7,053 research outputs found
Forage Quality of Cereal–Common Vetch at Different Age and Proportions
Cereal plant age at harvesting and the proportion of vetch in the harvested forage from cereal-common vetch mixtures might influence total forage quality. The objectives were to determine forage of a forage mixture cereal-vetch, from cereal harvested at two development stages and vetch at different proportion. Cereals were oats and triticale, cultivars: Chihuahua, Bicentenario and Siglo XXI, the last two were triticale; cereal development stages at harvest were: 50% flowering and hard grain. Vetch was harvested at two development stages: 100% flowering and pod formation, while vetch proportions in the forage mix were: 0, 0.25, 0.5, 0.75 and 1.0. Forage quality measures were: crude protein (CP), neutral detergent fiber (NDF), organic matter (OM), ether extract (EE) and dry matter digestibility (DMD). Statistical analysis was by linear regression; cereal cultivar was a categorical variable. Models developed showed a R2≥0.7871. As vetch proportion increased in the mix so did CP while NDF decreased, CP increased from 9.2 to 17.5% and 9.2 to 14.4% and NDF decreased from 71.4 to 57.6% and 79.1 to 58.9%, as vetch proportion increased, when cereal was harvested at 50% flowering and grain hard, respectively. OM and EE showed small changes over vetch proportion and cereal development stage. DMD showed major (p\u3c 0.05) changes with cereal development stage at harvesting. It was concluded that forage quality of cereal-vetch mix depends on vetch proportion and stage of development of the cereal at the time of harvest
Cosmological perturbations: a new gauge-invariant approach
A new gauge-invariant approach for describing cosmological perturbations is
developed. It is based on a physically motivated splitting of the stress-energy
tensor of the perturbation into two parts - the bare perturbation and the
complementary perturbation associated with stresses in the background
gravitational field induced by the introduction of the bare perturbation. The
complementary perturbation of the stress-energy tensor is explicitly singled
out and taken to the left side of the perturbed Einstein equations so that the
bare stress-energy tensor is the sole source for the perturbation of the metric
tensor and both sides of these equations are gauge invariant with respect to
infinitesimal coordinate transformations. For simplicity we analyze the
perturbations of the spatially-flat Friedmann-Lemaitre-Robertson-Walker dust
model. A cosmological gauge can be chosen such that the equations for the
perturbations of the metric tensor are completely decoupled for the h_{00},
h_{0i}, and h_{ij} metric components and explicitly solvable in terms of
retarded integrals.Comment: 10 pages, corrected proofs, published in PL
The Malagarasi River Does Not Form an Absolute Barrier to Chimpanzee Movement in Western Tanzania
The Malagarasi River has long been thought to be a barrier to chimpanzee movements in western Tanzania. This potential geographic boundary could affect chimpanzee ranging behavior, population connectivity and pathogen transmission, and thus has implications for conservation strategies and government policy. Indeed, based on mitochondrial DNA sequence comparisons it was recently argued that chimpanzees from communities to the north and to the south of the Malagarasi are surprisingly distantly related, suggesting that the river prevents gene flow. To investigate this, we conducted a survey along the Malagarasi River. We found a ford comprised of rocks that researchers could cross on foot. On a trail leading to this ford, we collected 13 fresh fecal samples containing chimpanzee DNA, two of which tested positive for SIVcpz. We also found chimpanzee feces within the riverbed. Taken together, this evidence suggests that the Malagarasi River is not an absolute barrier to chimpanzee movements and communities from the areas to the north and south should be considered a single population. These results have important consequences for our understanding of gene flow, disease dynamics and conservation management
Risk factors for delay in symptomatic presentation: a survey of cancer patients
Background: Delay in symptomatic presentation leading to advanced stage at diagnosis may contribute to poor cancer survival. To inform public health approaches to promoting early symptomatic presentation, we aimed to identify risk factors for delay in presentation across several cancers.
Methods: We surveyed 2371 patients with 15 cancers about nature and duration of symptoms using a postal questionnaire. We calculated relative risks for delay in presentation (time from symptom onset to first presentation >3 months) by cancer, symptoms leading to diagnosis and reasons for putting off going to the doctor, controlling for age, sex and deprivation group.
Results: Among 1999 cancer patients reporting symptoms, 21% delayed presentation for >3 months. Delay was associated with greater socioeconomic deprivation but not age or sex. Patients with prostate (44%) and rectal cancer (37%) were most likely to delay and patients with breast cancer least likely to delay (8%). Urinary difficulties, change of bowel habit, systemic symptoms (fatigue, weight loss and loss of appetite) and skin symptoms were all common and associated with delay. Overall, patients with bleeding symptoms were no more likely to delay presentation than patients who did not have bleeding symptoms. However, within the group of patients with bleeding symptoms, there were significant differences in risk of delay by source of bleeding: 35% of patients with rectal bleeding delayed presentation, but only 9% of patients with urinary bleeding. A lump was a common symptom but not associated with delay in presentation. Twenty-eight percent had not recognised their symptoms as serious and this was associated with a doubling in risk of delay. Embarrassment, worry about what the doctor might find, being too busy to go to the doctor and worry about wasting the doctor’s time were also strong risk factors for delay, but were much less commonly reported (<6%).
Interpretation: Approaches to promote early presentation should aim to increase awareness of the significance of cancer symptoms and should be designed to work for people of the lowest socioeconomic status. In particular, awareness that rectal bleeding is a possible symptom of cancer should be raised
Risk factors for delayed presentation and referral of symptomatic cancer: Evidence for common cancers
Background:It has been suggested that the known poorer survival from cancer in the United Kingdom, compared with other European countries, can be attributed to more advanced cancer stage at presentation. There is, therefore, a need to understand the diagnostic process, and to ascertain the risk factors for increased time to presentation.Methods:We report the results from two worldwide systematic reviews of the literature on patient-mediated and practitioner-mediated delays, identifying the factors that may influence these.Results:Across cancer sites, non-recognition of symptom seriousness is the main patient-mediated factor resulting in increased time to presentation. There is strong evidence of an association between older age and patient delay for breast cancer, between lower socio-economic status and delay for upper gastrointestinal and urological cancers and between lower education level and delay for breast and colorectal cancers. Fear of cancer is a contributor to delayed presentation, while sanctioning of help seeking by others can be a powerful mediator of reduced time to presentation. For practitioner delay, ‘misdiagnosis’ occurring either through treating patients symptomatically or relating symptoms to a health problem other than cancer, was an important theme across cancer sites. For some cancers, this could also be linked to inadequate patient examination, use of inappropriate tests or failing to follow-up negative or inconclusive test results.Conclusion:Having sought help for potential cancer symptoms, it is therefore important that practitioners recognise these symptoms, and examine, investigate and refer appropriately. © 2009 Cancer Research UK All rights reserved
Ultrastructural and functional fate of recycled vesicles in hippocampal synapses
Efficient recycling of synaptic vesicles is thought to be critical for sustained information transfer at central terminals. However, the specific contribution that retrieved vesicles make to future transmission events remains unclear. Here we exploit fluorescence and time-stamped electron microscopy to track the functional and positional fate of vesicles endocytosed after readily releasable pool (RRP) stimulation in rat hippocampal synapses. We show that most vesicles are recovered near the active zone but subsequently take up random positions in the cluster, without preferential bias for future use. These vesicles non-selectively queue, advancing towards the release site with further stimulation in an actin-dependent manner. Nonetheless, the small subset of vesicles retrieved recently in the stimulus train persist nearer the active zone and exhibit more privileged use in the next RRP. Our findings reveal heterogeneity in vesicle fate based on nanoscale position and timing rules, providing new insights into the origins of future pool constitution
Luminescent properties of Bi-doped polycrystalline KAlCl4
We observed an intensive near-infrared luminescence in Bi-doped KAlCl4
polycrystalline material. Luminescence dependence on the excitation wavelength
and temperature of the sample was studied. Our experimental results allow
asserting that the luminescence peaked near 1 um belongs solely to Bi+ ion
which isomorphically substitutes potassium in the crystal. It was also
demonstrated that Bi+ luminescence features strongly depend on the local ion
surroundings
Aplicación Móvil Para Notificar El Control De Medicamentos De Untratamiento Médico
This article presents the development of a mobile application aimed at notifying a patient about the schedules for taking their medical treatment. The intention is for this application to be useful for elderly individuals, caregivers of sick people, as well as anyone who undergoes constant medical treatment. That is why the graphical interface created is intuitive for the user. Upon opening the mobile application, a screen is displayed where, as a first step, the name of the medication is requested. Subsequently, the date and time when the medication will be taken must be entered, and this data is stored and can be viewed at the bottom. The use of this application will facilitate the proper management of a patient's medical treatment.El presente articulo muestra el desarrollo de una aplicación móvil, el cual tiene como objetivo notificar a un paciente sobre los horarios que debe de tomar su tratamiento medico. Se pretende que dicha aplicación sea util para personas de la tercera edad, cuidadores de personas enfermas, asà como tambien cualquier persona que lleve un tratamiento medico constante, es por esto que la interfaz grafica creada es intuitiva para el usuario. Al abrir la aplicación móvil se muestra una pantalla en donde como primera instancia se solicita el nombre del medicamento, posteriormente se tendrá que capturar la fecha y hora que tomará su medicamento, estos datos se almacenan y se podrá visualizar en la parte inferior. El uso de esta aplicación facilitará llevar el tratamiento médico adecuado de un paciente
Hepatoprotective effect of commercial herbal extracts on carbon tetrachloride-induced liver damage in Wistar rats
Background: The antioxidant and anti-inflammatory effects of arbutin protect against a number of diseases. Objectives: The present study evaluated the protective effect of arbutin against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Methods: Sixty-three Wistar rats were divided into nine groups. Groups I and II were the normal control groups. Group III, the hepatotoxic group, was given CCl4. Groups IV, VI, and VIII received different dosages of arbutin along with CCl4. Groups V, VII, and IX were administered different dosages of arbutin. The albumin content, total protein, and bilirubin were assayed to determine their serum and antioxidant levels; lipid peroxidation was assessed in the serum and liver tissue. Histological studies were carried out to confirm the biochemical results. Results: Treatment with CCl4 for 28 d decreased the levels of total protein and albumin and increased the level of bilirubin and lipid peroxidation. Arbutin treatment raised the level of albumin and lowered the lipid peroxidation to normal levels. Necrosis and fibrosis were observed in the liver tissue of CCl4-injected rats, and the administration of arbutin had a protective effect on the liver tissue. Conclusions: The results of this study showed that arbutin may protect the liver against CCl4-induced oxidative damage in rats. This hepatoprotective effect might be correlated with the antioxidant and free radical scavenger effects of arbutin
First report of Rhodnius montenegrensis (Hemiptera: Reduviidae: Triatominae) infection by Trypanosoma rangeli
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