120 research outputs found
Physiological and pathological aspects of Aβ in iron homeostasis via 5'UTR in the APP mRNA and the therapeutic use of iron-chelators
Many studies have highlighted the pathological involvement of iron accumulation and iron-related oxidative stress (OS) in Alzheimer's disease (AD). Iron was further demonstrated to modulate expression of the Alzheimer's amyloid precursor holo-protein (APP) by a mechanism similar to that of regulation of ferritin-L and -H mRNA translation through an iron-responsive element (IRE) in their 5' untranslated regions (UTRs). Here, we discuss two aspects of the link between iron and AD, in relation to the recently discovered IRE in the 5'UTR of APP mRNA. The first is the physiological aspect: a compensatory neuroprotective response of amyloid-β protein (Aβ) in reducing iron-induced neurotoxicity. Thus, given that Aβ possesses iron chelation sites, it is hypothesized that OS-induced intracellular iron may stimulate APP holo-protein translation (via the APP 5'UTR) and subsequently the generation of its cleavage product, Aβ, as a compensatory response that eventually reduces OS. The second is the pathological aspect: iron chelating compounds target the APP 5'UTR and possess the capacity to reduce APP translation, and subsequently Aβ levels, and thus represent molecules with high potential in the development of drugs for the treatment of AD
Impact of farmer producer organization on organic chilli production in Telangana, India
33-43Input intensive modern agriculture is adversely affecting human health and environment. Farmers of Telangana state have taken up organic chilli production with the assistance of FPOs. Primary data was collected from 120 farmers comprising 60 members and 60 non-members of FPO from two districts of Telangana through semi-structured interviews. The study found that the shift to organic chilli cultivation led to decrease in input use by 9.06% and yield by 23.4%. However, the gross return from organic chilli farming was 13.85% higher over that realised by non-members due to the efforts of FPOs. DEA analysis revealed that a higher proportion of member farmers (48%) had technical efficiency of more than 60% as compared to non-members (18%). FPOs were instrumental in reduction of transaction cost and number of intermediaries leading to the realization of a higher proportion of producer’s share in consumer’s rupee (65%). Discriminant function analysis revealed that the FPO promoting institutions (44%), ease of doing business (16%) and infrastructure facilities like storage, irrigation, electricity and credit have high influence on performance of the states with respect to FPOs
Multi Scale Curriculum CNN for Context-Aware Breast MRI Malignancy Classification
Classification of malignancy for breast cancer and other cancer types is
usually tackled as an object detection problem: Individual lesions are first
localized and then classified with respect to malignancy. However, the drawback
of this approach is that abstract features incorporating several lesions and
areas that are not labelled as a lesion but contain global medically relevant
information are thus disregarded: especially for dynamic contrast-enhanced
breast MRI, criteria such as background parenchymal enhancement and location
within the breast are important for diagnosis and cannot be captured by object
detection approaches properly.
In this work, we propose a 3D CNN and a multi scale curriculum learning
strategy to classify malignancy globally based on an MRI of the whole breast.
Thus, the global context of the whole breast rather than individual lesions is
taken into account. Our proposed approach does not rely on lesion
segmentations, which renders the annotation of training data much more
effective than in current object detection approaches.
Achieving an AUROC of 0.89, we compare the performance of our approach to
Mask R-CNN and Retina U-Net as well as a radiologist. Our performance is on par
with approaches that, in contrast to our method, rely on pixelwise
segmentations of lesions.Comment: Accepted to MICCAI 201
Adenosquamous carcinoma of breast in a 19 years old woman: a case report
<p>Abstract</p> <p>Background</p> <p>Adenosquamous carcinoma of the breast is a rare form of metaplastic breast carcinoma. We report such a case in a 19 years old female.</p> <p>Case presentation</p> <p>Case notes and histopathology were reviewed. Adenosquamous carcinoma was diagnosed on wide local excision and patient underwent skin-sparing mastectomy with Latissimus dorsi flap reconstruction.</p> <p>Conclusions</p> <p>Adenosquamous carcinoma of the breast is a rare form of metaplastic breast carcinoma. Data on correct management, follow-up and prognosis are very limited but given the high potential for local recurrence, aggressive surgery may be the only option.</p
Conjectures on exact solution of three - dimensional (3D) simple orthorhombic Ising lattices
We report the conjectures on the three-dimensional (3D) Ising model on simple
orthorhombic lattices, together with the details of calculations for a putative
exact solution. Two conjectures, an additional rotation in the fourth curled-up
dimension and the weight factors on the eigenvectors, are proposed to serve as
a boundary condition to deal with the topologic problem of the 3D Ising model.
The partition function of the 3D simple orthorhombic Ising model is evaluated
by spinor analysis, by employing these conjectures. Based on the validity of
the conjectures, the critical temperature of the simple orthorhombic Ising
lattices could be determined by the relation of KK* = KK' + KK'' + K'K'' or
sinh 2K sinh 2(K' + K'' + K'K''/K) = 1. For a simple cubic Ising lattice, the
critical point is putatively determined to locate exactly at the golden ratio
xc = exp(-2Kc) = (sq(5) - 1)/2, as derived from K* = 3K or sinh 2K sinh 6K = 1.
If the conjectures would be true, the specific heat of the simple orthorhombic
Ising system would show a logarithmic singularity at the critical point of the
phase transition. The spontaneous magnetization and the spin correlation
functions of the simple orthorhombic Ising ferromagnet are derived explicitly.
The putative critical exponents derived explicitly for the simple orthorhombic
Ising lattices are alpha = 0, beta = 3/8, gamma = 5/4, delta = 13/3, eta = 1/8
and nu = 2/3, showing the universality behavior and satisfying the scaling
laws. The cooperative phenomena near the critical point are studied and the
results obtained based on the conjectures are compared with those of the
approximation methods and the experimental findings. The 3D to 2D crossover
phenomenon differs with the 2D to 1D crossover phenomenon and there is a
gradual crossover of the exponents from the 3D values to the 2D ones.Comment: 176 pages, 4 figure
What Makes Entrepreneurs Happy? Determinants of Satisfaction Among Founders
This study empirically investigates factors influencing satisfaction levels of founders of new ventures, using a representative sample of 1,107 Dutch founders. We relate entrepreneurial satisfaction (with income, psychological burden and leisure time) to firm performance, motivation and human capital. Founders with high levels of specific human capital are more satisfied with income than those with high levels of general human capital. Intrinsic motivation and that of combining responsibilities lowers stress and leads to more satisfaction with leisure time. Women are more satisfied with their income than men, even though they have a lower average monthly turnover
A Cortical Attractor Network with Martinotti Cells Driven by Facilitating Synapses
The population of pyramidal cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal cells. The Martinotti cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal cells. This distinguishes these neurons from basket cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal cells via one or a few Martinotti cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical speed of processing, with cellular adaptation and synaptic depression having a less prominent role than previously thought
Phosphofructo-1-Kinase Deficiency Leads to a Severe Cardiac and Hematological Disorder in Addition to Skeletal Muscle Glycogenosis
Mutations in the gene for muscle phosphofructo-1-kinase (PFKM), a key regulatory enzyme of glycolysis, cause Type VII glycogen storage disease (GSDVII). Clinical manifestations of the disease span from the severe infantile form, leading to death during childhood, to the classical form, which presents mainly with exercise intolerance. PFKM deficiency is considered as a skeletal muscle glycogenosis, but the relative contribution of altered glucose metabolism in other tissues to the pathogenesis of the disease is not fully understood. To elucidate this issue, we have generated mice deficient for PFKM (Pfkm−/−). Here, we show that Pfkm−/− mice had high lethality around weaning and reduced lifespan, because of the metabolic alterations. In skeletal muscle, including respiratory muscles, the lack of PFK activity blocked glycolysis and resulted in considerable glycogen storage and low ATP content. Although erythrocytes of Pfkm−/− mice preserved 50% of PFK activity, they showed strong reduction of 2,3-biphosphoglycerate concentrations and hemolysis, which was associated with compensatory reticulocytosis and splenomegaly. As a consequence of these haematological alterations, and of reduced PFK activity in the heart, Pfkm−/− mice developed cardiac hypertrophy with age. Taken together, these alterations resulted in muscle hypoxia and hypervascularization, impaired oxidative metabolism, fiber necrosis, and exercise intolerance. These results indicate that, in GSDVII, marked alterations in muscle bioenergetics and erythrocyte metabolism interact to produce a complex systemic disorder. Therefore, GSDVII is not simply a muscle glycogenosis, and Pfkm−/− mice constitute a unique model of GSDVII which may be useful for the design and assessment of new therapies
Determinants of job satisfaction: a European comparison of self-employed and paid employees
The job satisfaction of self-employed and paid-employed workers is analyzed using the European Community Household Panel for the EU-15 covering the years 1994-2001. We distinguish between two types of job satisfaction: job satisfaction in terms of type of work and job satisfaction in terms of job security. Findings from our generalized ordered logit regressions indicate that self-employed individuals as compared to paid employees are more likely to be satisfied with their present jobs in terms of type of work and less likely to be satisfied in terms of job security. The findings also provide many insights into the determinants of the two types of job satisfaction for both self-employed and paid-employed workers
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