Organic Waste as Fertilizer in Semi-Arid Soils and Restoration in Mine Sites

The use of organic waste such as tannery sludge which has high organic matter, N and P content, as organic fertilizer is suitable for improving soil fertility in semi-arid soils and for remediation of abandoned mine sites. Retention of heavy metals on fractional processes of organic matter cannot be generalized, it depends on the chemical characterization of organic waste and soil. Addition of tannery sludge containing high concentrations of Cr and carbonates to semi-arid soils resulted in an increase in Cr loss in infiltration and runoff after 6 months of incubation followed by simulated rainfall. Under these characteristics, results suggest that tannery sludge represents a potential ha ls amended with organic compost. Chemical characteristics of organic waste such as nitrogen content, humified organic matter, pH, EC, CEC, ESP (interchangeable sodium percent), and SAR (sodium absorption ratio) are important properties to consider in organic matter amendment to semi-arid soils participating on the complexity and leaching of heavy metals and nutrients in the matrix of soil

Soil microbial biomass and organic matter dynamics in metal-contaminated soils

A main aim of this thesis was to compare and evaluate different microbiological methods (total biomass or microbial activity) to detect effects of heavy metals on the functioning of the soil ecosystem. The biomass methods, which included biomass C, biomass ninhydrin-N, biomass N, ATP, substrate induced respiration and the activity methods, which included CO, evolution and arginine ammonification reliably detected effects of heavy metals on the soil microbial ecosystem in metal-contaminated soils from the Woburn Market Garden Experiment which contained, due to past sludge applications, Zn, Cu or Ni at around current European Union (EU) upper limits and Cd at around three times the limit. Most microbiological indices were decreased by up to about 50% in the most metal- contaminated soils and the results were comparatively simple to interpret. Many more problems were encountered when soils from a non-experimental site in Spain, polluted by heavy metals from past mining activity, and now containing heavy metals at up to 27 times current EU limits were examined. Huge variability, caused, for example, by site variations in soil organic C, soil texture, agricultural management and topography, were encountered. While the biomass methods and most measurements of microbial activity (except COj-C evolved) gave some indication of a negative response to increases soil metal concentrations, linked parameters e.g. biomass specific respiration or biomass as a percentage of soil organic C provided much more sensitive indicators of the effects of metals on the soil ecosystem. It was concluded that extrapolation from the field experiment to the natural environment, while difficult, is now a practical proposition

Soil microbial biomass and organic matter dynamics in metal-contaminated soils

A main aim of this thesis was to compare and evaluate different microbiological methods (total biomass or microbial activity) to detect effects of heavy metals on the functioning of the soil ecosystem. The biomass methods, which included biomass C, biomass ninhydrin-N, biomass N, ATP, substrate induced respiration and the activity methods, which included CO, evolution and arginine ammonification reliably detected effects of heavy metals on the soil microbial ecosystem in metal-contaminated soils from the Woburn Market Garden Experiment which contained, due to past sludge applications, Zn, Cu or Ni at around current European Union (EU) upper limits and Cd at around three times the limit. Most microbiological indices were decreased by up to about 50% in the most metal- contaminated soils and the results were comparatively simple to interpret. Many more problems were encountered when soils from a non-experimental site in Spain, polluted by heavy metals from past mining activity, and now containing heavy metals at up to 27 times current EU limits were examined. Huge variability, caused, for example, by site variations in soil organic C, soil texture, agricultural management and topography, were encountered. While the biomass methods and most measurements of microbial activity (except COj-C evolved) gave some indication of a negative response to increases soil metal concentrations, linked parameters e.g. biomass specific respiration or biomass as a percentage of soil organic C provided much more sensitive indicators of the effects of metals on the soil ecosystem. It was concluded that extrapolation from the field experiment to the natural environment, while difficult, is now a practical proposition

Inferior vena cava filters: a review

Venous thromboembolism is an entity that ranges from deep vein thrombosis to pulmonary embolism, both are highly prevalent diseases in our environment and potentially fatal. The intention of this review is to compile information regarding the indications, contraindications, complications and comparison of different therapeutic methods in order to create an algorithm. An exhaustive review was performed with the available literature, using the PubMed, ScienceDirect, Scopus and Cochrane databases from 2004 to 2021. The search criteria were formulated to identify reports related to inferior vena cava filters. Venous thrombosis manifested as deep vein thrombosis or pulmonary embolism is a highly prevalent disease in our setting with high morbidity and mortality. Currently, different therapeutic options have been presented to address this pathology, in this review we focus on the developments regarding the use of vena cava filters. Reviewing the indications for the placement of a vena cava filter, we find absolute indications such as a contraindication to anticoagulation and high risk of massive pulmonary embolism. Pulmonary thromboembolism is a disease with high prevalence and mortality, we have highly effective and novel treatments such as the vena cava filter, patients should be selected carefully always taking into account the absolute and relative indications

The neurobiology of splitbrain crayfish

Background: They crayfish brain is segmented into two symmetrical hemiganglia. Normally both hemiganglia are in direct communication through a series of well-defined neural bridges that cross de midline to form reciprocal cross connections.Methods: An original study was carried out in the Department of Physiology of the Faculty of Medicine, UNAM during the period from August 2019 to August 2020. 13 Crayfish Procambarus clarkii weighing between 1g to 30g were used. Each eyestalk of the animals was tied to a displacement transducer coupled with a polygraph so that optomotor or electrical activity was bilaterally recorded. The separation of the right from the left hemiganglia from the cerebral or supraesophageal ganglion was performed with a sagittal section, splitbrain (SB).Results: The normal photo motor reflex in crayfish eye is measured as a gradual decrease in the ERG amplitude. During tactile stimulation, the visual activation of both eyestalks in normal crayfish leads to a highly regular bilateral activity. The regular activity can only be altered by disturbing the mechanoreceptors located in the shell surrounding the eyestalks.Conclusions: The procedure presented in this article provides unique characteristics for the study of the nervous system such as a detailed response of the bilateral optomotor reflex

Chronic venous insufficiency: a review

Chronic venous insufficiency (CVI) comprises a complete spectrum of morphological and functional abnormalities of the venous system1 including any long-term functional and morphological alteration. CVI accounts for several abnormalities of the venous system. It is a highly prevalent disease that causes serious economic consequences, a decrease in the quality of life and can lead to serious complications. An exhaustive review was performed with the available literature, using the PubMed, ScienceDirect, Scopus and Cochrane databases from 2004 to 2021. The search criteria were formulated to identify reports related to chronic venous insufficiency. The pathophysiology of chronic venous insufficiency begins with chronic venous hypertension and the dilation of the vessel, this leads to a series of pathological changes in the venous wall and surrounding tissues, in advanced stages of CVI, skin lesions are associated with an increased proliferation of skin capillaries and microcirculatory abnormalities that may be the result of an altered level of factors responsible for the angiogenic response, such as vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2) and angiostatin. In this review, updates on pathophysiology, clinic, diagnosis, classification and treatment of this disease are analyzed, with special emphasis on therapeutic options. Chronic venous insufficiency is a disease that affects the patient at several levels, mainly diminishing his/her quality of life. Currently there are various treatments ranging from habit modifications, pharmacological, to endovenous and surgical treatment.

Latitude gradient influences the age of onset of rheumatoid arthritis : a worldwide survey

The age of onset of rheumatoid arthritis (RA) is an important outcome predictor. Northern countries report an age of RA onset of around 50 years, but apparently, variability exists across different geographical regions. The objective of the present study is to assess whether the age of onset of RA varies across latitudes worldwide. In a proof-of-concept cross-sectional worldwide survey, rheumatologists from preselected cities interviewed 20 consecutive RA patients regarding the date of RA onset (RAO, when the patient first noted a swollen joint). Other studied variables included location of each city, rheumatologist settings, latitudes (10A degrees increments, south to north), longitudes (three regions), intracountry consistency, and countries' Inequality-adjusted Human Development Index (IHDI). Data from 2481 patients (82% females) were obtained from 126 rheumatologists in 77 cities of 41 countries. Worldwide mean age of RAO was 44 +/- 14 years (95% CI 44-45). In 28% of patients, RA began before age 36 years and before age 46 years in 50% of patients. RAO was 8 years earlier around the Tropic of Cancer when compared with northern latitudes (p <0.001, 95% CI 3.5-13). Multivariate analysis showed that females, western cities, and latitudes around the Tropic of Cancer are associated with younger age of RAO (R (2) 0.045, p <0.001). A positive correlation was found between the age of RAO and IHDI (r = 0.7, p <0.01, R (2) 0.5). RA often begins at an early age and onset varies across latitudes worldwide. We postulate that countries' developmental status and their geographical and geomagnetic location influence the age of RAO.Peer reviewe