2,242 research outputs found
Women's refolution at work
The renowned Age of Revolution encompasses the period between the American
Revolution (1776) and the so-called Spring of Nations in 1848, this being the height
of the revolutionary movements in Europe in the 19th century, though it may be
considered just the tip of the iceberg as far as civil rights movements for people from
all walks of life are concerned. The changes that occurred throughout this timespan
intended to move from feudal and absolutist systems, considered old-fashioned and
ill-suited, to constitutionalist states and republics that would be able to heed the
new values, e.g. liberalism, nationalism and socialism, as well as the demands of the
working classes, enduring the harmful effects of industrialisation. Working people
had been flowing into large industrial cities for over a century since the onset of the
Industrial Revolution, leaving behind their home places and settling in overcrowded,
rundown dwellings in appalling living conditions. The shift from working at home to
working in factories brought along a number of issues that would be the motivation
for setting up trade unions, namely the long working hours (between 12 and 14 hours
per day), the low wages, the cruel discipline and the fierce system of fines that was
applied, and the numerous accidents and health issues that ensued. Despite the overall
negative conditions, women and children were among those who suffered the
most, especially because the formerâs wages were regarded as secondary earnings
and thus less important than menâs. Consequently, from 1850s onwards, trade unions
began to fight for better paid workers and women were initially excluded from these
structures be it as members or leaders, being supported by social reformers instead.
As a case in point, it is worth mentioning Clementina Black who, in 1888, set forth a
demand for equal pay between men and women in the UK and the Bryant and May
match factory strike which was held in the same year. Bearing in mind this social and
historical context, our aim with this paper is two-fold: not only do we seek to focus
on unionist movements in the last half of the 19th century in the European context
as a means to fight against conservative and slavery-like practices in the workplace
but we also wish to emphasise the place and importance of working-class women in
this general workersâ assertion, particularly in their attempt to gain equal pay, a true
refolution that would be the motivational beacon for 20th century movements, such
as that of the suffragettes.info:eu-repo/semantics/publishedVersio
Cambrian ensialic rift-related magmatism in the Ossa-Morena Zone
The Late Ediacaran (c. 560â550 Ma) SĂ©rie Negra sediments of the ĂvoraâAracena metamorphic belt, Ossa-Morena Zone, SW Iberian Massif,
preserve a record of the erosion of an AvalonianâCadomian magmatic arc and subsequent related turbiditic sedimentation. Detrital zircon from the
SĂ©rie Negra is characterized by predominantly Ediacaran and Cryogenian ages, with few Paleoproterozoic and Archean cores, and a marked lack
of Grenvillian ages. These features, when combined with the metasediments' enrichment in LREE (La/Yb=14), negative Eu-anomalies, low
147Sm/144Nd values (0.121) and negative ΔNd550=â5.5, indicate that the protolith SĂ©rie Negra sediments were derived from a continental
magmatic arc.
A period of Late Cadomian (ca. 560â540 Ma) tectonism was followed by an extended episode of widespread bimodal magmatism related to
Cambrian (ca. 540â500 Ma) rifting. This tectonic inversion is expressed in the geological record by a regional Early Cambrian unconformity.
SHRIMP zircon UâThâPb ages from four felsic orthogneisses from the Ăvora Massif record Cambrian (527±10 Ma, 522±5 Ma, 517±6 Ma
and 505±5 Ma) crystallization ages for their igneous protoliths. This confirms the existence of widespread Lower Paleozoic igneous activity in the
Ossa-Morena Zone: (i) a Lower Cambrian (ca. 535â515 Ma) igneousâfelsic dominatedâsedimentary complex (with calc-alkaline signature and
associated carbonate and siliciclastic deposition), and (ii) a Middle Cambrianâ?Ordovician (ca. 515â490 Ma) igneousâbimodalâsedimentary
complex (with calc-alkaline and tholeiitic signatures and associated dominant siliciclastic deposition, but also carbonate sediments).
The Cambrian felsic magmatism was characterized by negative Eu-anomalies, (La/Lu)N=0.8â11, 147Sm/144Nd=0.1289â0.1447 and ΔNd500
ranging from â1.5 to â0.8. A tendency towards peraluminous compositions suggests late fractionation, low degrees of partial melting, or the
mixing of crustal and mantle-derived material in the magma source region. Some felsic rocks possibly represent the last residual melts of hightemperature,
zircon-undersaturated mafic magmas later affected by crustal contamination, while others indicate partial melting of crustal
metasediments variably contaminated by basaltic liquids.
The transition from early felsic dominated to later more mafic magmatism suggests the gradual opening of the system to tholeiitic NâE-MORB
products (ThN/TaNb1.0). The as yet undated (Cambrianâ?Ordovician) E-MORB amphibolites have 147Sm/144Nd=0.1478â0.1797 and ΔNd500
values ranging from +6.4 to +7.3, while the N-MORB amphibolites have 147Sm/144Nd=0.1818â0.1979 and ΔNd500 values of +5.8 and +7.0,
reaching a maximum of +9.1. In contrast, other amphibolites have a negative Ta-anomaly (1.35bThN/TaNb2.41) reminiscent of lavas from
âorogenicâ settings or alternatively, typical of crustally-contaminated within-plate magmas. These âVAB-likeâ amphibolites have 147Sm/144Nd
values ranging from 0.1639 to 0.1946 and ΔNd500 values of +3.5 to +5.2, suggesting derivation by crustal assimilation processes. The subalkaline
igneous precursors of the amphibolites were most likely generated in a rift setting by asthenospheric upwelling. These results strengthen the proposed geodynamic scenarios for the SW Iberian Massif by which Cadomian accretion gave rise to an ensialic
rift that developed into a proto-oceanic basin and incipient spreading (opening of the Rheic Ocean?). A similar transition from a convergent to a
divergent plate boundary during the Ediacaran to Cambrianâ?Ordovician has also been reported in other segments of the northern Gondwana
margin
Diseño de un enlace WI-FI autónomo como una solución de conectividad para zonas rurales.
Este documento describe la experiencia de diseño, implementaciĂłn y pruebas de campo de un enlace de largo alcance, alimentado con energĂa solar, utilizando radios Wi-Fi modificando parĂĄmetros de su MAC. El sistema es una alternativa para la conectividad de zonas rurales. Se utilizĂł el simulador RadioMobile durante el proceso de diseño. Se evaluĂł el desempeño del sistema entre dos estaciones separadas 10.22 Km alcanzĂĄndose una tasa promedio de transferencia en TCP de 13.8 Mbps. El sistema se diseñó para permitir una operaciĂłn continua de 24 horas durante 3 dĂas con bajos niveles de radiaciĂłn solar
Diseño de un enlace WI-FI autónomo como una solución de conectividad para zonas rurales.
Este documento describe la experiencia de diseño, implementaciĂłn y pruebas de campo de un enlace de largo alcance, alimentado con energĂa solar, utilizando radios Wi-Fi modificando parĂĄmetros de su MAC. El sistema es una alternativa para la conectividad de zonas rurales. Se utilizĂł el simulador RadioMobile durante el proceso de diseño. Se evaluĂł el desempeño del sistema entre dos estaciones separadas 10.22 Km alcanzĂĄndose una tasa promedio de transferencia en TCP de 13.8 Mbps. El sistema se diseñó para permitir una operaciĂłn continua de 24 horas durante 3 dĂas con bajos niveles de radiaciĂłn solar
Node assembly for waste level measurement: embrace the smart city
Municipal Solid Waste Management Systems (MSWMS) worldwide are currently facing pressure due to the rapid growth of the population in cities. One of the biggest challenges in this system is the inefficient expenditure of time and fuel in waste collection. In this regard, cities/- municipalities in charge of MSWMS could take advantage of information and communication technologies to improve the overall quality of their infrastructure. One particular strategy that has been explored and is showing interesting results is using a Wireless Sensors Network (WSN) to monitor waste levels in real-time and help decision-making regarding the need for collection. The WSN is equipped with sensing devices that should be carefully chosen considering the real scenario in which they will work. Therefore, in this work, three sets of sensors were studied to evaluate which is the best to be used in the future WSN assembled in Bragança, Portugal. Sets tested were HC-SR04 (S1), HC-SR04 + DHT11 (S2), and US-100 (S3). Tests considered for this work were air temperature and several distances. In the first, the performance of each set to measure a fixed target (metal and plastic box) was evaluated under different temperatures (1.7 - 37 â). From these results, two best sets were further used to assess distance measurement at a fixed temperature. This test revealed low absolute errors measuring the distances of interest in this work, ranging from 0.18% to 1.27%.This work has been supported by FCT - Fundação para a CiĂȘncia e Tecnologia within the R&D Units Project Scope: UIDB/05757/2020, UIDB/00690/2020, LA/P/0045/2020, UIDB/50020/2020, and UIDP/50020/2020. Adriano Silva was supported by FCT-MIT Portugal PhD grant SFRH/BD/151346/2021, and Thadeu Brito was supported by FCT PhD grant SFRH/BD/08598 /2020. Jose L. Diaz de Tuesta acknowledges the finantial support through the program of Atraccion de Talento of Atraccion al Talento of the Comunidad de Madrid (Spain) for the individual research grant 2020-T2/AMB-19836.info:eu-repo/semantics/acceptedVersio
Spatial and temporal patterns of Holocene precipitation change in the Iberian Peninsula
Precipitation is a key climate parameter of vegetation and ecosystems in the Iberian Peninsula. Here, we use a regional pollen-climate calibration model and fossil pollen data from eight sites from the Atlantic coast to southern Spain to provide quantitative reconstructions of annual precipitation trends and excursions and their regional patterns for the last 11 700 years. The Early Holocene (11 700 to 11 000 cal. a BP) was characterized by high precipitation values followed by a slowly declining trend until about 9000 cal. a BP in the south and about 8000 cal. a BP in the north. From 8000 to 6000 cal. a BP the reconstructed precipitation values are the highest in most records, especially in those located in the Mediterranean climatic region in the southern part of the peninsula, with maximum values nearly 100% higher than the modern reconstructed values. The results suggest a declining precipitation during the Late Holocene in the south, with a positive excursion at around 2500 cal. a BP, while in the north precipitation remained high until 500 cal. a BP. However, the Late Holocene climate reconstructions in the Iberian Peninsula are biased by intensifying human impact on vegetation. The statistical time series analyses using SiZer technique do not indicate any statistically significant high-frequency drought events in the region. In general, our results suggest regional differences in the precipitation patterns between the northern and southern parts of the peninsula, with a more distinct Middle Holocene period of high humidity in the south.Peer reviewe
Spatial and temporal patterns of Holocene precipitation change in the Iberian Peninsula
Precipitation is a key climate parameter of vegetation and ecosystems in the Iberian Peninsula. Here, we use a regional pollen-climate calibration model and fossil pollen data from eight sites from the Atlantic coast to southern Spain to provide quantitative reconstructions of annual precipitation trends and excursions and their regional patterns for the last 11 700 years. The Early Holocene (11 700 to 11 000 cal. a BP) was characterized by high precipitation values followed by a slowly declining trend until about 9000 cal. a BP in the south and about 8000 cal. a BP in the north. From 8000 to 6000 cal. a BP the reconstructed precipitation values are the highest in most records, especially in those located in the Mediterranean climatic region in the southern part of the peninsula, with maximum values nearly 100% higher than the modern reconstructed values. The results suggest a declining precipitation during the Late Holocene in the south, with a positive excursion at around 2500 cal. a BP, while in the north precipitation remained high until 500 cal. a BP. However, the Late Holocene climate reconstructions in the Iberian Peninsula are biased by intensifying human impact on vegetation. The statistical time series analyses using SiZer technique do not indicate any statistically significant high-frequency drought events in the region. In general, our results suggest regional differences in the precipitation patterns between the northern and southern parts of the peninsula, with a more distinct Middle Holocene period of high humidity in the south.Peer reviewe
Star Formation Under the Outflow: The Discovery of a Non-Thermal Jet from OMC-2 FIR 3 and its Relationship to the Deeply Embedded FIR 4 Protostar
We carried out multiwavelength (0.7-5 cm), multiepoch (1994-2015) Very Large
Array (VLA) observations toward the region enclosing the bright far-IR sources
FIR 3 (HOPS 370) and FIR 4 (HOPS 108) in OMC-2. We report the detection of 10
radio sources, seven of them identified as young stellar objects. We image a
well-collimated radio jet with a thermal free-free core (VLA 11) associated
with the Class I intermediate-mass protostar HOPS 370. The jet presents several
knots (VLA 12N, 12C, 12S) of non-thermal radio emission (likely synchrotron
from shock-accelerated relativistic electrons) at distances of ~7,500-12,500 au
from the protostar, in a region where other shock tracers have been previously
identified. These knots are moving away from the HOPS 370 protostar at ~ 100
km/s. The Class 0 protostar HOPS 108, which itself is detected as an
independent, kinematically decoupled radio source, falls in the path of these
non-thermal radio knots. These results favor the previously proposed scenario
where the formation of HOPS 108 has been triggered by the impact of the HOPS
370 outflow with a dense clump. However, HOPS 108 presents a large proper
motion velocity of ~ 30 km/s, similar to that of other runaway stars in Orion,
whose origin would be puzzling within this scenario. Alternatively, an apparent
proper motion could result because of changes in the position of the centroid
of the source due to blending with nearby extended emission, variations in the
source shape, and /or opacity effects.Comment: 16 pages, 4 figures, accepted for publication in The Astrophysical
Journa
Perception of medical students about courses based on peer-assisted learning in five Peruvian universities
Objectives: Peer-assisted learning (PAL) is a supportive strategy in medical education. In Peru, this method has been implemented by few universities. However, there are no consistent studies evaluating their acceptability by medical students. The objective of this study was to evaluate the perception of medical students about PAL in five Peruvian universities. Results: A total of 79 medical students were included in the study. The mean age was 20.1 ± 1.9 years, 54% were female, and 87% were in the first 4 years of study. Most of the students were satisfied with classes and peer teachers. Similarly, most of the students agreed with the interest in developing teaching skills. It was also observed that 97% of students approved to implement PAL in medical education programs.Revisión por pare
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