4,049 research outputs found
An Angiosperm species dataset reveals relationships between seed size and two-dimensional shape
Datasets containing information on seed size have been published and are currently available. Nevertheless, there is a lack in the literature of a dataset dedicated to seed shape. We present a preliminary version for a dataset on seed morphology based on a comparison of seed shape with geometric figures. Similarity of the outline of seed images with geometric models is considered as a basis to classify seeds according to the geometric figures they resemble (e.g., ellipse, oval, cardioid). This allows, first, the classification of plant species according to their geometric type of seed, and second, seed shape quantification. For each seed image, the percent of similarity of their outline with a geometric figure can be calculated as a J index. Similarity in absolute terms is considered only when the J index >90. This criterion is important to avoid ambiguity and increase discrimination. The dataset opens the possibility of studying the relationship between seed shape and other variables such as seed size, genome complexity, life form or adaptive responses
Compositional analysis of the association between mortality and 24-hour movement behaviour from NHANES
Aims:Previous prospective studies of the association between mortality and physical activity have generally not fully accounted for the interplay between movement behaviours. A compositional data modelling approach accounts for relative scale and co-dependency in time-use data across physical activity behaviours of the 24-hour day.
Methods:A prospective analysis of the National Health and Nutrition Examination Survey 2005-2006 on N = 1468 adults (d = 135 deaths) in ages 50-79 years was undertaken using compositional Cox regression analysis. Daily time spent in sedentary behaviour, light intensity (LIPA) and moderate-to-vigorous physical activity (MVPA) was determined from waist-mounted accelerometer data (Actigraph 7164) and supplemented with self-reported sleep data to determine the daily time-use composition.
Results:The composition of time spent in sedentary behaviour, LIPA, MVPA and sleep was associated with mortality rate after allowing for age and sex effects (p < 0.001), and remained significant when other lifestyle factors were added (p < 0.001). This was driven primarily by the preponderance of MVPA; however, significant changes are attributable to LIPA relative to sedentary behaviour and sleep, and sedentary behaviour relative to sleep. The final ratio ceased to be statistically significant after incorporating lifestyle factors. The preponderance of MVPA ceased to be statistically significant after incorporating health at outset and physical limitations on movement.
Conclusions: An association is inferred between survival rate and the physical activity composition of the day. The MVPA time share is important, but time spent in LIPA relative to sedentary behaviour and sleep is also a significant factor. Increased preponderance of MVPA may have detrimental associations at higher levels of MVPA
Test-retest reliability and minimal detectable change scores for fitness assessment in older adults with type 2 diabetes
Click on the DOI link to access the article (may not be free).Purpose: To assess the intraclass correlation coefficients (ICCs) and to determine the minimal detectable change (MDC95) scores of the data for the Hand Grip Strength Test, the Chair Sit and Reach Test (CSRT), the Timed "Up and Go" (TUG) test, the 6-Minute Walk Test (6MWT) and 30 seconds Sit to Stand Test (30s-STS) test in older adults with type 2 NIDDM.
Design: Test-retest reliability.
Methods: Eighteen subject participated in two sessions (1 week apart), which included the different tests.
Findings: High ICCs (>= 0.92) were found for all tests. The MDC95 scores were as follows: 4.0 kg for Hand Grip Strength Tests, 7.5 cm for the right leg-CSRT, 9.0 cm for the left leg-CSRT, 1.0 second for the TUG test, 27 m for the 6MWT, and 3.3 repetitions for the 30s-STS test.
Conclusions: All tests evaluated are reliable outcome measures for type 2 NID-DM patients. Clinical relevance: This study has generated novel MCD95 data, which will assist nursing practitioners in both prescribing the most beneficial exercise and interpreting posttreatment changes after rehabilitation in patients with T2DM
Factors Associated with the Risk of Falls of Nursing Home Residents Aged 80 or Older
Background: Falls are the leading cause of mortality and morbidity in older and represents
one of the major and most costly public health problems worldwide. Purpose: Evaluate the
influences of lower limb muscle performance, static balance, functional independence and
quality of life on fall risk as assessed with the Timed Up and Go test. Design: Crosssectional.
Methods: Fifty-two residents aged 80 or older were assessed and distributed in one
of the two study groups according to the time to complete the Timed Up and Go Test. A
Kistler force platform and linear transducer was used to determinate lower limb muscle
performance. Postural Stability was measured by recording the center of pressure. The
EuroQol-5 dimension was used to assess Health-Related Quality of Life and the Barthel Index
was used to examine functional status. Student t-test was performed to evaluate the
differences between groups. Correlations between variables were analyzed using Spearman or
Pearson coefficient. ROC analysis was used to determine the cut-off points related to a
decrease in the risk of a fall. Findings: Participants of no-fall risk group showed better lower
limb performance, quality of life, and functional status. Cut-off points were determined for
each outcome. Conclusions: Risk of falls in nursing home residents over the age of 80 is
associated with lower limb muscle performance, functional status and quality of Life.
Clinical Relevance: Cut-off points can be used by clinicians when working toward fall
prevention and could help in determining the optimal lower limb muscle performance level
for preventing falls
Biological Fixation of N2 in Mono and Polyspecific Legume Pasture in the Humid Mediterranean Zone of Chile
del Pozo, A (del Pozo, Alejandro). Univ Talca, Fac Ciencias Agr, Talca, ChileDespite annual legume pasture are of great importance for dryland agricultural systems in Mediterranean environments, there are few studies of N-2 biological fixation (NBF) reported in Chile. In this study the NBF of four annual legume species: subterranean clover (Trifolium subterraneum L.), yellow serradella (Ornithopus compressus L.), arrow-leaf clover (T. vesiculosum L.), and crimson clover (T. incarnatum L.) (Experiment 1), as well as seven mixtures of these species (Experiment 2) were assessed. The NBF was measured by the N-15 natural abundance technique. The objective was to determine NBF in the legume species and in distinct mixtures used. The study was carried out in an Andisol of the Andean Precordillera located in the humid Mediterranean zone of Chile. Pasture was evaluated for biomass; and total N and natural abundance of N-15 were analyzed in plant material samples. In Experiment 1 (monospecific legume species pasture), N derived from fixation ranged between 43 and 147 kg N ha(-1) and where T. vesiculosum and T. subterraneum presented statistical differences (P <= 0.05) in connection with the other species. In the legume mixtures (Experiment 2), N derived by fixation varied between 97 and 214 kg N ha(-1) where the 50-50 mixtures (T. subterraneum and O. compressus, or T. subterraneum and T. vesiculosum, respectively) had the highest N fixation. Fixed N ranged between 12 and 25 kg N t(-1) DM, showing significant differences among mono and polyspecific legume species
Pharmacology and Therapeutic Potential of Sigma1 Receptor Ligands
Sigma (σ) receptors, initially described as a subtype of opioid receptors, are now considered unique receptors. Pharmacological studies have distinguished two types of σ receptors, termed σ1 and σ2. Of these two subtypes, the σ1 receptor has been cloned in humans and rodents, and its amino acid sequence shows no homology with other mammalian proteins. Several psychoactive drugs show high to moderate affinity for σ1 receptors, including the antipsychotic haloperidol, the antidepressant drugs fluvoxamine and sertraline, and the psychostimulants cocaine and methamphetamine; in addition, the anticonvulsant drug phenytoin allosterically modulates σ1 receptors. Certain neurosteroids are known to interact with σ1 receptors, and have been proposed to be their endogenous ligands. These receptors are located in the plasma membrane and in subcellular membranes, particularly in the endoplasmic reticulum, where they play a modulatory role in intracellular Ca2+ signaling. Sigma1 receptors also play a modulatory role in the activity of some ion channels and in several neurotransmitter systems, mainly in glutamatergic neurotransmission. In accordance with their widespread modulatory role, σ1 receptor ligands have been proposed to be useful in several therapeutic fields such as amnesic and cognitive deficits, depression and anxiety, schizophrenia, analgesia, and against some effects of drugs of abuse (such as cocaine and methamphetamine). In this review we provide an overview of the present knowledge of σ1 receptors, focussing on σ1 ligand neuropharmacology and the role of σ1 receptors in behavioral animal studies, which have contributed greatly to the potential therapeutic applications of σ1 ligands
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