7,167 research outputs found

    Does cattle and sheep grazing under best management significantly elevate sediment losses? Evidence from the North Wyke Farm Platform, UK

    Get PDF
    Purpose: Intensive livestock grazing has been associated with an increased risk of soil erosion and concomitant negative impacts on the ecological status of watercourses. Whilst various mitigation options are promoted for reducing livestock impacts, there is a paucity of data on the relationship between stocking rates and quantified sediment losses. This evidence gap means there is uncertainty regarding the cost–benefit of policy preferred best management. Methods: Sediment yields from 15 hydrologically-isolated field scale catchments on a heavily instrumented ruminant livestock farm in the south west UK were investigated over ~26 months spread across six years. Sediment yields were compared to cattle and sheep stocking rates on long-term, winter (November–April) and monthly time scales. The impacts of livestock on soil vegetation cover and bulk density were also examined. Cattle were tracked using GPS collars to determine how grazing related to soil damage. Results: No observable impact of livestock stocking rates of 0.15 – 1.00 UK livestock units (LU) ha-1 for sheep and 0 - 0.77 LU ha-1 for cattle on sediment yields was observed at any of the three timescales. Cattle preferentially spent time close to specific fences where soils were visually damaged. However, there was no indication that livestock have a significant effect on soil bulk density on a field-scale. Livestock were housed indoors during winters when most rainfall occurs and best management practices were used which when combined with low erodibility clayey soils likely limited sediment losses. Conclusion: A combination of clayey soils and soil trampling in only a small proportion of the field areas lead to little impact from grazing livestock. Within similar landscapes with best practice livestock grazing management, additional targeted measures to reduce erosion are unlikely to yield a significant cost-benefit

    Does cattle and sheep grazing under best management significantly elevate sediment losses? Evidence from the North Wyke Farm Platform, UK

    Get PDF
    Purpose Intensive livestock grazing has been associated with an increased risk of soil erosion and concomitant negative impacts on the ecological status of watercourses. Whilst various mitigation options are promoted for reducing livestock impacts, there is a paucity of data on the relationship between stocking rates and quantified sediment losses. This evidence gap means there is uncertainty regarding the cost-benefit of policy preferred best management. Methods Sediment yields from 15 hydrologically isolated field scale catchments on a heavily instrumented ruminant livestock farm in the south west UK were investigated over similar to 26 months spread across 6 years. Sediment yields were compared to cattle and sheep stocking rates on long-term, winter (November-April), and monthly timescales. The impacts of livestock on soil vegetation cover and bulk density were also examined. Cattle were tracked using GPS collars to determine how grazing related to soil damage. Results No observable impact of livestock stocking rates of 0.15-1.00 UK livestock units (LU) ha(-1) for sheep, and 0-0.77 LU ha(-1) for cattle on sediment yields was observed at any of the three timescales. Cattle preferentially spent time close to specific fences where soils were visually damaged. However, there was no indication that livestock have a significant effect on soil bulk density on a field scale

    Antropoestratigrafía: nuevas unidades litológicas del Cuaternario controladas por la actividad humana

    Get PDF
    Many areas around the world such as the Mediterranean region have been inhabited without interruption for thousands of years. This is the case of the city of Barcelona (Spain), where remains of human settlements dating from pre-Roman times until the present have been found. A detailed geological mapping of the area occupied by the city of Barcelona raises a number of questions about the Holocene stratigraphy affected by human activity. In the old urban and surrounding areas most of the sedimentary deposits accumulated during settlement result from human interactions. Thus, new anthropostratigraphic units are proposed. The sedimentary deposits and the infill of rock excavations due to human presence may be divided into three categories: Natural lithoanthropogenic units (NAU) when their formation is not directly affected by anthropogenic activity but these contain artefacts of human origin. Induced lithoanthropogenic units (IAU) when natural processes together with human actions produce sedimentation or erosion due to natural phenomena; Constructed lithoanthropogenic units (CAU) when sedimentary accumulations and sharp contacts result from direct human activity.A lo largo de todo el globo terrestre, existen muchas zonas como la región mediterránea que han sido habitadas ininterrumpidamente durante miles de años. Este es el caso de la ciudad de Barcelona donde se han encontrado restos de asentamientos humanos desde los tiempos pre-romanos hasta la actualidad. Un mapa geológico detallado de la zona ocupada por la ciudad de Barcelona plantea una serie de interrogantes sobre la estratigrafía del Holoceno influenciado por la actividad humana. En la zona urbana antigua y en áreas circundantes, la mayoría de los depósitos acumulados durante el asentamiento se han producido por las interacciones humanas. Por tanto, se proponen nuevas unidades antropoestratigráficas. Los depósitos sedimentarios así como los rellenos de lasexcavaciones debidos a la presencia humana pueden ser divididos en tres categorías: Unidades litoantropogénicas naturales (NAU) cuando su generación no ha sido afectada directamente por la actividad humana, pero contienen diversos artefactos artificiales. Unidades litoantropogénicas inducidas (IAU) cuando los procesos naturales junto a las acciones humanas producen sedimentación o erosión debido a los fenómenos naturales. Unidades litoantropogénicas construidas (CAU) cuando las acumulaciones sedimentarias y los contactos nítidos son el resultado de la actividad humana directa

    Postoperative streptococcus constellatus bacteremia in a 75-year-old patient with pyometra: A case report

    Get PDF
    Background: Pyometra is an accumulation of pus in the uterine cavity. It is rare in the general population but more common in elderly women. If diagnosed in the early stage, life-threating conditions may be avoided. The most common etiological microorganisms of pyometra are Escherichia coli, Bacteroides species, Staphylococci (eg, epidermid-is) and Streptococci. Occasionally, atypical bacteria may be the cause. Case Report: We present the case of a 75-year-old woman, with multiple risk factors, admitted to the Gynecology Department with a 15-day history of yellowish-brown vaginal discharge. Because of rapid enlargement of the uterine cavi-ty, the patient underwent to endometrial curettage. Three hours after surgery, she developed a high-grade fe-ver, and Streptococcus constellatus was isolated in her blood cultures. A specific antibiotic therapy was admin-istered for a total of 14 days, resulting in complete resolution of the infection. Conclusions: This case report describes a rare case of bacteremia caused by Streptococcus constellatus, that resulted from a pyometra. The classic triad of symptoms (postmenopausal bleeding, vaginal discharge, and lower abdominal pain) may be helpful for diagnosis; however, 50% of patients are asymptomatic. An early recognition of the con-dition is important to avoid rare but risky consequences, such as perforation of the uterus itself. Nevertheless, surgery can cause dangerous complications such as bacteremia. A different spectrum of bacteria may be in-volved in the development of pyometra, even in atypical cases, mostly when multiple comorbidities are pres-ent. A correct evaluation and management of the patient is essential to guarantee a good prognosis in this rare infection

    Factors affecting site use preference of grazing cattle studied from 2000 to 2020 through GPS tracking - A review

    Get PDF
    Understanding the behaviour of grazing animals at pasture is crucial in order to develop management strategies that will increase the potential productivity of grazing systems and simultaneously decrease the negative impact on the environment. The objective of this review is to summarize and analyse the scientific literature that has addressed the site use preference of grazing cattle using global positioning systems (GPS) collars in the past 21 years (2000-2020) to aid the development of more sustainable grazing livestock systems. The 84 studies identified were undertaken in several regions of the world, in diverse production systems, under different climate conditions and with varied methodologies and animal types. This work presents the information in categories according to the main findings reviewed, covering management, external and animal factors driving animal movement patterns. The results show that some variables such as stocking rate, water and shade location, weather conditions and pasture (terrain and vegetation) characteristics have a significant impact on the behaviour of grazing cattle. Other types of bio-loggers can be deployed in grazing ruminants to gain insights into their metabolism and its relationship with the landscape they utilise. Changing management practices based on these findings could improve the use of grasslands towards more sustainable and productive livestock systems

    Produção de fitomassa leguminosas isoladas e consorciadas com milheto e teor relativo de clorofila em feijoeiro orgânico em plantio direto.

    Get PDF
    O objetivo do presente trabalho foi de avaliar a produção de fitomassa de leguminosas isoladas e consorciadas com milheto e seu efeito no teor de clorofila do feijoeiro comum orgânico em sistemas de plantio convencional e direto.CONAFE

    The genetic contribution of the NO system at the glutamatergic post-synapse to schizophrenia : further evidence and meta-analysis

    Get PDF
    NO is a pleiotropic signaling molecule and has an important role in cognition and emotion. In the brain, NO is produced by neuronal nitric oxide synthase (NOS-I, encoded by NOS1) coupled to the NMDA receptor via PDZ. interactions; this protein-protein interaction is disrupted upon binding of NOS1 adapter protein (encoded by NOS1AP) to NOS-I. As both NOS1 and NOS1AP were associated with schizophrenia, we here investigated these genes in greater detail by genotyping new samples and conducting a meta-analysis of our own and published data. In doing so, we confirmed association of both genes with schizophrenia and found evidence for their interaction in increasing risk towards disease. Our strongest finding was the NOS1 promoter SNP rs41279104, yielding an odds ratio of 1.29 in the meta-analysis. As findings from heterologous cell systems have suggested that the risk allele decreases gene expression, we studied the effect of the variant on NOS1 expression in human post-mortem brain samples and found that the risk allele significantly decreases expression of NOS1 in the prefrontal cortex. Bioinformatic analyses suggest that this might be due the replacement of six transcription factor binding sites by two new binding sites as a consequence of proxy SNPs. Taken together, our data argue that genetic variance in NOS1 resulting in lower prefrontal brain expression of this gene contributes to schizophrenia liability, and that NOS1 interacts with NOS1AP in doing so. The NOS1-NOS1AP PDZ interface may thus well constitute a novel target for small molecules in at least some forms of schizophrenia. PostprintPeer reviewe
    corecore