RESUMEN
It is structurally pertinent to understudy the important roles the self-compacting concrete (SCC) yield stress and plastic viscosity play in maintaining the rheological state of the concrete to flow. It is also important to understand that different concrete mixes with varying proportions of fine to coarse aggregate ratio and their nominal sizes produce different and corresponding flow- and fill-abilities, which are functions of the yield stress/plastic viscosity state conditions of the studied concrete. These factors have necessitated the development of regression models, which propose optimal rheological state behavior of SCC to ensure a more sustainable concreting. In this research paper on forecasting the rheological state properties of self-compacting concrete (SCC) mixes by using the response surface methodology (RSM) technique, the influence of nominal sizes of the coarse aggregate has been studied in the concrete mixes, which produced experimental mix entries. A total of eighty-four (84) concrete mixes were collected, sorted and split into training and validation sets to model the plastic viscosity and the yield stress of the SCC. In the field applications, the influence of the sampling sizes on the rheological properties of the concrete cannot be overstretched due to the importance of flow consistency in SCC in order to achieve effective workability. The RSM is a symbolic regression analysis which has proven to exercise the capacity to propose highly performable engineering relationships. At the end of the model exercise, it was found that the RSM proposed a closed-form parametric relationship between the outputs (plastic viscosity and yield stress) and the studied independent variables (the concrete components). This expression can be applied in the design and production of SCC with performance accuracies of above 95% and 90%, respectively. Also, the RSM produced graphical prediction of the plastic viscosity and yield stress at the optimized state conditions with respect to the measured variables, which could be useful in monitoring the performance of the concrete in practice and its overtime assessment. Generally, the production of SCC for field applications are justified by the components in this study and experimental entries beyond which the parametric relations and their accuracies are to be reverified.
Asunto(s)
Materiales de Construcción , Reología , Reología/métodos , Materiales de Construcción/análisis , Viscosidad , Ensayo de Materiales/métodos , Predicción/métodosRESUMEN
The purpose of this study was to characterize aerobic, anaerobic, handgrip strength, and body fat content (BF) characteristics in paralympic rowers (ROW) in order to determine motor disabled rowers' fitness level and if specific motor disabilities could impair performance in this specific population. Upper body anaerobic threshold (LacT), peak (PK-AnP), mean (M-AnP), and lower (L-AnP) anaerobic power, peak anaerobic power to weight ratio (RelPk-AnP) and fatigue index (FI) were measured by the Wingate test (WinT). Handgrip strength was also measured and skinfold sum was used to estimate BF and were compared with a reference group of recreational disabled athletes (CON). LacT was significantly higher (p < 0.01) in ROW compared with CON. RelPk-AnP and BF were significantly different (p < 0.05) in ROW compared with CON as well. All other measured parameters did not significantly differ between ROW and CON. In most of cases, rowers have shown a relative low performance level, induced probably by specific disabilities.
Asunto(s)
Personas con Discapacidad , Trastornos de la Destreza Motora/fisiopatología , Resistencia Física/fisiología , Deportes/fisiología , Tejido Adiposo/fisiología , Adulto , Umbral Anaerobio/fisiología , Antropometría/métodos , Prueba de Esfuerzo/métodos , Fuerza de la Mano/fisiología , Humanos , Masculino , Persona de Mediana Edad , Trastornos de la Destreza Motora/patología , Fatiga Muscular/fisiologíaRESUMEN
BACKGROUND: An epidemiology unit was established in Aruba in 1994. The primary focus was the development of an infrastructure for both surveillance and health information data systems. This effort resulted in the first analysis of available skin cancer data. METHODS: A retrospective study of cancer and particularly skin cancer cases at the local histopathology laboratory for the period 1980-1995 was performed. All available records with a cancer diagnosis were evaluated. RESULTS: During the study period, an increase in age-adjusted rates for both men and women was observed for basal cell carcinomas and squamous cell carcinomas. No temporal trend was discerned for malignant melanoma or other skin cancers because the numbers of cases were small. Lesions were most often seen on the nose, face, and arm. Dermatologists provided the majority of skin cancer diagnoses and demonstrated the greatest diagnostic accuracy. CONCLUSIONS: The presence of a central histopathology laboratory may provide small island states, like Aruba, with important public health data. This first description of Aruba's skin cancer epidemiology provides information that may be utilized for future public health action.
Asunto(s)
Neoplasias Cutáneas/epidemiología , Adulto , Factores de Edad , Carcinoma Basocelular/epidemiología , Carcinoma de Células Escamosas/epidemiología , Femenino , Humanos , Masculino , Melanoma/epidemiología , Persona de Mediana Edad , Indias Occidentales/epidemiologíaRESUMEN
This study presents and analyzes positional data on 18 helminth species forming the intestinal infracommunities of 59 Cichlasoma synspilum from southeastern Mexico. Interspecific interactions were found between 4 pairs of host specialists: Crassicutis cichlasomae (Digenea) with Neoechinorhynchus golvani (Acanthocephala), Spirocamallanus rebecae (Nematoda) with N. golvani, and Raillietnema kritscheri (Nematoda) with N. golvani. The interactions were expressed as negative correlations, positional shifts, and reductions in realized distribution. It is suggested that N. golvani produces unsuitable habitats for C. cichlasomae, S. rebecae, and R. kristscheri. All interactions were found among phylogenetically unrelated helminth specialists of cichlids.
Asunto(s)
Enfermedades de los Peces/parasitología , Helmintiasis Animal/parasitología , Helmintos/fisiología , Parasitosis Intestinales/veterinaria , Intestinos/parasitología , Percas/parasitología , Animales , Helmintos/clasificación , Parasitosis Intestinales/parasitologíaRESUMEN
A recombinant plasmid, pAD101, containing a DNA fragment of Acetobacter diazotrophicus strain PAL5 was isolated by its ability to restore Nif+ phenotype to a nifA- ntrC- double mutant of Azotobacter vinelandii. Hybridization with the nifA genes of Azospirillum brasilense located the nifA gene more precisely to specific fragments of pAD101. DNA sequencing of appropriate subclones of pAD101 revealed that the nifA gene was adjacent to the nifB gene in A. diazotrophicus, and the 5' end of the nifB gene was located downstream of the nitrogenase MoFe subunit gene, nifK. The deduced aminoacid sequence of A. diazotrophicus nifA and nifB gene were most similar to the NifA and NifB proteins of Azorhizobium caulinodans and Rhodobacter capsulatus, respectively. In addition, nucleotide sequences upstream of the A. diazotrophicus nifA-encoding region indicate features similar to those in the A. caulinodans nifA promoter region involved in O2 and fixed N regulation of nifA expression.
Asunto(s)
Acetobacter/genética , Genes Bacterianos , Plantas/microbiología , Secuencia de Bases , ADN Bacteriano/análisis , Datos de Secuencia Molecular , Fijación del Nitrógeno/genética , Hibridación de Ácido Nucleico , Análisis de Secuencia de ADNRESUMEN
A recombinant plasmid, pAD101, containing a DNA fragment of Acetobacter diazotrophicus strain PAL5 was isolated by its ability to restore Nif+ phenotype to a nifA- ntrC- double mutant of Azotobacter vinelandii. Hybridization with the nifA genes of Azospirillum brasilense located the nifA gene more precisely to specific fragments of pAD101. DNA sequencing of appropriate subclones of pAD101 revealed that the nifA gene was adjacent to the nifB gene in A. diazotrophicus, and the 5' end of the nifB gene was located downstream of the nitrogenase MoFe subunit gene, nifK. The deduced aminoacid sequence of A. diazotrophicus nifA and nifB gene were most similar to the NifA and NifB proteins of Azorhizobium caulinodans and Rhodobacter capsulatus, respectively. In addition, nucleotide sequences upstream of the A. diazotrophicus nifA-encoding region indicate features similar to those in the A. caulinodans nifA promoter region involved in O2 and fixed N regulation of nifA expression.
Asunto(s)
Acetobacter , Fijación del Nitrógeno , Plantas , Secuencia de Bases , ADN Bacteriano , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Análisis de Secuencia de ADNRESUMEN
The purpose of this study was to examine the influence of self-care education on illness behaviors and health locus of control of Mexican American women. Participants were randomly assigned to a control (n = 60) or experimental group (n = 60). Subjects completed the Multidimensional Health Locus of Control questionnaire and an Illness Behavior Assessment at pretest and 6-months. The experimental group received a self-care manual and participated in two 2-hour seminars on how to effectively use the textbook. The experimental group demonstrated a significant increase in self-care behaviors, and significant changes in Internal Health Locus of Control and Powerful Others Health Locus of Control. Chance Health Locus of Control was found to have a low, direct correlation with age, and a low, indirect correlation with education. The conclusion of this investigation is that self-care education can positively influence illness behaviors and Health Locus of Control in Mexican American women.
Asunto(s)
Conductas Relacionadas con la Salud , Educación en Salud , Americanos Mexicanos , Autocuidado , Salud de la Mujer , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Femenino , Humanos , Control Interno-Externo , Manuales como Asunto , México/etnología , Persona de Mediana Edad , Factores Socioeconómicos , Estados UnidosRESUMEN
Metazoan parasite communities of Crassostrea gigas and Ostrea edulis from Great Britain, Crassostrea virginica from Mexico, and Saccostrea commercialis from Australia are described and summarized in terms of species composition, species richness, total number of individuals and dominance. Metazoan parasite communities in all host species were composed of turbellarians and the metacercarial stage of digeneans, with the exception of S. commercialis where only metacercariae were found. Arthropods, including one copepod and one mite species, were present only in British oyster species. All metazoan parasite communities of oysters had few species and low density of individuals. Richest communities were found in C. virginica at both component and infracommunity level. The least diverse component community occurred in S. commercialis. Infracommunities in O. edulis and S. commercialis never exceeded one species per host. The host response against parasites is suggested as the principal factor responsible for depauperate parasite communities of oysters. Environmental factors characteristic of tropical latitudes are likely to have enhanced both the number of species and the densities of parasites per host in the infracommunities of C. virginica.
Asunto(s)
Helmintos/aislamiento & purificación , Ostreidae/parasitología , Animales , Artrópodos , Australia , México , Turbelarios/aislamiento & purificación , Reino UnidoRESUMEN
BACKGROUND: This experimental study was designed to examine the attitude changes and exercise adherence of a group of sedentary minority women. METHOD: Fifty sedentary Mexican American women participated in a 9-month, biweekly education and exercise program that was preceded by a 6-month program initiation composed of weekly interactions to facilitate trust between participants and researchers. RESULTS: Compared to Mexican American and Caucasian control groups, the experimental participants displayed significant changes in scores on the Exercise Benefits and Barriers Scales (EBBS) at three, six, and nine months. Adherence to the physical activity program was 84%. At pre-test, the Mexican American participants and controls displayed significantly lower EBBS scores than the Caucasian controls. CONCLUSIONS: The results of this study are examined in light of existing reports on the facilitation of attitudes toward exercise, exercise adherence and health promotion particularly in regard to understanding the barriers to physical activity for minorities. The findings of this study are particularly important given the paucity of research about health promotion for individuals who belong to minority groups.
RESUMEN
Pomphorhynchus patagonicus n. sp. is described from Lake Rosario, Chubut Province, Argentina. It is characterized by a long neck forming an asymmetrical bulb with 2 well differentiated dorsal protruberances and 14 alternating rows of 13 and 14 proboscis hooks, each row with a stout fourth hook. It most closely resembles Pomphorhynchus sebastichthydis Yamaguti, 1939, from Japan, but differs in the bulb protruberances and in having more rows of hooks and more hooks per row and in the shapes of the fourth and basal hooks. Among American species P. patagonicus shows some similarities to Pomphorhynchus yamagutii Schmidt and Hugghins, 1973, from Chile, but differs with respect to the longer neck, bulb protruberances, and proboscis armature. Pomphorhynchus patagonicus is endemic to Patagonia, where its definitive type host is the endemic fish Patagonina hatcheri (Atherinidae) and its intermediate host the endemic freshwater amphipod Hyalella patagonica. It has been found also in autochthonous fishes belonging to the families Galaxiidae and Percichthyidae and in introduced salmonid fishes.
Asunto(s)
Acantocéfalos/clasificación , Enfermedades de los Peces/parasitología , Agua Dulce , Helmintiasis Animal , Acantocéfalos/anatomía & histología , Animales , Argentina , Femenino , Peces , Helmintiasis/parasitología , MasculinoAsunto(s)
Brucelosis/diagnóstico , Adulto , Diagnóstico Diferencial , Femenino , Fiebre , Hepatomegalia , Hispánicos o Latinos , Humanos , México/etnología , Pancitopenia , EsplenomegaliaRESUMEN
Paterson demonstrates that drugs homoeopathic to a patient can induce a mutation of E Coli to non lactose fermenters associated with clinical relief, after a latent period of 10 to 14 days. This change may last from a few days to many months. He was the first to provide experimental evidence of the effectiveness of the homoeopathic remedies. (An altered diet may change the flora, but this is only for the duration of the diet.) a definite relationship was demonstrated between homoepathic remedies, non-lactose fermenting organisms and clinical syndrome. It is ironic that this clinico-pathological hypothesis, which is now being confirmed, has been so neglected by his homoeopathic colleagues. I have attempted to show that so far it provides the only rational grounds for the management of our present-day difficult clinical problems. It is time that homoeopathic physicians and bacteriologists combined to review his work. May I remind you that to date homoeopathy provides the sole solution to the two pharmacological barriers to the cure of patients - toxic side effects and tolerance?
Asunto(s)
Humanos , Bacillus Bach-Paterson/uso terapéutico , Bacillus Morgan Puro/normas , Bacillus Morgan Puro/uso terapéutico , Bacillus sycoccus/normas , Bacillus sycoccus/uso terapéutico , Bacillus Gaertner/normas , Bacillus Gaertner/uso terapéutico , Bacillus proteus/normas , Bacillus proteus/uso terapéutico , Bacillinum 7/normas , Bacillinum 7/uso terapéutico , Dysentery-Co/normas , Dysentery-Co/uso terapéutico , Bacillus Bach-Paterson/historia , Bacillus Bach-Paterson/normas , Heces/microbiología , Escherichia coliRESUMEN
By definition, homoeopathy is neither alternative nor complementary - terms which are associated with lay practitioners. It plays a part in the treatment of all patients, whether suffering from minor or serious illnesses, and underlines the necessity for full medical qualifications. There is every justification for the use of the terms "homoeopathic medicine" and "homoeopathioc physician" as instituted by Dr Geoffrey Martin in Liverpool. The "homoeopathic principle" is basic to the practice of homoeopathy, but there is an urgent need for physicians with the help of pharmacologists to review and extend properly controlled provings. Hahnemann in his Organon gives a simple explanation of how these drugs act. His explanation remains valid and logical today. There is ample scope for pharmacologists and physiologists to investigate in greater detail this revolutionary reactive approach which avoids toxic side effects. If the "quantum theory" of energy proves correct, the mystery of potentization is resolved. It would also explain why certain potencies are more effective than others. Physiologists and pharmacologists would be encouraged to investigate trituration and the lower potencies, as a help to solve their problems of drug bio-availability. I hope I have demonstrated that homoeopathy is a rational approach to the treatment of the sick, using naturally occurring laws. The spiritual approach hs no more reference to homoeopathy than to any other field of treatment and tends to distract attention from the specific homoeopathic approach