Grazing intensity affects the environmental impact of dairy systems.

Dairy products are major components of the human diet but are also important contributors to global environmental impacts. This study evaluated greenhouse gas (GHG) emissions, net energy intensity (NEI), and land use of confined dairy systems with increasing levels of pasture in the diet. A Wisconsin farm was modeled to represent practices adopted by dairy operations in a humid continental climate typical in the Great Lakes region and other climates that have large differences in seasonal temperatures. Five grazing scenarios (all of which contained some portion of confinement) were modeled based on different concentrations of dry matter intake from pasture and feed supplementation from corn grain, corn silage, and soybean meal. Scenarios that incorporate grazing consisted of 5 mo of pasture feeding from May to September and 7 mo of confined feeding from October to April. Environmental impacts were compared within the 5 scenarios that incorporate grazing and across 2 entirely confined scenarios with and without on-farm electricity production through anaerobic digestion (AD). To conduct a fair comparison, all scenarios were evaluated based on the same total amount of milk produced per day where resource inputs were adjusted according to the characteristics of each scenario. A cradle-to-farm gate life cycle assessment evaluated the environmental burdens that were partitioned by allocation between milk and meat and by system expansion when biogas-based electricity was produced. Overall, results for all scenarios were comparable. Enteric methane was the greatest contributor to GHG emissions, and the production of crops was the most energy-intense process. For the confined scenario without AD, GHG emissions were 0.87 kg of CO2 equivalents, NEI was 1.59 MJ, and land use was 1.59 m2/kg of fat- and protein-corrected milk (FPCM). Anaerobic digestion significantly reduced emissions to 0.28 kg of CO2 equivalents/kg of FPCM and reduced NEI to -1.26 MJ/kg of FPCM, indicating a net energy producing system and highlighting the potential of AD to improve the sustainability of confined systems. For scenarios that combined confinement and grazing, GHG emissions ranged from 0.84 to 0.92 kg of CO2 equivalents, NEI ranged from 1.42 to 1.59 MJ, and land use ranged from 1.19 to 1.26 m2/kg of FPCM. All environmental impacts were minimized in scenarios that supplemented enough feed to increase milk yield but maintained dry matter intake from pasture at a level high enough to reduce material and energy use.

Green cheese: partial life cycle assessment of greenhouse gas emissions and energy intensity of integrated dairy production and bioenergy systems.

The objective of this study was to evaluate the effect of integrating dairy and bioenergy systems on land use, net energy intensity (NEI), and greenhouse gas (GHG) emissions. A reference dairy farm system representative of Wisconsin was compared with a system that produces dairy and bioenergy products. This integrated system investigates the effects at the farm level when the cow diet and manure management practices are varied. The diets evaluated were supplemented with varying amounts of dry distillers grains with solubles and soybean meal and were balanced with different types of forages. The manure-management scenarios included manure land application, which is the most common manure disposal method in Wisconsin, and manure anaerobic digestion (AD) to produce biogas. A partial life cycle assessment from cradle to farm gate was conducted, where the system boundaries were expanded to include the production of biofuels in the analysis and the environmental burdens between milk and bioenergy products were partitioned by system expansion. Milk was considered the primary product and the functional unit, with ethanol, biodiesel, and biogas considered co-products. The production of the co-products was scaled according to milk production to meet the dietary requirements of each selected dairy ration. Results indicated that land use was 1.6 m2, NEI was 3.86 MJ, and GHG emissions were 1.02 kg of CO2-equivalents per kilogram of fat- and protein-corrected milk (FPCM) for the reference system. Within the integrated dairy and bioenergy system, diet scenarios that maximize dry distillers grains with solubles and implement AD had the largest reduction of GHG emissions and NEI, but the greatest increase in land use compared with the reference system. Average land use ranged from 1.68 to 2.01 m2/kg of FPCM; NEI ranged from -5.62 to -0.73 MJ/kg of FPCM; and GHG emissions ranged from 0.63 to 0.77 kg of CO2-equivalents/kg of FPCM. The AD contributed 65% of the NEI and 77% of the GHG emission reductions.

Efecto biológico de la hipertermia hídrica controlada sobre hueso sano de conejos / Biological effect of controlled fluid hyperthermia on rabbit healthy bones

La hipertermia hídrica se ha utilizado para tratamientos de diversas formas de cáncer, en hueso aún no se ha determinado cuál es su efecto; se realizó este estudio prospectivo para demostrar los cambios estructurales y metabólicos y los efectos en la consolidación de hueso expuesto a hipertermia hídrica. Se utilizaron 30 conejos de raza New-Zealand. Con peso entre 2.8 y 3.2 kg divididos en 9 grupos y 3 subgrupos, se realizó osteotomía en el tercio medio del fémur derecho; este segmento fue expuesto a hipertermia a 15, 20 y 25 grados centígrados, durante 50, 60 y 70 minutos, gammagrafía ósea cada cuatro semanas y radiográficos cada semana hasta la semana 13. Para el análisis estadístico se utilizó la prueba de post-hoc y test de Tukey, encontrando diferencias en las concentraciones de elementos químicos a temperaturas superiores a 60 grados durante 20 minutos con significancia estadística, retardo en la consolidación y evidencia de actividad metabólica. Se concluye que con la exposición a temperaturas de 60 grados durante 20 minutos se presentaron alteraciones morfológicas en potasio, magnesio, azufre y fósforo y retardo en la consolidación ósea. Estos resultados son usados como parámetros para el tratamiento con hipertermia hídrica controlada en tumores óseos.

Fluid hyperthermia has been used to treat various types of cancers, but its effects on bone have not been determined. The purpose of this prospective study was to show the structural and metabolic changes of bone exposed to fluid hyperthermia and the effects of the latter on bone healing. Thirty New Zealand rabbits were used, weighting 2.8-3.2 kg; they were divided into 9 groups and 3 subgroups. An osteotomy was performed in the mid third of the right femur and this segment was exposed to hyperthermia at 15, 20 and 25 degrees centigrade for 50, 60 and 70 minutes. A bone scan was performed every 4 weeks and X-rays were taken every week up to week 13. The post-hoc Tukey test was used for the statistical analysis. Differences were found in the concentration of chemicals at temperatures above 60 degrees for 20 minutes with statistical significance; bone healing was delayed and there was evidence of metabolic activity. We conclude that exposure to temperatures above 60 degrees for 20 minutes resulted in morphologic alterations in potassium, magnesium, sulfur and phosphorus, and delayed bone healing. These results are used as parameters for the treatment of bone tumors with fluid hyperthermia.

[Biological effect of controlled fluid hyperthermia on rabbit healthy bones]. / Efecto biológico de la hipertermia hídrica controlada sobre hueso sano de Conejos.

Fluid hyperthermia has been used to treat various types of cancers, but its effects on bone have not been determined. The purpose of this prospective study was to show the structural and metabolic changes of bone exposed to fluid hyperthermia and the effects of the latter on bone healing. Thirty New Zealand rabbits were used, weighting 2.8-3.2 kg; they were divided into 9 groups and 3 subgroups. An osteotomy was performed in the mid third of the right femur and this segment was exposed to hyperthermia at 15, 20 and 25 degrees centigrade for 50, 60 and 70 minutes. A bone scan was performed every 4 weeks and X-rays were taken every week up to week 13. The post-hoc Tukey test was used for the statistical analysis. Differences were found in the concentration of chemicals at temperatures above 60 degrees for 20 minutes with statistical significance; bone healing was delayed and there was evidence of metabolic activity. We conclude that exposure to temperatures above 60 degrees for 20 minutes resulted in morphologic alterations in potassium, magnesium, sulfur and phosphorus, and delayed bone healing. These results are used as parameters for the treatment of bone tumors with fluid hyperthermia.

The effect of the symbiosis between Tagetes erecta L. (marigold) and Glomus intraradices in the uptake of Copper(II) and its implications for phytoremediation.

Phytoremediation is an environmental biotechnology that seeks to remediate pollution caused by bioaccumulative toxins like copper (Cu). Symbiotic mycorrhizal associations can increase the uptake and delivery of low mobility nutrients and micronutrients to the host plant because they solubilize these substances and increase their catchment area. To analyze the effect of mycorrhizae on the phytoaccumulation of Cu, we studied their ability to solubilize Cu(II) and enhance its absorption by the plant Tagetes erecta L. colonized with the arbuscular mycorrhizal fungus Glomus intraradices. Plants were grown for nine weeks in a growth chamber under controlled conditions of temperature, relative humidity and photoperiod. Cu was added in the insoluble form of CuO to simulate the insoluble Cu-O affixed species in soil. The biotic and abiotic parameters of colonization, foliar area, biomass and the pH of leachates were determined as functions of the Cu concentration that was measured in the roots, shoots and leachates by AAS. The results of Cu absorption showed that the colonized plants accumulated more Cu in the roots as well as the whole plant and that both the colonized and non-colonized plants displayed the typical behavior of Cu excluders. Mycorrhizal colonization of the roots resulted in a proliferation of vesicles and this was observed to scale with root tissue Cu concentrations. Also, the G. intraradices-T. erecta system displayed a higher resistance to the toxicity induced by Cu while nonetheless improving the indices of phytoaccumulative yields. These results suggest that G. intraradices possibly accumulates Cu in its vesicles thereby enhancing the Cu tolerance of T. erecta even while increasing root Cu accumulation. The parameters of bioconcentration factor and translocation factor measured in this work suggest that the system T. erecta-G. intraradices can potentially phytostabilize Cu in contaminated soils.

Electron microscopic studies of ion- and H2O-transporting epithelial cells in the horizontal ampulla of the pigeon.

Earlier morphological studies of the epithelial structure in the semicircular canals of mammals have focused on the sensory cells of the crista ampullaris. This report draws attention to the fact that there exist at least seven further cell types in the horizontal ampulla walls of pigeon with various functions; the role of ion- and H2O-transporting epithelial cells is dealt with here in detail. While the dark cells appear to play a decisive role in the regulation of ionic composition, the cells in the planum semilunatum may transport H2O and assist in the regulation of endolymph volume. In addition, protein-secreting structures are located in the apical region of the cells of the planum semilunatum. The question whether the proteins are dispersed in the endolymph or contribute to cupula formation remains unclear. The morphology and possible functions of these two cell types are discussed on the basis of electron microscopic results.

Relationship between physical and psychosocial dysfunction in Mexican patients with vertigo: a cross-cultural validation of the vertigo symptom scale.

The Vertigo Symptom Scale (VSS) was designed to assess and differentiate symptoms of: (a) balance disorder; and (b) somatic anxiety and autonomic arousal in patients complaining of dizziness and vertigo. Although it has been translated for use in countries other than the UK, where it was originally developed, its validity in different languages and cultures has not previously been evaluated. This study examined the structure, reliability, and discriminative power of a Spanish translation of the VSS administered to a Mexican sample of 172 dizzy patients and 40 healthy controls. Scores on the two subscales of the VSS not only discriminated between patients and controls, but were also sensitive to differences between patient groups classified on the basis of diagnosis, test results, and occupational disability. The pattern of intercorrelations between symptoms, anxiety, depression, and handicap in the Mexican sample was almost identical to that observed in the original UK sample.

Ultrastructural characteristics of Gardnerella vaginalis infection in the heterosexual couple.

Adhesion and penetration of Gardnerella vaginalis into the male urethral and female vaginal epithelial cells were evaluated in a prospective cohort study of infected females and their sexual partners. Vaginal secretions of 10 women with culture proven G. vaginalis infection and semen samples of their asymptomatic husbands were analyzed with conventional optical and electron microscopy. G. vaginalis was isolated in 50% of the male sexual partners of women harboring the microorganism. G. vaginalis adheres to the plasmatic membrane and penetrates into the cytoplasm of both vaginal and urethral epithelial cells. The ability of G. vaginalis to colonize the male lower genital tract may have clinical relevance with respect to the role of the male partner in the reinfection of women.

[Ultrastructural analysis of placentas with villitis. Retrospective study]. / Análisis ultraestructural de placentas con villitis. Estudio retrospectivo.

A villitis is a focal or multifocal inflammatory reaction of chorionic villi with infiltration of mononuclear cells and usually is associated with fibrinoid necrosis. The aetiology of villitis could be a transplacental infection of the fetus, especially with virus (VIV), in normal placentae however, the presence of villitis is referred as villitis of unknown ethiology (VED). This study was designed to characterize villitis lesions of 11 placentae, four VIV and seven VED, ultrastructural descriptive comparisons of both types of villitis are discussed. Biopsies were processed with the conventional optic and electronic microscopy techniques. Our ultrastructural observations confirmed the presence of virus in four placentae whereas no virus or bacteria were found in seven placentae. Microvilli were absent or markedly diminished, this finding was associated to the presence of fibrinoid necrosis in the stroma and clinically to intrauterine growth retardation, 4 preterm pregnancies and one obitus. Trophoblast alterations were found in both types of villitis, basal membrane thickness, is some cases associated to electrodense material similar to calcium deposites, vascuolization and the presence of edema in the stroma was observed. In some cases we noted the presence of focal fibrin deposits associated to necrosis zones in the stroma, calcium precipitates and mielinic bodies. Fetal vessels obliteration and intravascular thrombi were found in the syncitiotrophoblast placentae with viral particles CMV or rubivirus associated to an increment in Hofbauer cells and basal membrane calcifications. From our ultrastructural observations, we conclude that both types of villitis are associated to a typic immunologic reaction that induce lose of trophoblast microvilli, mononuclear infiltration and edema. This placental alterations reduce dramatically the maternofetal exchange of gases, nutrients and other active peptides and could be the cause of fetal growth retardation, inmadurity or death.

Ultrastructural findings in placentae of HIV-positive women.

PIP: Transmission of human immunodeficiency virus (HIV) from an infected mother to the fetus has been shown to occur. The route of infection is probably through the placenta, yet the exact mechanism of how this occurs is still unclear. Researchers in Mexico report in this article their findings on placental tissue taken from 9 HIV-seropositive women. The placentas from new deliveries were sectioned and the tissue fixed and embedded in plastic. Thin sections were cut, stained, and examined using transmission electron microscopy (TEM). HIV-like particles were found near or inside the trophoblastic villi in 4 placental specimens examined. In one case these particles were found in the endothelium of the umbilical artery. Mast-like cells were found in the free villous stroma in 2 tissue samples. Vertical transmission of HIV has been a major source of HIV infections in Europe and the US. On the other hand, Mexico doesn't report similar findings. The authors suggest that this is the case because of lower female drug use. It is still unclear why some babies from HIV-seropositive mothers become infected while others do not.^ieng

Electron microscopy of Chlamydia trachomatis infection of the male genital tract.

Semen specimens and testicular and epididymis biopsy from a patient of an infertile marriage were examined by transmission electron microscopy. Intraepithelial vesicles containing C. trachomatis were present in remaining cytoplasmic droplets in spermatozoa, desquamated epithelial cells, and stereocilia from epididymis. Elementary bodies were demonstrated in connective tissue from testes and in Leydig cells. The association between the microorganisms and spermatozoa contribute to the decreased motility and necrospermia. The morphologic alterations in epididymis are responsible for decreased sperm maturation. The damage to Leydig cells can be demonstrated only by electron microscopy.

El trasplante cardiaco en Colombia / Cardiac transplantation in Colombia

El programa de trasplante cardiaco ha sido posible entre nosotros, gracias al esfuerzo de dos grupos medicos que trabajando en estrecha colaboracion, han logrado poner a disposicion de los pacientes cardiacos terminales, este recurso terapeutico de amplia aceptacion en el mundo cientifico de hoy. La experiencia con 12 pacientes trasplantados ha dejado ensenanzas muy utiles y alentadoras que nos llevan a seguir adelante con el programa

[Prevalence of microscopic coronary atheroma in young adults from Mexico City]. / Prevalencia del ateroma coronario microscópico en adultos jóvenes de la Ciudad de México.

The prevalence of microscopic atheroma in the proximal left anterior descending coronary artery was studied in thirty young males aged 20 to 29 years, living in Mexico City, who died in urban accidents. All of them were either unemployed or labor workers with a socioeconomical status considered to be representative of the majority of young males living in Mexico City. It was found that coronary atheroma was present in 11 of them (33%) with variable degrees of luminal obstruction. In two of them the luminal obstruction was greater than 75%. The prevalence found in this group was significantly different to that found in younger and older males who also died in accidents. Since the prevalence of coronary atheroma was not related to ventricular hypertrophy, valvular or congenital heart disease our findings indicate that in Mexico City as in other geographical regions, coronary atherosclerosis is not an unusual finding in males in the third decade of life, with a low socioeconomical status.