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PubMed2004

Socioemotional selectivity theory, aging, and health: the increasingly delicate balance between regulating emotions and making tough choices.

After providing an introductory overview of socioemotional selectivity theory, we review empirical evidence for its basic postulates and consider the implications of the predicted cognitive and behavioral changes for physical health. The main assertion of socioemotional selectivity theory is that when boundaries on time are perceived, present-oriented goals related to emotional meaning are prioritized over future-oriented goals aimed at acquiring information and expanding horizons. Such motivational changes, which are strongly correlated with chronological age, systematically influence social preferences, social network composition, emotion regulation, and cognitive processing. On the one hand, there is considerable reason to believe that such changes are good for well-being and social adjustment. On the other hand, the very same motivational changes may limit health-related information-seeking and influence attention, memory, and decision-making such that positive material is favored over negative information. Grounding our arguments in socioemotional selectivity theory, we consider possible ways to tailor contexts such that disadvantages are avoided.

Aging↗

PubMed2003

Patterns of larval dispersal and their effect on the maintenance of a blue mussel hybrid zone in southwestern England.

The blue mussels Mytilus edulis and M. galloprovincialis hybridize in southwestern England. Within this hybrid zone environmentally based directional selection favors individuals with alleles specific to M. galloprovincialis. What forces are countering this directional selection and allowing for the maintenance of a stable hybrid population are unknown. We used both the genetics of recently settled larvae and a fine-scale model of the physical oceanography of the region to determine the patterns of larval dispersal throughout the hybrid zone and the bordering parental populations. Evidence from both the model and the genetics suggests that the hybrid zone lies between two barriers to dispersal. Start Point separates the M. edulis population from the hybrid zone and allows minimal dispersal from the hybrid zone into the M. edulis population, but none in the other direction. Likewise, the M. galloprovincialis populations along the northern coast of Cornwall regularly receive immigrating larvae from the hybrid zone, but larvae from the M. galloprovincialis population do not enter the hybrid zone. However, larvae settling at hybrid zone sites have high frequencies of alleles specific to M. edulis, suggesting that reproductive barriers, selection in the larval stage, or gene flow from an undetermined source is effectively balancing the directional selection observed in the adults.

Animals↗

PubMed2001

A pilot study of attention deficits, balance control and falls in the subacute stage following stroke.

OBJECTIVES: To (1) identify and monitor changes in deficits of attention and balance in the subacute stage following stroke, (2) investigate fall events, (3) explore relationships between deficits of attention, balance and falling post stroke. DESIGN: A prospective observational study. SETTING: Hospitalized patients with stroke were recruited from a rehabilitation ward. SUBJECTS: Fourteen subjects were recruited, 13 subjects (age 21-80 years) completed all assessments. Ten had right and three had left hemispheric lesions. Eight subjects were male. MAIN OUTCOME MEASURES: Subjects were assessed on two occasions during a six-week period. Standardized tests were used to measure unilateral visual neglect, sustained and selective attention and balance. Fall histories were collected by chart review and semi-structured interview. RESULTS: At the initial assessment six subjects had sustained auditory attention deficit, eight had deficits of auditory selective attention, 12 had visual selective attention deficits and seven subjects presented with visual inattention. Scores for visual inattention and visual selective attention improved over time (p = 0.006, p = 0.026 respectively) as did scores for balance control (p = 0.001). Auditory selective attention scores at the first assessment were found to correlate with measures of balance (p < 0.01), subjects with normal attention scores achieved better balance scores. Four subjects fell at least once during the six weeks. Scores for attention and balance of fallers were not found to be significantly different from the scores of nonfallers. CONCLUSIONS: The sample size was small but high levels of attention deficit were identified. Findings suggest a weak or no relationship between attention deficits and falls. Further studies are required to explore the extent of attention deficits post stroke and its impact on balance control and falling.

Accidental Falls↗

PubMed1981

Selective versus standard hyperalimentation. A randomized prospective study.

Fifty consecutive surgical patients were included in a randomized prospective study to determine the relative advantages and disadvantages of two types of nutritional support systems: one, selective hyperalimentation, relies on a balanced substrate formula, while the other, standard hyperalimentation, depends on carbohydrate and protein to satisfy the energy requirements of the patient. The patients who received the balanced substrate formula had significantly fewer complications than those receiving standard hyperalimentation, even though both groups achieved positive energy and nitrogen balance. The enhanced safety of selective hyperalimentation suggests its therapeutic superiority as a basic nutritional support system for a busy surgical service.

Glucose↗

PubMed2003

Gauging the significance of atomic oxygen [O(3P)] in sulfoxide photochemistry. A method for hydrocarbon oxidation.

A liquid-phase photolysis of 1,2-benzodiphenylene sulfoxide, 1, and dibenzothiophene sulfoxide, 2, was used to generate atomic oxygen [O(3P)] or an equivalent active oxygen species. The reaction for sulfoxide photodeoxygenation was similar to a microwave discharge method for generating O(3P) atoms in the condensed phase (Zadok, E.; Rubinraut, S.; Mazur, Y. J. Org. Chem. 1987, 52, 385-90). Sulfoxide photodeoxygenation is a potentially clean method for O(3P) production compared to the microwave discharge method. With Argon purging of the sulfoxide sample before photolysis, the method can preclude a secondary oxidation process involving molecular oxygen. Our study focused on the results of oxidation products in the reaction of styrene, 3, and on the dependence of substrates that provided an opportunity to vary the electronic and steric effects. The sulfoxide photochemistry is rationalized with the primary formation of O(3P) in which a charge-transfer interaction between O(3P) and substrate precedes oxidation. Functionalization of hydrocarbons takes place under mild photolysis conditions of 1 and 2, which leads to an interesting possibility for the synthetic use of atomic oxygen, O(3P). Alkanes give principally alcohols. Alkenes give principally epoxides and ketones. For comparison, hydroxyl radicals are more reactive and less selective toward hydrocarbons compared to O(3P) atoms. On the other hand, O(3P) atoms balance reactivity and selectivity and involve the oxidation of inert alkanes typically inaccessible to peracid, dioxirane, ozone, and singlet molecular oxygen chemistry. The findings from this study may be useful to those interested in generating high-value oxygenated compounds from readily available petroleum components.

Journal Article↗

PubMed1993

[The karyotypic characteristics of a skin fibroblast line from the Indian muntjac cultured with different sera].

The karyotypic structure of the Indian muntjak skin fibroblast cell line, with 7 chromosomes in modal class, was compared in the cells cultures, with 10 and 3% of fetal calf serum of two different lots. In addition, the effect of the same serum lot on chromosome variability in the two different Indian muntjac skin fibroblast sublines differing in the modal class stability was investigated. In both the cases, the serum affects the cell distribution for the chromosome number. The analysis of correlations between the main and other structure variants of the karyotype (MSVK and SVK) showed that the karyotypic variants are selected for the balanced genotype rather than for particular chromosomes. The changed cultural conditions resulted primary in the selection of the preexisting SVK to convert into MSVK. The lowering in the serum content to 3% induced the increase in chromosome aberrations. The frequency of chromosome aberrations depends on both the serum lot and the chromosomal composition of sublines. Chromosomal breaks and dicentrics are the predominant types of chromosomal disturbances. Dicentrics are produced mainly by chromosomes 1 and 2. The data obtained may suggest that sera could affect karyological characteristics of cultured cells. This indicates that the cytogenetical monitoring is necessary during a long-term cultivation of cell lines.

Animals↗

PubMed2002

Activity-bioavailability balance in oral drug development for a selected group of 6-fluoroquinolones.

A nomogram is proposed to select the best candidate in drug development studies with quinolones and is intended to substitute other possible models. The nomogram is referred to as an activity-bioavailability balance (ABB) because it includes the following two criteria: ABB = [(1/gm MIC drug candidate)/ (1/gm MIC ciprofloxacin)].[(F(calc) drug candidate)/( F(calc) ciproflaxacin)]. The in vitro activity of a group of 4'N-alkyl-ciprofloxacin derivatives was determined together with that of ciprofloxacin, initially against some reference strains and subsequently against 159 clinical isolates of eight selected species. The inverse of the geometric mean of the lowest concentration of drug at which the original inoculum was reduced to no more than two colonies (1/gm MIC), as an antimicrobial activity parameter, and the absolute oral bioavailability index (F(calc)), as predicted from in situ intestinal absorption rate constants, were used for calculation of the ABB values, which ranged from 0.1 to 17 for the species and compounds tested. Ciprofloxacin was the best candidate only against Escherichia coli, whereas 4'N-methyl- and/or 4'N-ethyl-ciprofloxacin showed better or much better ABB values than the model drug, and can be selected as potential drug candidates against the remaining clinical strains. The procedure described could be a useful technique for further drug development studies.

Administration, Oral↗

PubMed2002

Target selection for reaching and saccades share a similar behavioral reference frame in the macaque.

The selection of one of two visual stimuli as a target for a motor action may depend on external as well as internal variables. We examined whether the preference to select a leftward or rightward target depends on the action that is performed (eye or arm movement) and to what extent the choice is influenced by the target location. Two targets were presented at the same distance to the left and right of a fixation position and the stimulus onset asynchrony (SOA) was adjusted until both targets were selected equally often. This balanced SOA time is then a quantitative measure of selection preference. In two macaque monkeys tested, we found the balanced SOA shifted to the left side for left-arm movements and to the right side for right-arm movements. Target selection strongly depended on the horizontal target location. By varying eye, head, and trunk position, we found this dependency embedded in a head-centered behavioral reference frame for saccade targets and, somewhat counter-intuitively, for reach targets as well. Target selection for reach movements was influenced by the eye position, while saccade target selection was unaffected by the arm position. These findings suggest that the neural processes underlying target selection for a reaching movement are to a large extent independent of the coordinate frame ultimately used to make the limb movement, but are instead closely linked to the coordinate frame used to plan a saccade to that target. This similarity may be indicative of a common spatial framework for hand-eye coordination.

Animals↗

PubMedDate not supplied

Selective serotonin reuptake inhibitors in pediatric depression: is the balance between benefits and risks favorable?

Recent controversies surrounding the use of selective serotonin reuptake inhibitors (SSRIs) have highlighted the need to reassess potential benefits, as well as potential risks of this class of medications in the treatment of pediatric depression. The recent availability of data from meta-analyses of published and unpublished antidepressant trials, epidemiological studies, and the Treatment for Adolescents with Depression Study (TADS) has facilitated a reanalysis of this risk/benefit relationship. Despite reviewing similar data, various regulatory agencies have arrived at rather disparate conclusions regarding the data, resulting in continued controversy. Although all groups appear to agree that careful assessment, education regarding risks, and closer monitoring are essential for SSRIs, only the U.S. Food and Drug Administration (FDA) and the U.K. Medicine and Health Care Products Regulatory Agency maintain that an acceptable risk/benefit relationship exists for fluoxetine. The European Medicines Agency concluded that the SSRIs should not be used in the treatment of depression in children and adolescents. The authors of this review have taken into consideration many of these same data and offer a critical discussion of the pros and cons of SSRIs in pediatric depression. The authors have concluded that SSRIs -- in particular, fluoxetine -- do have a role in the treatment of pediatric depression.

Adolescent↗

PubMed2006

Environmentally induced dispersal under heterogeneous logistic growth.

We consider a single-species model which is composed of several habitats connected by linear migration rates and having logistic growth. A spatially varying, temporally constant environment is introduced by the non-homogeneity of its carrying capacity. Under this condition any type of purely diffusive behavior, characterized in our model by symmetric migration rates, produces an unbalanced population distribution, i.e. some locations receive more individuals than can be supported by the environmental carrying capacity, while others receive less. Using an evolutionarily stable strategy (ESS) approach we show that an asymmetric migration mechanism, induced by the heterogeneous carrying capacity of the environment, will be selected. This strategy balances the inflow and outflow of individuals in each habitat (balanced dispersal), as well as 'balancing' the spatial distribution relative to variation in carrying capacity (the Ideal Free Distribution from habitat selection theory). We show that several quantities are maximized or minimized by the evolutionarily stable dispersal strategy.

Animal Migration↗

PubMed2005

Preconception gender selection: a threat to the natural sex ratio?

This brief paper summarizes a series of postal investigations on the acceptance of selection for X or Y spermatozoa. These were conducted mainly in Germany but also in the UK, the Netherlands and the US. Selected families were approached with a series of questions about their wish to use sperm selection, and their choice of boys or girls. In general, large majorities opposed this approach for family balancing or sex selection on the basis of cost and inconvenience of the treatment. The view was expressed that its use in medicine was more acceptable. Care was taken to compose a series of open questions to particular sections of the population, e.g.men versus women, differing ages, and families with imbalanced sex ratios. More favourable responses arose, for example in pregnant women. Overall, all four nations had large majorities against the use of sex selection.

Adult↗

PubMed1986

Adequacy of a modular tube feeding diet for burned patients.

Recent research on nutrition needs following thermal injury suggests that carbohydrate and caloric excess must be avoided while an attempt is made to meet relatively large protein requirements. The nutrition regimen in this investigation for adult and pediatric burned patients provides calories at twice the predicted basal metabolic rate, protein at 2.5 gm/kg/day, and carbohydrate at 5 mg/kg/minute. Lipids are provided to meet the caloric deficit after protein and carbohydrate administration. Even though such nutrients are readily provided parenterally, the high carbohydrate content of standard tube feedings makes it difficult to provide adequate protein without excess of carbohydrate and calories. As a result, a modular tube feeding, containing appropriate macro- and micronutrients and tailored to the individual patient, has been used in our burn units. The adequacy of the diet was assessed by the effect on nitrogen balance, weight change, selected serum indexes of visceral metabolism, and compliance with planned dietary goals. Patients remained in positive nitrogen balance more than 80% of the time while the modular diet was used in conjunction with other modes of therapy (parenteral and/or oral). More than 90% of the time, positive balance was achieved when the modular diet was used as the sole source of nutrition. Compliance with the caloric goal and physicians' diet orders for the modular diet exceeded, on average, the 80% level, which has previously been the established lower limit. The results in this study suggest that the modular diet is an appropriate method of nutrition support.

Adult↗

PubMed1990

Selective hypergravity stimulation: its effects on the human balance and gait functions. A model to assess, in normal gravity conditions, some aspects of the perturbations induced on human body by microgravity conditions.

To assess on Earth some reactions of the muscle mechanoreceptors to transitions from normogravity to microgravity, we studied the effects of transitions from hypergravity to normogravity. Hypergravity was selectively applied to the extensor muscles by increasing their activity during half an hour by means of 2 rubber extensible springs stretched from shoulders to feet. Immediate effects and post effects of such a stimulation were measured on quantifying dynamic balance (angular or linear displacement) and gait functions (spatio-temporal parameters and inferior limb length variations). The main results are: (1) a post effect on the balance function, appearing 3 minutes after the end of the selective hypergravity stimulus and improving the efficiency of balance function compared with the basal one, (2) a post effect on the gait function, appearing immediately after the end of the selective stimulation. It concerns the measures which quantify the gait phases during which flexor muscles are active (swing phases). It decreases the efficiency of the gait function compared with the basal one, It disappears 3 minutes after the end of the selective hypergravity stimulation. According to these results, if the effects on the muscle mechanoreceptors of the transitions from normogravity, to microgravity looks like those of transitions from hypergravity to normogravity, post effects could be a mechanism of the motor perturbations at the beginning of the orbital flights.

Adult↗

PubMed1984

Calorie and protein intake and balance of men and women consuming self-selected diets.

The calorie and protein intakes of 16 women and 13 men consuming self-selected diets over a 1-yr period were determined. During four 7-day balance periods, corresponding to the four seasons of the year, duplicates of diets consumed and urine and feces excreted were collected for analysis and calculations of available energy and nitrogen balance. During the four balance periods, the food intakes and thus the calorie and protein intake of the subjects decreased as documented by 7-day food records immediately before and after the balance periods. This unexpected decrease in food consumption made the nitrogen (N) balance results difficult to interpret. The energy digestibility of these diets ranged from 87 to 98% (mean +/- SD, 93.7 +/- 2.3). The nitrogen digestibility of the diets ranged from 80 to 96% (mean +/- SD, 88.6 +/- 3.4). The analyzed calorie values (heats of combustion) of the diet composites were approximately the same as calorie values of these diets calculated from diet records using food tables. This is surprising since calorie values in food tables are available energies which have been corrected by a coefficient of availability.

Adult↗

PubMed1989

[A fundamental study on the influence of posterior artificial tooth forms on denture movements during mastication].

The form of posterior artificial tooth is an essential factor related to denture stability during mastication and to masticatory ability. Generally, cusp teeth are selected out of consideration for balance during eccentric occlusion. From another viewpoint, cuspless teeth are selected to ensure stability and to prevent the occurrence of lateral vectors caused by the inclination of the occlusal facet. It has been reported, however, that the counterbalance phenomenon occurring between occlusal facets decreases the lateral vector. Moreover, cusp teeth are useful in increasing the possibility of establishing bilateral balance. Guidelines for selecting posterior artificial teeth in the production of functional dentures are diverse and cannot be said to have been firmly established yet. This model experiment, which employed complete lower dentures, was designed to provide basic information for discussing the influence of occlusal facets of cusp teeth on denture movements during mastication and to arrive at some clinical suggestions for selecting posterior artificial teeth. Artificial teeth with cusp angles of 0 degrees, 10 degrees, 20 degrees, and 30 degrees were made by adjusting setting conditions on a condylar type articulator. Four kinds of experimental dentures were made and used in measuring horizontal movements of lower dentures during the crushing of experimental food. Final phase of chewing stroke was taken into consideration in establishing two types of loading direction. One type was at 70 degrees (DL 70 degrees) to the occlusal plane on the frontal plane and from the outer side (the working side). The other type was 90 degrees (DL 90 degrees) to the occlusal plane. Maximum load was 15kg and the denture displacement was analyzed at 2kg, 4kg, 8kg and 15kg. Experimental foods were smoked cuttlefish (sectile food), raisins (food flattened under pressure), and peanuts (crushable food). Analyses were made of experimental denture movement patterns and denture displacement amounts. Results 1. Experimental denture movement patterns differed according to the nature of the experimental food. The pattern in the case of smoked cuttlefish was mainly of the C type; that is, primarily motion first to the balancing side and then to the working side. The pattern for raisins was mainly of the S type; that is, primarily motion first to the working side, then to the balancing side, and then to the working side again. Several patterns appeared in the case of peanuts.(ABSTRACT TRUNCATED AT 400 WORDS)

Bicuspid↗

PubMed1999

Within- and between-species DNA sequence variation and the 'footprint' of natural selection.

Extensive DNA data emerging from genome-sequencing projects have revitalized interest in the mechanisms of molecular evolution. Although the contribution of natural selection at the molecular level has been debated for over 30 years, the relevant data and appropriate statistical methods to address this issue have only begun to emerge. This paper will first present the predominant models of neutral, nearly neutral, and adaptive molecular evolution. Then, a method to identify the role of natural selection in molecular evolution by comparing within- and between-species DNA sequence variation will be presented. Computer simulations show that such methods are powerful for detecting even very weak selection. Examination of DNA variation data within and between Drosophila species suggests that 'silent' sites evolve under a balance between weak selection and genetic drift. Simulated data also show that sequence comparisons are a powerful method to detect adaptive protein evolution, even when selection is weak or affects a small fraction of nucleotide sites. In the Drosophila data examined, positive selection appears to be a predominant force in protein evolution.

DNA↗

PubMed2004

Dynamics of the iodine-goitrogen balance in the thyroid status of catfish from selected fresh and brackish water bodies.

The study was designed to investigate the dynamics of the goitrogen-iodine balance in Igbokoda brackish and Ogbese fresh water bodies in Ondo State, Nigeria. The parameters determined include iodine, thiocyanate, chloride, nitrate, calcium, magnesium hardness, calcium hardness, total hardness, and total coliform counts in water, sediment and/or fish (flesh and serum). The fish were subjected to a number of treatments (boiling with water or sodium chloride solution, frying or roasting) prior to analysis. The iodine level (microg I/100g) in the flesh of fish varied with size, treatment and location; it increased with size, was reduced by some treatments (boiling with either water or NaCl solution), while frying and roasting did not affect the level. The least values were 93.45 (Ogbese fish boiled with NaCl solution) and 160.94 (Igbokoda fish boiled with either water or NaCl solution). On the whole, Igbokoda (160.94-314.08) had higher values than Ogbese (93.45-205.06). Serum iodine (microg I/100mL) was equally higher in Igbokoda (5.00-9.00) compared to Ogbese (2.80-5.00). Only the large sized fish of Ogbese recorded a value of 5.00 micromol/L for thiocyanate while this parameter was not detected in other samples. The calculated I/goitrogen ratios (I/Ca, I/NO3, I/Cl and I/SCN) were higher for Igbokoda water than Ogbese water with the exception of I/Mg. This was equally reinforced by the total count of coliforms (goitrogenic), which was higher in Ogbese (3.0 x 10(3)) than in Igbokoda (2.7 x 10(3)). These results indicate that the Igbokoda brackish water body would be a better source of iodine than Ogbese fresh water body for the population dependent on them.

Animals↗

PubMed1992

Variation in O-antigens, niche-specific selection and bacterial populations.

Bacterial populations usually consist of distinct clones, often apparently adapted to specific niches. A formal model is developed whereby niche-specific selection maintains the polymorphisms involved in clonal adaptation. Infrequent transfer of non-adaptive alleles to a clone is balanced by the selection for the resident adaptive allele. The model can account for the extensive polymorphism in surface antigens observed in bacteria, and also for the existence of sympatric clones of pathogenic species which differ in host range and/or mode of pathogenesis. Niche-specific selection combined with low levels of genetic transfer can also account for the high level of neutral variation in bacteria, and indirectly for their ability to respond rapidly to environmental changes.

Adaptation, Physiological↗