415 research outputs found

    Clavicle length and shoulder breadth in hominoid evolution

    Full text link
    For a given body mass, hominoids have longer clavicles than typical monkeys, reflecting the laterad reorientation of the hominoid glenoid. Relative length of the clavicle varies among hominoids, with orangutans having longer clavicles than expected for body mass and gorillas and chimpanzees having shorter clavicles than expected. Modern humans conform to the general hominoid distribution, but Neandertals have longer clavicles than expected for their size. [TRUNCATED

    Comparative primate birth mechanics and the evolution of human childbirth

    Full text link
    Modern humans have large, encephalized neonates, delivered through an anteroposteriorly narrow maternal pelvis constrained by adaptation to bipedality. As a result, human birth is unusually laborious, difficult, and dangerous. The evolutionary background for these difficulties is unclear. Previous comparative studies of nonhuman primates have focused on the pelvic inlet, which is a region of constraint in humans but not in other primates. Therefore, the true obstetric constraints in other species remain unknown. This dissertation documents and quantifies human and other primate birth-canal morphology between the three traditional obstetric planes (inlet, midplane, and outlet). Computer-generated images of scanned specimens of 23 extant anthropoid species and five fossil hominins are used to compare the entire birth canals as three-dimensional entities, documenting and analyzing the functionally relevant metrics of the maternal pelvis and the fetus and their species-specific obstetric constraints. In fossil hominin species for which pelvic material is fragmentary, composite pelves were reconstructed. Measurements on these pelves allow for an estimation of the factors (fetal head and shoulders, pelvic morphology) that produce points of potential dystocia, and shed light on how the modern human birth mechanism evolved. The results of these analyses indicate that some non-human primates have obstetric constraints that exceed those of modern humans. The cephalopelvic disproportion in these species is alleviated through various mechanisms which are unattainable in humans, such as a face-first fetal presentation. Human childbirth can no longer be described as uniquely difficult compared to that of the other primates. Among fossil hominins, birth canal morphology exhibits shape variations that differ from those in modern humans and would have promoted different patterns and mechanisms of birth. The locations of maximum obstetric constraints also vary among hominin species, and the pattern of interspecific variation does not present a linear evolutionary trajectory from “easy” to “difficult” childbirth. The risk of prolapse that accompanies hominin bipedality does result in an adaptation to reduce obstetric constraints, fetal cranial molding, which may have arisen in the hominin lineage ~700,000 years earlier than previously thought

    Azoto

    Get PDF
    1. Introduzione p. 282 2. Determinazione dell\u2019azoto totale con analizzatore elementare p. 284 3. Determinazione dell\u2019azoto totale con metodo semi-micro-Kjeldahl p. 284 4. Determinazione dell\u2019azoto totale con metodo semi-micro-Kjeldahl modificato p. 287 5. Determinazione dell\u2019azoto totale estraibile con soluzione salina con metodo micro-Kjeldahl p. 291 6. Determinazione dell\u2019azoto totale estraibile con soluzione salina con metodo micro-Kjeldahl modificato p.294 7. Determinazione colorimetrica degli ioni ammonio estraibili p. 296 8. Determinazione colorimetrica degli ioni nitrato estraibili p. 298 9. Estrazione dell\u2019azoto totale idrolizzabile con acido cloridrico p. 300 10.Determinazione dell\u2019azoto totale idrolizzabile con acido cloridrico secondo il metodo micro-Kjeldahl p. 30

    Current and Potential Use of Citrus Essential Oils.

    Get PDF
    Since the Middle Ages, citrus essential oils (EOs) have been widely used for their bactericidal, virucidal, fungicidal, antiparasitical, insecticidal, medicinal and cosmetic proprieties. Also nowadays, they find important applications in pharmaceutical, sanitary, cosmetic, agricultural and food industries. The best method to extract EOs from citrus plant tissue is steam distillation because of a variety of extracted volatile molecules such as terpenes and terpenoids, phenol-derived aromatic components and aliphatic components. In vitro physicochemical assays classify most of them as antioxidants

    Lysis of soil microbial cells by CO2 or N2 high pressurization compared with chloroform fumigation

    Get PDF
    The classical chloroform fumigation-incubation (CFI) and fumigation-extraction (CFE) methods are nowadays among the most used for determining soil microbial biomass, although the chloroform lysing of microbial cells is not always complete. Here, we have tested a physical method, used for sterilizing foods but never in soil, based on N-2 or CO2 high pressurization (N2HP or CO2HP, respectively) to cause microbial cell lysis. The N2HP and CO2HP were tested on two soils differing for their organic matter content, one agricultural (AGR) and one forest (FOR), and firstly were compared with the CFI. The CO2 extra-flush from both soils during 10-d incubation by N2HP was lower than that by CFI method, whereas that by CO2HP was greater. Then, the lysis by CO2HP was compared with that by the CFE method by varying CO2 pressure and duration. The CO2HP, at proper conditions, was more efficient than CFE method to cause the lysis of soil microbial cells. Moreover, both CO2 pressure value and duration were important in increasing the extractable organic C compared to the CFE. The most successful combination of high CO2 pressure and duration was 4.13 MPa and 32 h. However, we cannot exclude that CO2HP might have caused the release of soil organic C not ascribable to living organic matter. Further studies using C-13 and/or N-15-labeled microbial cells should assess the release of abiotic organic C

    Enzymatic activity of anthropogenic proto-organic soils in soilless farming

    Get PDF
    In soilless agriculture and horticulture coir is the more used substratum to grow plants because it is widely available and more environmentally friendly than sphagnum or peat. In Italy, soilless agriculture concerns an area of about 1,000 hectares, particularly concentrated in Sicily. The southern coastal belt of this region is the area interested by the most significant experiences in the application of techniques of soilless cultivation that, recently, has been used also for growing table grapes. Starting from the above consideration we suppose that the features of the coconut fiber underlay an evident transformation and that even after few years of table grape cultivation, such organic material undergone to a transformation that allows for the formation of a proto-organic soil (a proto-Histosol, we supposed). If this is true, we believe that, in this case, to speak about soilless cultivation is for sure misleading for the common people, as we should define this cultivation \u201con anthropogenic soils\u201d instead. To fit the aims of this survey we used a big greenhouse devoted to soilless cultivation of table grape in a farm in the Southern SicilyWe have considered the enzymatic activity that characterized the coconut fiber after 3 cycles of cultivation of table grapes. We used as a control the coconut fiber that the farmer used to prepare pots for soilless cultivation and coconut fiber of: 6 pots at the end of the first productive cycle 6 pots at the end of the second cycle and 3 pots at the end of the third cycle. On these organic samples we investigated three enzymes, belonging to oxydoreductase (catalase and dehydrogenase) and hydrolase (urease) classes. Statistical analysis of the investigated enzymes was developed using IBM Statistic SPSS v20 by ANOVA, Tukey test HSD for p 0.01 and Multivariate Statistical Analysis. Results have shown significant differences in enzymes content and quality among coir tests. The use of the coco fiber, as nutritive substratum under fertigation, has positively influenced the growing and proliferation of soil microbes and thus enzymatic activity. In merely 3 productive cycles the stage of decomposition of the organic residues changed highlighting a substantial evolution of such organic material

    Reconstructing birth in \u3ci\u3eAustralopithecus sediba\u3c/i\u3e

    Get PDF
    Hominin birth mechanics have been examined and debated from limited and often fragmentary fossil pelvic material. Some have proposed that birth in the early hominin genus Australopithecus was relatively easy and ape-like, while others have argued for a more complex, human-like birth mechanism in australopiths. Still others have hypothesized a unique birth mechanism, with no known modern equivalent. Preliminary work on the pelvis of the recently discovered 1.98 million-year-old hominin Australopithecus sediba found it to possess a unique combination of Homo and Australopithecus-like features. Here, we create a composite pelvis of Australopithecus sediba to reconstruct the birth process in this early hominin. Consistent with other hominin species, including modern humans, the fetus would enter the pelvic inlet in a transverse direction. However, unlike in modern humans, the fetus would not need additional rotations to traverse the birth canal. Further fetal rotation is unnecessary even with a Homo-like pelvic midplane expansion, not seen in earlier hominin species. With a birth canal shape more closely associated with specimens from the genus Homo and a lack of cephalopelvic or shoulder constraints, we therefore find evidence to support the hypothesis that the pelvic morphology of Australopithecus sediba is a result of locomotor, rather than strictly obstetric constraints

    Effetti degli oli essenziali di agrumi applicati in post-emergenza sul controllo delle infestanti e sulla comunit\ue0 microbica del suolo

    Get PDF
    Sebbene gli erbicidi sintetici ad oggi siano il mezzo pi\uf9 utilizzato per il controllo delle erbe infestanti, \ue8 ampiamente dimostrato che essi hanno un impatto negativo sul suolo, sull'ambiente e, inoltre, iniziano a manifestarsi fenomeni di resistenza. Pertanto, \ue8 importante sviluppare mezzi alternativi che siano al contempo efficaci e rispettosi dell\u2019ambiente. Gli olii essenziali estratti dalle piante sono stati da sempre utilizzati per molteplici usi come agenti battericidi, virucidi, fungicidi, insetticidi, medicinali e cosmetici. Diversi studi hanno dimostrato tali attivit\ue0 degli oli essenziali estratti dagli agrumi, ma scarsi sono gli studi che hanno investigato il loro potenziale uso come erbicidi. Inoltre, anche se diversi studi hanno dimostrato un effetto antimicrobico, tali studi sono stati condotti prevalentemente in vitro e non in vivo. Obiettivo del presente lavoro \ue8 stato quello di valutare la potenzialit\ue0 degli oli essenziali estratti dalle bucce di limone e arancia i) per limitare lo sviluppo delle erbe infestanti e ii) il loro effetto sulla comunit\ue0 microbica del suolo. Gli oli essenziali testati sono stati estratti per idrodistillazione e con pressa a freddo: LI e AI, olio essenziale di limone e arancio, rispettivamente, estratti con pressa a freddo; LU e AU, olio essenziale di limone e arancio, rispettivamente, estratti tramite idrodistillazione. Ai fini del presente lavoro, il suolo utilizzato \ue8 stato prelevato presso un campo sperimentale dell'Universit\ue0 degli Studi di Palermo. Dopo il prelievo, il suolo \ue8 stato essiccato all'aria e setacciato con setaccio con fori del diametro di un centimetro. Successivamente, 500 grammi di suolo sono stati posti in 20 vaschette di alluminio (10 7 20 cm) ed incubati in condizioni naturali. Durante l\u2019incubazione il suolo \ue8 stato mantenuto al 50% della sua capacit\ue0 idrica di campo (WHC). Dopo l\u2019emergenza delle piantine, ovvero alla comparsa della terza foglia (ventesimo giorno dall\u2019inizio dell\u2019incubazione), ciascun olio essenziale \ue8 stato applicato nebulizzandolo sulle piantine, a giorni alterni per una settimana (tre applicazioni in totale). Per ogni vaso e per ogni trattamento, sono stati applicati 5 mL di una soluzione contenente 1 L di acqua, 10 mL di olio essenziale e 1 mL di emulsionante. Nel suolo di controllo la soluzione applicata alle piantine non conteneva olio essenziale. Dopo 15 giorni dall\u2019ultima applicazione dei trattamenti, i suoli sono stati campionati in modo totale, setacciati ed analizzati per la determinazione del carbonio della biomassa microbica (metodo fumigazione-estrazione), respirazione basale (emissione di CO2) e struttura della comunit\ue0 microbica (analisi degli acidi grassi dei fosfolipidi). Inoltre, per ogni trattamento sono stati determinati alcuni parametri delle piante come peso secco e fresco totale, numero di specie e numero di piante per specie. In questo lavoro vengono riportati e discussi i principali risultati

    Las muchachas se fueron, de migraciones y sentires. sobre poemas afrocolombianos que cuentan historias y construyen sujeto femenino

    Get PDF
    Durante la segunda mitad del siglo veinte, la mujer negra que habita en los municipios, ríos y zonas rurales del Pacífico Sur colombiano migra hacia Buenaventura y Santiago de Cali en busca de una nueva vida. Travesía física y espiritual que la poeta guapireña Mary Grueso Romero narra en sus poemas “La negra en la ciudad”, “El mariro que rejé” y “Juramento materno” para construir un sujeto femenino que revindica su valor como ser humano, en una sociedad que la ha invisibilizado y menos preciado durante décadas. “Las muchachas se fueron: de migraciones y sentires” constituye un aporte importante a la memoria histórica, social y política de la población femenina que reside en esta región del país, a través de versos y personajes que, aunque ficcionales, encuentran su raíz en mujeres negras de carne y hueso, poseedoras de una historia que merece ser contadaBreve descripción de Cajambre. Breve descripción de Guapi. Sucedió un febrero (ese primer encuentro con la “pintora de mulecas negras”). A ese amor que nunca olviré (inspirado en Eusebia). Capítulo I: Modelos culturales de ser mujer en el Pacifico colombiano: primeros acercamientos al sujeto femenino en la poesía afrocolombiana de Mary Grueso Romero. Capítulo II: Del río asfalto: narrativas urbanas y transformaciones socioculturales de la mujer negra del Pacifico como discurso y memoria histórica en el poema afrocolombiano de Mary Grueso Romero. A las negritas que roncaban el canalete (inspirado en Lucrecia Panchano). Capítulo III: Pintora de mujeres negras: contexto, discurso y género en los poemas La negra en la ciudad, El mariro que rejé y Juramento materno de Mary Grueso Romero. A mis antepasadas (Inspirado en Mary Grueso Romero). Capítulo IV: Mary Grueso Romero: mujer negra, poeta e historiadora del Pacífico colombiano. Capítulo V: De migraciones y sentires. Travesía inconclusa. Glosario. Bibliografí
    corecore