution, in amounts systematically proportional to x and thus the Fe(II)/Fe(III) ratio. A mechanistic reaction model was developed entailing mobile B-site Fe(II) supplying a highly interactive surface phase that undergoes interfacial electron transfer with oxidants in solution, sustained by outward Fe(II) migration from particle interiors and concurrent inward migration of charge-balancing cationic vacancies in a ratio of 3:1.

Revision of the structure of Cs2CuSi5O12 leucite as orthorhombic Pbca.

The crystal structure of a hydrothermally synthesized leucite analogue Cs(2)CuSi(5)O(12) has been determined and refined using the Rietveld method from high-resolution synchrotron X-ray and neutron powder diffraction data. This structure is based on the topology and cation-ordering scheme of the Pbca leucite structure of Cs(2)CdSi(5)O(12), and exhibits five ordered Si sites and one ordered Cu tetrahedrally coordinated (T) site. This structure for Cs(2)CuSi(5)O(12) is topologically identical to other known leucite structures and is different from that originally proposed by Heinrich & Baerlocher [(1991), Acta Cryst. C47, 237-241] in the tetragonal space group P4(1)2(1)2. The crystal structure of a dry-synthesized leucite analogue Cs(2)CuSi(5)O(12) has also been refined; this has the Ia3d cubic pollucite structure with disordered T sites.

Functional impairment severity is associated with health status among older persons with intellectual disability and cerebral palsy.

BACKGROUND: Studies have noted high rates of specific health disorders in adults with cerebral palsy (CP). However, it remains unclear how growing older with a lifelong neuromotor physical disability confers risk for health outcomes in adults who have both intellectual disability (ID) and CP. AIM: To assess the relationship between health status in older adults with ID either with or without coincident diagnoses of CP. METHOD: Health status data were drawn from 1373 adults aged 33 to 79 years with ID living in small group homes in New York State. Their health status was defined by the presence of common health disorders. Of these, 177 subjects had coincident CP. Prevalence data for nine diseases representing different organ systems were obtained and compared in individuals with and without CP. A Severity of Functional Impairment Index (SFII) was developed based on subjects' capabilities in activities of daily living (ADLs) and mobility. Two logistic regression analyses were conducted to determine if CP diagnosis was an independent predictor of health disorder prevalence, or rather exerted effects similar to those without CP via severity of functional impairment as determined by SFII scores. In addition, older age, gender, and severity of intellectual disability were examined as predictors of health disorder prevalence in all study subjects. RESULTS: Individuals with CP had higher frequencies in four out of the nine health disorders (overweight/obesity, gastroesophageal reflux, urinary tract infections and dysphagia). Analysis revealed a statistically significant association between SFII score and CP diagnosis. CP diagnosis alone was a statistically significant predictor for all of the above four common disorders; however, after adjustment for SFII score was included in health disorder models, only dysphagia showed an independent correlation with a CP diagnosis. CONCLUSION: With the exception of dysphagia, impairment in ADLs and walking capabilities, and not CP diagnosis alone, accounted for disparities in specific diseases. Although the diagnosis of CP may be correlated with functional impairment, it alone may play a minor role in determining health trajectories in older persons with conjoint ID and CP.

Crystal structures and cation ordering in Cs2MgSi5O12, Rb2MgSi5O12 and Cs2ZnSi5O12 leucites.

The crystal structures of the leucite analogues Cs(2)MgSi(5)O(12), Cs(2)ZnSi(5)O(12) and Rb(2)MgSi(5)O(12) have been determined by synchrotron X-ray powder diffraction using Rietveld refinement in conjunction with (29)Si MAS NMR spectroscopy. These leucites are framework structures with distinct tetrahedral sites (T sites) occupied by Si and a divalent cation (either Mg or Zn in these samples); there is also a monovalent extra-framework cation (either Cs or Rb in these samples). The refined crystal structures were based on the Pbca leucite structure of Cs(2)CdSi(5)O(12), thus a framework with five ordered Si T sites and one ordered Cd T site was used as the starting model for refinement. (29)Si MAS NMR shows five distinct Si T sites for Cs(2)MgSi(5)O(12) and Rb(2)MgSi(5)O(12), but six Si T sites for Cs(2)ZnSi(5)O(12). The refined structures for Cs(2)MgSi(5)O(12) and Rb(2)MgSi(5)O(12) were determined with complete T-site ordering, but the refined structure for Cs(2)ZnSi(5)O(12) was determined with partial disorder of Mg and Si over two of the T sites.

Cation occupancies in Mg, Co, Ni, Zn, Al ferrite spinels: a multi-element EXAFS study.

The distribution of cations between tetrahedral (A) sites and octahedral (B) sites in ferrite spinels has been studied using K-edge x-ray absorption spectroscopy. The samples include natural and synthetic end-member magnetites (Fe3O4), a natural Mn- and Zn-rich magnetite (franklinite) and synthetic binary, ternary and quaternary ferrites of stoichiometry M(²+)M2(³+)O4, where M(²+) = Mg, Co, Ni, Zn and M(³+) = Fe, Al. XAS data were obtained for all metals. Complete, unfiltered, EXAFS spectra were refined to determine the percentage distribution of each element over the A and B sites and these data were combined with microprobe analyses to quantify the tetrahedral occupancy for each element in each sample. Measured site occupancies and an internally consistent set of (M-O)(A) and (M-O)(B) bond lengths were used to calculate unit-cell parameters, which show excellent agreement with measured values, pointing to the reliability of the measured occupancy factors. The average occupancies determined for the tetrahedral sites in ferrites are (atoms per formula unit) Mg 0.44, Co 0.24, Ni 0.11, Zn 0.76, Al 0.11 and Fe(³+) 0.92-0.19. The wide range found for Fe(³+) is consistent with it playing a relatively passive role by making good any A-site deficit left by the other competing cations.

Physical activity for adolescents with intellectual disability.

Numerous studies have described an association between participation in physical activity and an enhanced sense of well-being. These findings have been documented in both genders across the lifespan. Connections between exercise and positive physical, psychological, emotional and educational outcomes have also been found. New findings indicate that is an ongoing and increasing tendency for sedentary lifestyles across age groups and gender in many countries. In addition, there are many factors that work together to contribute to a sedentary lifestyle in individuals with intellectual and developmental disability (ID/DD). These findings are concerning, and indicate that people with ID/DD are at relatively high risk for the development of multiple negative consequences of physical inactivity. This review presents current literature that addresses the question of physical activity in adolescents with ID/DD. In addition, this review presents the connection between higher levels of physical fitness and better health in youths with ID/DD. Strategies to promote physical activity in the adolescent population with ID/DD are presented. The available evidence base strongly supports the high need for the establishment of community based, easily accessible physical activity programs for children and adolescents with ID/DD.

Associations between behavior disorders and health status among older adults with intellectual disability.

Few studies have examined the relationship of behavior and health status among aging persons with intellectual and developmental disabilities (I/DD). Behavioral disorders, which often are coincident with functional decline in older persons with I/DD, may be more related to medical morbidity than previously reported. This cross-sectional study examined the association between health status and behavior disorders with increasing age in a cohort of 60,752 adults with I/DD clustered into four adult-age groupings (21-44, 45-59, 60-74, and >74). Age grouping data suggested an association between morbidity and increased likelihood of behavior symptoms in all but the oldest age grouping. The magnitude of the association and trend varied by specific disease across age groupings compared to that found in healthy cohorts. About 25% of the adults with I/DD had psychiatric diagnoses and the frequency of such diagnoses did not decrease with age grouping. These results suggest that adverse health status may increase the likelihood of persistent behavioral disturbances in older persons with I/DD. Moreover, behavioral disorders may be sentinels for occult medical morbidity, which in turn may be responsive to intervention.

Health characteristics and health services utilization in older adults with intellectual disability living in community residences.

BACKGROUND: The health status and health needs of adults with intellectual disability (ID) change with advancing age, and are often accompanied by difficulties with vision, hearing, mobility, stamina and some mental processes. AIM: The present study collected health status information on a large cohort of adults with ID aged > or = 40 years living in small group, community-based residences in two representative areas of New York State, USA. METHOD: Adult group home residents with ID aged between 40 and 79 years (n = 1371) were surveyed to determine their health status and patterns of morbidity. RESULTS: Most subjects were characterized as being in good health. The frequency of cardiovascular, musculoskeletal and respiratory conditions, and sensory impairments increased with age, while neurological, endocrine and dermatological diseases did not. Psychiatric and behavioural disorders declined with increasing age, at least through 70 years of age. Although most conditions increased with age, their frequency varied by sex and level of ID. Frequencies of age-related organ system morbidity were compared to data from the National Health and Nutrition Evaluation Survey III. It was found that adults with ID had a lower overall reported frequency of cardiovascular risk factors, including hypertension and hyperlipidaemia, and adult-onset diabetes. Inconsistencies with mortality data among older adults with ID were observed (which showed equal if not greater prevalence of deaths as a result of cardiovascular disease and cancer). CONCLUSION: These results suggest that either a cohort effect is operating (i.e. contemporary populations are healthier than previous populations), or that there may be under-recognition of select risk factors and diseases.

Ethanol-induced conditioned place aversion in mice.

Previous studies have shown that ethanol produces conditioned place preference (CPP) in mice when injections are given immediately before exposure to the conditioned stimulus (CS). Paradoxically, however, injection of ethanol immediately after the CS produces conditioned place aversion (CPA). Four experiments were conducted to characterize the parametric boundaries of CPA produced by post-CS ethanol exposure. Experiment 1 showed that CPA is positively related to ethanol dose, with significant CPA at 2 and 4 g / kg, but not at 1 g / kg. Experiment 2 revealed an inverse relationship between CPA and trial duration, i.e. significant CPA occurred when the trial duration was 5, 15 or 30 min, but not when it was 60 or 90 min. Experiment 3 indicated that ethanol pre-exposure (eight daily injections) significantly reduced subsequent development of CPA. Finally, experiment 4 showed that repeated exposure to the CS alone (six 30 min exposures to each CS) after CS-ethanol pairings produced complete extinction of CPA. The same extinction procedure also completely eliminated CPP induced by pre-CS injections of ethanol. Overall, these studies demonstrate that CPA induced by post-CS ethanol injection is influenced by many of the same variables that affect CPP produced by pre-CS ethanol injection in mice. However, these findings do not resolve the issue of whether the 'before-versus-after' effect in ethanol place conditioning is better explained by assuming ethanol produces only rewarding effects or by assuming that ethanol produces both rewarding and aversive effects.

Mortality and morbidity among older adults with intellectual disability: health services considerations.

PURPOSE: Described is a study of the mortality and morbidity characteristics of 2752 adults with intellectual disability, age 40 and older, who died over a 10 year period in one American state. RESULTS: The main finding was that although individuals in the current generation of older adults with intellectual disability still generally die at an earlier age than do adults in the general population (average age at death: 66.1 years), many adults with intellectual disability live as long as their age peers in the general population. The results suggest that the longevity of adults with intellectual disability, whose aetiology is not attributable to organic causes, is progressively increasing. The results also confirm an increased longevity for adults with Down syndrome (average age at death: 55.8 years). Findings also showed that the causes of death for the study cohort were similar to those of the general older population, with cardiovascular, respiratory and neoplastic diseases among the most prominent causes of death. CONCLUSIONS: It was proposed that clinical and prophylactic health practices could have significant social and health care consequences for delaying the onset or minimizing the occurrence of life threatening diseases (and thus prolonging life) in adults with intellectual disability. It was suggested that clinical practices could be implemented that deter the onset and lessen the impact and burden of older age-related diseases and secondary conditions and that greater attention needs to be given to training of health care professionals in the area of geriatric medicine and intellectual disability.

Extinction of ethanol-induced conditioned place preference and conditioned place aversion: effects of naloxone.

Four experiments examined the effect of naloxone pretreatment on the expression and extinction of ethanol-induced conditioned place preference (experiments 1, 2, 4) or conditioned place aversion (experiments 1, 3). DBA/2 J mice received four pairings of a distinctive tactile (floor) stimulus (CS) with injection of ethanol (2 g/kg) given either immediately before or after 5-min exposure to the CS. A different stimulus was paired with injection of saline. Pre-CS injection of ethanol produced conditioned place preference, whereas post-CS injection of ethanol produced conditioned place aversion. Both behaviors extinguished partially during repeated choice testing after vehicle injection. Naloxone (10 mg/kg) had little effect on the initial expression of conditioned place preference, but facilitated its extinction. Moreover, repeated naloxone testing resulted in the expression of a weak conditioned place aversion to the CS that initially elicited a place preference. In contrast, naloxone (1.5 or 10 mg/kg) enhanced expression of conditioned place aversion, thereby increasing its resistance to extinction. A control experiment (experiment 4) indicated that repeated testing with a different aversive drug, lithium chloride, did not affect rate of extinction or produce an aversion to the CS previously paired with ethanol. These findings do not support the suggestion that naloxone facilitates the general processes that underlie extinction of associative learning. Also, these data are not readily explained by the conditioning of place aversion at the time of testing. Rather, naloxone's effects appear to reflect a selective influence on maintenance of ethanol's conditioned rewarding effect, an effect that may be mediated by release of endogenous opioids. Overall, these findings encourage further consideration of the use of opiate antagonists in the treatment of alcoholism.

Preretirement planning of female registered nurses.

Knowledge of preretirement planning among women has not been a major focal point for researchers. The purpose of this study was to test a model for understanding preretirement planning among working women and to describe and explain preretirement health and financial plans. A multivariate method of analysis was used with a sample of 145 working female registered nurses, 40 years of age or older, from a major health sciences institution. Data were collected with a mailed questionnaire that measured knowledge, beliefs, and attitudes of women regarding health and financial preretirement planning. The results of this study indicated that formal and informal methods of planning for retirement were limited. Knowledge of health maintenance issues and economic issues were found to be helpful in making plans for the retirement years. This study identifies strengths and weaknesses in the preretirement planning process of working women and contributes to the expansion of knowledge to reduce problems during retirement.

2p X-ray Absorption Spectroscopy in the Earth Sciences.

A complete knowledge of 3d transition-metal valencies, site occupancies and site symmetries is essential for a full understanding of mineral/melt energetics and behaviour. Over the last few years, significant advances in both instrumentation and theory associated with synchrotron radiation sources and experiments have enabled the development of 2p X-ray absorption spectroscopy as a sensitive, element-specific site and valency probe. The potential of this technique in the Earth sciences is discussed in this paper with examples reflecting the variety of problems set by 3d transition metals in natural systems.

Proactive versus reactive recruitment and retention strategies.

With so many options available to nurses today, it is imperative to recognize the importance of not only recruiting but retaining nurses within the organization as well as the profession. This study identifies recruitment and retention strategies that nurses deem important. Although numerous responses were noted, continuing education was the most frequently cited benefit for recruitment and retention of nurses.

Perioperative experience: an essential component for nursing education.

1. Many of today's nursing curricula have limited or no exposure in perioperative nursing. This deficit probably has contributed to the current crisis level in the shortage of nurses occurring in this area. 2. As a recruitment tool and orientation package, the clinical practicum and perioperative elective are a cost-effective means of teaching, increase the self-esteem of the graduates, and provide long-term problem solving experiences. 3. In addition to applying accrued theory to a clinical setting for an extended period, students are allowed to experience an area of nursing without a formal commitment to an agency.