scholarly journals Macroscopic aspects of Saimiri sciureus dura mater

2011 ◽  
Vol 31 (suppl 1) ◽  
pp. 7-10 ◽  
Author(s):  
José Fernando Marques Barcellos ◽  
Érika Branco ◽  
Emerson T Fioretto ◽  
Aline A Imbeloni ◽  
José A.P.C Muniz ◽  
...  

Saimiri sciureus is a small New World primate (NHP) commonly called macaco-de-cheiro that inhabits the tropical forests of the Amazon basin. Anatomical features are not well studied in most primates, and the encephalic morphology and related structures are still quite unknown. Comparative anatomy of the meninges in South American primates is still scarce. Dura mater, arachnoid and pia mater are a group of stratified layers that surrounds and promotes protection to the medulla spinalis. This study aimed to shed light on the anatomy of dura mater in Samiri sciureus in order to contribute to the neuroscience in primates. We investigated three young females and two males of S. sciureus. Specimens were fixed through perfusion with a 10% formaldehyde aqueous solution. In S. sciureus encephalus few gyrus and circunvolutions, and a very delicate system consisting of eight sinus venosus was found between the dura mater layers. Based on our findings, we can conclude that the Saimiri sciureus dura mater is quite similar to other mammals, however we detected a new sinus venosus formation at the level of parietal bone, named sinus parietalis, what appears to be its first description.

2021 ◽  
Author(s):  
Marcela Eduarda Della Libera de Godoy ◽  
Valdir F. Novello ◽  
Francisco William Cruz

<p>South American Monsoon System (SAMS) and its main feature, the South American Convergence Zone (SACZ) are responsible for the major distribution of moisture in South America. The current work presents a novel high-resolution oxygen isotope record (δ<sup>18</sup>O) based on speleothems from southwest Amazon basin (Brazil), right at SAMS' core region and SACZ onset, where there is still a gap of high resolution paleoclimate records. The novel δ<sup>18</sup>O record presents an average of 3 year-resolution, composed by 1344 stable isotope analysis performed in two speleothems with a well-resolved chronology (37 U/Th ages) with average errors <1%. This work aims to describe the rainfall variability of the core region of the South American monsoon for the last 3k years and to take a broader look at precipitation patterns over Amazon basin. The Rondônia δ18O record shows three main stages throughout this time period. The first is from -1000 to ~400 CE, where it’s in accordance with most of other paleorecords from the Amazon basin. the second segment  is from ~400 to 1200 CE, when there is a continuous increase in the δ18O record until it reaches its highest values around 850 CE during the MCA (800-1200 CE), which is in accordance with western Amazon records, whilst the record in eastern Amazon presents an opposite trend. Thus, a precipitation dipole over Amazon emerges from ~400 CE onwards, majorly triggered by anomalous climate changes such as MCA, where western (eastern) Amazon is drier (wetter). During LIA (1450-1800 CE), on the other hand, Rondônia record presents its lowest values, also agreeing with western records and with records under the influence of SACZ whilst on eastern Amazon a drier period is established. Therefore, with this novel paleoclimate record located at the core region of SAMS, it's possible to evidence the dynamics of the precipitation dipole over the Amazon region, as well as understand the SACZ intensity variations.</p>


1926 ◽  
Vol 22 (12) ◽  
pp. 1405-1405

Dr. Bronnikov reported a case of Jackson's epilepsy treated operatively. A patient after being wounded with a hammer of the parietal bone first suffered paralysis of the right arm and difficulty in speaking, and after 2 months he had epileptiform seizures every 6 days. In the 4th month, he underwent surgery to remove fragments of the internal lamina pressing on the dura mater, and the defect was closed with a piece of fascia lata with fatty tissue. The patient was demonstrated 3 months after the operation; he had no seizures, his speech was normal, and his hand function had been restored.


1873 ◽  
Vol 19 (87) ◽  
pp. 465-466
Author(s):  
Batty Tuke

Professor Betz, of Kiew, has lately produced brain sections, which have attracted very considerable attention in Vienna. His specimens are of vast extent. He appears to be able to produce thin sections of an entire hemisphere. We append his method of hardening and cutting as it is stated in the “Correspondentze Blatt der deutschen Gesellschaft für Psychiatrie und Gerichtlich Psychologie, Jan., 1873.” The method of hardening which we wish to bring into notice is as follows:—observing that differences exist in the treatment of the spinal-cord, cerebrum and cerebellum. The spinal-cord—after tbe careful removal of the dura mater, it is placed in spirit of from 75 to 80 per cent., which is tinged a clear brown colour by the addition of Iodine. After from one to three days, during which the preparation must stand in a cool temperature, the Pia Mater and the Arachnoid are also removed; the specimen remaining in the spirit, to which a few drops of Iodine must be added daily for three days, maintaining an ordinary temperature. It is then transferred to a three per cent. solution of Chromate of Potass, and back again to the cool temperature. Here it hardens thoroughly, which is known by the fluid becoming turbid, and by the formation of a brown deposit upon the preparation. When this occurs, it must be immediately thoroughly washed with water, and immersed in a solution of Chromate of Potass, from a half to one per cent. strength, in which it will not become too hard or brittle.


Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1594 ◽  
Author(s):  
Beatriz Garcia ◽  
Renata Libonati ◽  
Ana Nunes

The Amazon basin has experienced severe drought events for centuries, mainly associated with climate variability connected to tropical North Atlantic and Pacific sea surface temperature anomalous warming. Recently, these events are becoming more frequent, more intense and widespread. Because of the Amazon droughts environmental and socioeconomic impacts, there is an increased demand for understanding the characteristics of such extreme events in the region. In that regard, regional models instead of the general circulation models provide a promising strategy to generate more detailed climate information of extreme events, seeking better representation of physical processes. Due to uneven spatial distribution and gaps found in station data in tropical South America, and the need of more refined climate assessment in those regions, satellite-enhanced regional downscaling for applied studies (SRDAS) is used in the reconstruction of South American hydroclimate, with hourly to monthly outputs from January 1998. Accordingly, this research focuses on the analyses of recent extreme drought events in the years of 2005 and 2010 in the Amazon Basin, using the SRDAS monthly means of near-surface temperature and relative humidity, precipitation and vertically integrated soil moisture fields. Results from this analysis corroborate spatial and temporal patterns found in previous studies on extreme drought events in the region, displaying the distinctive features of the 2005 and 2010 drought events.


Author(s):  
André Salim Khayat ◽  
Paulo Pimentel de Assumpção ◽  
Bruna Claudia Meireles Khayat ◽  
Taíssa Maíra Thomaz Araújo ◽  
Jéssica Almeida Batista-Gomes ◽  
...  

AbstractThe clinical condition COVID-19, caused by SARS-CoV-2, was declared a pandemic by the WHO in March 2020. Currently, there are more than 5 million cases worldwide, and the pandemic has increased exponentially in many countries, with different incidences and death rates among regions/ethnicities and, intriguingly, between sexes. In addition to the many factors that can influence these discrepancies, we suggest a biological aspect, the genetic variation at the viral S protein receptor in human cells, ACE2 (angiotensin I-converting enzyme 2), which may contribute to the worse clinical outcome in males and in some regions worldwide. We performed exomics analysis in native and admixed South American populations, and we also conducted in silico genomics databank investigations in populations from other continents. Interestingly, at least ten polymorphisms in coding, noncoding and regulatory sites were found that can shed light on this issue and offer a plausible biological explanation for these epidemiological differences. In conclusion, ACE2 polymorphisms should influence epidemiological discrepancies observed among ancestry and, moreover, between sexes.


2021 ◽  
Author(s):  
Juan P. Sierra ◽  
C. Junquas ◽  
J. C. Espinoza ◽  
H. Segura ◽  
T. Condom ◽  
...  

Abstract Amazonian deforestation has accelerated during the last decade, threatening an ecosystem where almost one third of the regional rainfall is transpired by the local rainforest. Due to the precipitation recycling, the southwestern Amazon, including the Amazon-Andes transition region, is particularly sensitive to forest loss. This study evaluates the impacts of Amazonian deforestation in the hydro-climatic connectivity between the Amazon and the eastern tropical Andes during the austral summer (December-January-February) in terms of hydrological and energetic balances. Using 10-year high-resolution simulations (2001–2011) with the Weather Research and Forecasting Model, we analyze control and deforestation scenario simulations. Regionally, deforestation leads to a reduction in the surface net radiation, evaporation, moisture convergence and precipitation (~ 20%) over the entire Amazon basin. In addition, during this season, deforestation increases the atmospheric subsidence over the southern Amazon and weakens the regional Hadley cell. Atmospheric stability increases over the western Amazon and the tropical Andes inhibiting convection in these areas. Consequently, major deforestation impacts are observed over the hydro-climate of the Amazon-Andes transition region. At local scale, nighttime precipitation decreases in Bolivian valleys (~ 20–30%) due to a strong reduction in the humidity transport from the Amazon plains toward Andes linked to the South American low-level jet. Over these valleys, a weakening of the daytime upslope winds is caused by local deforestation, which reduces the turbulent fluxes at lowlands. These alterations in rainfall and atmospheric circulation could impact the rich Andean ecosystems and its tropical glaciers.


Author(s):  
Cameron Jones

While it is certainly true that more academic studies have focused on the North American missions, in terms of their historical impact South American missions were just as important to the frontiers of Spain and Portugal’s American empires. The massive size alone of the frontier region, stretching from the upper reaches of the Amazon basin to the headwaters of the Paraná as well as stretching across the lower Southern Cone, meant numerous missionary enterprises emerged in an attempt to evangelize the peoples who inhabited these regions. While small handfuls of Dominicans, Mercedarians, and Augustinians would engage in such efforts, most missions were established by the Jesuits or Franciscans. Certainly, for the Jesuits, or the Society of Jesus as they are properly known, American missions represented an extension of the Counter-Reformation for which they were created. Starting in the mid-16th century, this relatively new organization, founded in 1534, began in earnest to “reduce” the Indigenous peoples into their missions. These activities, however, abruptly ended when the Jesuits were expelled from both the Portuguese and Spanish empires in 1759 and 1767 respectfully. The much older Franciscan order had extensive experience in popular missions in Europe and was one of the first orders of regular clergy in the Americas. Franciscans, like the Jesuits, engaged in evangelizing activities throughout both North and South America from the colonial period to the present. The expulsion of the Jesuits, however, pushed them further to the forefront of missionizing efforts in the late colonial period. This acceleration of Franciscan missionary activity was aided by the establishment of the Apostolic Institute in 1682. The Institute created a pipeline of missionaries from Spain to come directly to frontier areas with funding from the crown. While this aided missionary efforts throughout South America, particularly in areas abandoned by the Jesuits, it embroiled the missionaries in the politics of the Bourbon reforms and their obsession with limited clerical power. Ultimately, while missionizing efforts continued into the Republican period, their association with the Spanish and Portuguese crowns led to widespread suppression and secularization following independence. The historiographical divide in the field tends to lie between usually older, Eurocentric histories by scholar-clerics which focus on the missionaries themselves, and newer studies carried out by more secular professional historians that examine how Indigenous populations were affected by the inherent imperialism of the missions, though exceptions abound.


Zootaxa ◽  
2020 ◽  
Vol 4751 (1) ◽  
pp. 75-104
Author(s):  
MAURICIO M. ROCHA ◽  
ELIANA M. CANCELLO

In this contribution we present updates on the taxonomy and morphology of the South American species of Amitermes. Two new species are described: Amitermes bandeirai, sp. n., from Brazil, and Amitermes lilloi, sp. n., from Argentina. Amitermes nordestinus is a junior synonym of Amitermes aporema. The imago of A. aporema is described for the first time. Detailed comparative gut anatomy of the eight species is presented for the first time. The geographic distribution of Amitermes in South America is expanded and the distribution patterns of some species are discussed. 


1889 ◽  
Vol 35 (150) ◽  
pp. 261-271 ◽  

S. Beljahow communicated to the Psychiatric Association of St. Petersburg his observations on four brains of senile dements (“Neurologisches Centralblatt,” No. 3, 1887). Three of these subjects were women. The weights of the brains were 1030, 1035, 1080, and 1100 grammes. Their ages ran from 64 to 75 years. The pathological alterations were similar in all the four cases. There was hardening of the cranial bones; in some cases the diploe had entirely disappeared. The dura mater was found united with the cranium; there was also pachymeningitis hæmorrhagica. The pia mater was thickened, and when detached from the cortex brought away a portion of matter with it. The convolutions were slender; the fissures wider than usual; the cortical portion of the brain diminished in thickness; the vessels of the base of the brain, especially the basilar carotids and the arteries of the Sylvian fissure, were sclerosed and their walls in some places calcified.


1991 ◽  
Vol 74 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Hiroaki Sakamoto ◽  
Akira Hakuba ◽  
Ken Fujitani ◽  
Shuro Nishimura

✓ In a series of 75 patients with surgically treated lipomyelomeningoceles, the neurological condition of six patients deteriorated 6 months to 14 years after the operation due to repeat tethering of the spinal cord. The tethering resulted from postoperative dense adhesion between the cord and the overlying dura mater. Two of the six patients underwent conventional repeat untethering procedures, and the remaining four were successfully treated with a new surgical technique developed by the authors to prevent such dural adhesion. For this procedure, after complete untethering of the spinal cord, the lumbosacral cord is retained in the center of the dural sac by fine stay sutures between the pia mater of the conus medullaris and the ventral dura mater. In addition, the dura mater is tacked to the posterior arch which is reconstructed with bone grafts at one or two bifid vertebral levels. During a postoperative follow-up period of 1 to 3 years, no further deterioration has been observed and magnetic resonance studies have demonstrated a space filled with cerebrospinal fluid (CSF) around the lumbosacral cord. The authors conclude that long-term observation, both neurological and radiological, is essential even after successful repair of a lipomyelomeningocele. This new surgical procedure can maintain a CSF bath around the lumbosacral cord, thus preventing dural adhesion. Application of this technique will hopefully be beneficial in lipomyelomeningocele patients with a high risk of cord retethering after initial repair.


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