High Level Of Association Research Articles

The Mobility Scale for Acute Stroke Patients: concurrent validity.

A new scale, the Mobility Scale for Acute Stroke Patients (MSAS), was developed to specifically discriminate between the lower levels of mobility found in acute stroke patients in the first two weeks post onset. The aim of this study was to investigate the concurrent validity of this new scale with other established scales. Concurrent validity was assessed with respect to four other well-validated measures: Motor Assessment Scale (MAS), Functional Ambulation Classification system (FAC), Functional Independence Measure (FIM), and Barthel Index (BI). The measures selected for comparison contained items similar to those in the MSAS. From a total of 539 patients who were admitted over a two-year period with a primary diagnosis of stroke, 106 satisfied the criteria for inclusion in this study. The MSAS was found to have a high level of concurrent validity (r > 0.80) when the total score was correlated with the total scores of the MAS, FAC, FIM (mobility and ADL) and BI. A high level of association was found between the nonbed mobility items (sit to stand, stand and walk) of the MSAS and the mobility items (toileting, transfers, walk and stairs) of the FIM and BI. There was a weaker association between the MSAS items and the ADL items (activities of daily living) of the BI and FIM. A new scale designed specifically for acute stroke patients was found to have a high degree of concurrent validity when compared with four other scales containing similar items.

Adapting the Use of Microswitches to Foster Response Awareness and Word Association

In this study, the use of microswitches was adapted to foster response awareness and word association for two persons with multiple disabilities. A microswitch activation/ response produced a spoken word indicating the consequences available for it. Repeating that response after the word led to the occurrence of the consequences. Repeating the specific response, rather than emitting a different one, was considered a sign of response awareness. Both persons learned to repeat the appropriate responses after the words, showing signs of response awareness. They also showed moderate to high levels of association of the words presented as probes (outside of the above sequence) with the related responses. Implications of the data and the use of this approach in the persons' daily contexts are discussed.

Effect of pH on the association of denatured whey proteins with casein micelles in heated reconstituted skim milk.

Skim milk was adjusted to pH values between 6.5 and 6.7 and heated (80, 90, and 100 degrees C) for up to 60 min. Changes in casein micelle size, level of whey protein denaturation, and level of whey protein association with the micelles were monitored for each milk sample. Changes in casein micelle size were markedly affected by the pH at heating. At low pH (6.5-6.55), the casein micelle size increased markedly during the early stages of heating, and the size plateaued on prolonged heating. The maximum increase in size was approximately 30-35 nm. In contrast, at high pH (6.7), much smaller changes in size were observed on heating and the maximum increase in size was only approximately 10 nm. An intermediate behavior was observed at pH values between these two extremes. The rate of denaturation of the major whey proteins, alpha-lactalbumin and beta-lactoglobulin, was essentially unaffected by the pH at heating for the small pH changes involved in this study, and the changes in casein micelle size were poorly related to the level of whey protein denaturation. In contrast, the level of denatured whey proteins associating with the micelles was markedly dependent on the pH at heating, with high levels of association at pH 6.5-6.55 and low levels of association at pH 6.7. Changes in casein micelle size were related to the levels of denatured whey proteins that were associated with the casein micelles, although there was a small deviation from linearity at low levels of association (<15%). Further studies on reconstituted and fresh milk samples at smaller pH steps confirmed that the association of whey proteins with the casein micelles was markedly affected by the pH at heating. These results indicate that the changes in casein micelle size induced by the heat treatment of skim milk were a consequence of the whey proteins associating with the casein micelles and that the level of association was markedly influenced by small pH changes of the milk. It was not possible to determine whether the association itself influenced the casein micelle size or whether parallel reactions involving micellar aggregation caused the increase in micelle size as whey protein association progressed.

Eastern Curlew numbers at high-tide roosts versus low-tide feeding grounds: a comparison at three spatial scales

We compared summer numbers of the Eastern Curlew (Numenius madagascariensis) in Moreton Bay counted on low-tide feeding grounds with those counted on high-tide roosts, at several spatial scales. In total, the average summer count at 30 focal roost sites was 1851 and the corresponding average summer count at adjacent feeding grounds was 1728, a close match given the potential sources of error in both data sets. Counts also corresponded well when feeding grounds were broken up into smaller-scale groups and associated with adjacent roost sites. Larger-area (around 5 km) groupings of continuous feeding habitat gave high levels of association (76–83% of the variation in roost-site numbers explained by variation in feeding-site numbers), which weakened when the sites were grouped at a finer scale (around 500 m), although it remained statistically significant (42% of variation explained). Within Moreton Bay, the distance over which the Eastern Curlew typically operate may be in the order of 5–10 km, with high mobility between alternate roosts and/or feeding grounds occurring at or below this distance.

Optically stimulated luminescence dating of Holocene relict foredunes, Guichen Bay, South Australia

Optically stimulated luminescence (OSL) dating of quartz sand (106–150 or 150–200 μm) in bioclastic carbonate–quartz sediments sampled from coastal relict foredunes (beach ridges) was undertaken to evaluate the utility of the OSL method for studies of dune dynamics and to quantify rates of coastal progradation. Twelve sediment samples from a 4 km transect across a Holocene embayment fill at Guichen Bay, South Australia, were measured for their luminescence characteristics. Apart from one age inversion attributed to recent disturbance associated with mining, the OSL ages are in sequential order when considered in the context of their associated error terms. The OSL ages indicate an extremely rapid initial phase of sedimentation (i.e. 1600 m within a few hundred years, approximately 5 ka ago) followed by a constant rate of progradation for the past 4 ka of 0.39 m/a, with a high level of association between distance across the embayment fill and luminescence age for this time interval. An average rate of dune development of one dune every 80 yr from 3900 yr ago to the present day is apparent. The OSL ages for the late Holocene indicate that the present beach state is largely in equilibrium with sediment supply.

Genetic diversity of Streptococcus suis strains isolated from pigs and humans as revealed by pulsed-field gel electrophoresis.

The genetic diversity of 123 Streptococcus suis strains of capsular types 2, 1/2, 3, 7, and 9, isolated from pigs in France and from humans in different countries, was evaluated by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI. The method was highly discriminative (D = 0.98), results were reproducible, and the PFGE analysis was easy to interpret. Among all S. suis strains, 74 PFGE patterns were shown. At 60% homology, three groups (A, B, and C) were identified, and at 69% homology, eight subgroups (a to h) were observed. Strains isolated from diseased pigs or from humans were statistically clustered in group B, especially in subgroup d. By contrast, S. suis strains isolated from clinically healthy pigs were preferentially included in subgroup b of group A. Relationships could be established between capsular types 1/2, 3, and 9 and groups A, e, and B, respectively. S. suis strains isolated from humans were homogeneous, and a very high level of association between these strains and four DNA patterns was observed. The PFGE used in this study is a very useful tool for evaluating the genetic diversity of S. suis strains, and it would be used for epidemiological investigations.

Adequação do teste de condutividade elétrica para determinar a qualidade fisiológica de sementes de jacarandá-da-bahia (Dalbergia nigra (Vell.) Fr.All. ex Benth.)

Para testar o efeito da temperatura e do tempo de embebição nos valores de condutividade elétrica e verificar sua aplicabilidade para determinar a qualidade fisiológica de sementes de Dalbergia nigra (jacarandá-da-bahia), foram utilizadas sementes colhidos em três anos (lote I _ 1998; lote II _ 1997 e lote III - 1994). Inicialmente determinou-se o teor de água e depois conduziu-se os testes de germinação em laboratório e viveiro, utilizando-se quatro repetições de 25 sementes. Para estudar a condutividade elétrica (CE) foram utilizadas quatro repetições de 50 sementes. Cada subamostra foi colocada em recipiente contendo 75ml de água deionizada, embebidas por 6, 12, 18, 24, 30 e 36 horas, a 20, 25 e 30ºC. Sementes do lote II apresentaram maiores valores na primeira contagem da germinação, diferindo significativamente dos demais lotes. O lote III apresentou qualidade inferior. Com o aumento do período e da temperatura de embebição ocorreu aumento nos valores de CE das sementes dos três lotes. O lote III mostrou qualidade fisiológica inferior a dos lotes I e II, que apresentaram valores mais elevados de CE. Não houve diferenciação entre os lotes I e II. Concluiu-se que o teste de CE foi eficiente para diferenciar os lotes de sementes de Dalbergia nigra, com alto grau de associação com o teste de germinação.

INTERFERENCE OF MACROPHAGES WITH IMMUNOTARGETING OF LIPOSOMES

ABSTRACTWe investigated the binding, uptake and intracellular degradation of immunoliposomes by isolated rat liver macrophages in vitro. Immunoliposomes were prepared either by coupling a randomly thiolated anti-CC531 rat colon adenocarcinoma monoclonal antibody to bilayer-incorporated MPB-PE by means of a thioether linkage or by attaching it through its Fc moiety to the distal terminus of hydrazide-modified PEG-DSPE. The two immunoliposome preparations clearly differ in their interaction with the tumor target cells, as well as with the macrophages. At comparable antibody densities both cell types show 1.5–2-fold higher levels of association for the Hz-PEG-immunoliposomes than for the MPB-PEG-immunoliposomes. We provide evidence that immunoliposome macrophage-interaction is both Fc-receptor and scavenger receptor mediated to about equal extents. At low antibody density the hydrazide immunoliposomes favor interaction with the tumor cells to that with macrophages. At higher antibody densities, on the other hand, interaction of these liposomes with the macrophages is increasingly favored, mostly due to enhanced scavenger receptor mediated uptake. The rate of intracellular degradation of (immuno)liposomes internalized by liver macrophages is barely influenced by the presence of either PEG or immunoglobulins on the liposomal surface.

New tools for studying integration and modularity.

The study of phenotypic integration concerns the modular nature of organismal phenotypes. The concept provides a rationale for why certain subsets of phenotypic traits show particularly high levels of association over development and/or evolution. The techniques detailed in this report facilitate the generation and testing of hypotheses of phenotypic integration and trait interaction. The approach advocated for exploring patterns of interaction among traits is based on the statistical notion of conditional independence, incorporated in a technique known as graphical modeling. The use of graphical models is illustrated with an application to a well-known biological dataset of fowl skeletal measurements, previously analyzed by Sewall Wright. A definition of phenotypic modularity is given, based on a notion of mutual information, which provides a consistent criterion for recognizing and delimiting integrated subsets of traits and which can be related to standard models of multivariate selection.

Scaling up adoption and impact of agroforestry technologies: Experiences from western Kenya

Community-based organisations are increasingly considered a sustainable way to scale up the benefits of agricultural research and development from a few farmers in isolated pilot project areas to spread more widely across geographical and socio-economic gradients, and to do so quickly. This paper describes and highlights lessons learned from several research and development organisations in western Kenya using different community-based approaches to scale up agroforestry and other biological options to improve soil fertility among resourcepoor smallholders. The main benefits of such approaches are that the link between farmers, government extension, and other service providers is strengthened; information flow and awareness of the options available is rapid among farmers; and farmers' participation and innovation is enhanced. For effective service delivery, however, some higher level of association is necessary that goes beyond individual farmers or groups such as youth-, women-, or church-based organisations. Nevertheless, experience from a pilot project involving the International Centre for Research in Agroforestry and some key national research and development institutions shows that village, sublocation or location committees are often inactive without strong follow-up, which is best provided by such local institutions as government extension staff close to farmers or NGOs. Most of these institutions, however, have limited resources and information. To mitigate these problems and to better share experiences among individual organisations and projects in the region, a strategic consortium of the key institutions was formed. There are high hopes concerning the consortium, although it is too early to determine its effectiveness.

Examination of the validity and reliability of the accusport blood lactate analyser

Clough et al. (1997) reported that 95% of lactate values obtained using an Accusport analyser may be up to 2.6 mM below or 2.1 mM above YSI 2300 analyser values over the range 0-16 mM. This variability is substantial and unsuitable for research purposes, The objectives of this study were to re-examine the specific validity and reliability of an Accusport analyser and to develop a regression equation to improve the accuracy of Accusport measurements. Duplicate measurements of lactate concentration were made on both an Accusport (Boehringer Mannheim) and Analox LM3 Multi Channel analyser on 17 blood samples taken from two subjects performing a discontinuous incremental exercise protocol. Analysis of duplicate measurements revealed good test-retest reliability for Accusport (TEM 0.35 mM; SEM 0.24 mM; ICC r = 0.995) and Analox (TEM 0.07 mM; SEM 0.09 mM; ICC r = 0.999). The mean values for duplicate samples recorded on both the Accusport and Analox between the lactate range of 1-13 mM revealed an average difference between the two analysers of 1.7 mM (P< 0.01, range 1.0-2.9 mM) but values demonstrated a high level of association (ICC r = 0.853; P< 0.05). The level of agreement indicated that in 95% of cases the differences would lie between + 0.5 to + 3.0 mM with the Accusport values always higher than Analox. Linear regression analysis calculated the following equation to predict Analox values from Accusport values: Analox = -0.749 + 0.837Accusport (R2 = 0.990). The results showed the portable Accusport analyser to be reliable and it demonstrated good association with Analox LM3 lactate analyser measures. However, a need exists to develop specifically generated regressions from Accusport and Analox LM3 analyser measures to provide more accurate results when interpreting lactate values from Accusport measures taken in the field.

Self-report quality of life measure for people with schizophrenia: the SQLS.

Quality of life is the subject of growing interest and investigation. To develop and validate a short, self-report quality of life questionnaire (the Schizophrenia Quality of Life Scale, SQLS). People with schizophrenia in Liverpool were recruited via the NHS. Items, generated from in-depth interviews, were developed into an 80-item self-report questionnaire. Data were factor analysed, and a shorter form measure was tested for reliability and validity. This measure was administered together with other self-report measures--SF-36, GHQ-12 and HADS--to assess validity. Data were analysed to produce a final 30-item questionnaire, comprising three scales ('psychosocial', 'motivation and energy', and 'symptoms and side-effects') addressing different SQLS dimensions. Internal consistency reliability of the scale was found to be satisfactory. There was a high level of association with relevant SF-36, GHQ-12 and HADS scores. The SQLS was completed within 5-10 minutes. It possesses internal reliability and construct validity, and promises to be a useful tool for the evaluation of new treatment regimes for people with schizophrenia.

Effects of herbivore‐bearing adult trees of the oak Quercus crispula on the survival of their seedlings

The acorn‐producing oak Quercus crispula Blume is shade‐tolerant and its seedlings were found to be underdispersed on the forest floor, forming seedling aggregations near fertile canopy trees. However, 84.4% of the seedlings were dead within 2 years, with the highest mortality near the adult canopy trees of Q. crispula. This was mostly due to the high levels of herbivory by lepidopteran larvae. The most serious damage was caused by spring consumers, which fed on the leaves of canopy trees in June and, when the food quality of the leaves declined, fell down to the forest floor to consume the juveniles, including the seedlings. Contrary to the expectation of the herbivore–host arms race theory, most of the herbivores were polyphagous. The most dominant spring consumer Telorta edentata (Leech) was also polyphagous, and its distribution on the forest floor showed a high level of association with the distribution of dead oak seedlings.

Correlations between reported and measured ultraviolet radiation exposure of mothers and young children.

Cumulative and intermittent sun exposure are risk factors for skin cancer, highlighting the need to monitor exposure during childhood. There is currently very little available information concerning the accuracy of self-reported levels of sun exposure, particularly for very young children. In this study, UV radiation (UVR) exposure measured by polysulfone dosimeters worn on the wrist was compared with a measure of estimated exposure using a diary based on recall at the end of the 4 day study period and ambient dosimetric measures. Results of the study indicate that the relative UVR exposures expressed as a fraction of daily total ambient received during the 4 day period by young children and mothers are similar. A high level of association was obtained for the estimated levels of exposure between young children and their mothers. Moderate correlations were evident for dosimeter readings of mother and child on weekends with no significant association on weekdays. The association between estimated exposure and dosimeter readings was poor and needs improvement. This may be achieved by greater consideration of structural and environmental factors that influence the levels of UVR exposure received by individuals and by increasing the level of specificity in the measurement instruments. Methodological issues such as recall of exposure after several days, quantity of sun exposure and more precise measurement of grades of exposure when outside may have more impact than previously expected, and further information is being sought with a larger sample for exposure during the summer months.

The effects of interactions with reef residents on the settlement

Recruitment limitation models of coral reef fishes assume that interactions between demersal individuals and settling larvae are of little consequence to local population dynamics, as are interactions among reef residents. To test this premise, I examined the effects of interactions on the settlement and persistence of the ocean surgeonfish, Acanthurus bahianus. I also looked at behavioural exchanges among ocean surgeonfish of different sizes and between ocean surgeonfish and other reef residents to determine whether the nature of these exchanges changes ontogenetically. Settlement of ocean surgeonfish to Tague Bay Reef, St. Croix, U.S.V.I. was increased in the presence of conspecifics and decreased in the presence of a common Caribbean damselfish, the beaugregory Stegastes leucostictus. Additionally, post-settlement persistence was negatively related to the level of aggression received from beaugregories. Interactions among ocean surgeonfish and between ocean surgeonfish and damselfish were size-dependent; the largest and smallest size classes had higher levels of association with conspecifics than did the middle size classes, and larger size classes received more aggression from damselfish than did the smaller size classes. These results suggest that behavioural interactions may significantly affect the distribution, abundance and early post-settlement persistence of ocean surgeonfish settlers, and that the nature of these interactions changes over the lifetime of individuals.

The Northwick Park Dependency Score (NPDS): a measure of nursing dependency in rehabilitation.

Disability scores, such as the Functional Independence Measure (FIM) and Barthel Index, have been shown to correlate with care needs but cannot be used to assess them directly, as they do not indicate the number of people required to help with a task, nor the time taken. The Northwick Park Dependency Score (NPDS) is an ordinal scale that can be used to assess impact on nursing time. It takes 3-5 minutes to complete. Together with a short set of additional questions, it may be used directly to assess care needs in the community and to facilitate discharge planning. To develop and evaluate the NPDS for use in a rehabilitation setting. (1) DEVELOPMENT: Following a survey of existing instruments, tasks were selected on the basis of their impact on nursing time and divided into Basic Care Needs (BCN) and Special Nursing Needs (SNN). Cut-off points were devised to reflect the number of helpers needed and time taken. Following evaluation of the NPDS version 5, minor changes were made to produce version 6 which was re-evaluated on a smaller scale. (2) EVALUATION: Inter-rater and intra-rater reliability were tested in a cohort of 23 inpatients using five senior nurses. Analysis included assessment of degree of association, significant differences, absolute agreement, and agreement +1 level. Although there is no gold standard, the BCN section should correlate inversely with independently assessed Barthel scores. Re-evaluation of version 6 was undertaken using the same method of analysis in a cohort of 21 patients using three senior nurses. On initial evaluation inter-rater reliability testing showed an excellent level of association in total composite score between each pair of nurses (rho = 0.73-0.92, p <0.01) and agreement +1 level for individual items ranged from 73 to 100%. Significant disagreements were in six items. On re-evaluation following minor modification, high levels of association were still seen for total BCN, SNN and composite scores both between and within raters, with very satisfactory levels of agreement for individual items. The BCN section of the NPDS showed good inverse correlation with Barthel scores (rho = 0.91, p <0.01). The NPDS is simple and practical to use in a busy setting. It is shown to be reliable and valid in its assessment of nursing dependency on the ward. Its translation into a directly costable measure of continuing care needs in the community now requires evaluation.

Marker Selection for the Transmission/Disequilibrium Test, in Recently Admixed Populations

Recent admixture between genetically differentiated populations can result in high levels of association between alleles at loci that are <=10 cM apart. The transmission/disequilibrium test (TDT) proposed by Spielman et al. (1993) can be a powerful test of linkage between disease and marker loci in the presence of association and therefore could be a useful test of linkage in admixed populations. The degree of association between alleles at two loci depends on the differences in allele frequencies, at the two loci, in the founding populations; therefore, the choice of marker is important. For a multiallelic marker, one strategy that may improve the power of the TDT is to group marker alleles within a locus, on the basis of information about the founding populations and the admixed population, thereby collapsing the marker into one with fewer alleles. We have examined the consequences of collapsing a microsatellite into a two-allele marker, when two founding populations are assumed for the admixed population, and have found that if there is random mating in the admixed population, then typically there is a collapsing for which the power of the TDT is greater than that for the original microsatellite marker. A method is presented for finding the optimal collapsing that has minimal dependence on the disease and that uses estimates either of marker allele frequencies in the two founding populations or of marker allele frequencies in the current, admixed population and in one of the founding populations. Furthermore, this optimal collapsing is not always the collapsing with the largest difference in allele frequencies in the founding populations. To demonstrate this strategy, we considered a recent data set, published previously, that provides frequency estimates for 30 microsatellites in 13 populations.

Alcoholism in social classes and occupations in Sweden.

A number of studies have shown variations in the occurrence of alcoholism between different socioeconomic groups and occupations, but it has not been clear to what extent this is related to the average alcohol consumption in the same socioeconomic groups or occupations. The relationship between socioeconomic group and occupation and hospital discharge 1981-1983 due to 'diagnoses related to alcoholism' (AD) (alcohol psychosis, alcoholism, and alcohol intoxication) and liver cirrhosis was studied in a cohort of 375,035 men and 140,139 women in 13 counties in Sweden who had reported the same occupation in the censuses of 1960 and 1970. Data on alcohol consumption in different socioeconomic groups and occupations were collected from a conscription investigation and from the Swedish twin registry with data from 1969/70 and 1973 respectively. Intermediate or higher non-manual employees had lower risk of AD as well as of liver cirrhosis compared to manual workers for both sexes. Among males several, mostly blue-collar, occupations had increased relative risks of AD. A high level of association was found between the relative risks of AD and liver cirrhosis in socioeconomic groups, and the relative risk of AD in occupations, and the average alcohol consumption in the same socioeconomic groups/occupations among males. Such an association was not evident among women. The study shows, contrary to previous Swedish evidence, that there is a strong relationship between the incidence of alcoholism in socioeconomic groups and occupations and the average alcohol consumption in these groups among men.

Alexithymia, immunity and cervical intraepithelial neoplasia: replication.

In a previous study [Psychother Psychosom 1994;61:199-204] we investigated the relationship between alexithymia, carcinogenesis and immunity in a group of women who were unconscious sufferers from precancerous lesions of the cervix (CIN). The results of this study showed a high level of association between alexithymia and CIN and, an even more interesting fact, between alexithymia and reduced levels of immunity. The aim of the present study is to check the results of the previous one by testing a larger group (43 women affected by cervical dysplasia and 67 healthy women) and by the use of a self-administered test for detection of alexithymia, the well-validated Twenty-Item Toronto Alexithymia Scale (TAS-20). The results confirm that women suffering from CIN have higher average TAS-20 ratings (55) than normal women (47.32) and that the level of alexithymia detected in the group of women suffering from dysplasia (42.5%) is higher than that of normal women (12.85%). Moreover, the present study confirms that alexithymic women have lower rates of a number of lymphocyte subsets than non-alexithymic women. This study fully confirms the results of our previous work and those of a number of other studies: (1) personality might be one of the factors jointly responsible for the outbreak of cancer; (2) the immune system appears to play an important part as a mediator between personality and cancer.

Turn-taking in mother-adolescent conversations about sexuality and conflict

The current study examined the nature and style of mother-adolescent conversations, how these conversations differ by subject matter, and dyadic and individual differences. Thirty-one mother-adolescent dyads (17 boys, 14 girls) with a child between the ages of 11 and 14 had a nonstructured conversation, and conversations about conflict and sexuality. They also completed questionnaires on beliefs about acquired immunodeficiency syndrome (AIDS). Conversations were measured for turn taking, total number of words, and conversational dominance, as well as nonverbal measures of affiliation, shame, and contempt. Conversations about sexuality involved less turn taking, fewer words, and more mother dominance than nonstructured conversations. Conversations about conflicts involved less turn taking but more words than nonstructured conversations. Some gender and age differences were found. More interactive conflict conversations contained higher levels of affiliation, and lower levels of child shame than conversations with fewer turns or higher mother dominance. In addition, children in more interactive dyads possessed a larger percentage of their mother's AIDS knowledge, and worried about AIDS a moderate amount.