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“A gente se vira nas entregas”: experiências de trabalho dos cicloentregadores à luz do discurso empreendedor
(Universidade Federal de São Carlos, 2024-06-14) Perin, João Pedro Ferreira; Pires, Aline Suelen; https://lattes.cnpq.br/8860270341724853; https://orcid.org/0000-0001-5932-1050; https://lattes.cnpq.br/6043529633287444; https://orcid.org/0000-0001-7045-7397
Au milieu des récentes évolutions impliquant l'intensification de la flexibilité des relations et des contrats de travail, associée à l'impératif d'une rationalité entrepreneuriale comme moyen de justifier les modes d'être et de vivre dans le monde d'aujourd'hui, la plateformisation du travail se consolide de plus en plus. Le travail sur plateforme correspond aux activités qui sont médiées, organisées et régies par le biais de plateformes numériques. Ces dernières années, plusieurs villes brésiliennes ont vu apparaître des livreurs à vélo via des applications, plus connus sous le nom de livreurs à vélo. Cette catégorie est principalement composée de jeunes noirs et périphériques. Dans ce contexte, cette étude vise à comprendre et analyser comment l'entrepreneuriat est assimilé et utilisé en tant que stratégie construite, redéfinie et expérimentée par les livreurs à vélo dans la municipalité de São Paulo-SP. Cette recherche a été menée auprès des livreurs par application dans la capitale pauliste, en se concentrant sur un groupe de cyclistes livreurs près de la Praça da República. L'étude, d'ethnographie, a impliqué une observation participante et des entretiens approfondis, analysant les trajectoires des interviewés. Les résultats indiquent qu'une partie significative des livreurs à vélo rejette les relations de travail dont le cadre normatif est l'emploi salarié (contrat de travail). Cet horizon d'attentes est construit autour de la perception de liberté et d'autonomie, ce qui signifie objectivement la possibilité de définir ses propres horaires de travail, perçue de manière positive. Pour eux, l'idée de l'entrepreneuriat a une valorisation positive et représente une possibilité réelle de vie et de travail compatible avec leurs valeurs. Les livreurs à vélo assimilent la culture entrepreneuriale à travers un ensemble de pratiques et de valeurs qui forment une éthique de la débrouillardise, développée tout au long de leurs trajectoires de vie complexes, marquées par des environnements incertains, rares et parfois violents. Cela conduit à des interprétations variées du discours entrepreneurial, l'adaptant à leurs besoins quotidiens pour atteindre des objectifs spécifiques et planifier des stratégies financières et des projets d'avenir.
Aspectos da fresagem em pavimentos reforçados com geossintéticos e impacto do fresado (RAP) nas propriedades de misturas asfálticas recicladas
(Universidade Federal de São Carlos, 2024-06-14) Souza, Tiago Rodrigues; Correia, Natália de Souza; https://lattes.cnpq.br/2172645507238077; https://lattes.cnpq.br/6863267919854381
With the growing use of geosynthetic interlayers, such as geogrids, geotextiles and paving geocomposites in asphalt rehabilitation projects, there is an anticipated increase in cases where asphalt layers containing these interlayers need to be milled. While there is substantial experience in milling traditional asphalt layers, the presence of polymeric or fiberglass interlayers introduces new challenges to pavement engineering. As a result, understanding how the milling process for asphalt layers with geosynthetic interlayers differs from conventional asphalt milling has become increasingly important. The milled material, referred to as Reclaimed Asphalt Pavement (RAP) when containing geosynthetics, here nominated G-RAP, exhibits unique characteristics that differentiate it from conventional RAP. Due to the limited information on the milling processes and characteristics of RAP produced from geosynthetic-reinforced pavements, it is essential to explore the millability of these reinforced pavements and the challenges associated with milling them. Furthermore, research should be conducted to assess the feasibility of reusing G-RAP in the production of new recycled asphalt mix. This study involved constructing an experimental test track with five different geosynthetic-reinforced asphalt sections at Salvador International Airport in Brazil. The findings indicated that all geosynthetic interlayers were capable of being milled without causing inefficiencies in the milling operations. Successful milling was achieved by operating at the maximum milling speed of 320 rpm, with the use of water. Fiberglass products were observed to mill effectively, while polymeric products showed minor entanglements. It is recommended that the milling depth be at least 25 mm below the geosynthetic position within the asphalt layers. G-RAPs were collected and characterized, showing physical differences and positive mechanical influences in new HMA mixtures recycled with 20% G-RAP, particularly in Marshall stability, Indirect Tensile Strength, and Resilient Modulus Marshall stability. The results of the present study confirm that geosynthetic-reinforced asphalt layers are millable, with potential for the reuse of the generated G-RAP in new asphalt mixtures.
Administração crônica de melatonina sobre o tecido ósseo de ratas com hipoestrogenismo induzido
(Universidade Federal de São Carlos, 2024-06-14) Castro, Milena Rossales; Beck, Wladimir Rafael; https://lattes.cnpq.br/3124811889307056
Hypoestrogenism is associated with imbalances in bone tissue. Hormonal deficiency compromises bone remodeling and increases the chances of fractures. In this context, melatonin has been studied as a promising pharmacological method and an alternative to treatments with adverse effects. However, bone is not a simple organ to modulate, and there are inconclusive findings in the literature regarding the appropriate hormonal protocol to observe impacts on bone properties. In the present study, we evaluated the effects of chronic melatonin administration under hypoestrogenism conditions on bone parameters commonly compromised by estrogen deficiency. Forty female Wistar rats were randomly divided into four groups: control group (GC); ovariectomized group (GO); melatonin group (GM); and ovariectomized + melatonin group (GOM). GO and GOM underwent bilateral ovariectomy at 15 weeks of age to induce hypoestrogenism. One week later, daily administration of melatonin (10 mg/kg) by orogastric gavage began, during the animals' nighttime period, over 12 weeks. After this intervention period, femurs were collected and bone tissue analyses were conducted, including metric, physical, chemical, and mechanical measurements. Data are presented as mean ± standard deviation and were analyzed using two-way ANOVA to compare the effects of ovariectomy (OVX) and melatonin (MEL), with Newman-Keuls post-hoc test at a 5% significance level. The results show that MEL increased bone length (F=10.02, p<0.05), with no effect from OVX. OVX reduced bone density (F=28.76, p<0.01) and mineral density (F=50.34, p<0.01), with no effect from MEL. OVX increased bone water content (F=29.58, p<0.01) and reduced mineral percentage (F=36.87, p<0.01), with no effect from MEL on both. In the cortical fracture test, OVX had no effect on maximum load and fracture load, while MEL increased both properties (F=9.93, p<0.01; F=7.36, p<0.05). For calcium and phosphorus content, there was no significant effect from OVX and MEL. Overall, OVX caused impairments in bone parameters, and MEL had partial beneficial effects, but was not effective in neutralizing all the consequences of estrogen deficiency. Despite this, considering the comprehensive analysis of the investigated parameters, hormonal treatment showed potential in mitigating bone quality deterioration in contexts of osteometabolic disorders induced by hypoestrogenism.
Plantas indicadoras e relações edafológicas em hortas urbanas no município de São Paulo (SP)
(Universidade Federal de São Carlos, 2024-06-14) Souza, Angélica Oliveira de; Nascimento, Ana Paula Branco do; https://lattes.cnpq.br/1522795968175184; https://orcid.org/0000-0001-5342-8359; Borsatto, Ricardo Serra; https://lattes.cnpq.br/5988987575101933; https://lattes.cnpq.br/1540034194021657; https://orcid.org/0009-0009-1966-8397
Sustainable agriculture is one of the pathways to sustainable development of the planet. In this context, urban gardens can contribute to the Sustainable Development Goals (SDGs) of the 2030 Agenda, proposed by the United Nations (UN) in 2015. The present study aimed to characterize urban gardens in the municipality of São Paulo, verify the presence of spontaneous plants, and their correlation with soil nutrients. Ten urban gardens were selected within the municipality of São Paulo. Initially, the gardens were characterized through the author's visits, using photographs and observations with the respective managers. Next, the species of spontaneous plants present in these spaces were identified and quantified. Subsequently, a phytosociological survey was conducted. Finally, soil analyses were performed to correlate soil quality with the spontaneous plants found in the gardens. During the on-site visits, it was found that these gardens contribute to the SDGs by conserving green areas in the city, promoting environmental education, social interaction, production, and access to healthy food for the urban and peri-urban population. The most representative (relative importance) spontaneous plant species found, with invasive potential, were Trapoeraba (Commelina benghalensis L.), Picão-branco (Galinsoga parviflora Cav.) and Dinheiro-em-penca (Callisia repens.). Soil analyses demonstrated some positive correlations between plants and nutrients, indicating the amount of organic matter in the species with the highest relative importance, such as Commelina benghalensis, Amaranthus sp., and Galinsoga parviflora. But studies with a larger number of samples are still needed to obtain more conclusive results. Some of the plants found have food and medicinal potential.