286 research outputs found
The von Economo neurons in frontoinsular and anterior cingulate cortex in great apes and humans
The von Economo neurons (VENs) are large bipolar neurons located in frontoinsular (FI) and anterior cingulate cortex in great apes and humans, but not other primates. We performed stereological counts of the VENs in FI and LA (limbic anterior, a component of anterior cingulate cortex) in great apes and in humans. The VENs are more numerous in humans than in apes, although one gorilla approached the lower end of the human range. We also examined the ontological development of the VENs in FI and LA in humans. The VENs first appear in small numbers in the 36th week post-conception, are rare at birth, and increase in number during the first 8 months after birth. There are significantly more VENs in the right hemisphere than in the left in FI and LA in postnatal brains of apes and humans. This asymmetry in VEN numbers may be related to asymmetries in the autonomic nervous system. The activity of the inferior anterior insula, which contains FI, is related to physiological changes in the body, decision-making, error recognition, and awareness. The VENs appear to be projection neurons, although their targets are unknown. We made a preliminary study of the connections of FI cortex based on diffusion tensor imaging in the brain of a gorilla. The VEN-containing regions connect to the frontal pole as well as to other parts of frontal and insular cortex, the septum, and the amygdala. It is likely that the VENs in FI are projecting to some or all of these structures and relaying information related to autonomic control, decision-making, or awareness. The VENs selectively express the bombesin peptides neuromedin B (NMB) and gastrin releasing peptide (GRP) which are also expressed in another population of closely related neurons, the fork cells. NMB and GRP signal satiety. The genes for NMB and GRP are expressed selectively in small populations of neurons in the insular cortex in mice. These populations may be related to the VEN and fork cells and may be involved in the regulation of appetite. The loss of these cells may be related to the loss of satiety signaling in patients with frontotemporal dementia who have damage to FI. The VENs and fork cells may be morphological specializations of an ancient population of neurons involved in the control of appetite present in the insular cortex in all mammals. We found that the protein encoded by the gene DISC1 (disrupted in schizophrenia) is preferentially expressed by the VENs. DISC1 has undergone rapid evolutionary change in the line leading to humans, and since it suppresses dendritic branching it may be involved in the distinctive VEN morphology
Title: Von Economo Neurons in the Elephant Brain
Abstract Von Economo neurons (VENs), previously found in humans, all of the great ape species, and four cetacean species, are also present in African and Indian elephants. The VENs in the elephant are primarily found in similar locations to those in the other species. They are most abundant in the fronto-insular cortex (area FI) and are also present at lower density in the anterior cingulate cortex. Additionally, they are found in a dorsolateral prefrontal area and less abundantly in the region of the frontal pole. The VEN morphology appears to have arisen independently in hominids, cetaceans, and elephants, and may reflect a specialization for the rapid transmission of crucial social information in very large brains
Peristaltic Transport of a Physiological Fluid in an Asymmetric Porous Channel in the Presence of an External Magnetic Field
The paper deals with a theoretical investigation of the peristaltic transport
of a physiological fluid in a porous asymmetric channel under the action of a
magnetic field. The stream function, pressure gradient and axial velocity are
studied by using appropriate analytical and numerical techniques. Effects of
different physical parameters such as permeability, phase difference, wave
amplitude and magnetic parameter on the velocity, pumping characteristics,
streamline pattern and trapping are investigated with particular emphasis. The
computational results are presented in graphical form. The results are found to
be in perfect agreement with those of a previous study carried out for a
non-porous channel in the absence of a magnetic field
Acute Subarachnoid Hemorrhage and Cardiac Abnormalities: Takotsubo Cardiomyopathy or Neurogenic Stunned Myocardium? a case report
Abstract
Introduction
Cardiac abnormalities can be seen with subarachnoid hemorrhage. To date, there have been isolated case reports of transient left ventricular apical ballooning cardiomyopathy, also known as Takotsubo cardiomyopathy in patients suffering from subarachnoid hemorrhage.
Case presentation
An adult female was brought to the emergency department with somnolence. A 3 × 3 mm ruptured basilar aneurysm was found and successfully embolized. Two days after the patient developed acute heart failure. Troponin-I was elevated to 4.2 (normal \u3c0.4). On ECG, new symmetric T wave inversion in V3, V4, V5 with prolonged QT were evident. Transthoracic echocardiogram showed severe systolic dysfunction with an ejection fraction of 20% and akinetic apex along with the distal left ventricular segments, consistent with Takotsubo cardiomyopathy. Myocardial contrast echocardiography showed a decrease in capillary blood flow and volume in the akinetic areas with delayed contrast replenishment, sparing the basal segments. A repeat study 2 weeks later showed near normalization of the perfusion parameters. The patient improved with medical management. A repeat echocardiogram, a month later revealed an ejection fraction of 45% with no identifiable wall motion abnormality.
Conclusion
Our case, as well as others reported previously, supports the diagnosis of Takotsubo cardiomyopathy in patients with Subarachnoid Hemorrhage who fulfill the clinical and imaging description of this syndrome
SOLAR POWERED IRRIGATION SYSTEM FOR TURF AREA
Solar water pumping system may be a competitive application for remote and luxurious areas where power costs a lot. One may argue that solar photovoltaic water pumping systems not only comprises an environmentally friendly solution, but also contributes substantially to the satisfaction of remote communities’ water consumption needs. Therefore, the study aimed to manage pump for sprinkler irrigation system operated by solar power in small area of turf. The required hydraulic experiment and measurements were conducted using Direct-coupled photovoltaic pumping system to operating sprinkler irrigation network at the experimental farm of soil and water Research Department, Nuclear Research Center, located at Inshas, Sharkia Governorate, Atomic Energy Authority, Egypt. The essential idea to operate the sprinkler irrigation system and fulfill the water needs of turf area was to use a locally assembled pump-set to match the photovoltaic generator unsteady output. Results indicated that, solar radiation increased during summer (April and July), so the electric power, pump discharge, pressure head, Hydraulic horsepower (hp) and Photovoltaic conversion efficiency are affected as solar radiation changed. Four mathematical equations has been derived to illustrate the relationship between solar radiation and electric power, pump discharge pressure head , water hp and Photovoltaic conversion efficiency (PVCE) during the day hours
Phosphorus And Nitrogen Fertilization Of Soybean In The Nigerian Savanna
Soybean (Glycine max) is a major cash crop in the savannas of Nigeria although productivity is typically
constrained by poor soil fertility. The objective of this research was to determine the interactive effect
of N and P on soybean productivity in the northern Guinea and Sudan savannas of northeast Nigeria.
Experiments were conducted using locally adapted early and late maturing cultivars. Two rates of N and
three rates of P fertilizer were also compared at both sites over two years. At both sites, pods plant−1 and
seed yield were higher in 2006 than in 2007, possibly due to better rainfall distribution in 2006. Nitrogen
fertilizer had no significant effect on seed yield or pods plant−1. Application of P fertilizer increased pods
plant−1 by 40–66%. Averaged across site and year, seed yield with no P was 1057.2 kg ha−1 while yield
with 20 and 40 kg ha−1 P were 1941.0 kg ha−1 and 2371.5 kg ha−1, respectively. No significant interaction
effect between N and P fertilizer on seed yield and pods plant−1 was observed. The late maturing cultivar
yielded less than the earlier maturity group cultivar in 2007 likely due to moisture stress. For optimum
seed yield 40 kg of P fertilizer ha−1 is recommended for soybean production in both locations. Our results
suggest that N fertilizer is not critical for soybean production in this area
The von Economo neurons in the frontoinsular and anterior cingulate cortex
The von Economo neurons (VENs) are large bipolar neurons located in the frontoinsular cortex (FI) and limbic anterior (LA) area in great apes and humans but not in other primates. Our stereological counts of VENs in FI and LA show them to be more numerous in humans than in apes. In humans, small numbers of VENs appear the 36th week postconception, with numbers increasing during the first 8 months after birth. There are significantly more VENs in the right hemisphere in postnatal brains; this may be related to asymmetries in the autonomic nervous system. VENs are also present in elephants and whales and may be a specialization related to very large brain size. The large size and simple dendritic structure of these projection neurons suggest that they rapidly send basic information from FI and LA to other parts of the brain, while slower neighboring pyramids send more detailed information. Selective destruction of VENs in early stages of frontotemporal dementia (FTD) implies that they are involved in empathy, social awareness, and self‐control, consistent with evidence from functional imaging
The von Economo neurons in the frontoinsular and anterior cingulate cortex
The von Economo neurons (VENs) are large bipolar neurons located in the frontoinsular cortex (FI) and limbic anterior (LA) area in great apes and humans but not in other primates. Our stereological counts of VENs in FI and LA show them to be more numerous in humans than in apes. In humans, small numbers of VENs appear the 36th week postconception, with numbers increasing during the first 8 months after birth. There are significantly more VENs in the right hemisphere in postnatal brains; this may be related to asymmetries in the autonomic nervous system. VENs are also present in elephants and whales and may be a specialization related to very large brain size. The large size and simple dendritic structure of these projection neurons suggest that they rapidly send basic information from FI and LA to other parts of the brain, while slower neighboring pyramids send more detailed information. Selective destruction of VENs in early stages of frontotemporal dementia (FTD) implies that they are involved in empathy, social awareness, and self‐control, consistent with evidence from functional imaging
Outcomes and rate of return to play in elite athletes following arthroscopic surgery of the hip.
BACKGROUND: The tremendous physical demands of elite performance increase the risk of elite athletes sustaining various orthopaedic injuries. Hip pain is common in high-level athletes representing up to 6% of all athletic injuries. Expedient diagnosis and effective treatment are paramount for their future sporting careers and to prevent subsequent joint degeneration. PURPOSE: This systematic review aimed to evaluate the outcome and the rate of return to play (RTP) following arthroscopic procedures in the hip (osteoplasty, chondroplasty, labral repair and/or debridement, capsulotomy, capsulorrhaphy or any soft tissue procedure) in elite athletes. Elite athletes were defined as those who represented their country in international contests or were competing professionally for the purpose of this study. METHODS: A computer-based systematic search, following the PRISMA Guidelines, was performed on CENTRAL, PUBMED, EMBASE, SCOPUS, EBSCO, Google Scholar and Web of Science from inception until January 1, 2020, identifying studies that looked at return to sports post-hip arthroscopy in elite athletes. Weighted means were calculated for the RTP rate and duration and for patient-reported outcome measures (PROMs). RESULTS: After eligibility screening, 22 articles were included with a total of 999 male and seven female patients, 1146 hips and a mean age of 28.4 ± 3.2 years. The mean follow-up period was 35.8 ± 13.4 months and 15.9 ± 9.6% of athletes had undergone bilateral procedures. Overall, 93.9% (95% CI: 90.5, 96.6, P < 0.0001) of patients demonstrated RTP after 6.8 ± 2.1 months post-surgery and all PROMs improved post-operatively. During follow-up, 9.6% (95% CI: 5.2, 15.2, P = 0.025) patients needed further intervention. CONCLUSION: A high percentage of elite athletes return to the same level of competition after hip arthroscopy, with a low rate of further interventions. Hip arthroscopy appears to be an efficacious treatment for hip and/or groin pain, caused by pathologies such as FAI or labral tears, in elite athletes in the shorter term. Long term outcomes need further evaluation
Investigation of the physical-mechanical properties and durability of high-strength concrete with recycled PET as a partial replacement for fine aggregates
In this study, PET plastic waste, which is a type of polymer commonly used in the manufacture of plastic bottles, has been incorporated into concrete by partially replacing the natural fine aggregate. An experimental study was conducted by casting and testing 90 concrete cylinders and 54 concrete cubes. A concrete mixture was designed in which the natural fine aggregate was substituted partially with PET plastic waste (PW) at a ratio of 0%, 25%, and 50%, with various w/c ratios of.40,.45, and.55. Physical, mechanical, and durability properties were assessed. The downside of the test results show degradation in each of the following characteristics: slump, compressive strength, splitting tensile strength, ultrasonic pulse velocity, water absorption, and porosity. The degradation of these characteristics increased with the increase in the volume of plastic aggregate (PA) and the w/c ratio. While the positive side of the results showed that with the increase of the PA volume and the w/c ratio, the fresh and dry densities decreased further, and by using 50% PET, the dry density became below 2000 kg/m3. Therefore, it is classified as lightweight concrete. Moreover, the fracture of concrete changed from brittle to more ductile compared to control concrete. Also, the thermal conductivity decreased significantly (11%–47%), and by using 50% of PET, the thermal conductivity became less than.71 W/mK, and accordingly, classified as a bearing insulator
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