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Random Selection (random + selection)
Selected AbstractsDynamic matching of forager size to resources in the continuously polymorphic leaf-cutter ant, Atta colombica (Hymenoptera, Formicidae)ECOLOGICAL ENTOMOLOGY, Issue 6 2006E. CLARK Abstract 1.,Ergonomic optimisation theory proposes that by increasing variation in worker morphology, social insect colonies may increase their dietary breadth; however, little is known about how this relationship operates at the colony level. This study examines the colony-level pattern of forager size allocation to resource sites in a natural setting. 2.,Using a biologically relevant measure of toughness, it is shown that leaf-cutter ant colonies exploit a variety of plant resources that vary significantly in toughness at any given time. 3.,Forager size is shown to be matched to the toughness of plant material, with larger ants harvesting tougher material. 4.,Furthermore, outbound foragers travelling to a harvest site are matched in size to the toughness of plant material contained within the site and are not a random selection of available foragers. The match between forager size and plant toughness may reduce the number of wasted trips and ill-matched foragers. 5.,The observed colony-level pattern of forager allocation could be the result of learning by individual foragers, or the result of information shared at the colony level. [source] A UK-based investigation of inter- and intra-observer reproducibility of Gleason grading of prostatic biopsiesHISTOPATHOLOGY, Issue 6 2006J Melia Aims:, The frequency of prostatic core biopsies to detect cancer has been increasing with more widespread prostate specific antigen (PSA) testing. Gleason score has important implications for patient management but morphological reproducibility data for British practice are limited. Using literature-based criteria nine uropathologists took part in a reproducibility study. Methods:, Each of the nine participants submitted slides from consecutive cases of biopsy-diagnosed cancer assigned to the Gleason score groups 2,4, 5,6, 7 and 8,10 in the original report. A random selection of slides was taken within each group and examined by all pathologists, who were blind to the original score. Over six circulations, new slides were mixed with previously read slides, resulting in a total of 47 of 81 slides being read more than once. Results:, For the first readings of the 81 slides, the agreement with the consensus score was 78% and overall interobserver agreement was , 0.54 for Gleason score groups 2,4, 5,6, 7, 8,10. Kappa values for each category were 0.33, 0.56, 0.44 and 0.68, respectively. For the 47 slides read more than once, intra-observer agreement was 77%, , 0.66. The study identified problems in core biopsy interpretation of Gleason score at levels 2,4 and 7. Patterns illustrated by Gleason as 2 tended to be categorized as 3 because of the variable acinar size and unassessable lesional margin. In slides with consensus Gleason score 7, 13% of readings were scored 6 and in slides with consensus 6, 18% of readings were scored 7. Conclusions:, Recommendations include the need to increase objectivity of the Gleason criteria but limits of descriptive morphology may have to be accepted. [source] Attitudes and opinions of oral health and oral care among community-dwelling elderly subjects in Sweden: an interview studyINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 1 2004K Andersson Objective: The aim of this study was to investigate attitudes and opinions of old, independently living people about their oral health and how it has affected them through life. Material and methods: A random selection of 12 individuals was made in a group of 79 individuals who earlier participated in a study about self-reported oral health. The average age was 78.4 years. An interview guide was used as support to focus on oral health. The respondents themselves decided what was important within the topics. The respondents were encouraged to speak freely about their childhood, family, social relations, memories from early dental care, general health situation, experience from health care, life and their future. The interviews were recorded and extended from 60 to 90 min. All of them were transcribed and analysed with phenomenological method inspired by Giogi. The analysis was made by two researchers independently. After 11 interviews, no new information was found; similar opinions, answers and stories recurred. Results: Seven of 11 respondents were born and grown up in the countryside and had moved to Stockholm in the forties. Awareness about dental care was generally low. Many of them have terrible memories from early dental visits, and the dentist was authoritarian and rough. Many had no memories of brushing their teeth as a child. Most of the respondents went to dentists as adults and when they could afford to pay by themselves. After retirement, all have continuous dental care and have visited a dental hygienist during the last 20 years. Nine of 11 have regular contact with a dental hygienist. Most of them are satisfied with their oral health and want to continue being clean and healthy in the mouth. Conclusions: Most of the respondents experienced an improved oral health, information and instructions from the dental hygienist have affected their self-care. Many tell that they have become more aware and carry out the oral hygiene more carefully after retirement. All of them experience that oral health affects the quality of life. [source] Accounting for uncertainty in QTL location in marker-assisted pre-selection of young bulls prior to progeny testJOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2002A. STELLA The objective of this study was to evaluate whether the efficacy of marker assisted selection (MAS) could be improved by considering a confidence interval (CI) of QTL position. Specifically, MAS was applied for within-family selection in a stochastic simulation of a closed nucleus herd. The location and effect of the QTL were estimated by least squares interval mapping with a granddaughter design and marker information was then used in a top down scheme. Three approaches were used to select the best bull within full sibships of 3 or 40 bulls. All three were based on the probability of inheriting the favorable allele from the grandsire (PROB). The first method selected the sib with the highest PROB at the location with the highest F-ratio (MAX). The other two approaches were based on sums of estimated regression coefficients weighted by PROB at each cM within a 95% CI based on either bootstrapping (BOOT) or approximate LOD scores (LOD). Accounting for CI increased the relative genetic gain in all scenarios. The average breeding value (BV) of the selected bulls was increased by 2.00, 2.60 and 2.59% when MAS was applied using MAX, BOOT and LOD, respectively, compared to random selection (h2=0.30). Selected bulls carried the correct allele in 63.0, 68.5, 67.6 and 50.1% of the cases for MAX, BOOT, LOD and random selection, respectively. Berü;cksichtigung der Unsicherheit von QTL Positionen bei Marker-gestü;tzter Vorselektion von jungen Bullen vor der Nachkommenprü;fung Das Ziel dieser Studie war es zu prüfen, ob die Effizienz von MAS (Marker gestützte Selektion) durch Berücksichtigung des Konfidenzintervalls (CI) einer QTL Position verbessert werden kann. Es wurde MAS bei der Selektion innerhalb Familien in einer geschlossenen Nukleus Herde in einer stochastischen Simulation angewandt. Die Postition und der Effekt des QTL wurden in einem Granddaughter Design mit einer Least=Square Intervall Kartierung geschätzt. Die Marker Informationen wurden dann in einem top-down-Schema verwendet. Drei Ansätze fanden Verwendung, um den besten Bullen innerhalb von Vollgeschwistern von 3 oder 40 Bullen zu selektieren. Alle drei Ansätze basieren auf der Wahrscheinlichkeit, ein zu bevorzugendes Allel vom Grossvater zu erben (PROB). Bei der ersten Methode wurden die Geschwister mit der höchsten PROB an der Position mit dem höchsten F-Wert selektiert (MAX). Die beiden anderen Ansätze basierten auf den Summen der geschätzten Regressionskoeffizienten, gewichtet nach PROB an jedem cM innerhalb eines 95%igen CI, das entweder auf Bootstrapping (BOOT) oder approximativen LOD Scores (LOD) basiert. Die Berücksichtigung des CI vergrösserte den relativen genetischen Fortschritt in allen Szenarien. Bei Anwendung von MAS waren die durchschnittlichen Zuchtwerte der selektierten Bullen bei Verwendung von MAX, BOOT und LOD verglichen mit zufälliger Selektion (h2=0,30) um 2,00, 2,60 und 2,59% gestiegen. Die selektierten Bullen trugen das richtige Allel bei den entsprechenden Berechnungen MAX, BOOT, LOD und zufälliger Selektion in 63,0, 68,5, 67,6 und 50,1% der Fälle. [source] The Roles of Gender and Affirmative Action Attitude in Reactions to Test Score Use Methods,JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 9 2000Donald M. Truxillo The present study explored the effects of 2 variables, affirmative action (AA) attitude and gender, on reactions to 3 test score use (TSU) methods: top-down selection. banding with random selection, and banding with preferences. In a study of 94 upper-division and graduate business students, AA attitude was associated with different reactions to TSU methods in terms of fairness and organizational attractiveness. Moreover, women with negative AA attitudes and men rated banding with preferences lower than the other two methods, but women with positive AA attitudes did not Results are discussed in terms of applicant reactions models, implications for organizations and future research. [source] Risk factors for small-for-gestational-age babies: The Auckland Birthweight Collaborative StudyJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 4 2001JMD Thompson Objective: This case-control study determined whether internationally recognized risk factors for small-for-gestational-age (SGA) term babies were applicable in New Zealand. Methodology: All babies were born at 37 or more completed weeks of gestation in one of three hospitals in Auckland. Cases weighed less than the sex specific 10th percentile for gestational age at birth, and controls (appropriate-for-gestational-age (AGA)) were a random selection of heavier babies. Information was collected by maternal interview and from obstetric databases. Results: Information from 1714 completed interviews (844 SGA and 870 AGA) was available for analysis. Computerized obstetric records were available for 1691 of the 1701 women who consented to such access. In a multivariate analysis allowing for sex, gestational age at birth, social class and other potential confounders, mothers who smoked had a significantly increased risk of an SGA baby (adjusted OR 2.41; 95% CI 1.78,;3.28), as did primiparous mothers (adjusted OR 1.34; 95% CI 1.03,;1.73), mothers of Indian ethnicity (adjusted OR 3.22; 95% CI 1.95,;5.30), women with pre-eclamptic toxaemia (adjusted OR 2.42; 95% CI 1.08,;5.40) and those with pre-existing hypertension toxaemia (adjusted OR 5.49; 95% CI 1.81,;16.71). Mothers of SGA infants were shorter (P < 0.001) and reported lower prepregnancy body weights (P < 0.001) than mothers of AGA infants. The population attributable fraction for smoking suggests that up to 18% of SGA infants born in the ABC Study could be related to maternal smoking. Conclusions: Risk factors associated with SGA births in other countries are also important in New Zealand. Smoking in pregnancy is an important and potentially modifiable behaviour, and efforts to decrease the number of women who smoke during pregnancy should be encouraged. [source] NEURAL NETWORK PREDICTION OF PERMEABILITY IN THE EL GARIA FORMATION, ASHTART OILFIELD, OFFSHORE TUNISIAJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2001J.H. Ligtenberg The Lower Eocene El Garia Formation forms the reservoir rock at the Ashtart oilfield, offshore Tunisia. It comprises a thick package of mainly nummulitic packstones and grainstones with variable reservoir quality. Although porosity is moderate to high, permeability is often poor to fair with some high permeability streaks. The aim of this study was to establish relationships between log-derived data and core data, and to apply these relationships in a predictive sense to uncored intervals. An initial objective was to predict from measured logs and core data the limestone depositional texture (as indicated by the Dunham classification), as well as porosity and permeability. A total of nine wells with complete logging suites, multiple cored intervals with core plug measurements together with detailed core interpretations were available. We used a fully-connected Multi-Layer-Perceptron network (a type of neural network) to establish possible non-linear relationships. Detailed analyses revealed that no relationship exists between log response and limestone texture (Dunham class). The initial idea to predict Dunham class, and subsequently to use the classification results to predict permeability, could not therefore be pursued. However, further analyses revealed that it was feasible to predict permeability without using the depositional fabric, but using a combination of wireline logs and measured core porosity. Careful preparation of the training set for the neural network proved to be very important. Early experiments showed that low to fair permeability (1,35 mD) could be predicted with confidence, but that the network failed to predict the high permeability streaks. "Balancing " the data set solved this problem. Balancing is a technique in which the training set is increased by adding more examples to the under-sampled part of the data space. Examples are created by random selection from the training set and white noise is added. After balancing, the neural network's performance improved significantly. Testing the neural network on two wells indicated that this method is capable of predicting the entire range of permeability with confidence. [source] Influences of alkyl group chain length and polar head group on chemical skin permeation enhancementJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2001Kevin S. Warner Abstract Previous investigations in our laboratory on the influence of the n -alkanols and the 1-alkyl-2-pyrrolidones as skin permeation enhancers for steroid molecules as permeants demonstrated that the enhancer potencies (based on aqueous concentration values) of these two homologous series were the same when compared at the same alkyl chain length; that is, the contribution of the hydroxyl group and that of the pyrrolidone group to enhancer potency were the same. The purpose of the present study was to further investigate what was believed to be a somewhat surprising finding, and two additional homologous series, the 1,2-alkanediols and N,N -dimethylalkanamides, were selected for study as enhancers. Corticosterone (CS) flux enhancement along the lipoidal pathway of hairless mouse skin stratum corneum was determined with 1,2-hexane-, 1,2-octane-, and 1,2-decanediol and with N,N -dimethylhexanamide, N,N - dimethylheptanamide, N,N -dimethyloctanamide, and N,N -dimethylnonanamide as enhancers. The enhancement factor (E) for the lipoidal pathway was calculated from the CS permeability coefficient and the CS solubility data over a 4 to 100 range of E values. Comparisons of the enhancer potencies of all four homologous series revealed that the enhancer potencies of all were very nearly the same when compared at equal alkyl group chain length. Moreover, the contribution of each of the polar head groups toward the enhancer potency was essentially constant, independent of the alkyl group chain length. It was reasoned that this outcome was either the result of the random selection of four polar head groups making the same contribution to enhancer potency or the result of these particular polar head groups not contributing to enhancer potency. To test the hypothesis that the former was more likely than the latter and that a suitable semipolar organic phase may mimic the microenvironment of the polar head group at the site of enhancer action, n -octanol,phosphate buffered saline (PBS) and n -hexane,PBS partition coefficients were determined for all the enhancers. The n -octanol,PBS partition coefficients for the enhancers, but not the n -hexane,PBS partition coefficients, were very nearly the same when compared at equal alkyl group chain lengths; this result supports the hypothesis that each of the four polar head groups likely contributes the same toward the enhancer potency and locates in the semipolar region of the hairless mouse skin stratum corneum lipid bilayers, which is well-approximated by water-saturated n -octanol. © 2001 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 90:1143,1153, 2001 [source] Appointments to boards and committees via lottery, a pathway to fairness and diversityJOURNAL OF PUBLIC AFFAIRS, Issue 2 2009Lyn Carson Public appointments for committees or boards can be controversial due to cronyism or pandering to demands of noisy or powerful interest groups. One relatively unexplored method for selecting committee or board members is random selection which has advantages beyond interrupting cronyism. This paper canvasses the strengths and weaknesses of an unusual selection method and makes a case for the use of a lottery as a robust process that will lend legitimacy and credibility to committee or board governance. Copyright © 2009 John Wiley & Sons, Ltd. [source] Effects of Gender and Size on Feed Acquisition in the Pacific White Shrimp Litopenaeus vannameiJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2006Dustin R. Moss Pacific white shrimp, Litopenaeus vannamei, are sexually dimorphic for growth, where subadult and adult females typically are larger than males of the same age. This character may be attributed to physiological and/or behavioral differences between the sexes. To determine if growth differences are the result of a more aggressive feeding behavior by females, four concurrent feeding trials were conducted to study the effects of gender and size on feed acquisition time. Feeding trials consisted of tanks (three replicate tanks per trial) stocked with (1) all females with small- and large-size groups, (2) all males with small- and large-size groups, (3) a random selection of males and females (resulting in larger females than males), and (4) males and females of equal size. Depending on the trial, tanks were stocked with either an equal number of males and females or small and large shrimp. Shrimp were fed a limited ration of squid, and the total feeding time (TFT) of shrimp between groups within a tank was compared. Results show that both gender and size are important factors in TFT as large shrimp out-competed small shrimp in both all-female and all-male feeding trials. Gender is more important than size as males out-competed females for feed even when they were smaller than competing females. These results suggest that sexual growth dimorphism is not the result of more aggressive feeding by females. In fact, males have a competitive advantage over females in acquiring feed. These results are counterintuitive because females typically are larger than males. Additional research is needed to investigate the physiological basis for sexual growth dimorphism in this commercially important shrimp. [source] Identification of Diverse Database Subsets using Property-Based and Fragment-Based Molecular DescriptionsMOLECULAR INFORMATICS, Issue 6 2002Mark Ashton Abstract This paper reports a comparison of calculated molecular properties and of 2D fragment bit-strings when used for the selection of structurally diverse subsets of a file of 44295 compounds. MaxMin dissimilarity-based selection and k -means cluster-based selection are used to select subsets containing between 1% and 20% of the file. Investigation of the numbers of bioactive molecules in the selected subsets suggest: that the MaxMin subsets are noticeably superior to the k -means subsets; that the property-based descriptors are marginally superior to the fragment-based descriptors; and that both approaches are noticeably superior to random selection. [source] Cross-cultural assessment of the Contextual Memory Test (CMT)OCCUPATIONAL THERAPY INTERNATIONAL, Issue 4 2000Health Studies, Naomi Josman PhD, OTR Faculty of Social Welfare Abstract The Contextual Memory Test (CMT) measures aspects of memory and metamemory of people with cognitive disabilities. The assessment tool was originally developed and standardized in the United States. The objectives of this study were: (1) to evaluate the applicability of the CMT to an Israeli population; (2) to further investigate the construct validity of the CMT to discriminate among age groups; and (3) to analyse the 40 items on the CMT from a cultural point of view. The CMT was administered to 217 typical Israeli adults, grouped into three age categories, closely matching those in the US normative study (Toglia, 1993). Similar levels of performance were obtained for Israelis and Americans on the various test components. Statistically significant differences between American and Israeli subjects' performance levels were evident in three memory components in the elderly groups (group 3) and in only two memory components in the young group (group 1). In addition, within-sample comparisons of the three Israeli age groups yielded significant age effects for recall, recognition, strategy use and general awareness. This study confirmed discriminant validity for the CMT. The tool seems to be highly appropriate for use by occupational therapists in assessing memory and metamemory with American and Israeli adult subjects. The relatively small size of the age groups and the lack of random selection of subjects are limitations of this study. Therefore, it is recommended that the study be replicated with a larger and randomized sample. The multifaceted nature of the assessment provides much more information than traditional recall scores, and the metamemory components enhance both differential diagnosis and appropriate planning of treatment. Copyright © 2000 Whurr Publishers Ltd. [source] Psychosocial impact among the public of the severe acute respiratory syndrome epidemic in TaiwanPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 4 2006CHIH-HUNG KO md Abstract, During the 2003 outbreak, severe acute respiratory syndrome (SARS) spread to more than 30 countries. Not only did it cause severe health problems but it also imposed a great psychological impact on the public. SARS emerged in Taiwan during April 2003. This study investigates the psychosocial impact and the associated factors of depression of the SARS epidemic in Taiwan when the epidemic had just been controlled. A total of 1552 respondents were recruited in the study by random selection from the telephone book. Demographic data, SARS experience, self-perceived health state, neighborhood relationships, and depression were surveyed by telephone interviewing. Respondents were grouped as ,impacted group' and ,non-impacted group' according to whether they or their friends and family had been quarantined, or suspected of being infected. The psychosocial impact and associated factors were compared between the two groups. The ,impacted group' had higher depressive levels, poorer neighborhood relationships, poorer self-perceived health, and a higher economic impact than the ,non-impacted group'. The poorer self-perceived health and economic impact factors were associated with depression. The neighborhood relationship factor was negatively associated with depression for the ,impacted group', but not for the ,non-impacted group'. The ,impacted group' had experienced greater psychosocial impact possibly due to the SARS impact, the economic downturn, poor self-perceived health conditions, and decreased social support systems. An appropriate mental health intervention to improve the self-perceived health condition, to provide instrumental and psychological support for the ,impacted group', and to decrease the stigmatization and discrimination from the public could have buffered the psychological impact from this epidemic disaster. [source] Optimal selection method for establishing an inbred strain of laboratory animals with high performance for litter size at weaningANIMAL SCIENCE JOURNAL, Issue 2 2008Masahiro SATOH ABSTRACT The optimal selection method was investigated for establishing an inbred strain of laboratory animals with high performance for litter size at weaning (LSW). A Monte Carlo computer simulation was used to assess the effects of our selection methods on the genetic change of LSW under the continuous use of full-sib mating for 20 generations. Smaller number of growing animals of each sex per litter and genetic evaluation for selection using a BLUP animal model increased LSW. Use of information on another trait genetically related to LSW, larger population size, and greater number of generations for random selection before starting full-sib mating were useful for establishing an inbred strain of laboratory animals with high performance for LSW. It was concluded that LSW can be increased by directional selection when establishing inbred strains. [source] Higher taxa are effective surrogates for species in the selection of conservation reserves in estuariesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 6 2009Mohammad Reza Shokri Abstract 1.The lack of information about marine biodiversity is problematic for the selection of conservation reserves that aim to protect representative samples of biodiversity. A number of surrogate measures for biodiversity have been suggested as a potential solution to this problem. 2.The present study tested the effectiveness of using higher taxa of macroinvertebrates as a surrogate for species-level identification to depict spatial variation in species richness and assemblage variation and to select conservation reserves in one estuary in south-east Australia. 3.Spatial patterns of richness and assemblage variation for species were significantly correlated with patterns defined from genera, families, orders, classes, and phyla with a decline in the magnitude of correlation coefficients from finer to coarser resolutions. A network of reserves selected to include representatives of all phyla, classes, orders, families and genera coincidentally included 54%, 61.7%, 75%, 92.6%, 98.8% species in 8.3%, 13.9%, 17.7%, 44.4% and 58.3% of grid cells, respectively. However, only reserves selected for genera, families and orders performed significantly better than random selection. 4.Percentage of species represented by orders, families and genera in a realistic level of available grid cells for conservation (i.e. 13.9%) were very close ranging between 70 and 73.5%. A factor diminishing the performance of order as surrogate for species richness was related to the difficulty of identifying many macroinvertebrates to the order level. Therefore, it is concluded that genus- and family-level identification is an effective surrogate for species-level identification for conservation planning in estuaries. Copyright © 2008 John Wiley & Sons, Ltd. [source] Availability and Quality of Computed Tomography and Magnetic Resonance Imaging Equipment in U.S. Emergency DepartmentsACADEMIC EMERGENCY MEDICINE, Issue 8 2008Adit A. Ginde MD Abstract Objectives:, The objective was to determine the availability and quality of computed tomography (CT) and magnetic resonance imaging (MRI) equipment in U.S. emergency departments (EDs). The authors hypothesized that smaller, rural EDs have less availability and lower-quality equipment. Methods:, This was a random selection of 262 (5%) U.S. EDs from the 2005 National Emergency Department Inventories (NEDI)-USA (http://www.emnet-usa.org/). The authors telephoned radiology technicians about the presence of CT and MRI equipment, availability for ED imaging, and number of slices for the available CT scanners. The analysis was stratified by site characteristics. Results:, The authors collected data from 260 institutions (99% response). In this random sample of EDs, the median annual patient visit volume was 19,872 (interquartile range = 6,788 to 35,757), 28% (95% confidence interval [CI] = 22% to 33%) were rural, and 27% (95% CI = 21% to 32%) participated in the Critical Access Hospital program. CT scanners were present in 249 (96%) institutions, and of these, 235 (94%) had 24/7 access for ED patients. CT scanner resolution varied: 28% had 1,4 slice, 33% had 5,16 slice, and 39% had a more than 16 slice. On-site MRI was available for 171 (66%) institutions, and mobile MRI for 53 (20%). Smaller, rural, and critical access hospitals had lower CT and MRI availability and less access to higher-resolution CT scanners. Conclusions:, Although access to CT imaging was high (>90%), CT resolution and access to MRI were variable. Based on observed differences, the availability and quality of imaging equipment may vary by ED size and location. [source] Parental mental health, education, age at childbirth and child development from six to 18 monthsACTA PAEDIATRICA, Issue 5 2009For-Wey Lung Abstract Aim: To investigate the effect six-month parental mental health has on children's six and 18-month development. Parental covariates of age and education were also analysed. Methods: Through a national random selection, 21 648 babies were selected. Parental self perceived overall mental health was measured using 36-Item Short Form Health Survey (SF-36) and children's development using the Taiwan Birth Cohort Study (TBCS) instrument which measures gross motor, fine motor, language and social dimensions of children's development. Results: Both multiple linear regression and structural equation modeling showed that when the covariates of parental education and age at childbirth were added, the effect parental mental health has on children's development decreases. Additionally, maternal mental health had a more persistent and pervasive effect than paternal mental health. Father's mental health at six months had a delayed effect, in that its influence was seen only with children's development at 18 months. Of the three factors of parental mental health, education and age at childbirth, parental education had the most pervasive and persistent effect on children's development. Conclusion: Although parental mental health has an effect on children's development, parental education and age at childbirth are vital confounding factors, which should be considered in future studies. Clinical health care providers should provide childcare resources and instructions to younger, less educated and parents with mental symptoms. [source] Ridge alterations following tooth extraction with and without flap elevation: an experimental study in the dogCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2009Mauricio G. Araújo Abstract Background: Different approaches were advocated to preserve or improve the dimension and contour of the ridge following tooth extraction. In some of studies, socket ,flapless extraction' apparently had a successful outcome. Aim: The objective of the present experiment was to compare hard tissue healing following tooth extraction with or without the prior elevation of mucosal full-thickness flaps. Material and methods: Five mongrel dogs were used. The two second mandibular premolars (2P2) were hemi-sected. The mesial roots were retained. By random selection the distal root in one side was removed after the elevation of full-thickness flaps while on the contralateral side, root extraction was performed in a flapless procedure. The soft tissue wound was closed with interrupted sutures. After 6 months of healing, the dogs were euthanized and biopsies were sampled. From each experimental site, four ground sections , two from the mesial root and two from the healed socket , were prepared, stained and examined in the microscope. Results: The data showed that the removal of a single tooth (root) during healing caused a marked change in the edentulous ridge. In the apical and middle portions of the socket site minor dimensional alterations occurred while in the coronal portion of the ridge the reduction of the hard tissue volume was substantial. Similar amounts of hard tissue loss occurred during healing irrespective of the procedure used to remove the tooth was, i.e. flapless or following flap elevation. Conclusion: Tooth loss (extraction) resulted in marked alterations of the ridge. The size of the alveolar process was reduced. The procedure used for tooth extraction , flapless or following flap elevation , apparently did not influence the more long-term outcome of healing. [source] | |||||||||||||||||||