Nitrogen translocation by Highland cattle grazing in Alnus viridis-encroached pastures.

During the last decades, Alnus viridis has expanded over former montane pastures and meadows, due to land use and abandonment. This nitrogen-fixing woody species has triggered negative agro-environmental impacts, such as nitrogen (N) leaching, soil acidification and a reduced biodiversity. The aim of this study was to estimate the N translocation from A. viridis-encroached areas to adjacent open pastures by Highland cattle. In 2019 and 2020, Highland cattle herds equipped with GPS collars were placed in four A. viridis-encroached paddocks across Italy and Switzerland. The N content was measured in A. viridis leaves, herbaceous vegetation, and cattle dung pats, which were collected throughout the grazing season. Using GPS locations and collar activity sensors, livestock activity phases were discriminated. The N ingested by cattle was estimated through the N content of herbaceous vegetation and A. viridis leaves of vegetation patches visited by cattle during 24 h before dung sampling (N24H). The N content of herbaceous vegetation significantly increased with increasing A. viridis cover. The average N content in dung pats (31.2 ± 3.4 g.kg-1 DM) was higher than average values from literature on grazing cattle. Moreover, it was positively related to the N24H. Most of this N (29.5 ± 10.3 kg ha-1 yr-1) was translocated towards resting areas, which generally occurred on flat open pastures. Our results highlight the potential of Highland cattle to effectively translocate part of the ingested N from A. viridis-encroached towards targeted open areas, thus bringing new perspective for forage yield and quality improvement in the long-term. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s10705-023-10282-0

CFL’S CYCLE AS A METHOD OF RELIABILITY DETERMINATION AND PREMATURE DISPOSAL

En este trabajo se muestran los resultados del ciclado de una población de 86 lámparas. 82 de bajo consumo y 4 incandescentes. Las mismas han sido sometidas a las condiciones consideradas más perjudiciales para este tipo de dispositivos. Así, se definieron ciclos de funcionamiento nocturno, de 8 a 12 horas de duración, con periodos de operación de 30 minutos y de 2 minutos de reposo. Esto, presupone un número de conmutaciones fuera del estándar admitido y condiciones de operación desfavorables.This paper shows the results of the cycling of a population of 86 lamps. 82 low-power and 4 incandescent. They have been subjected to more adverse conditions considered for these devices. By this way, night cycles of operation were defined, from 8 to 12 hours, with operation periods of 30 min. and 2 min. standing. This presupposes a number of non-standard switches admitted and unfavorable operating conditions

Improvements in power factor by replacing fluorescent tubes with equivalent LED tubes

El reciente reemplazo de la iluminación del túnel sub fluvial Uranga - Silvestre Begnis, que une las ciudades de Paraná y Santa Fe en la República Argentina, ha planteado una serie de interrogantes técnicos respecto del reemplazo por nuevas tecnologías de iluminación. En esta obra, 4.200 tubos fluorescentes T8 de 36 W fueron reemplazados por tubos de nueva Tecnología LED 14 W. El reemplazo se fundamentó en la necesidad de reducir el consumo energético y lograr una reducción de los costos operativos. Entre las principales hipótesis antes de la obra, se evaluó un incremento de la distorsión armónica total, a partir de conectar cargas no lineales. Entre las especificaciones del pliego de obra se indicaron límites máximos de THD tolerables. Sin embargo, no se tuvo en cuenta la THD original propia del uso de balastos electromagnéticos con tubos fluorescentes. En este trabajo se muestran las mejoras detectadas en los parámetros de calidad eléctrica, a partir de la utilización de equipos LED con características adecuadas. Los resultados muestran una notable mejora del factor de potencia, con valores cercanos a 0,9 y una reducción del contenido armónico a niveles tan bajos como 18 %. Como efecto negativo se detectó la presencia de modulación de HF en la señal de corriente en el análisis individual de cada equipo. Sin embargo, en la instalación masiva es posible observar una notable reducción de la señal de pulsado propia de la configuración del driver.The recent replacement of the illumination of the sub fluvial tunnel Uranga – Silvestre Begnis, that joins the cities of Paraná and Santa Fe in the Argentinean Republic, has raised a number of technical questions regarding the replacement for new lighting technologies. In this work, 4200 fluorescent tubes T8 of 36w were replaced by new technology LED tubes of 14w. The replacement was based on the need to reduce energy consumption and to achieve a reduction in operating costs. Among the main hypothesis before the work, an increase in the total harmonic distortion from connecting nonlinear loads was evaluated. Among the specifications of the statement work, maximum permissible THD limits were indicated. However, the original THD of the use of electromagnetic ballasts with fluorescent tubes was not take into consideration. This work shows the improvements detected in the parameters of electrical quality from the use of LED equipment with suitable characteristics. The results show a remarkable improvement of power factor with values close to 0.9 and a reduction of the harmonics content to levels as low as 18%. As a negative effect, the presence of HF modulation was detected in the current signal in the individual analysis of each equipment. Nevertheless, in the mass installation process, it is possible to observe a noticeable reduction of the pulse signal characteristic of the driver configuration

Increased EEG gamma band activity in Alzheimer’s disease and mild cognitive impairment

High frequency (30–70 Hz) gamma band oscillations in the human electro-encephalogram (EEG) are thought to reflect perceptual and cognitive processes. It is therefore interesting to study these measures in cognitive impairment and dementia. To evaluate gamma band oscillations as a diagnostic biomarker in Alzheimer’s disease (AD) and mild cognitive impairment (MCI), 15 psychoactive drug naïve AD patients, 20 MCI patients and 20 healthy controls participated in this study. Gamma band power (GBP) was measured in four conditions viz. resting state, music listening, story listening and visual stimulation. To evaluate test–retest reliability (TRR), subjects underwent a similar assessment one week after the first. The overall TRR was high. Elevated GBP was observed in AD when compared to MCI and control subjects in all conditions. The results suggest that elevated GBP is a reproducible and sensitive measure for cognitive dysfunction in AD in comparison with MCI and controls

Cold truths: how winter drives responses of terrestrial organisms to climate change

Winter is a key driver of individual performance, community composition, and ecological interactions in terrestrial habitats. Although climate change research tends to focus on performance in the growing season, climate change is also modifying winter conditions rapidly. Changes to winter temperatures, the variability of winter conditions, and winter snow cover can interact to induce cold injury, alter energy and water balance, advance or retard phenology, and modify community interactions. Species vary in their susceptibility to these winter drivers, hampering efforts to predict biological responses to climate change. Existing frameworks for predicting the impacts of climate change do not incorporate the complexity of organismal responses to winter. Here, we synthesise organismal responses to winter climate change, and use this synthesis to build a framework to predict exposure and sensitivity to negative impacts. This framework can be used to estimate the vulnerability of species to winter climate change. We describe the importance of relationships between winter conditions and performance during the growing season in determining fitness, and demonstrate how summer and winter processes are linked. Incorporating winter into current models will require concerted effort from theoreticians and empiricists, and the expansion of current growing-season studies to incorporate winter

Effects of global change on insect pollinators: multiple drivers lead to novel communities

Global change drivers, in particular climate change, exotic species introduction, and habitat alteration, affect insect pollinators in numerous ways. In response, insect pollinators show shifts in range and phenology, interactions with plants and other taxa are altered, and in some cases pollination services have diminished. Recent studies show some pollinators are tracking climate change by moving latitudinally and elevationally, while others are not. Shifts in insect pollinator phenology generally keep pace with advances in flowering, although there are exceptions. Recent data demonstrate competition between exotic and native bees, along with rapid positive effects of exotic plant removal on pollinator richness. Genetic analyses tie bee fitness to habitat quality. Across drivers, novel communities are a common outcome that deserves more study

Opportunities to enhance pollinator biodiversity in solar parks

Renewable power capacity is increasing globally in response to energy decarbonisation, with solar photovoltaic (PV) projected to be the dominant renewable. A significant proportion of solar PV is deployed as ground-mounted solar parks with potential implications for the hosting ecosystem. Given their relatively rapid introduction, the impacts on land use and the local environment are poorly understood. However, if deployed and managed strategically, solar parks could offer unique opportunities to enhance the local environment and benefit biodiversity, with implications for ecosystem components such as pollinators. With a focus on north-west Europe, we systematically review the available evidence on how land management practices relevant to solar parks can enhance pollinator biodiversity. We assessed 185 articles for the quantity and agreement of evidence for 27 management interventions and assigned a confidence score to each finding. We show that a range of interventions applied to solar parks could increase their ability to enhance pollinator biodiversity. We then use our assessment to synthesise ten evidence-based recommendations on how to improve solar park management for pollinators by providing foraging and reproductive resources, undergoing considered management practices, increasing landscape heterogeneity and connectivity and providing microclimatic variation. Ensuring beneficial management of rapidly growing solar parks contributes to their wider environmental sustainability, with positive implications for both pollinator conservation and the energy sector in general