RESUMEN
Catch-and-release (CR) angling has been used to assist management programs seeking to promote the conservation and recovery of some recreational fish stocks by decreasing mortality from fishing. However, without appropriate fish handling, this activity may cause damage and injuries to individual fish, causing mortality. Therefore, CR should be allowed under some circumstances that ensure higher rates of survival to achieve the goals of the conservation measures. Thus, we experimentally tested the CR effects on dourado (Salminus brasiliensis) by comparing caught-and-released fish (CR fish) with uncaught fish (control fish) in a pond and estimating individual mortality rates related to seven air exposure times (AET: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s and 840 s). We also determined a safe limit for fish handling and investigated the length and weight gain variations. We found that an increase in AET affects fish survival and that the limit of handling time for this species was 546 s; after this threshold, the individual probability of death exceeds 5%. The length and weight gain of CR fish did not differ significantly from the control fish. We believe that CR is efficient for S. brasiliensis because it does not significantly impair their organic growth and causes little or no mortality if handling is performed properly; thus, it could be employed to assist conservation programs.(AU)
O pesque e solte (PS) tem sido utilizado para auxiliar programas de manejo que buscam promover a conservação e recuperação de estoques de peixes esportivos, através da redução da mortalidade pela pesca. Entretanto, sem a manipulação adequada dos peixes, essa atividade pode causar injúrias nos indivíduos, causando mortalidade. Dessa maneira, o PS deve ser permitido sob circunstâncias que possam garantir altas taxas de sobrevivência, de modo que as metas das medidas de conservação sejam atingidas. Assim, testamos experimentalmente os efeitos do PS sobre o dourado (Salminus brasiliensis), através da comparação de peixes capturados e liberados (peixes de PS) com peixes não capturados (peixes de controle) em um tanque de cultivo. Estimamos as taxas de mortalidades individuais relacionadas a sete tempos de exposição ao ar (TEA: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s e 840 s). Determinamos um limite seguro para a manipulação do peixe e investigamos as variações no ganho de comprimento e peso. Foi encontrado que o aumento no TEA afetou a sobrevivência do peixe e que o limite de tempo para a manipulação da espécie foi de 546 s; depois desse limite, a probabilidade individual de morte excede 5%. O ganho de comprimento e peso dos peixes de PS não diferiu significativamente dos peixes de controle. Acreditamos que o PS é eficiente para o S. brasiliensis porque não afeta significativamente seu crescimento orgânico e causa pouca ou nenhuma mortalidade se a manipulação for realizada corretamente. Concluímos que a atividade pode ser empregada para auxiliar programas de conservação.(AU)
Asunto(s)
Animales , Explotaciones Pesqueras , Peces , Mortalidad , Tasa de SupervivenciaRESUMEN
Abstract Catch-and-release (CR) angling has been used to assist management programs seeking to promote the conservation and recovery of some recreational fish stocks by decreasing mortality from fishing. However, without appropriate fish handling, this activity may cause damage and injuries to individual fish, causing mortality. Therefore, CR should be allowed under some circumstances that ensure higher rates of survival to achieve the goals of the conservation measures. Thus, we experimentally tested the CR effects on dourado (Salminus brasiliensis) by comparing caught-and-released fish (CR fish) with uncaught fish (control fish) in a pond and estimating individual mortality rates related to seven air exposure times (AET: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s and 840 s). We also determined a safe limit for fish handling and investigated the length and weight gain variations. We found that an increase in AET affects fish survival and that the limit of handling time for this species was 546 s; after this threshold, the individual probability of death exceeds 5%. The length and weight gain of CR fish did not differ significantly from the control fish. We believe that CR is efficient for S. brasiliensis because it does not significantly impair their organic growth and causes little or no mortality if handling is performed properly; thus, it could be employed to assist conservation programs.
Resumo O pesque e solte (PS) tem sido utilizado para auxiliar programas de manejo que buscam promover a conservação e recuperação de estoques de peixes esportivos, através da redução da mortalidade pela pesca. Entretanto, sem a manipulação adequada dos peixes, essa atividade pode causar injúrias nos indivíduos, causando mortalidade. Dessa maneira, o PS deve ser permitido sob circunstâncias que possam garantir altas taxas de sobrevivência, de modo que as metas das medidas de conservação sejam atingidas. Assim, testamos experimentalmente os efeitos do PS sobre o dourado (Salminus brasiliensis), através da comparação de peixes capturados e liberados (peixes de PS) com peixes não capturados (peixes de controle) em um tanque de cultivo. Estimamos as taxas de mortalidades individuais relacionadas a sete tempos de exposição ao ar (TEA: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s e 840 s). Determinamos um limite seguro para a manipulação do peixe e investigamos as variações no ganho de comprimento e peso. Foi encontrado que o aumento no TEA afetou a sobrevivência do peixe e que o limite de tempo para a manipulação da espécie foi de 546 s; depois desse limite, a probabilidade individual de morte excede 5%. O ganho de comprimento e peso dos peixes de PS não diferiu significativamente dos peixes de controle. Acreditamos que o PS é eficiente para o S. brasiliensis porque não afeta significativamente seu crescimento orgânico e causa pouca ou nenhuma mortalidade se a manipulação for realizada corretamente. Concluímos que a atividade pode ser empregada para auxiliar programas de conservação.
Asunto(s)
Animales , Characiformes , Explotaciones Pesqueras , PecesRESUMEN
Catch-and-release (CR) angling has been used to assist management programs seeking to promote the conservation and recovery of some recreational fish stocks by decreasing mortality from fishing. However, without appropriate fish handling, this activity may cause damage and injuries to individual fish, causing mortality. Therefore, CR should be allowed under some circumstances that ensure higher rates of survival to achieve the goals of the conservation measures. Thus, we experimentally tested the CR effects on dourado (Salminus brasiliensis) by comparing caught-and-released fish (CR fish) with uncaught fish (control fish) in a pond and estimating individual mortality rates related to seven air exposure times (AET: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s and 840 s). We also determined a safe limit for fish handling and investigated the length and weight gain variations. We found that an increase in AET affects fish survival and that the limit of handling time for this species was 546 s; after this threshold, the individual probability of death exceeds 5%. The length and weight gain of CR fish did not differ significantly from the control fish. We believe that CR is efficient for S. brasiliensis because it does not significantly impair their organic growth and causes little or no mortality if handling is performed properly; thus, it could be employed to assist conservation programs.
Asunto(s)
Characiformes , Animales , Explotaciones Pesqueras , PecesRESUMEN
Abstract Catch-and-release (CR) angling has been used to assist management programs seeking to promote the conservation and recovery of some recreational fish stocks by decreasing mortality from fishing. However, without appropriate fish handling, this activity may cause damage and injuries to individual fish, causing mortality. Therefore, CR should be allowed under some circumstances that ensure higher rates of survival to achieve the goals of the conservation measures. Thus, we experimentally tested the CR effects on dourado (Salminus brasiliensis) by comparing caught-and-released fish (CR fish) with uncaught fish (control fish) in a pond and estimating individual mortality rates related to seven air exposure times (AET: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s and 840 s). We also determined a safe limit for fish handling and investigated the length and weight gain variations. We found that an increase in AET affects fish survival and that the limit of handling time for this species was 546 s; after this threshold, the individual probability of death exceeds 5%. The length and weight gain of CR fish did not differ significantly from the control fish. We believe that CR is efficient for S. brasiliensis because it does not significantly impair their organic growth and causes little or no mortality if handling is performed properly; thus, it could be employed to assist conservation programs.
Resumo O pesque e solte (PS) tem sido utilizado para auxiliar programas de manejo que buscam promover a conservação e recuperação de estoques de peixes esportivos, através da redução da mortalidade pela pesca. Entretanto, sem a manipulação adequada dos peixes, essa atividade pode causar injúrias nos indivíduos, causando mortalidade. Dessa maneira, o PS deve ser permitido sob circunstâncias que possam garantir altas taxas de sobrevivência, de modo que as metas das medidas de conservação sejam atingidas. Assim, testamos experimentalmente os efeitos do PS sobre o dourado (Salminus brasiliensis), através da comparação de peixes capturados e liberados (peixes de PS) com peixes não capturados (peixes de controle) em um tanque de cultivo. Estimamos as taxas de mortalidades individuais relacionadas a sete tempos de exposição ao ar (TEA: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s e 840 s). Determinamos um limite seguro para a manipulação do peixe e investigamos as variações no ganho de comprimento e peso. Foi encontrado que o aumento no TEA afetou a sobrevivência do peixe e que o limite de tempo para a manipulação da espécie foi de 546 s; depois desse limite, a probabilidade individual de morte excede 5%. O ganho de comprimento e peso dos peixes de PS não diferiu significativamente dos peixes de controle. Acreditamos que o PS é eficiente para o S. brasiliensis porque não afeta significativamente seu crescimento orgânico e causa pouca ou nenhuma mortalidade se a manipulação for realizada corretamente. Concluímos que a atividade pode ser empregada para auxiliar programas de conservação.
RESUMEN
Abstract Catch-and-release (CR) angling has been used to assist management programs seeking to promote the conservation and recovery of some recreational fish stocks by decreasing mortality from fishing. However, without appropriate fish handling, this activity may cause damage and injuries to individual fish, causing mortality. Therefore, CR should be allowed under some circumstances that ensure higher rates of survival to achieve the goals of the conservation measures. Thus, we experimentally tested the CR effects on dourado (Salminus brasiliensis) by comparing caught-and-released fish (CR fish) with uncaught fish (control fish) in a pond and estimating individual mortality rates related to seven air exposure times (AET: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s and 840 s). We also determined a safe limit for fish handling and investigated the length and weight gain variations. We found that an increase in AET affects fish survival and that the limit of handling time for this species was 546 s; after this threshold, the individual probability of death exceeds 5%. The length and weight gain of CR fish did not differ significantly from the control fish. We believe that CR is efficient for S. brasiliensis because it does not significantly impair their organic growth and causes little or no mortality if handling is performed properly; thus, it could be employed to assist conservation programs.
Resumo O pesque e solte (PS) tem sido utilizado para auxiliar programas de manejo que buscam promover a conservação e recuperação de estoques de peixes esportivos, através da redução da mortalidade pela pesca. Entretanto, sem a manipulação adequada dos peixes, essa atividade pode causar injúrias nos indivíduos, causando mortalidade. Dessa maneira, o PS deve ser permitido sob circunstâncias que possam garantir altas taxas de sobrevivência, de modo que as metas das medidas de conservação sejam atingidas. Assim, testamos experimentalmente os efeitos do PS sobre o dourado (Salminus brasiliensis), através da comparação de peixes capturados e liberados (peixes de PS) com peixes não capturados (peixes de controle) em um tanque de cultivo. Estimamos as taxas de mortalidades individuais relacionadas a sete tempos de exposição ao ar (TEA: 120 s, 240 s, 360 s, 480 s, 600 s, 720 s e 840 s). Determinamos um limite seguro para a manipulação do peixe e investigamos as variações no ganho de comprimento e peso. Foi encontrado que o aumento no TEA afetou a sobrevivência do peixe e que o limite de tempo para a manipulação da espécie foi de 546 s; depois desse limite, a probabilidade individual de morte excede 5%. O ganho de comprimento e peso dos peixes de PS não diferiu significativamente dos peixes de controle. Acreditamos que o PS é eficiente para o S. brasiliensis porque não afeta significativamente seu crescimento orgânico e causa pouca ou nenhuma mortalidade se a manipulação for realizada corretamente. Concluímos que a atividade pode ser empregada para auxiliar programas de conservação.
RESUMEN
Changes in diet and eating behavior along with excessive consumption of sugar or fat and a sedentary lifestyle are related to increased obesity and its associated comorbidities. The aim of this study was to investigate the role of the type of macronutrients on specific health benefits associated with the weight loss in treating obesity. A total of 30 obese women (34.89±3.04 kg/m(2) and 43.3±5.34 years) participated in an interdisciplinary therapy approach to lifestyle change, which consisted of nutritional counseling, exercise, and psychological therapy for over a period of 26 weeks. The profile was obtained by anthropometric measurements and body composition by bioelectrical impedance analysis (BIA). Usual food intake was assessed with 3-day food record diaries and blood tests were used to determine metabolic and adipokines parameters. After therapy, there was significant reduction in all anthropometric and body composition variables. Food consumption also decreased while still providing adequate nutrient intake. There was significant improvement in LDL-cholesterol, PAI-1, leptin, CRP, ICAM-1, and VCAM-1. Lower dietary carbohydrate and fat intake led to weight loss. The effect of lower carbohydrate intake on weight loss is related to changes in body composition and leptin levels. Weight loss by reducing fat intake modified the inflammatory process and cardiovascular risk, indicating dietary fat as an independent predictor factor of cell adhesion molecules. Therefore, decreasing dietary fat consumption had greater impact on the inflammatory process on obese individuals. Our results show that the type of macronutrient influences the health benefits associated with weight loss.
Asunto(s)
Grasas de la Dieta/administración & dosificación , Obesidad/sangre , Obesidad/terapia , Adulto , Proteína C-Reactiva/metabolismo , LDL-Colesterol/sangre , Femenino , Humanos , Inflamación , Molécula 1 de Adhesión Intercelular/sangre , Leptina/sangre , Persona de Mediana Edad , Inhibidor 1 de Activador Plasminogénico/sangre , Molécula 1 de Adhesión Celular Vascular/sangreRESUMEN
Hyperleptinemia has emerged as a marker of proinflammatory status, while the adiponectin/leptin ratio has been used to identify anti-inflammatory state. In this context, the aims of the present study were to investigate the role of leptinemia, adjusted by tertiles, on inflammatory state in obese adults according to obesity degree. This is a cross-sectional study comprised of 43 obese adults. The anthropometric variables and body composition were analyzed, as well as markers of inflammation such as leptin, adiponectin, and plasminogen activator inhibitor. Subjects were grouped using adjusted tertiles of the leptin levels. The major finding was the negative correlation between leptin concentration with adiponectin/leptin ratio (r=-0.622, p=0.000) and the positive correlation with leptin/adiponectin ratio (r=0.622, p=0.000). Indeed, both ratios were decreased and increased, respectively, according to the obesity degree. Furthermore, in the stepwise multiple linear regression analysis, the high degree of obesity was an independent predictor of leptinemia when adjusted for age and BMI (ß=0.588, p=0.000 and ß=0.778, p=0.005). Finally, the strong negatively correlation between the leptinemia with adiponectin/leptin ratio and the positive correlation with leptin/adiponectin ratio reinforce the role of this adipokine as a biomarker of inflammation in obese adults, according to obesity degree. Our findings can elucidate that hyperleptinemic status was a major factor in the proinflammatory status related to higher obesity degree. All together, these data reinforce the role of leptinemia state as a mediator of inflammation in obese adults.
Asunto(s)
Mediadores de Inflamación/inmunología , Leptina/inmunología , Obesidad/inmunología , Adulto , Biomarcadores/sangre , Composición Corporal , Índice de Masa Corporal , Estudios Transversales , Femenino , Humanos , Mediadores de Inflamación/sangre , Leptina/sangre , Masculino , Persona de Mediana Edad , Obesidad/sangre , Obesidad/fisiopatología , Adulto JovenRESUMEN
The aim of the present study was to determine whether specific subgroups of schizophrenic patients, grouped according to electrodermal characteristics, show differences in the N-acetylaspartate/creatine plus choline (NAA / (Cr + Cho)) ratios in the frontal, cingulate and perirolandic cortices. Skin conductance levels (SCL) and skin conductance responses to auditory stimulation were measured in 38 patients with schizophrenia and in the same number of matched healthy volunteers (control). All subjects were submitted to multivoxel proton magnetic resonance spectroscopic imaging. When compared to the control group, patients presented significantly lower NAA / (Cr + Cho) ratios in the right dorsolateral prefrontal cortex (schizophrenia = 0.95 ± 0.03; control = 1.12 ± 0.04) and in the right (schizophrenia = 0.88 ± 0.02; control = 0.94 ± 0.03) and left (schizophrenia = 0.84 ± 0.03; control = 0.94 ± 0.03) cingulates. These ratios did not differ between electrodermally responsive and non-responsive patients. When patients were divided into two groups: lower SCL (less than the mean SCL of the control group minus two standard deviations) and normal SCL (similar to the control group), the subgroup with a lower level of SCL showed a lower NAA / (Cr + Cho) ratio in the left cingulate (0.78 ± 0.05) than the controls (0.95 ± 0.02, P < 0.05) and the subgroup with normal SCL (0.88 ± 0.03, P < 0.05). There was a negative correlation between the NAA / (Cr + Cho) ratio in the left cingulate of patients with schizophrenia and the duration of the disease and years under medication. These data suggest the existence of a schizophrenic subgroup characterized by low SCL that could be a consequence of the lower neuronal viability observed in the left cingulate of these patients.
Asunto(s)
Adulto , Femenino , Humanos , Masculino , Ácido Aspártico/análogos & derivados , Corteza Cerebral/química , Colina/análisis , Creatina/análisis , Respuesta Galvánica de la Piel/fisiología , Esquizofrenia/metabolismo , Estimulación Acústica , Ácido Aspártico/análisis , Estudios de Casos y Controles , Espectroscopía de Resonancia Magnética/métodos , Protones , Factores Socioeconómicos , Esquizofrenia/fisiopatologíaRESUMEN
The aim of the present study was to determine whether specific subgroups of schizophrenic patients, grouped according to electrodermal characteristics, show differences in the N-acetylaspartate/creatine plus choline (NAA / (Cr + Cho)) ratios in the frontal, cingulate and perirolandic cortices. Skin conductance levels (SCL) and skin conductance responses to auditory stimulation were measured in 38 patients with schizophrenia and in the same number of matched healthy volunteers (control). All subjects were submitted to multivoxel proton magnetic resonance spectroscopic imaging. When compared to the control group, patients presented significantly lower NAA / (Cr + Cho) ratios in the right dorsolateral prefrontal cortex (schizophrenia = 0.95 +/- 0.03; control = 1.12 +/- 0.04) and in the right (schizophrenia = 0.88 +/- 0.02; control = 0.94 +/- 0.03) and left (schizophrenia = 0.84 +/- 0.03; control = 0.94 +/- 0.03) cingulates. These ratios did not differ between electrodermally responsive and non-responsive patients. When patients were divided into two groups: lower SCL (less than the mean SCL of the control group minus two standard deviations) and normal SCL (similar to the control group), the subgroup with a lower level of SCL showed a lower NAA / (Cr + Cho) ratio in the left cingulate (0.78 +/- 0.05) than the controls (0.95 +/- 0.02, P < 0.05) and the subgroup with normal SCL (0.88 +/- 0.03, P < 0.05). There was a negative correlation between the NAA / (Cr + Cho) ratio in the left cingulate of patients with schizophrenia and the duration of the disease and years under medication. These data suggest the existence of a schizophrenic subgroup characterized by low SCL that could be a consequence of the lower neuronal viability observed in the left cingulate of these patients.
Asunto(s)
Ácido Aspártico/análogos & derivados , Corteza Cerebral/química , Colina/análisis , Creatina/análisis , Respuesta Galvánica de la Piel/fisiología , Esquizofrenia/metabolismo , Estimulación Acústica , Adulto , Ácido Aspártico/análisis , Estudios de Casos y Controles , Femenino , Humanos , Espectroscopía de Resonancia Magnética/métodos , Masculino , Protones , Esquizofrenia/fisiopatología , Factores SocioeconómicosRESUMEN
The present study is a trial on expressing the whole state of a psychiatric ward as a linear combination of base states in a Hilbert space. Real data were collected by observing the behavior of the patients from the psychiatric ward of the Clinical Hospital from Faculdade de Medicina de Ribeirão Preto for 12 days and, according to standard procedures, 18 behavioral parameters were daily measured for each patient. The whole data set was analyzed and, by taking the standard grades as eigenstates, the state of the ward was daily expressed by a linear combination of them, allowing the estimation of state transition matrices and of the quantum variability measure. Coefficients of the linear combination can be interpreted as square roots of probabilities and informational entropy is associated to each state resulting in the classical variability measure. Temporal evolutions of the classical and quantum variability measures are plotted trying to relate them to the behavioral state of the whole ward.
Asunto(s)
Pacientes Internos/psicología , Relaciones Interpersonales , Trastornos Mentales/psicología , Modelos Psicológicos , Servicio de Psiquiatría en Hospital , Entropía , Humanos , Proyectos Piloto , Escalas de Valoración PsiquiátricaRESUMEN
The objective of the present study was to evaluate the factor structure of Bech's version of the Brief Psychiatric Rating Scale (BPRS), translated into Portuguese. The BPRS was administered to a heterogeneous group of psychiatric inpatients (N = 98) and outpatients (N = 62) in a University Hospital. Each patient was evaluated from one to eight times. The interval between consecutive interviews was one week for the inpatients and one month for the outpatients. The results were submitted to factorial analysis. The internal consistency of the total scale and of each factor was also estimated. Factorial analysis followed by normalized orthogonal rotation (Varimax) yielded four factors: Withdrawal-Retardation, Thinking Disorder, Anxious-Depression and Activation. Internal consistency measured by Cronbach's alpha coefficient ranged from 0.766 to 0.879. The data show that the factor structure of the present instrument is similar to that of the American version of the BPRS which contains 18 items, except for the absence of the fifth factor of the latter scale, Hostile-Suspiciousness.
Asunto(s)
Escalas de Valoración Psiquiátrica Breve , Trastornos Mentales/diagnóstico , Brasil , Análisis Factorial , Femenino , Humanos , Masculino , PsicometríaRESUMEN
The objective of the present study was to evaluate the factor structure of Bech's version of the Brief Psychiatric Rating Scale (BPRS), translated into Portuguese. The BPRS was administered to a heterogeneous group of psychiatric inpatients (N = 98) and outpatients (N = 62) in a University Hospital. Each patient was evaluated from one to eight times. The interval between consecutive interviews was one week for the inpatients and one month for the outpatients. The results were submitted to factorial analysis. The internal consistency of the total scale and of each factor was also estimated. Factorial analysis followed by normalized orthogonal rotation (Varimax) yielded four factors: Withdrawal-Retardation, Thinking Disorder, Anxious-Depression and Activation. Internal consistency measured by Cronbach's alpha coefficient ranged from 0.766 to 0.879. The data show that the factor structure of the present instrument is similar to that of the American version of the BPRS which contains 18 items, except for the absence of the fifth factor of the latter scale, Hostile-Suspiciousness
Asunto(s)
Humanos , Masculino , Femenino , Escalas de Valoración Psiquiátrica Breve , Trastornos Mentales , Brasil , Estudio de Evaluación , Análisis Factorial , PsicometríaRESUMEN
OBJECTIVE: To assess the beneficial impact of a structured interview on the reliability of BPRS ratings in raters with low clinical experience. METHOD: Each patient was rated once a week in two separate interviews, conducted on the same day. The first interview was conducted by a rater with low clinical experience (recruited from a group of five residents in psychiatry and one clinical psychologist in training). All second interviews were conducted by the same highly experienced psychiatrist. RESULTS: The number of items with full agreement between observers increased with the use of SIG. The value of intraclass correlation coefficients for individual items and the total score also increased, approaching reported studies with experienced raters. CONCLUSION: These results suggest that the use of SIG reduces variability of information gathering in reliability testing of BPRS with less experienced raters.
Asunto(s)
Trastornos Mentales/diagnóstico , Escalas de Valoración Psiquiátrica , Humanos , Entrevistas como Asunto , Variaciones Dependientes del Observador , Competencia Profesional , Reproducibilidad de los ResultadosRESUMEN
A study of the hematological parameters, glycogen, glucose, and lactate, and the activity of malate and lactate dehydrogenases was carried out in blood and tissues of fishes submitted to two, four, and six hours of hypoxia and recuperation. Only after 4 h of hypoxia was there a drop in liver glucose. Alter 16 h, a drop in lactate and a rise in glucose in practically all tissues signaled a recuperation of the metabolism, probably due to ASR (aerial surface respiration). Lactate formed during hypoxia was canalized to heart and brain for oxidation and used for neoglucogenesis. There were no changes in hematological parameters nore in the activity of malate and lactate dehydrogenases during normoxia and hypoxia, which suggest that these adaptive mechanisms may not be involved during hypoxia. Glycogen concentrations did not show variation during hypoxia either.
Asunto(s)
Oxidorreductasas de Alcohol/metabolismo , Metabolismo de los Hidratos de Carbono , Peces/metabolismo , Hipoxia/metabolismo , Lactatos/metabolismo , Animales , Glucosa/metabolismo , Glucógeno/metabolismo , Hipoxia/sangre , L-Lactato Deshidrogenasa/metabolismo , Malato Deshidrogenasa/metabolismo , Factores de TiempoRESUMEN
The feasibility of obtaining the electron transfer rate from steady-state fluorescence spectroscopy was investigated. Polymeric films with a fixed concentration of an electron donor molecule were studied as a function of an electron acceptor concentration. The transfer studied was from tetraphenylporphyrin to duroquinone in a polystyrene matrix. The data were analyzed according to Perrin model and the critical radius for electron transfer obtained was 7.1 A. There was an attempt to obtain the electron transfer rate from the nearest-neighbor and Inokuti-Hirayama models, but the parameters that define the rate could not be unequivocally determined.
Asunto(s)
Benzoquinonas/química , Electrones , Porfirinas/química , Espectrometría de Fluorescencia , Fenómenos Químicos , Química Física , Matemática , Modelos Químicos , EspectrofotometríaRESUMEN
Mastitis caused by Prototheca spp or Nocardia spp is considered to be difficult to treat. Both microorganisms are contaminants commonly found in soil. The occurrence of mastitis caused by these agents was studied in a particular dairy farm. In this herd, the animals were kept at pasture overnight and during daytime were brought to a pen where they were fed. This pen accumulated mud and faeces, particularly in the rainy season. During milking, pre-dipping of the teats was performed with an iodide solution, but they were not washed, so a layer of soil and faeces remained which may have contaminated the milking equipment. The herd comprised 91 lactating animals and 47 dry cows. For microbiological examination, 107 milk samples were collected from lactating cows and 186 samples of mammary secretions from the dry cows. Prototheca spp were isolated from 14.55% of the milk samples and Nocardia spp from 4.55%. Prototheca spp were isolated from 8.06% of the secretion samples from dry cows and Nocardia spp were isolated from 2.15% samples. The high occurrence of mastitis due to these environmental agents reflects the problem of keeping animals in muddy pastures and pens, and the defective pre-milking hygiene for the teats.
Asunto(s)
Brotes de Enfermedades/veterinaria , Mastitis Bovina/epidemiología , Mastitis Bovina/microbiología , Nocardiosis/veterinaria , Nocardia/aislamiento & purificación , Prototheca/aislamiento & purificación , Animales , Brasil , Bovinos , Corynebacterium/aislamiento & purificación , Enterobacteriaceae/aislamiento & purificación , Femenino , Haemophilus/aislamiento & purificación , Vivienda para Animales , Nocardiosis/etiología , Staphylococcus/aislamiento & purificación , Streptococcus/aislamiento & purificación , Levaduras/aislamiento & purificaciónRESUMEN
Photoacoustic spectroscopy was used to determine the critical distance for electron transfer from porphyrin to quinone molecules randomly dispersed in a polymeric matrix. An enhancement of the porphyrin signal was observed as the quinone concentration was increased. The data was analyzed according to the Perrin model and it was found that the electron transfer occurred if the porphyrin-quinone distance was less than 33 A. To confirm the validity of the method, the fluorescence quenching was also measured for the same samples. In this case, the same critical distance was obtained.
Asunto(s)
Porfirinas/química , Quinonas/química , Acústica , Transporte de Electrón , Luz , Espectrometría de Fluorescencia/instrumentación , Espectrometría de Fluorescencia/métodos , Espectrofotometría/instrumentación , Espectrofotometría/métodos , TermodinámicaRESUMEN
The equilibrium and kinetics of methemoglobin conversion to hemichrome induced by dehydration were investigated by visible absorption spectroscopy. Below about 0.20 g water per g hemoglobin only hemichrome was present in the sample; above this value, an increasing proportion of methemoglobin appeared with the increase in hydration. The transition between the two derivatives showed a time-dependent biphasic behavior and was observed to be reversible. The rates obtained for the transition of methemoglobin to hemichrome were 0.31 and 1.93 min-1 and for hemichrome to methemoglobin 0.05 and 0.47 min-1. We suggest that hemichrome is a reversible conformational state of hemoglobin and that the two rates observed for the transition between the two derivatives reflect the alpha- and beta-chains of hemoglobin.
Asunto(s)
Hemoproteínas/química , Metahemoglobina/química , Agua/farmacología , Desecación , Humanos , Cinética , Conformación Proteica/efectos de los fármacos , EspectrofotometríaRESUMEN
Our aim is to study the binding of nitric oxide to human hemoglobin with different water contents. The binding is investigated using electron paramagnetic resonance (EPR), considering the paramagnetic character of the nitric oxide hemoglobin derivative. The EPR spectra obtained are made up of two types of spectrum whose proportions vary with the decrease in hydration down to about 0.25 g H2O per g protein, and are constant below this value. The two types of spectrum are interpreted as two possible configurations of the heme pocket in different populations of nitric oxide hemoglobin.