WorldWideScience

Sample records for neurofibrillary tangles observed

  1. Neurofibrillary tangles in dementia pugilistica are ubiquitinated.

    OpenAIRE

    Dale, G E; Leigh, P. N.; P. Luthert; Anderton, B H; Roberts, G. W.

    1991-01-01

    Ubiquitin, a protein thought to be involved in the ATP-dependent non-lysosomal degradation of abnormal proteins, has already been identified as a component of neurofibrillary tangles in Alzheimer's disease. We have examined ubiquitin immunoreactivity in a unique collection of brains from 16 ex-boxers including 11 with dementia pugilistica. Neurofibrillary tangles of dementia pugilistica were labelled with an affinity purified antiserum to ubiquitin, and BF10, a monoclonal antibody to a neurof...

  2. Diffuse neurofibrillary tangles with calcification: a new presenile dementia.

    OpenAIRE

    Kosaka, K

    1994-01-01

    The term "diffuse neurofibrillary tangles with calcification" (DNTC) is proposed for a new form of presenile dementia. It is characterised by slowly progressive cortical dementia in the presenium, localised temporal or temporofrontal lobar atrophy, numerous neurofibrillary tangles widespread in the cerebral cortex, and pronounced calcareous deposits; 16 cases of DNTC, have been reported.

  3. Neurofibrillary tangles in some cases of dementia pugilistica share antigens with amyloid beta-protein of Alzheimer's disease.

    OpenAIRE

    Allsop, D; Haga, S; Bruton, C; Ishii, T.; Roberts, G. W.

    1990-01-01

    Formalin-fixed, paraffin-embedded temporal lobe sections from eight former boxers' brains were examined using an immunohistochemical method with antibodies to amyloid beta protein. In accord with recent observations in Alzheimer's disease, significant numbers of beta-protein immunoreactive neurofibrillary tangles (NFT) were observed in three cases. Most of these immunoreactive NFTs appeared to be tombstone tangles, although not all such tangles were stained. This immunoreaction was completely...

  4. [F-18]-AV-1451 binding correlates with postmortem neurofibrillary tangle Braak staging.

    Science.gov (United States)

    Marquié, Marta; Siao Tick Chong, Michael; Antón-Fernández, Alejandro; Verwer, Eline E; Sáez-Calveras, Nil; Meltzer, Avery C; Ramanan, Prianca; Amaral, Ana C; Gonzalez, Jose; Normandin, Marc D; Frosch, Matthew P; Gómez-Isla, Teresa

    2017-06-13

    [F-18]-AV-1451, a PET tracer specifically developed to detect brain neurofibrillary tau pathology, has the potential to facilitate accurate diagnosis of Alzheimer's disease (AD), staging of brain tau burden and monitoring disease progression. Recent PET studies show that patients with mild cognitive impairment and AD dementia exhibit significantly higher in vivo [F-18]-AV-1451 retention than cognitively normal controls. Importantly, PET patterns of [F-18]-AV-1451 correlate well with disease severity and seem to match the predicted topographic Braak staging of neurofibrillary tangles (NFTs) in AD, although this awaits confirmation. We studied the correlation of autoradiographic binding patterns of [F-18]-AV-1451 and the stereotypical spatiotemporal pattern of progression of NFTs using legacy postmortem brain samples representing different Braak NFT stages (I-VI). We performed [F-18]-AV-1451 phosphor-screen autoradiography and quantitative tau measurements (stereologically based NFT counts and biochemical analysis of tau pathology) in three brain regions (entorhinal cortex, superior temporal sulcus and visual cortex) in a total of 22 cases: low Braak (I-II, n = 6), intermediate Braak (III-IV, n = 7) and high Braak (V-VI, n = 9). Strong and selective [F-18]-AV-1451 binding was detected in all tangle-containing regions matching precisely the observed pattern of PHF-tau immunostaining across the different Braak stages. As expected, no signal was detected in the white matter or other non-tangle containing regions. Quantification of [F-18]-AV-1451 binding was very significantly correlated with the number of NFTs present in each brain region and with the total tau and phospho-tau content as reported by Western blot and ELISA. [F-18]-AV-1451 is a promising biomarker for in vivo quantification of brain tau burden in AD. Neuroimaging-pathologic studies conducted on postmortem material from individuals imaged while alive are now needed to confirm these observations.

  5. An autopsy case of a centenarian with the pathology of senile dementia of the neurofibrillary tangle type.

    Science.gov (United States)

    Iwasaki, Yasushi; Deguchi, Akira; Mori, Keiko; Ito, Masumi; Mimuro, Maya; Yoshida, Mari

    2017-03-01

    A Japanese woman showed slowly progressive memory disturbance since the age of 85 years. Later, disorientation gradually appeared. Head computed tomography revealed severe hippocampal atrophy, particularly in the posterior portion, and lateral ventricular dilatation, particularly in the inferior horn at the age of 99 years. The amygdala was relatively preserved from atrophy, and atrophy of the frontal lobe was relatively mild for her age. Apolipoprotein E gene analysis showed the ε3 homozygous phenotype. The woman died at the age of 101 years, and her clinical diagnosis was mild Alzheimer's disease. No apparent behavioural and psychological symptoms of dementia were observed during the disease course. Autopsy revealed severe hippocampal atrophy with numerous neurofibrillary tangles and ghost tangles, particularly in the hippocampal region, but senile plaques were rarely observed in the brain. The pathological findings were compatible with senile dementia of the neurofibrillary tangle type, whereas other neurodegenerative disorders were not recognized. The clinicopathologic findings of the present case are considered significant for the clinical diagnosis and pathogenesis of senile dementia of the neurofibrillary tangle type. © 2016 The Authors. Psychogeriatrics © 2016 Japanese Psychogeriatric Society.

  6. Evidence for participation of aluminum in neurofibrillary tangle formation and growth in Alzheimer's disease.

    Science.gov (United States)

    Walton, J R

    2010-01-01

    This study examines hippocampal CA1 cells from brains of aged humans, with and without Alzheimer's disease, for hyperphosphorylated tau and aluminum during early neurofibrillary tangle (NFT) formation and growth. A very small proportion of hippocampal pyramidal cells contain cytoplasmic pools within their soma that either appear homogeneous or contain short filaments (i.e., early NFTs). The cytoplasmic pools are aggregates of an aluminum/hyperphosphorylated tau complex similar to that found in mature NFTs. The photographic evidence presented combines with existing evidence to support a role for aluminum in the formation and growth of NFTs in neurons of humans with Alzheimer's disease.

  7. Expression of CD74 is increased in neurofibrillary tangles in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Castellani Rudy J

    2008-09-01

    Full Text Available Abstract Alzheimer disease (AD is a chronic neurodegenerative disease that is characterized by progressive memory loss. Pathological markers of AD include neurofibrillary tangles, accumulation of amyloid-β plaques, neuronal loss, and inflammation. The exact events that lead to the neuronal dysfunction and loss are not completely understood. However, pro-inflammatory cytokines, such as interleukin-1β, interleukin-6, and tumor necrosis factor α, are increased in AD, along with gene expression of major histocompatibility complex (MHC class II molecules and macrophage migration inhibitory factor (MIF. MHC class II molecules are found in microglia of the brain, while MIF is found in both microglia and neurons of the hypothalamus, hippocampus, and cortex. MIF is not only a lymphocyte mediator but also a pituitary factor with endocrine properties and can mediate phosphorylation of the extracellular signal-regulated kinase-1/2 MAP kinases pathway. In this study, we looked at CD74, an integral membrane protein that acts as both a chaperone for MHC class II molecules as well as a receptor binding site for MIF. CD74 was recently found to be increased in microglia in AD cases compared to age-matched controls, but has not been reported in neurons. In our analysis, immunohistochemistry revealed a significant increase in CD74 primarily in neurofibrillary tangles, amyloid-β plaques, and microglia. This is the first finding to our knowledge that CD74 is increased in neurons of AD cases compared to age-matched control cases.

  8. [Primary age-related tauopathy (PART): a novel term to describe age-related tangle pathology encompassing a wide range from cognitively normal condition to senile dementia of the neurofibrillary tangle type].

    Science.gov (United States)

    Yamada, Masahito

    2016-03-01

    It has been reported that neurofibrillary tangles (NFTs) are commonly observed in older people, and that some of older individuals with dementia have a large amount of NFTs in the medial temporal lobe without amyloid(Aβ) plaques, which have been referred to as senile dementia of the NFT type (SD-NFT), tangle-predominant senile dementia (TPSD), or tangle-only dementia. In 2014, our international collaborative group proposed a new term, "primary age-related tauopathy(PART)", to describe such age-related tangle pathology, clinically encompassing a wide range from normal to cognitive impairment/ dementia (SD-NFT). This nomenclature would provide a conceptual foundation for future studies leading to development of clinical diagnosis for this condition.

  9. Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy.

    Science.gov (United States)

    Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

    2014-03-06

    Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. "Tangle busting" compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 min, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Neuropathologically defined subtypes of Alzheimer's disease differ significantly from neurofibrillary tangle-predominant dementia.

    Science.gov (United States)

    Janocko, Nicholas J; Brodersen, Kevin A; Soto-Ortolaza, Alexandra I; Ross, Owen A; Liesinger, Amanda M; Duara, Ranjan; Graff-Radford, Neill R; Dickson, Dennis W; Murray, Melissa E

    2012-11-01

    Alzheimer's disease (AD) can be classified based on the relative density of neurofibrillary tangles (NFTs) in the hippocampus and association cortices into three subtypes: typical AD, hippocampal-sparing AD (HpSp AD), and limbic-predominant AD (LP AD). AD subtypes not only have pathologic, but also demographic, clinical, and genetic differences. Neurofibrillary tangle-predominant dementia (NFTD), a disorder with NFTs relatively restricted to limbic structures, shares this feature with LP AD raising the possibility that NFTD is a variant of AD. The objective criteria for pathologic diagnosis of NFTD are not available. A goal of this study was to design a mathematical algorithm that could diagnose NFTD from NFT and senile plaque (SP) counts in hippocampus and association cortices, analogous to that used to subtype AD. Moreover, we aimed to compare pathologic, demographic, clinical, and genetic features of NFTD (n = 18) with LP AD (n = 19), as well as the other AD subtypes, typical AD (n = 52) and HpSp AD (n = 17). Using digital microscopy, we confirmed that burden of phospho-tau (CP13) and of an NFT conformational epitope (Ab39) correlated with NFT densities and showed expected patterns across AD subtypes. HpSp AD had the highest and LP AD had the lowest burden of cortical CP13 and Ab39 immunoreactivity. On the other hand, cortical β-amyloid burden did not significantly differ between AD subtypes. Semi-quantitative assessment of SPs in the basal ganglia did show HpSp AD to have significantly more frequent presence of SPs compared to typical AD, which was more frequent than LP AD. Compared to LP AD, NFTD had an older age at disease onset and shorter disease duration, as well as lower Braak NFT stage. NFTs and SPs on thioflavin-S fluorescent microscopy, as well as CP13, Ab39, and Aβ immunoreactivities were very low in the frontal cortex of NFTD, differentiating NFTD from AD subtypes, including LP AD. MAPT H1H1 genotype frequency was high (~70 %) in NFTD and LP AD

  11. Factors responsible for neurofibrillary tangles and neuronal cell losses in tauopathy.

    Science.gov (United States)

    Wakasaya, Yasuhito; Kawarabayashi, Takeshi; Watanabe, Mitsunori; Yamamoto-Watanabe, Yukiko; Takamura, Ayumi; Kurata, Tomoko; Murakami, Tetsuro; Abe, Koji; Yamada, Kiyofumi; Wakabayashi, Koichi; Sasaki, Atsushi; Westaway, David; Hyslop, Peter St George; Matsubara, Etsuro; Shoji, Mikio

    2011-04-01

    TgTauP301L mice that overexpress the mutant human tauP301L present in FTDP-17 reproduce neurofibrillary tangles (NFTs), neuronal cell losses, memory disturbance, and substantial phenotypic variation. To demonstrate factors responsible for NFT formation and neuronal cell losses, sets of TgTauP301L for comparison with or without NFTs and neuronal cell losses were studied with oligonucleotide microarrays. Gene expressions were altered in biological pathways, including oxidative stress, apoptosis, mitochondrial fatty acid betaoxidation, inflammatory response pathway, and complement and coagulation cascade pathways. Among 24 altered genes, increased levels of apolipoprotein D (ApoD) and neuronal PAS domain protein 4 (Npas4) and decreased levels of doublecortin (DCX) and potassium channel, voltage-gated, shaker-related subfamily, β member 1 (Kcnab1) were found in the TgTauP301L with NFTs and neuronal cell losses, Alzheimer's brains, and tauopathy brains. Thus, many biological pathways and novel molecules are associated with NFT formation and neuronal cell losses in tauopathy brains. Copyright © 2011 Wiley-Liss, Inc.

  12. Senile dementia of the neurofibrillary tangle type (tangle-only dementia): neuropathological criteria and clinical guidelines for diagnosis.

    Science.gov (United States)

    Yamada, Masahito

    2003-12-01

    Senile dementia of the NFT type (SD-NFT) is a subset of dementia in the elderly, characterized by numerous NFT in the hippocampal region and absence or scarcity of senile plaques throughout the brain. Senile dementia-NFT has also been referred to as tangle-only dementia, NFT-predominant form of SD, SD with tangles, or limbic NFT dementia. Herein are proposed the criteria for neuropathological diagnosis of SD-NFT: (i) late-onset dementia with abundant NFT in the hippocampal region and absence or scarcity of senile plaques (amyloid beta protein deposits) throughout the brain; and (ii) exclusion of other dementias with NFT. Some elderly individuals suffering from memory disorder without obvious dementia have neuropathological findings similar to SD-NFT, and they would represent a condition in the process of formation of the SD-NFT pathology. Guidelines for the clinical diagnosis of SD-NFT are also proposed; development of reliable diagnostic tests is necessary to differentiate AD and other neurodegenerative dementias from SD-NFT.

  13. Linking traumatic brain injury to chronic traumatic encephalopathy: identification of potential mechanisms leading to neurofibrillary tangle development.

    Science.gov (United States)

    Lucke-Wold, Brandon Peter; Turner, Ryan Coddington; Logsdon, Aric Flint; Bailes, Julian Edwin; Huber, Jason Delwyn; Rosen, Charles Lee

    2014-07-01

    Significant attention has recently been drawn to the potential link between head trauma and the development of neurodegenerative disease, namely chronic traumatic encephalopathy (CTE). The acute neurotrauma associated with sports-related concussions in athletes and blast-induced traumatic brain injury in soldiers elevates the risk for future development of chronic neurodegenerative diseases such as CTE. CTE is a progressive disease distinguished by characteristic tau neurofibrillary tangles (NFTs) and, occasionally, transactive response DNA binding protein 43 (TDP43) oligomers, both of which have a predilection for perivascular and subcortical areas near reactive astrocytes and microglia. The disease is currently only diagnosed postmortem by neuropathological identification of NFTs. A recent workshop sponsored by National Institute of Neurological Disorders and Stroke emphasized the need for premortem diagnosis, to better understand disease pathophysiology and to develop targeted treatments. In order to accomplish this objective, it is necessary to discover the mechanistic link between acute neurotrauma and the development of chronic neurodegenerative and neuropsychiatric disorders such as CTE. In this review, we briefly summarize what is currently known about CTE development and pathophysiology, and subsequently discuss injury-induced pathways that warrant further investigation. Understanding the mechanistic link between acute brain injury and chronic neurodegeneration will facilitate the development of appropriate diagnostic and therapeutic options for CTE and other related disorders.

  14. Bridging integrator 1 (BIN1) protein expression increases in the Alzheimer's disease brain and correlates with neurofibrillary tangle pathology.

    Science.gov (United States)

    Holler, Christopher J; Davis, Paulina R; Beckett, Tina L; Platt, Thomas L; Webb, Robin L; Head, Elizabeth; Murphy, M Paul

    2014-01-01

    Recent genome wide association studies have implicated bridging integrator 1 (BIN1) as a late-onset Alzheimer's disease (AD) susceptibility gene. There are at least 15 different known isoforms of BIN1, with many being expressed in the brain including the longest isoform (iso1), which is brain-specific and localizes to axon initial segments and nodes of Ranvier. It is currently unknown what role BIN1 plays in AD. We analyzed BIN1 protein expression from a large number (n = 71) of AD cases and controls from five different brain regions (hippocampus, inferior parietal cortex, inferior temporal cortex, frontal cortex (BA9), and superior and middle temporal gyri). We found that the amount of the largest isoform of BIN1 was significantly reduced in the AD brain compared to age-matched controls, and smaller BIN1 isoforms were significantly increased. Further, BIN1 was significantly correlated with the amount of neurofibrillary tangle (NFT) pathology but not with either diffuse or neuritic plaques, or with the amount of amyloid-β peptide. BIN1 is known to be abnormally expressed in another human disease, myotonic dystrophy, which also features prominent NFT pathology. These data suggest that BIN1 is likely involved in AD as a modulator of NFT pathology, and that this role may extend to other human diseases that feature tau pathology.

  15. Quantification of immunohistochemical findings of neurofibrillary tangles and senile plaques for a diagnosis of dementia in forensic autopsy cases.

    Science.gov (United States)

    Takayama, Mio; Kashiwagi, Masayuki; Matsusue, Aya; Waters, Brian; Hara, Kenji; Ikematsu, Natsuki; Kubo, Shin-Ichi

    2016-09-01

    We report the quantification of immunohistochemical findings for a diagnosis of dementia in autopsy cases among older decedents. Autopsy cases were selected with the following requirements: >65yo; no head injuries, thermal injuries, or heat stroke; no intracranial lesions; and within 48h of death. Among cases that met all requirements, 10 had a clinical diagnosis of dementia were included in dementia group. Non-dementia group consisted of 38 cases without any record of dementia. To compare these groups, immunohistochemically, beta-amyloid, tau protein, gephyrin, and IL-33 were examined in five regions. Quantitative analysis was performed by collecting with image data analyzed using analysis software. Image data on tau-immunopositive neurofibrillary tangles (NFT) and beta-amyloid-positive senile plaques (SP) were photographed. Criteria for dementia were made by counting and measuring NFT and SP from image data using software. Differences in SP and NFT were effective for discriminating between the two groups. These criteria may reveal the presence and progression of dementia. Total of tau-positive NFT in Ammon's horn (AH) may be useful for diagnosing dementia. When the total is more than 41 in approximately 6mm(2) of AH, the possibility of dementia is considered. Total of beta-amyloid-positive SP in the parahippocampal gyrus (PHG) may be useful for diagnosing dementia. When the total in approximately 5mm(2) of PHG is more than 47, the possibility of dementia is considered. Immunohistochemical staining may be more useful for obtaining image data for quantification than conventional staining techniques, such as Bielschowsky-Hirano's silver staining. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Neurofibrillary tangles and the deposition of a beta amyloid peptide with a novel N-terminal epitope in the brains of wild Tsushima leopard cats.

    Science.gov (United States)

    Chambers, James K; Uchida, Kazuyuki; Harada, Tomoyuki; Tsuboi, Masaya; Sato, Masumi; Kubo, Masahito; Kawaguchi, Hiroaki; Miyoshi, Noriaki; Tsujimoto, Hajime; Nakayama, Hiroyuki

    2012-01-01

    Beta amyloid (Aβ) deposits are seen in aged individuals in many of the mammalian species that possess the same Aβ amino acid sequence as humans. Conversely, neurofibrillary tangles (NFT), the other hallmark lesion of Alzheimer's disease (AD), are extremely rare in these animals. We detected Aβ deposits in the brains of Tsushima leopard cats (Prionailurus bengalensis euptilurus) that live exclusively on Tsushima Island, Japan. Aβ42 was deposited in a granular pattern in the neuropil of the pyramidal cell layer, but did not form argyrophilic senile plaques. These Aβ deposits were not immunolabeled with antibodies to the N-terminal of human Aβ. Sequence analysis of the amyloid precursor protein revealed an amino acid substitution at the 7th residue of the Aβ peptide. In a comparison with other mammalian animals that do develop argyrophilic senile plaques, we concluded that the alternative Aβ amino acid sequence displayed by leopard cats is likely to be related to its distinctive deposition pattern. Interestingly, most of the animals with these Aβ deposits also developed NFTs. The distributions of hyperphosphorylated tau-positive cells and the two major isoforms of aggregated tau proteins were quite similar to those seen in Alzheimer's disease. In addition, the unphosphorylated form of GSK-3β colocalized with hyperphosphorylated tau within the affected neurons. In conclusion, this animal species develops AD-type NFTs without argyrophilic senile plaques.

  17. Neurofibrillary tangles and the deposition of a beta amyloid peptide with a novel N-terminal epitope in the brains of wild Tsushima leopard cats.

    Directory of Open Access Journals (Sweden)

    James K Chambers

    Full Text Available Beta amyloid (Aβ deposits are seen in aged individuals in many of the mammalian species that possess the same Aβ amino acid sequence as humans. Conversely, neurofibrillary tangles (NFT, the other hallmark lesion of Alzheimer's disease (AD, are extremely rare in these animals. We detected Aβ deposits in the brains of Tsushima leopard cats (Prionailurus bengalensis euptilurus that live exclusively on Tsushima Island, Japan. Aβ42 was deposited in a granular pattern in the neuropil of the pyramidal cell layer, but did not form argyrophilic senile plaques. These Aβ deposits were not immunolabeled with antibodies to the N-terminal of human Aβ. Sequence analysis of the amyloid precursor protein revealed an amino acid substitution at the 7th residue of the Aβ peptide. In a comparison with other mammalian animals that do develop argyrophilic senile plaques, we concluded that the alternative Aβ amino acid sequence displayed by leopard cats is likely to be related to its distinctive deposition pattern. Interestingly, most of the animals with these Aβ deposits also developed NFTs. The distributions of hyperphosphorylated tau-positive cells and the two major isoforms of aggregated tau proteins were quite similar to those seen in Alzheimer's disease. In addition, the unphosphorylated form of GSK-3β colocalized with hyperphosphorylated tau within the affected neurons. In conclusion, this animal species develops AD-type NFTs without argyrophilic senile plaques.

  18. Neurofibrillary tangle pathology and Braak staging in chronic epilepsy in relation to traumatic brain injury and hippocampal sclerosis: a post-mortem study

    Science.gov (United States)

    Liu, Joan Y.W.; Thompson, Pam; Phadke, Rahul; Narkiewicz, Marta; Martinian, Lillian; Marsdon, Derek; Koepp, Matthias; Caboclo, Luis; Catarino, Claudia B.; Sisodiya, Sanjay M.

    2011-01-01

    The long-term pathological effects of chronic epilepsy on normal brain ageing are unknown. Previous clinical and epidemiological studies show progressive cognitive decline in subsets of patients and an increased prevalence of Alzheimer's disease in epilepsy. In a post-mortem series of 138 patients with long-term, mainly drug-resistant epilepsy, we carried out Braak staging for Alzheimer's disease neurofibrillary pathology using tau protein immunohistochemistry. The stages were compared with clinicopathological factors, including seizure history and presence of old traumatic brain injury. Overall, 31% of cases were Braak Stage 0, 36% Stage I/II, 31% Stage III/IV and 2% Stage V/VI. The mean age at death was 56.5 years and correlated with Braak stage (P epilepsy series (P type (generalized or complex partial), seizure frequency, age of onset and duration of epilepsy with Braak stage although higher Braak stages were noted with focal more than with generalized epilepsy syndromes (P epilepsy although progression to high Braak stages was infrequent. Traumatic brain injury, but not seizures, was associated with tau protein accumulation in this series. It is likely that Alzheimer's disease pathology is not the sole explanation for cognitive decline associated with epilepsy. PMID:21903728

  19. Neurofibrillary tangle pathology and Braak staging in chronic epilepsy in relation to traumatic brain injury and hippocampal sclerosis: a post-mortem study.

    Science.gov (United States)

    Thom, Maria; Liu, Joan Y W; Thompson, Pam; Phadke, Rahul; Narkiewicz, Marta; Martinian, Lillian; Marsdon, Derek; Koepp, Matthias; Caboclo, Luis; Catarino, Claudia B; Sisodiya, Sanjay M

    2011-10-01

    The long-term pathological effects of chronic epilepsy on normal brain ageing are unknown. Previous clinical and epidemiological studies show progressive cognitive decline in subsets of patients and an increased prevalence of Alzheimer's disease in epilepsy. In a post-mortem series of 138 patients with long-term, mainly drug-resistant epilepsy, we carried out Braak staging for Alzheimer's disease neurofibrillary pathology using tau protein immunohistochemistry. The stages were compared with clinicopathological factors, including seizure history and presence of old traumatic brain injury. Overall, 31% of cases were Braak Stage 0, 36% Stage I/II, 31% Stage III/IV and 2% Stage V/VI. The mean age at death was 56.5 years and correlated with Braak stage (P pathological evidence of traumatic brain injury that was significantly associated with higher Braak stages (P brain injury (P pathology. In summary, there is evidence of accelerated brain ageing in severe chronic epilepsy although progression to high Braak stages was infrequent. Traumatic brain injury, but not seizures, was associated with tau protein accumulation in this series. It is likely that Alzheimer's disease pathology is not the sole explanation for cognitive decline associated with epilepsy.

  20. AAV-tau mediates pyramidal neurodegeneration by cell-cycle re-entry without neurofibrillary tangle formation in wild-type mice.

    Directory of Open Access Journals (Sweden)

    Tomasz Jaworski

    Full Text Available In Alzheimer's disease tauopathy is considered secondary to amyloid, and the duality obscures their relation and the definition of their respective contributions.Transgenic mouse models do not resolve this problem conclusively, i.e. the relative hierarchy of amyloid and tau pathology depends on the actual model and the genes expressed or inactivated. Here, we approached the problem in non-transgenic models by intracerebral injection of adeno-associated viral vectors to express protein tau or amyloid precursor protein in the hippocampus in vivo. AAV-APP mutant caused neuronal accumulation of amyloid peptides, and eventually amyloid plaques at 6 months post-injection, but with only marginal hippocampal cell-death. In contrast, AAV-Tau, either wild-type or mutant P301L, provoked dramatic degeneration of pyramidal neurons in CA1/2 and cortex within weeks. Tau-mediated neurodegeneration proceeded without formation of large fibrillar tau-aggregates or tangles, but with increased expression of cell-cycle markers.We present novel AAV-based models, which demonstrate that protein tau mediates pyramidal neurodegeneration in vivo. The data firmly support the unifying hypothesis that post-mitotic neurons are forced to re-enter the cell-cycle in primary and secondary tauopathies, including Alzheimer's disease.

  1. Interaction of Aluminum with PHFτ in Alzheimer’s Disease Neurofibrillary Degeneration Evidenced by Desferrioxamine-Assisted Chelating Autoclave Method

    Science.gov (United States)

    Murayama, Harunobu; Shin, Ryong-Woon; Higuchi, Jun; Shibuya, Satoshi; Muramoto, Tamaki; Kitamoto, Tetsuyuki

    1999-01-01

    To demonstrate that aluminum III (Al) interacts with PHFτ in neurofibrillary degeneration (NFD) of Alzheimer’s disease (AD) brain, we developed a “chelating autoclave method” that allows Al chelation by using trivalent-cationic chelator desferrioxamine. Its application to AD brain sections before Morin histochemistry for Al attenuated the positive fluorescence of neurofibrillary tangles, indicating Al removal from them. This method, applied for immunostaining with phosphorylation-dependent anti-τ antibodies, significantly enhanced the PHFτ immunoreactivity of the NFD. These results suggest that each of the phosphorylated epitopes in PHFτ are partially masked by Al binding. Incubation of AD sections with AlCl3 before Morin staining revealed Al accumulation with association to neurofibrillary tangles. Such incubation before immunostaining with the phosphorylation-dependent anti-τ antibodies abolished the immunolabeling of the NFD and this abolition was reversed by the Al chelation. These findings indicate cumulative Al binding to and thereby antigenic masking of the phosphorylated epitopes of PHFτ. Al binding was further documented for electrophoretically-resolved PHFτ on immunoblots, indicating direct Al binding to PHFτ. In vitro aggregation by AlCl3 was observed for PHFτ but was lost on dephosphorylation of PHFτ. Taken together, phosphorylation-dependent and direct PHFτ-Al interaction occurs in the NFD of the AD brain. PMID:10487845

  2. Antibodies to presenilin proteins detect neurofibrillary tangles in Alzheimer's disease

    National Research Council Canada - National Science Library

    Murphy, GM, Jr; Forno, LS; Ellis, WG; Nochlin, D; Levy-Lahad, E; Poorkaj, P; Bird, TD; Jiang, Z; Cordell, B

    1996-01-01

    GM Murphy Jr, LS Forno, WG Ellis, D Nochlin, E Levy-Lahad, P Poorkaj, TD Bird, Z Jiang and B Cordell Department of Psychiatry and Behavioral Sciences, Stanford University Medical Center, California, USA...

  3. Computing with Colored Tangles

    Directory of Open Access Journals (Sweden)

    Avishy Y. Carmi

    2015-07-01

    Full Text Available We suggest a diagrammatic model of computation based on an axiom of distributivity. A diagram of a decorated colored tangle, similar to those that appear in low dimensional topology, plays the role of a circuit diagram. Equivalent diagrams represent bisimilar computations. We prove that our model of computation is Turing complete and with bounded resources that it can decide any language in complexity class IP, sometimes with better performance parameters than corresponding classical protocols.

  4. Diffuse neurofibrillary tangles with calcification (Kosaka–Shibayama disease) in Japan

    National Research Council Canada - National Science Library

    Ukai, Katsuyuki; Kosaka, Kenji

    2016-01-01

    ... ’ was initially proposed by Kosaka in 1994. Although 26 autopsies and 21 clinical patients with DNTC have been described in Japan to date, DNTC has rarely been reported in the European and North American published work...

  5. Human Truncated Tau Induces Mature Neurofibrillary Pathology in a Mouse Model of Human Tauopathy.

    Science.gov (United States)

    Zimova, Ivana; Brezovakova, Veronika; Hromadka, Tomas; Weisova, Petronela; Cubinkova, Veronika; Valachova, Bernadeta; Filipcik, Peter; Jadhav, Santosh; Smolek, Tomas; Novak, Michal; Zilka, Norbert

    2016-09-06

    Alzheimer's disease (AD) represents the most common neurodegenerative disorder. Several animal models have been developed in order to test pathophysiological mechanisms of the disease and to predict effects of pharmacological interventions. Here we examine the molecular and behavioral features of R3m/4 transgenic mice expressing human non-mutated truncated tau protein (3R tau, aa151-391) that were previously used for efficacy testing of passive tau vaccine. The mouse model reliably recapitulated crucial histopathological features of human AD, such as pre-tangles, neurofibrillary tangles, and neuropil threads. The pathology was predominantly located in the brain stem. Transgenic mice developed mature sarkosyl insoluble tau complexes consisting of mouse endogenous and human truncated and hyperphosphorylated forms of tau protein. The histopathological and biochemical features were accompanied by significant sensorimotor impairment and reduced lifespan. The sensorimotor impairment was monitored by a highly sensitive, fully-automated tool that allowed us to assess early deficit in gait and locomotion. We suggest that the novel transgenic mouse model can serve as a valuable tool for analysis of the therapeutic efficacy of tau vaccines for AD therapy.

  6. [{sup 18}F]THK-5117 PET for assessing neurofibrillary pathology in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Ryuichi [Tohoku University, Division of Neuro-imaging, Institute of Development, Aging and Cancer, Sendai (Japan); Okamura, Nobuyuki [Tohoku University, Division of Neuro-imaging, Institute of Development, Aging and Cancer, Sendai (Japan); Tohoku University School of Medicine, Department of Pharmacology, Sendai (Japan); Furumoto, Shozo [Tohoku University, Frontier Research Institute for Interdisciplinary Science, Sendai (Japan); Tohoku University, Division of Radiopharmaceutical Chemistry, Cyclotron and Radioisotope Center, Sendai (Japan); Furukawa, Katsutoshi; Ishiki, Aiko; Tomita, Naoki; Arai, Hiroyuki [Tohoku University, Department of Geriatrics and Gerontology, Institute of Development, Aging and Cancer, Sendai (Japan); Hiraoka, Kotaro; Watanuki, Shoichi; Miyake, Masayasu; Matsuda, Rin; Inami, Akie; Tashiro, Manabu [Tohoku University, Division of Cyclotron Nuclear Medicine, Cyclotron and Radioisotope Center, Sendai (Japan); Shidahara, Miho [Tohoku University, Division of Cyclotron Nuclear Medicine, Cyclotron and Radioisotope Center, Sendai (Japan); Tohoku University School of Medicine, Division of Medical Physics, Sendai (Japan); Ishikawa, Yoichi; Tago, Tetsuro; Funaki, Yoshihito; Iwata, Ren [Tohoku University, Division of Radiopharmaceutical Chemistry, Cyclotron and Radioisotope Center, Sendai (Japan); Yoshikawa, Takeo; Yanai, Kazuhiko [Tohoku University School of Medicine, Department of Pharmacology, Sendai (Japan); Kudo, Yukitsuka [Tohoku University, Division of Neuro-imaging, Institute of Development, Aging and Cancer, Sendai (Japan); Tohoku University, Division of Radiopharmaceutical Chemistry, Cyclotron and Radioisotope Center, Sendai (Japan)

    2015-03-20

    Visualization of the spatial distribution of neurofibrillary tangles would help in the diagnosis, prevention and treatment of dementia. The purpose of the study was to evaluate the clinical utility of [{sup 18}F]THK-5117 as a highly selective tau imaging radiotracer. We initially evaluated in vitro binding of [{sup 3}H]THK-5117 in post-mortem brain tissues from patients with Alzheimer's disease (AD). In clinical PET studies, [{sup 18}F]THK-5117 retention in eight patients with AD was compared with that in six healthy elderly controls. Ten subjects underwent an additional [{sup 11}C]PiB PET scan within 2 weeks. In post-mortem brain samples, THK-5117 bound selectively to neurofibrillary deposits, which differed from the binding target of PiB. In clinical PET studies, [{sup 18}F]THK-5117 binding in the temporal lobe clearly distinguished patients with AD from healthy elderly subjects. Compared with [{sup 11}C]PiB, [{sup 18}F]THK-5117 retention was higher in the medial temporal cortex. These findings suggest that [{sup 18}F]THK-5117 provides regional information on neurofibrillary pathology in living subjects. (orig.)

  7. Alzheimer's disease neurofibrillary degeneration: pivotal and multifactorial.

    Science.gov (United States)

    Iqbal, Khalid; Wang, Xiaochuan; Blanchard, Julie; Liu, Fei; Gong, Cheng-Xin; Grundke-Iqbal, Inge

    2010-08-01

    Independent of the aetiology, AD (Alzheimer's disease) neurofibrillary degeneration of abnormally hyperphosphorylated tau, a hallmark of AD and related tauopathies, is apparently required for the clinical expression of the disease and hence is a major therapeutic target for drug development. However, AD is multifactorial and heterogeneous and probably involves several different aetiopathogenic mechanisms. On the basis of CSF (cerebrospinal fluid) levels of Abeta(1-42) (where Abeta is amyloid beta-peptide), tau and ubiquitin, five different subgroups, each with its own clinical profile, have been identified. A successful development of rational therapeutic disease-modifying drugs for AD will require understanding of the different aetiopathogenic mechanisms involved and stratification of AD patients by different disease subgroups in clinical trials. We have identified a novel aetiopathogenic mechanism of AD which is initiated by the cleavage of SET, also known as inhibitor-2 (I(2)(PP2A)) of PP2A (protein phosphatase 2A) at Asn(175) into N-terminal (I(2NTF)) and C-terminal (I(2CTF)) halves and their translocation from the neuronal nucleus to the cytoplasm. AAV1 (adeno-associated virus 1)-induced expression of I(2CTF) in rat brain induces inhibition of PP2A activity, abnormal hyperphosphorylation of tau, neurodegeneration and cognitive impairment in rats. Restoration of PP2A activity by inhibition of the cleavage of I(2)(PP2A)/SET offers a promising therapeutic opportunity in AD with this aetiopathogenic mechanism.

  8. Synthetic tau fibrils mediate transmission of neurofibrillary tangles in a transgenic mouse model of Alzheimer's-like tauopathy

    National Research Council Canada - National Science Library

    Iba, Michiyo; Guo, Jing L; McBride, Jennifer D; Zhang, Bin; Trojanowski, John Q; Lee, Virginia M-Y

    2013-01-01

    ...) comprising filamentous tau protein. Although emerging evidence suggests that tau pathology may be transmitted, we demonstrate here that synthetic tau fibrils are sufficient to transmit tau inclusions in a mouse model...

  9. Seidel-Smith cohomology for tangles

    DEFF Research Database (Denmark)

    Rezazadegan, Reza

    2009-01-01

    We generalize the “symplectic Khovanov cohomology” of Seidel and Smith (Duke Math J 134(3):453–514, 2006) to tangles using the notion of symplectic valued topological field theory introduced by Wehrheim and Woodward (arXiv:0905.1368).......We generalize the “symplectic Khovanov cohomology” of Seidel and Smith (Duke Math J 134(3):453–514, 2006) to tangles using the notion of symplectic valued topological field theory introduced by Wehrheim and Woodward (arXiv:0905.1368)....

  10. Mutual information in the Tangled Nature Model

    DEFF Research Database (Denmark)

    Jones, Dominic; Sibani, Paolo

    2010-01-01

    We consider the concept of mutual information in ecological networks, and use this idea to analyse the Tangled Nature model of co-evolution. We show that this measure of correlation has two distinct behaviours depending on how we define the network in question: if we consider only the network...

  11. Tau accumulation in the nucleus accumbens in tangle-predominant dementia

    Science.gov (United States)

    2014-01-01

    Background Tangle-predominant dementia (TPD) is characterized neuropathologically by numerous neurofibrillary tangles in the limbic areas with no or occasional senile plaques throughout the brain. TPD is an under-recognized disease, while it is a common cause of dementia in those over 80 years of age. In the present study, we describe hyperphosphorylated tau (tau) accumulation in the nucleus accumbens (Acb) in patients with TPD. Results We investigated immunohistochemically the brain tissues from 7 patients with TPD, 22 with Alzheimer disease (AD) and 11 non-demented aged subjects. In the Acb of all 7 TPD patients, a considerable number of tau positive neurons were found together with many neuropil threads. The tau deposits in the Acb were labeled with all the anti-tau antibodies used in the present study. They included conformational change-specific, phosphorylation-specific and phosphorylation-independent antibodies. The Acb consists of the predominant medium-sized neurons with a small number of large neurons. Both the cell types were affected by tau pathology in TPD. Tau accumulation in the majority of such neurons appeared to be pretangle-like, diffuse deposits with only occasional paired helical filament formation. Tau positive neurons were also found in the Acb in some AD and non-demented aged subjects but much fewer in the majority of cases. The immunoblot analyses of fresh frozen samples of the Acb and parahippocampal cortex from 3 TPD and 3 AD patients revealed that the insoluble tau in the Acb was a mixture of the 3- and 4-repeat isoforms. Conclusions To our knowledge, this is the first report on the occurrence of tau accumulation in the Acb in TPD. The Acb receives direct and massive projections from the hippocampal CA1 and subiculum where neurofibrillary tangles are known to occur more frequently in TPD than in AD. The prevalence of abnormal tau accumulation in the Acb in TPD may support the idea that abnormal tau aggregation propagates via neural

  12. Plaques and tangles as well as Lewy-type alpha synucleinopathy are associated with formed visual hallucinations.

    Science.gov (United States)

    Jacobson, Sandra A; Morshed, Trisha; Dugger, Brittany N; Beach, Thomas G; Hentz, Joseph G; Adler, Charles H; Shill, Holly A; Sabbagh, Marwan N; Belden, Christine M; Sue, Lucia I; Caviness, John N; Hu, Chengcheng

    2014-09-01

    Previous research has linked complex or formed visual hallucinations (VH) to Lewy-type alpha-synucleinopathy (LTS) in neocortical and limbic areas. As Alzheimer's disease pathology often co-occurs with LTS, we questioned whether this pathology - amyloid plaques and neurofibrillary tangles - might also be linked to VH. We performed a semi-quantitative neuropathological study across brainstem, limbic, and cortical structures in subjects with a documented clinical history of VH and a clinicopathological diagnosis of Parkinson's disease (PD), Alzheimer's disease (AD), or dementia with Lewy bodies (DLB). 173 subjects - including 50 with VH and 123 without VH - were selected from the Arizona Study of Aging and Neurodegenerative Disorders. Clinical variables examined included the Mini-mental State Exam, Hoehn & Yahr stage, and total dopaminergic medication dose. Neuropathological variables examined included total and regional LTS and plaque and tangle densities. A significant relationship was found between the density of LTS and the presence of VH in PD, AD, and DLB. Plaque and tangle densities also were associated with VH in PD (p = .003 for plaque and p = .004 for tangles) but not in AD, where densities were high regardless of the presence of hallucinations. Furthermore, with DLB cases excluded, comorbidity of PD and AD was significantly more prevalent among subjects + VH than subjects -VH (p < .001). These findings suggest that both AD and PD neuropathology contribute to the pathogenesis of VH. Incident VH could be predictive of concomitant AD/PD pathology even when criteria are not met for a second diagnosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Prostate-derived sterile 20-like kinases (PSKs/TAOKs) phosphorylate tau protein and are activated in tangle-bearing neurons in Alzheimer disease.

    Science.gov (United States)

    Tavares, Ignatius A; Touma, Dona; Lynham, Steven; Troakes, Claire; Schober, Megan; Causevic, Mirsada; Garg, Ritu; Noble, Wendy; Killick, Richard; Bodi, Istvan; Hanger, Diane P; Morris, Jonathan D H

    2013-05-24

    In Alzheimer disease (AD), the microtubule-associated protein tau is highly phosphorylated and aggregates into characteristic neurofibrillary tangles. Prostate-derived sterile 20-like kinases (PSKs/TAOKs) 1 and 2, members of the sterile 20 family of kinases, have been shown to regulate microtubule stability and organization. Here we show that tau is a good substrate for PSK1 and PSK2 phosphorylation with mass spectrometric analysis of phosphorylated tau revealing more than 40 tau residues as targets of these kinases. Notably, phosphorylated residues include motifs located within the microtubule-binding repeat domain on tau (Ser-262, Ser-324, and Ser-356), sites that are known to regulate tau-microtubule interactions. PSK catalytic activity is enhanced in the entorhinal cortex and hippocampus, areas of the brain that are most susceptible to Alzheimer pathology, in comparison with the cerebellum, which is relatively spared. Activated PSK is associated with neurofibrillary tangles, dystrophic neurites surrounding neuritic plaques, neuropil threads, and granulovacuolar degeneration bodies in AD brain. By contrast, activated PSKs and phosphorylated tau are rarely detectible in immunostained control human brain. Our results demonstrate that tau is a substrate for PSK and suggest that this family of kinases could contribute to the development of AD pathology and dementia.

  14. Lipids: Part of the tangled web

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, R.M.

    1992-08-01

    Analysis of LDL subclasses by non-denaturing gradient gel electrophoresis has led to the identification of a subclass pattern characterized by predominance of small LDL, designated LDL subclass pattern B. The prevalence of pattern B in the general population is approximately 25%, but varies as a function of age and gender, being relatively uncommon in children and in premenopausal women. The remainder of the population has a predominance of larger LDL (pattern A) or an intermediate pattern. Our findings indicate that LDL subclass pattern B is an integral part of the tangled web'' of interrelated coronary disease risk factors associated with insulin resistance. It may be that the pathologic features of this lipoprotein profile, including the relative atherogenicity of small, dense LDL and IDL, contribute importantly to the increased risk of cardiovascular disease in subjects with insulin resistance and hypertension. Furthermore, pattern B serves as a marker for a common genetic trait which may underlie a substantial portion of the familial predisposition to coronary artery disease in the general population. Studies of hormonal, dietary, and pharmacologic influences on expression of this atherogenic phenotype should lead to more effective identification and management of high-risk individuals, and improved approaches to disease prevention in high-risk families.

  15. Lipids: Part of the tangled web

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, R.M.

    1992-08-01

    Analysis of LDL subclasses by non-denaturing gradient gel electrophoresis has led to the identification of a subclass pattern characterized by predominance of small LDL, designated LDL subclass pattern B. The prevalence of pattern B in the general population is approximately 25%, but varies as a function of age and gender, being relatively uncommon in children and in premenopausal women. The remainder of the population has a predominance of larger LDL (pattern A) or an intermediate pattern. Our findings indicate that LDL subclass pattern B is an integral part of the ``tangled web`` of interrelated coronary disease risk factors associated with insulin resistance. It may be that the pathologic features of this lipoprotein profile, including the relative atherogenicity of small, dense LDL and IDL, contribute importantly to the increased risk of cardiovascular disease in subjects with insulin resistance and hypertension. Furthermore, pattern B serves as a marker for a common genetic trait which may underlie a substantial portion of the familial predisposition to coronary artery disease in the general population. Studies of hormonal, dietary, and pharmacologic influences on expression of this atherogenic phenotype should lead to more effective identification and management of high-risk individuals, and improved approaches to disease prevention in high-risk families.

  16. Oh What a Tangled Biofilm Web Bacteria Weave

    Science.gov (United States)

    ... Home Page Oh What a Tangled Biofilm Web Bacteria Weave By Elia Ben-Ari Posted May 1, ... a suitable surface, some water and nutrients, and bacteria will likely put down stakes and form biofilms. ...

  17. The Solubilization of Model Alzheimer Tangles: Reversing the β-Sheet Conformation Induced by Aluminum with Silicates

    Science.gov (United States)

    Fasman, Gerald D.; Moore, Cathy D.

    1994-11-01

    Neurofibrillary tangles are one of two lesions found in the brain of Alzheimer disease victims. With synthetic peptide fragments of human neurofilament NF-M17 (Glu-Glu-Lys-Gly-Lys-Ser-Pro-Val-Pro-Lys-Ser-Pro-Val-Glu-Glu-Lys-Gly, phosphorylated and unphosphorylated), CD studies were done to examine the effect of sodium orthosilicate on the conformational state produced by Al3+ on fragments of neuronal proteins. Previous studies had shown a conformational transition from α-helix and random to β-pleated sheet upon addition of Al3+ to both phosphorylated and unphosphorylated peptides. If sufficient quantities of Al3+ are added, the peptide precipitates from solution. The ability to reverse or slow the progression of aggregation was examined. Al3+ binding was reversed with 1-2 molar equivalents of sodium orthosilicate (with respect to Al3+), altering the conformation from β-sheet to random coil and resulting in a CD spectrum similar to that of the initial peptide. The tight binding of the SiO4-_4 with the Al3+ provides the mechanism for this transition. These results provide additional information toward understanding the role of aluminum in the Alzheimer diseased brain and suggest the investigation of the possible use of silicates as a therapeutic agent.

  18. Tangle-Free Finite Element Mesh Motion for Ablation Problems

    Science.gov (United States)

    Droba, Justin

    2016-01-01

    Mesh motion is the process by which a computational domain is updated in time to reflect physical changes in the material the domain represents. Such a technique is needed in the study of the thermal response of ablative materials, which erode when strong heating is applied to the boundary. Traditionally, the thermal solver is coupled with a linear elastic or biharmonic system whose sole purpose is to update mesh node locations in response to altering boundary heating. Simple mesh motion algorithms rely on boundary surface normals. In such schemes, evolution in time will eventually cause the mesh to intersect and "tangle" with itself, causing failure. Furthermore, such schemes are greatly limited in the problems geometries on which they will be successful. This paper presents a comprehensive and sophisticated scheme that tailors the directions of motion based on context. By choosing directions for each node smartly, the inevitable tangle can be completely avoided and mesh motion on complex geometries can be modeled accurately.

  19. The Tangled Nature Model of evolutionary dynamics reconsidered

    DEFF Research Database (Denmark)

    Andersen, Christian Walther; Sibani, Paolo

    2016-01-01

    The Tangled Nature Model of biological and cultural evolution features interacting agents which compete for limited resources and reproduce in an error prone fashion and at a rate depending on the `tangle' of interactions they maintain with others. The set of interactions linking a TNM individual...... all the interactions, while increasing $K$ up to the length of the genome ensures an increasing level of trait inheritance. We show that the distribution of the interactions generated by our rule is nearly independent of the value of $K$. Changing $K$ strengthens the core structure of the ecology......, leads to population abundance distributions which are better approximated by log-normal probability densities and increases the probability that a species extant at time $t_{\\rm w}$ is also extant at a later time $t$. In particular, survival probabilities are shown to decay as powers of the ratio $t...

  20. Expression of Alzheimer-Type Neurofibrillary Epitopes in Primary Rat Cortical Neurons Following Infection with Enterococcus faecalis.

    Science.gov (United States)

    Underly, Robert; Song, Mee-Sook; Dunbar, Gary L; Weaver, Charles L

    2015-01-01

    The neurofibrillary tau pathology and amyloid deposits seen in Alzheimer's disease (AD) also have been seen in bacteria-infected brains. However, few studies have examined the role of these bacteria in the generation of tau pathology. One suggested link between infection and AD is edentulism, the complete loss of teeth. Edentulism can result from chronic periodontal disease due to infection by Enterococcus faecalis. The current study assessed the ability to generate early Alzheimer-like neurofibrillary epitopes in primary rat cortical neurons through bacterial infection by E. faecalis. Seven-day old cultured neurons were infected with E. faecalis for 24 and 48 h. An upward molecular weight shift in tau by Western blotting (WB) and increased appearance of tau reactivity in cell bodies and degenerating neurites was found in the 48 h infection group for the antibody CP13 (phospho-Serine 202). A substantial increase in reactivity of Alz-50 was seen at 24 and 48 h after infection. Furthermore, extensive microtubule-associated protein 2 (MAP2) reactivity also was seen at 24 and 48 h post-infection. Our preliminary findings suggest a potential link between E. faecalis infection and intracellular changes that may help facilitate early AD-like neurofibrillary pathology. HighlightsEnterococcus faecalis used in the generation of AD neurofibrillary epitopes in rat.Infection increases Alz-50, phospho-Serine 202 tau, and MAP2 expression.Infection by Enterococcus may play a role in early Alzheimer neurofibrillary changes.

  1. Tangle-Free Mesh Motion for Ablation Simulations

    Science.gov (United States)

    Droba, Justin

    2016-01-01

    Problems involving mesh motion-which should not be mistakenly associated with moving mesh methods, a class of adaptive mesh redistribution techniques-are of critical importance in numerical simulations of the thermal response of melting and ablative materials. Ablation is the process by which material vaporizes or otherwise erodes due to strong heating. Accurate modeling of such materials is of the utmost importance in design of passive thermal protection systems ("heatshields") for spacecraft, the layer of the vehicle that ensures survival of crew and craft during re-entry. In an explicit mesh motion approach, a complete thermal solve is first performed. Afterwards, the thermal response is used to determine surface recession rates. These values are then used to generate boundary conditions for an a posteriori correction designed to update the location of the mesh nodes. Most often, linear elastic or biharmonic equations are used to model this material response, traditionally in a finite element framework so that complex geometries can be simulated. A simple scheme for moving the boundary nodes involves receding along the surface normals. However, for all but the simplest problem geometries, evolution in time following such a scheme will eventually bring the mesh to intersect and "tangle" with itself, inducing failure. This presentation demonstrates a comprehensive and sophisticated scheme that analyzes the local geometry of each node with help from user-provided clues to eliminate the tangle and enable simulations on a wide-class of difficult problem geometries. The method developed is demonstrated for linear elastic equations but is general enough that it may be adapted to other modeling equations. The presentation will explicate the inner workings of the tangle-free mesh motion algorithm for both two and three-dimensional meshes. It will show abstract examples of the method's success, including a verification problem that demonstrates its accuracy and

  2. Entropy in the Tangled Nature Model of evolution

    DEFF Research Database (Denmark)

    Roach, Ty N.F.; Nulton, James; Sibani, Paolo

    2017-01-01

    interpretation is supported by mathematical arguments using simulation data generated by the Tangled Nature Model (TNM), a stochastic model of evolving ecologies. We define two types of configurational entropy and study their empirical time dependence obtained from the data. Both entropy measures increase...... logarithmically with time, while the entropy per individual decreases in time, in parallel with the growth of emergent structures visible from other aspects of the simulation. We discuss the biological relevance of these entropies to describe niche space and functional space of ecosystems, as well as their use...

  3. Caspase-Cleaved Tau Co-Localizes with Early Tangle Markers in the Human Vascular Dementia Brain.

    Science.gov (United States)

    Day, Ryan J; Mason, Maria J; Thomas, Chloe; Poon, Wayne W; Rohn, Troy T

    2015-01-01

    Vascular dementia (VaD) is the second most common form of dementia in the United States and is characterized as a cerebral vessel vascular disease that leads to ischemic episodes. Whereas the relationship between caspase-cleaved tau and neurofibrillary tangles (NFTs) in Alzheimer's disease (AD) has been previously described, whether caspase activation and cleavage of tau occurs in VaD is presently unknown. To investigate a potential role for caspase-cleaved tau in VaD, we analyzed seven confirmed cases of VaD by immunohistochemistry utilizing a well-characterized antibody that specifically detects caspase-cleaved tau truncated at Asp421. Application of this antibody (TauC3) revealed consistent labeling within NFTs, dystrophic neurites within plaque-rich regions and corpora amylacea (CA) in the human VaD brain. Labeling of CA by the TauC3 antibody was widespread throughout the hippocampus proper, was significantly higher compared to age matched controls, and co-localized with ubiquitin. Staining of the TauC3 antibody co-localized with MC-1, AT8, and PHF-1 within NFTs. Quantitative analysis indicated that roughly 90% of PHF-1-labeled NFTs contained caspase-cleaved tau. In addition, we documented the presence of active caspase-3 within plaques, blood vessels and pretangle neurons that co-localized with TauC3. Collectively, these data support a role for the activation of caspase-3 and proteolytic cleavage of TauC3 in VaD providing further support for the involvement of this family of proteases in NFT pathology.

  4. Hippocampal connectivity and Alzheimer's dementia: effects of synapse loss and tangle frequency in a two-component model.

    Science.gov (United States)

    Samuel, W; Masliah, E; Hill, L R; Butters, N; Terry, R

    1994-11-01

    Our prior research on patients with Alzheimer's disease (AD) found a high correspondence between premortem dementia and accumulation of neurofibrillary tangles (NFTs) with concurrent loss of synapse density in several brain regions. In the present study, we examined these same clinicopathologic relationships in the context of seven subregions of the hippocampal formation using a sample of 16 AD patients who had been administered three well-known mental status tests antemortem. We found NFT counts to be most strongly correlated with degree of dementia when they were seen in CA1, the subiculum, and CA4; NFTs in these subregions appeared significantly clustered on factor analysis. Synapse loss was most strongly correlated with dementia when it occurred in the molecular layers of the dentate fasciculus and stratum lacunosum, CA2/3, and CA4; synapse loss in these subregions appeared significantly clustered on factor analysis. In general, these results were compatible with a two-component model of hippocampal connectivity and function in the context of AD. The first component consists of subregions preceding CA1 in a hypothesized input-processing sequence intrinsic to the hippocampus that summates neuronal excitation and that influences cognition primarily through synapse density. The second component consists of an "output module," mainly CA1 and the subiculum, that receives the processed signal, passes it on to extrahippocampal cortical and subcortical targets, and affects cognition primarily by NFT accumulation in output neurons. A "net pathology" score combining standardized z-scores for synapse density and NFTs was significantly correlated with all three mental status measures in all hippocampal subregions except the entorhinal cortex, and stepwise regressions on these data found net pathology in CA4 to be the most independent significant predictor of premortem dementia.

  5. Tangle-Free Finite Element Mesh Motion for Ablation Problems

    Science.gov (United States)

    Droba, Justin

    2016-01-01

    In numerical simulations involving boundaries that evolve in time, the primary challenge is updating the computational mesh to reflect the physical changes in the domain. In particular, the fundamental objective for any such \\mesh motion" scheme is to maintain mesh quality and suppress unphysical geometric anamolies and artifacts. External to a physical process of interest, mesh motion is an added component that determines the specifics of how to move the mesh given certain limited information from the main system. This paper develops a set of boundary conditions designed to eliminate tangling and internal collision within the context of PDE-based mesh motion (linear elasticity). These boundary conditions are developed for two- and three-dimensional meshes. The paper presents detailed algorithms for commonly occuring topological scenarios and explains how to apply them appropriately. Notably, the techniques discussed herein make use of none of the specifics of any particular formulation of mesh motion and thus are more broadly applicable. The two-dimensional algorithms are validated by an extensive verification procedure. Finally, many examples of diverse geometries in both two- and three-dimensions are shown to showcase the capabilities of the tangle-free boundary conditions.

  6. Immunotherapy Targeting Pathological Tau Conformers in a Tangle Mouse Model Reduces Brain Pathology with Associated Functional Improvements

    National Research Council Canada - National Science Library

    Asuni, Ayodeji A; Boutajangout, Allal; Quartermain, David; Sigurdsson, Einar M

    2007-01-01

    .... Here, we present that active immunization with a phosphorylated tau epitope, in P301L tangle model mice, reduces aggregated tau in the brain and slows progression of the tangle-related behavioral phenotype...

  7. Expression of Alzheimer-type Neurofibrillary Epitopes in Primary Rat Cortical Neurons Following Infection with Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Robert eUnderly

    2016-01-01

    Full Text Available The neurofibrillary tau pathology and amyloid deposits seen in Alzheimer's disease (AD also have been seen in bacteria-infected brains. However, few studies have examined the role of these bacteria in the generation of tau pathology. One suggested link between infection and Alzheimer’s disease is edentulism, the complete loss of teeth. Edentulism can result from chronic periodontal disease due to infection by Enterococcus faecalis. The current study assessed the ability to generate early Alzheimer-like neurofibrillary epitopes in primary rat cortical neurons through bacterial infection by Enterococcus faecalis. Seven-day old cultured neurons were infected with Enterococcus faecalis for 24- and 48-hours. An upward molecular weight shift in tau by western blotting and increased appearance of tau reactivity in cell bodies and degenerating neurites was found in the 48-hour infection group for the antibody CP13 (phospho-Serine-202. A substantial increase in reactivity of Alz-50 was seen at 24- and 48- hours after infection. Furthermore, extensive MAP2 reactivity also was seen at 24- and 48-hours post-infection. Our preliminary findings suggest a potential link between Enterococcus faecalis infection and intracellular changes that may help facilitate early AD-like neurofibrillary pathology.

  8. Homoclinic tangle of separatrix of the simple map

    Science.gov (United States)

    Pressley, Latoya; Guest, Tanzania; Johnson, Nakeisha; Punjabi, Alkesh; Ali, Halima

    2014-10-01

    The simple map is the simplest symplectic map that has the generic magnetic topology of divertor tokamaks. The generating function of the simple map is S (x , y) = x2 /2 + y2 /2-y3/3. S = 1/6 gives the separatrix surface. The scaling of safety factor on the magnetic axis, q0, with map parameter k is used to calculate the number of iterations of the simple map, Np , that is equivalent to a single toroidal circuit of the tokamak. The scaling of root mean square deviation of energy on the q95 surface with map parameter k is taken as the estimate of magnetic asymmetry to represent the magnetic perturbation from map parameter k. These data is used in the forward and backward simple maps to calculate the homoclinic tangle of the separatrix of divertor tokamaks from magnetic asymmetries. This work is supported by Grants DE-FG02-01ER54624, DE-FG02-04ER54793, and DE-FG02-07ER54937.

  9. Four Ways to Get Tangled Up in Russian

    Directory of Open Access Journals (Sweden)

    Maria Nordrum

    2014-11-01

    Full Text Available In this paper I will analyze the four Natural Perfectives of the simplex verb путатьipf ‘tangle up’, namely впутатьpf, спутатьpf, перепутатьpf and запутатьpf. According to Janda et al. (2013:103, “prefix variation” is a phenomenon that applies to 27% of all Russian verbs and is caused by the ability of prefixes to “focus the meanings of a simplex verb in different ways” (op. cit.:162. My question is: Is it possible to predict the choice of prefix when there is prefix variation? And, if yes: How?  My hypothesis is that the choice of prefix largely depends on the construction in which the verb appears and the semantics of its internal argument. Thus, I consider two factors in my analysis: Factor 1 Constructions and Factor 2 Semantics of the Internal Argument. My findings indicate that both factors are vital and, more specifically, that the choice of prefix for this verb to a large extent can be predicted by six tendencies that I will discuss thoroughly. I will argue that these six tendencies are of great relevance to second language learners, like myself, who often find themselves confused at the number of prefixes and, more specifically, Natural Perfectives available for a given verb. The topic of this paper has been born from a desire to gain insight with practical value in second language learning.

  10. Heteroclinic tangle phenomena in nanomagnets subject to time-harmonic excitations

    Energy Technology Data Exchange (ETDEWEB)

    Serpico, C.; Quercia, A.; Perna, S. [DIETI, Università di Napoli “Federico II,” I-80125 Napoli (Italy); Bertotti, G.; Ansalone, P. [Istituto Nazionale di Ricerca Metrologica, I-10135 Torino (Italy); D' Aquino, M. [Dip. di Ingegneria, Università di Napoli “Parthenope,” I-80143 Napoli (Italy); Mayergoyz, I. [ECE Department and UMIACS, University of Maryland, College Park, Maryland 20742 (United States)

    2015-05-07

    Magnetization dynamics in uniformly magnetized nanomagnets excited by time-harmonic (AC) external fields or spin-polarized injected currents is considered. The analysis is focused on the behaviour of the AC-excited dynamics near saddle equilibria. It turns out that this dynamics has a chaotic character at moderately low power level. This chaotic and fractal nature is due to the phenomenon of heteroclinic tangle which is produced by the combined effect of AC-excitations and saddle type dynamics. By using the perturbation technique based on Melnikov function, analytical formulas for the threshold AC excitation amplitudes necessary to create the heteroclinic tangle are derived. Both the cases of AC applied fields and AC spin-polarized injected currents are treated. Then, by means of numerical simulations, we show how heteroclinic tangle is accompanied by the erosion of the safe basin around the stable regimes.

  11. The Dispersion State of Tangled Multi-Walled Carbon Nanotubes Affects Their Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Chika Kuroda

    2016-11-01

    Full Text Available The medical applications of carbon nanotubes (CNTs have garnered much attention. However, evaluating the safety of CNTs remains difficult, and no consensus has been reached. Moreover, assessing the biosafety of multi-walled CNTs (MWCNTs, which can become tangled during manufacturing, is challenging because they do not readily disperse. We studied how the dispersion state of tangled MWCNTs affects their cytotoxicity, using three sonicators. Flotube 9110 (FT9110, tangled MWCNTs, were dispersed in two dispersants (fetal bovine serum and polysorbate 80 using a new type of sonicator (PR-1 and two conventional sonicators. The size and cytotoxicity of the dispersed FT9110 were measured using the BEAS-2B human bronchial epithelial cell line. The PR-1 dispersed the FT9110 to agglomerates <200 nm in diameter; FT9110 dispersed with the PR-1 did not show cytotoxicity regardless of dispersant. The other sonicators dispersed the FT9110 to particles >1000 nm in diameter, and cytotoxicity depended on the dispersant. We found that excluding cells adhered to agglomerated FT9110 before evaluating cytotoxicity can lead to false-positive results. The PR-1 sonicator dispersed tangled FT9110 to many single fibers, which showed lower cytotoxicity than conventionally-sonicated MWCNTs. We suggest that dispersion state should be accounted for when evaluating the cytotoxicity of MWCNTs.

  12. Rapunzel Loves Merida: Melodramatic Expressions of Lesbian Girlhood and Teen Romance in Tangled, Brave, and Femslash.

    Science.gov (United States)

    Kapurch, Katie

    2015-01-01

    This article explores the melodramatic expression of lesbian girlhood and teen romance in Disney's Tangled (2010) and Disney Pixar's Brave (2012), as well as "Meripunzel" femslash, fan-authored romantic pairings of the animations' female protagonists. First, Anne Sexton's poem, "Rapunzel," offers a literary precedent for exploring lesbian themes in the fairy tale. The next section shows how Tangled and Brave invoke the narrative conventions of the family melodrama. This generic association reveals the films' uses of rhetoric familiar to youth coming-out narratives, as well as other visual and aural coding suggestive of queer styles. The last section shows how Meripunzel femslash taps into the films' existing melodramatic narrative forms and visual aesthetics, rehearsing their coming-out rhetoric while addressing the pleasures of and problems facing lesbian teen romance. I conclude by problematizing the often conventional expressions of lesbian girlhood in femslash, ultimately arguing for their empowering potential, especially as they indicate revised definitions of "princess."

  13. Inducing autophagy by rapamycin before, but not after, the formation of plaques and tangles ameliorates cognitive deficits.

    Directory of Open Access Journals (Sweden)

    Smita Majumder

    Full Text Available Previous studies have shown that inducing autophagy ameliorates early cognitive deficits associated with the build-up of soluble amyloid-β (Aβ. However, the effects of inducing autophagy on plaques and tangles are yet to be determined. While soluble Aβ and tau represent toxic species in Alzheimer's disease (AD pathogenesis, there is well documented evidence that plaques and tangles also are detrimental to normal brain function. Thus, it is critical to assess the effects of inducing autophagy in an animal model with established plaques and tangles. Here we show that rapamycin, when given prophylactically to 2-month-old 3xTg-AD mice throughout their life, induces autophagy and significantly reduces plaques, tangles and cognitive deficits. In contrast, inducing autophagy in 15-month-old 3xTg-AD mice, which have established plaques and tangles, has no effects on AD-like pathology and cognitive deficits. In conclusion, we show that autophagy induction via rapamycin may represent a valid therapeutic strategy in AD when administered early in the disease progression.

  14. Effect of fermented sea tangle on the alcohol dehydrogenase and acetaldehyde dehydrogenase in Saccharomyces cerevisiae.

    Science.gov (United States)

    Cha, Jae-Young; Jeong, Jae-Jun; Yang, Hyun-Ju; Lee, Bae-Jin; Cho, Young-Su

    2011-08-01

    Sea tangle, a kind of brown seaweed, was fermented with Lactobacillus brevis BJ-20. The gamma-aminobutyric acid (GABA) content in fermented sea tangle (FST) was 5.56% (w/w) and GABA in total free amino acid of FST was 49.5%. The effect of FST on the enzyme activities and mRNA protein expression of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) involved in alcohol metabolism in Saccharomyces cerevisiae was investigated. Yeast was cultured in YPD medium supplemented with different concentrations of FST powder [0, 0.4, 0.8, and 1.0% (w/v)] for 18 h. FST had no cytotoxic effect on the yeast growth. The highest activities and protein expressions of ADH and ALDH from the cell-free extracts of S. cerevisiae were evident with the 0.4% and 0.8% (w/v) FST-supplemented concentrations, respectively. The highest concentrations of GABA as well as minerals (Zn, Ca, and Mg) were found in the cell-free extracts of S. cerevisiae cultured in medium supplemented with 0.4% (w/v) FST. The levels of GABA, Zn, Ca, and Mg in S. cerevisiae were strongly correlated with the enzyme activities of ADH and ALDH in yeast. These results indicate that FST can enhance the enzyme activities and protein expression of ADH and ALDH in S. cerevisiae.

  15. Holocene pollen and sediment record from the tangle lakes area, central Alaska

    Science.gov (United States)

    Ager, Thomas A.; Sims, John D.

    1981-01-01

    Pollen and sediments have been analyzed from a 5.5 meter‐length core of lacustrine sediments from Tangle Lakes, in the Gulkana Upland south of the Alaska Range (63 ° 01 ‘ 46”; N. latitude, 146° 03 ‘ 48 “ W. longitude). Radiocarbon ages indicate that the core spans the last 4700 years. The core sediments are sandy silt and silty clay; the core shows distinct rhythmic laminations in the lower 398 cm. The laminae appear to be normally graded; peat fibers and macerated plant debris are more abundant near the tops of the laminae. Six volcanic‐ash layers are present in the upper 110 cm of the core.Present‐day vegetation of the Tangle Lakes area is mesic shrub tundra and open spruce woodland, with scattered patches of shrub willow (Salix), balsam poplar (P. balsamifera), spruce (Picea), paper birch (Betula papyrifera), and alder (Alnus). Pollen analysis of 27 core samples suggests that this vegetation type has persisted throughout the past 4700 years, except for an apparently substantial increase in Picea beginning about 3500 years B.P. Percentages of Picea pollen are very low (generally 1–3 percent) in the lower 2 meters of core (ca. 4700 to 3500 years B.P.), but rise to 13–18 percent in the upper 3.4 meters (ca. 3500 years B.P. to present). Previously reported data from this area indicate that Picea trees initially arrived in the Tangle Lakes area about 9100 years B.P., at least 2.5 to 3 thousand years after deglaciation of the region. The present investigation suggests that Picea trees became locally scarce or died out sometime after about 9000 years B.P. but before 4700 years B.P., then reinvaded the area about 3500 years B.P. If this extrapolated age for the Picea reinvasion is accurate it suggests that local expansion of the Picea population coincides with the onset of a Neoglacial interval of cooler, moister climate. This is an unexpected result, because intervals of cooler climate generally coincide with lowering of the altitudinal limit of

  16. 3D printed cat tongue is a self-cleaning, tangle-teasing brush

    Science.gov (United States)

    Noel, Alexis; Hu, David

    A cat's tongue is covered in an array of spines called papillae. These spines are thought to be used in grooming and rasping meat from bones of prey, although no mechanism has been given. We use high-speed video to film a cat grooming. We show that the spines on the tongue act as low pass filters for tangles in hair. The tongue itself is highly elastic, while the spines are rigid. We 3D print a cat tongue mimic and show that the nonlinear force applied by the spines helps to increase efficacy of grooming. The tongue also provides frictional anisotropy with backward-facing spines, allowing for self-cleaning properties post-groom.

  17. Vortex arrays and ciliary tangles underlie the feeding-swimming tradeoff in starfish larvae

    CERN Document Server

    Gilpin, William; Prakash, Manu

    2016-01-01

    Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey. These bands are strongly conserved across taxa spanning four major superphyla, and they are responsible for the unusual morphologies of many invertebrates. However, few studies have investigated their underlying hydrodynamics. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly-evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary "tangles" analogous to topological defects that break-up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modeling suggest that these vortices create a physical tradeoff between feeding and swimming, which manifests as distinct flow patterns or "eigenstrokes" representing each behavior---potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hyd...

  18. Evolution and non-equilibrium physics: A study of the Tangled Nature Model

    Science.gov (United States)

    Becker, Nikolaj; Sibani, Paolo

    2014-01-01

    We argue that the stochastic dynamics of interacting agents which replicate, mutate and die constitutes a non-equilibrium physical process akin to aging in complex materials. Specifically, our study uses extensive computer simulations of the Tangled Nature Model (TNM) of biological evolution to show that punctuated equilibria successively generated by the model's dynamics have increasing entropy and are separated by increasing entropic barriers. We further show that these states are organized in a hierarchy and that limiting the values of possible interactions to a finite interval leads to stationary fluctuations within a component of the latter. A coarse-grained description based on the temporal statistics of quakes, the events leading from one component of the hierarchy to the next, accounts for the logarithmic growth of the population and the decaying rate of change of macroscopic variables. Finally, we question the role of fitness in large-scale evolution models and speculate on the possible evolutionary role of rejuvenation and memory effects.

  19. Tangled Narratives and Wicked Problems: A Complex Case of Positioning and Politics in a Diverse School Community

    Science.gov (United States)

    Nguyen, Thu Suong Thi; Scribner, Samantha M. Paredes; Crow, Gary M.

    2012-01-01

    The case of Allen Elementary School presents tangled narratives and wicked problems describing the multidimensionality of school community work. Using multiple converging and diverging vignettes, the case points to the distinctiveness of individual experience in schools; the ways institutionalized organizational narratives become cultural…

  20. Sleep deprivation impairs memory, tau metabolism, and synaptic integrity of a mouse model of Alzheimer's disease with plaques and tangles.

    Science.gov (United States)

    Di Meco, Antonio; Joshi, Yash B; Praticò, Domenico

    2014-08-01

    Several studies have highlighted the frequency of sleep disturbances in Alzheimer's disease (AD). However, whether they are secondary to the disease or per se increase its risk remains to be fully investigated. The aim of the current investigation was to study the effect of sleep deprivation (SD) on the development of AD phenotype in a transgenic mouse model with plaques and tangles, the 3xTg mice. We evaluated the functional and biological consequences on 3xTg mice that underwent 4 hours sleep restrain per day for 8 weeks. Compared with controls, behavioral assessment showed that SD-treated mice had a significant decline in their learning and memory. Although no differences were detected in the levels of soluble amyloid-β peptides, the same animals displayed a decrease in tau phosphorylation, which associated with a significant increase in its insoluble fraction. In addition, we observed that SD resulted in lower levels of postsynaptic density protein 95 and increased glial fibrillary acidic protein levels. Finally, although total levels of the transcription factor cellular response element binding protein were unchanged, its phosphorylated form was significantly diminished in brains of sleep-deprived mice when compared with controls. Our study underlines the importance of SD as a chronic stressor, which by modulating biochemical processes influences the development of memory impairments and AD neuropathologies. Correction of SD could be a viable therapeutic strategy to prevent the onset or slow the progression of AD in individuals bearing this risk factor. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Vortex arrays and ciliary tangles underlie the feeding-swimming tradeoff in starfish larvae

    Science.gov (United States)

    Gilpin, William; Prakash, Vivek N.; Prakash, Manu

    2016-11-01

    Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey. These bands are strongly conserved across taxa spanning four major superphyla, and they are responsible for the unusual morphologies of many invertebrates. However, few studies have investigated their underlying hydrodynamics. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly-evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary "tangles" analogous to topological defects that break-up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modeling demonstrate that these vortices create a physical tradeoff between feeding and swimming in heterogenous environments, which manifests as distinct flow patterns or "eigenstrokes" representing each behavior-potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hydrodynamic function generalizes to other invertebrates, and illustrates the potential effects of active boundary conditions in other biological and synthetic systems.

  2. Vortex arrays and ciliary tangles underlie the feeding-swimming trade-off in starfish larvae

    Science.gov (United States)

    Gilpin, William; Prakash, Vivek N.; Prakash, Manu

    2017-04-01

    Many marine invertebrates have larval stages covered in linear arrays of beating cilia, which propel the animal while simultaneously entraining planktonic prey. These bands are strongly conserved across taxa spanning four major superphyla, and they are responsible for the unusual morphologies of many invertebrate larvae. However, few studies have investigated their underlying hydrodynamics. Here, we study the ciliary bands of starfish larvae, and discover a beautiful pattern of slowly evolving vortices that surrounds the swimming animals. Closer inspection of the bands reveals unusual ciliary `tangles' analogous to topological defects that break up and re-form as the animal adjusts its swimming stroke. Quantitative experiments and modelling demonstrate that these vortices create a physical trade-off between feeding and swimming in heterogeneous environments, which manifests as distinct flow patterns or `eigenstrokes' representing each behaviour--potentially implicating neuronal control of cilia. This quantitative interplay between larval form and hydrodynamic function may generalize to other invertebrates with ciliary bands, and illustrates the potential effects of active boundary conditions in other biological and synthetic systems.

  3. Continuous variable tangle, monogamy inequality, and entanglement sharing in Gaussian states of continuous variable systems

    Energy Technology Data Exchange (ETDEWEB)

    Adesso, Gerardo; Illuminati, Fabrizio [Dipartimento di Fisica ' E R Caianiello' , Universita degli Studi di Salerno (Italy); CNISM and CNR-Coherentia, Gruppo di Salerno (Italy); and INFN Sezione di Napoli-Gruppo Collegato di Salerno (Italy); Via S Allende, 84081 Baronissi, SA (Italy)

    2006-01-15

    For continuous-variable (CV) systems, we introduce a measure of entanglement, the CV tangle (contangle), with the purpose of quantifying the distributed (shared) entanglement in multimode, multipartite Gaussian states. This is achieved by a proper convex-roof extension of the squared logarithmic negativity. We prove that the contangle satisfies the Coffman-Kundu-Wootters monogamy inequality in all three-mode Gaussian states, and in all fully symmetric N-mode Gaussian states, for arbitrary N. For three-mode pure states, we prove that the residual entanglement is a genuine tripartite entanglement monotone under Gaussian local operations and classical communication. We show that pure, symmetric three-mode Gaussian states allow a promiscuous entanglement sharing, having both maximum tripartite residual entanglement and maximum couplewise entanglement between any pair of modes. These states are thus simultaneous CV analogues of both the GHZ and the W states of three qubits: in CV systems monogamy does not prevent promiscuity, and the inequivalence between different classes of maximally entangled states, holding for systems of three or more qubits, is removed.

  4. Evaluation of 8-week body weight control program including sea tangle (Laminaria japonica) supplementation in Korean female college students

    OpenAIRE

    You, Jeong Soon; Sung, Min Jung; Chang, Kyung Ja

    2009-01-01

    This study was conducted to evaluate the effects of a body weight control program with supplementation of sea tangle (20 g/day) on 22 female college students. The contents of the program for 8 weeks contained diet therapy, exercise and behavioral modification through nutrition education. Body composition, dietary habit scores, serum lipid profiles, daily nutrient intakes and the quality of life were assessed at the beginning and at the end of the program. Average age of subjects and height we...

  5. Neuroinflammation and common mechanism in Alzheimer's disease and prion amyloidosis: amyloid-associated proteins, neuroinflammation and neurofibrillary degeneration

    NARCIS (Netherlands)

    Rozemuller, A.J.M.; Jansen, C.; Carrano, A.; van Haastert, E.S.; Hondius, D.; van der Vies, S.M.; Hoozemans, J.J.M.

    2012-01-01

    Background: In cases with a long (>1 year) clinical duration of prion disease, the prion protein can form amyloid deposits. These cases do not show accumulation of 4-kDa β-amyloid, which is observed in amyloid deposits in Alzheimer's disease (AD). In AD, amyloid is associated with inflammation and

  6. Observation

    Science.gov (United States)

    Kripalani, Lakshmi A.

    2016-01-01

    The adult who is inexperienced in the art of observation may, even with the best intentions, react to a child's behavior in a way that hinders instead of helping the child's development. Kripalani outlines the need for training and practice in observation in order to "understand the needs of the children and...to understand how to remove…

  7. Micro-evolution of toxicant tolerance: from single genes to the genome's tangled bank.

    Science.gov (United States)

    van Straalen, Nico M; Janssens, Thierry K S; Roelofs, Dick

    2011-05-01

    abandoned. These data, added to a genome-wide gene expression profiling study reported earlier shows that evolution of tolerance takes place in a complicated molecular network, not unlike an internal tangled bank. © The Author(s) 2011. This article is published with open access at Springerlink.com

  8. The Visual Metaphor of Disability in Sarah Leavitt's Graphic Memoir Tangles: A story about alzheimer's, my mother, and me

    Directory of Open Access Journals (Sweden)

    Renata Lucena Dalmaso

    2015-01-01

    Borrowing George Lakoff and Mark Johnson’s Conceptual Metaphor theory, and its implications for the study of visual metaphors, this article seeks to investigate the representation of the disabled body in the graphic memoir Tangles: A Story about Alzheimer’s, My Mother, and Me (2012, by Sarah Leavitt. The genre of comics, as a cross-discursive medium, is prolific in the use of visual metaphor as a narrative technique and Leavitt’s graphic memoir, in particular, employs visual metaphor in the depiction of her mother’s experience of Alzheimer’s, as someone slowly distancing herself from her family.

  9. Evaluation of 8-week body weight control program including sea tangle (Laminaria japonica) supplementation in Korean female college students.

    Science.gov (United States)

    You, Jeong Soon; Sung, Min Jung; Chang, Kyung Ja

    2009-01-01

    This study was conducted to evaluate the effects of a body weight control program with supplementation of sea tangle (20 g/day) on 22 female college students. The contents of the program for 8 weeks contained diet therapy, exercise and behavioral modification through nutrition education. Body composition, dietary habit scores, serum lipid profiles, daily nutrient intakes and the quality of life were assessed at the beginning and at the end of the program. Average age of subjects and height were 20.8 years and 161.9 cm, respectively. After 8 weeks, there were significant reductions in body weight, body fat mass, percent body fat, waist-hip ratio and BMI. The dietary habit score such as a balanced diet, regularity of mealtime, overeating, eating while watching TV or using the computer and eating salty food were increased significantly. Serum lipid levels such as total cholesterol level, LDL-cholesterol level and triglyceride level were decreased but not significantly. There were decreases in intake of energy, protein and fat and increases in intakes of dietary fiber, folic acid, calcium and potassium from the beginning to the end of the program. There were significant improvements on subcomponents of quality of life; physical functioning, general-health and vitality. The limitation of this study was the fact that there was no control group, but an overall evaluation suggests the 8-week body weight control program consisting of diet therapy, exercise and behavioral modification with supplementation of sea tangle would be helpful to improve the body composition, dietary habits, daily nutrient intakes and quality of life in Korean female college students.

  10. Medline Plus

    Full Text Available In a person with Alzheimer disease, neurofibrillary tangles and plaques develop causing both structural and chemical problems in the brain. Alzheimer disease appears to disconnect ...

  11. Vibration transmission through sheet webs of hobo spiders (Eratigena agrestis) and tangle webs of western black widow spiders (Latrodectus hesperus).

    Science.gov (United States)

    Vibert, Samantha; Scott, Catherine; Gries, Gerhard

    2016-11-01

    Web-building spiders construct their own vibratory signaling environments. Web architecture should affect signal design, and vice versa, such that vibratory signals are transmitted with a minimum of attenuation and degradation. However, the web is the medium through which a spider senses both vibratory signals from courting males and cues produced by captured prey. Moreover, webs function not only in vibration transmission, but also in defense from predators and the elements. These multiple functions may impose conflicting selection pressures on web design. We investigated vibration transmission efficiency and accuracy through two web types with contrasting architectures: sheet webs of Eratigena agrestis (Agelenidae) and tangle webs of Latrodectus hesperus (Theridiidae). We measured vibration transmission efficiencies by playing frequency sweeps through webs with a piezoelectric vibrator and a loudspeaker, recording the resulting web vibrations at several locations on each web using a laser Doppler vibrometer. Transmission efficiencies through both web types were highly variable, with within-web variation greater than among-web variation. There was little difference in transmission efficiencies of longitudinal and transverse vibrations. The inconsistent transmission of specific frequencies through webs suggests that parameters other than frequency are most important in allowing these spiders to distinguish between vibrations of prey and courting males.

  12. Effect of Sea Tangle ( and Charcoal Supplementation as Alternatives to Antibiotics on Growth Performance and Meat Quality of Ducks

    Directory of Open Access Journals (Sweden)

    M. M. Islam

    2014-02-01

    Full Text Available A total of 150 growing ducks were assigned to five dietary treatments to study the effect of sea tangle and charcoal (STC supplementation on growth performance and meat characteristics in a completely randomized design. There were six replicates and five ducklings in each replication. The five dietary treatments were control, antibiotic, and 0.1%, 0.5%, and 1% STC supplemented diets. No significant differences were found on ADG, ADFI, and gain:feed among treatments in different weeks. The overall (0 to 3 weeks ADFI decreased in antibiotic treatment (p<0.05 whereas the gain:feed increased significantly upon 1.0% STC supplementation compared to control (p<0.05. No significant variation was found in meat chemical composition except crude fat content which was high in 1.0% STC dietary group (p<0.05. Meat cholesterol was reduced in 0.1% STC group (p<0.05 compared to other dose levels while serum cholesterol was unaffected. High density lipoprotein (HDL content was high in 1.0% STC (p<0.05 and low density lipoprotein (LDL was low in 0.1% and 1.0% STC dietary groups (p = 0.06. No significant effect was found on the thiobarbituric acid reactive substances (TBARS of fresh meat, whereas the TBARS value of meat preserved for 1 week was reduced significantly in STC dietary groups (p<0.05. The 0.1% STC dietary group showed an increased myristic acid (p = 0.07 content whereas, the content of eicosapentaenoic (EPA and docosahexaenoic (DHA acids increased in STC supplementation than antibiotic group (p<0.05. An increased concentration of omega-3 fatty acids and a reduced ratio of n-6/n-3 PUFA ratio was found upon 1.0% STC supplementation compared to antibiotic dietary group (p<0.05. Therefore, 1.0% STC dietary supplementation can be used as alternatives to antibiotics in duck production.

  13. Rational Design of in Vivo Tau Tangle-Selective Near-Infrared Fluorophores: Expanding the BODIPY Universe.

    Science.gov (United States)

    Verwilst, Peter; Kim, Hye-Ri; Seo, Jinho; Sohn, Nak-Won; Cha, Seung-Yun; Kim, Yeongmin; Maeng, Sungho; Shin, Jung-Won; Kwak, Jong Hwan; Kang, Chulhun; Kim, Jong Seung

    2017-09-27

    The elucidation of the cause of Alzheimer's disease remains one of the greatest questions in neurodegenerative research. The lack of highly reliable low-cost sensors to study the structural changes in key proteins during the progression of the disease is a contributing factor to this lack of insight. In the current work, we describe the rational design and synthesis of two fluorescent BODIPY-based probes, named Tau 1 and Tau 2. The probes were evaluated on the molecular surface formed by a fibril of the PHF6 (306VQIVYK311) tau fragment using molecular docking studies to provide a potential molecular model to rationalize the selectivity of the new probes as compared to a homologous Aβ-selective probe. The probes were synthesized in a few steps from commercially available starting products and could thus prove to be highly cost-effective. We demonstrated the excellent photophysical properties of the dyes, such as a large Stokes shift and emission in the near-infrared window of the electromagnetic spectrum. The probes demonstrated a high selectivity for self-assembled microtubule-associated protein tau (Tau protein), in both solution and cell-based experiments. Moreover, the administration to an acute murine model of tauopathy clearly revealed the staining of self-assembled hyperphosphorylated tau protein in pathologically relevant hippocampal brain regions. Tau 1 demonstrated efficient blood-brain barrier penetrability and demonstrated a clear selectivity for tau tangles over Aβ plaques, as well as the capacity for in vivo imaging in a transgenic mouse model. The current work could open up avenues for the cost-effective monitoring of the tau protein aggregation state in animal models as well as tissue staining. Furthermore, these fluorophores could serve as the basis for the development of clinically relevant sensors, for example based on PET imaging.

  14. Tangled Up in Knots: Structures of Inactivated Forms of E. coli Class Ia Ribonucleotide Reductase

    Energy Technology Data Exchange (ETDEWEB)

    Zimanyi, Christina M.; Ando, Nozomi; Brignole, Edward J.; Asturias, Francisco J.; Stubbe, JoAnne; Drennan, Catherine L. (MIT); (Scripps)

    2012-10-23

    Ribonucleotide reductases (RNRs) provide the precursors for DNA biosynthesis and repair and are successful targets for anticancer drugs such as clofarabine and gemcitabine. Recently, we reported that dATP inhibits E. coli class Ia RNR by driving formation of RNR subunits into {alpha}{sub 4}{beta}{sub 4} rings. Here, we present the first X-ray structure of a gemcitabine-inhibited E. coli RNR and show that the previously described {alpha}{sub 4}{beta}{sub 4} rings can interlock to form an unprecedented ({alpha}{sub 4}{beta}{sub 4}){sub 2} megacomplex. This complex is also seen in a higher-resolution dATP-inhibited RNR structure presented here, which employs a distinct crystal lattice from that observed in the gemcitabine-inhibited case. With few reported examples of protein catenanes, we use data from small-angle X-ray scattering and electron microscopy to both understand the solution conditions that contribute to concatenation in RNRs as well as present a mechanism for the formation of these unusual structures.

  15. Navigating the patent landscapes for nanotechnology: English gardens or tangled grounds?

    Science.gov (United States)

    Sylvester, Douglas J; Bowman, Diana M

    2011-01-01

    The patent landscape, like a garden, can tell you much about its designers and users: their motivations, biases, and general interests. While both patent landscapes and gardens may appear to the casual observer as refined and ordered, an in-depth exploration of the terrain is likely to reveal unforeseen challenges including, for example, alien species, thickets, and trolls. As this chapter illustrates, patent landscapes are dynamic and have been forced to continually evolve in response to technological innovation. While emerging technologies such as biotechnology and information communication technology have challenged the traditional patent landscape, the overarching framework and design have largely remained intact. But will this always be the case? The aim of this chapter is to highlight how nanotechnology is challenging the existing structures and underlying foundation of the patent landscape and the implications thereof for the technology, industry, and public more generally. The chapter concludes by asking the question whether the current patent landscape will be able to withstand the ubiquitous nature of the technology, or whether nanotechnology will be a catalyst for governments and policy makers for overhauling the current landscape design.

  16. Pathology of the Superior Colliculus in Chronic Traumatic Encephalopathy.

    Science.gov (United States)

    Armstrong, Richard A; McKee, Ann C; Cairns, Nigel J

    2017-01-01

    To investigate neuropathological changes in the superior colliculus in chronic traumatic encephalopathy. The densities of the tau-immunoreactive neurofibrillary tangles, neuropil threads, dot-like grains, astrocytic tangles, and neuritic plaques, together with abnormally enlarged neurons, typical neurons, vacuolation, and frequency of contacts with blood vessels, were studied across the superior colliculus from pia mater to the periaqueductal gray in eight chronic traumatic encephalopathy and six control cases. Tau-immunoreactive pathology was absent in the superior colliculus of controls but present in varying degrees in all chronic traumatic encephalopathy cases, significant densities of tau-immunoreactive neurofibrillary tangles, NT, or dot-like grains being present in three cases. No significant differences in overall density of the tau-immunoreactive neurofibrillary tangles, neuropil threads, dot-like grains, enlarged neurons, vacuoles, or contacts with blood vessels were observed in control and chronic traumatic encephalopathy cases, but chronic traumatic encephalopathy cases had significantly lower mean densities of neurons. The distribution of surviving neurons across the superior colliculus suggested greater neuronal loss in intermediate and lower laminae in chronic traumatic encephalopathy. Changes in density of the tau-immunoreactive pathology across the laminae were variable, but in six chronic traumatic encephalopathy cases, densities of tau-immunoreactive neurofibrillary tangles, neuropil threads, or dot-like grains were significantly greater in intermediate and lower laminae. Pathological changes were not correlated with the distribution of blood vessels. The data suggest significant pathology affecting the superior colliculus in a proportion of chronic traumatic encephalopathy cases with a laminar distribution which could compromise motor function rather than sensory analysis.

  17. Tangling with telecomes

    CSIR Research Space (South Africa)

    Roux, S

    2011-07-01

    Full Text Available At the CSIR’s National Laser Centre, a team of researchers is pursuing Free Space Quantum Communication: transmitting optical signals by using the quantum properties of laser light. The aim is to provide secure and safe ways of communication using...

  18. Tangled up in black - a study of the activist strategies of the Black Power movement through the life of Gary Foley

    OpenAIRE

    Howell, Edwina Maurey

    2017-01-01

    Tangled Up in Black is a work of anthropology that both critiques and celebrates the discipline as much as it does the subject of the thesis, ‘A study of the activist strategies of the Black Power movement (in Australia) through the life of Gary Foley’. It is most influenced by the life work of the subject, Gary Foley as well as that of anthropologist Michael Taussig and philosopher and literary critic, Walter Benjamin, in particular his ‘Thesis on the Philosophy of History’. I have enga...

  19. Aluminum and Alzheimer's disease, a personal perspective after 25 years.

    Science.gov (United States)

    Perl, Daniel P; Moalem, Sharon

    2006-01-01

    It is now 25 years since the publication of our original paper investigating the association aluminum with Alzheimer's disease. This publication reported on the results of scanning electron microscopy coupled x-ray spectrometry microprobe elemental studies of both neurofibrillary tangle-bearing and tangle-free neurons in the hippocampus of cases of Alzheimer's disease and controls. Peaks related to the presence of aluminum were consistently detected within the tangle-bearing neurons. This paper supported the association of aluminum and Alzheimer's disease on the cellular level of resolution and caused considerable interest and discussion. Subsequent work demonstrated prominent evidence of aluminum accumulation in the tangle-bearing neurons of cases of amyotrophic lateral sclerosis/parkinsonism-dementia complex of Guam. This latter observation has now been replicated using five different forms of microanalysis. Finally, using laser microprobe mass analysis, we demonstrated that the abnormally high aluminum-related signal which we originally detected was actually located within the neurofibrillary tangle, itself, and was accompanied by excess concentrations of iron. Although it is unlikely that aluminum represents an etiologic cause of Alzheimer's disease, we believe that this highly reactive element, known to cross-link hyperphosphorylated proteins, may play an active role in the pathogenesis of critical neuropathologic lesion in Alzheimer's disease and other related disorders.

  20. Dementia Pugilistica with clinical features of Alzheimer's disease

    OpenAIRE

    Renata Areza-Fegyveres; Sergio Rosemberg; Castro, Rosa Maria R.P.S.; Claudia Sellitto Porto; Valéria Santoro Bahia; Paulo Caramelli; Ricardo Nitrini

    2007-01-01

    A 61-year-old ex-boxer presented with a three-year history of progressive memory decline. During a seven-year follow-up period, there was a continuous cognitive decline, very similar to that usually observed in Alzheimer's disease. Parkinsonian, pyramidal or cerebellar signs were conspicuously absent. Neuropathological examination revealed the typical features of dementia pugilistica: cavum septi pellucidi with multiple fenestrations, numerous neurofibrillary tangles in the cerebral isocortex...

  1. Investigation on metal elements in the brain tissues from DNTC patients

    Energy Technology Data Exchange (ETDEWEB)

    Ide-Ektessabi, Ari E-mail: h51167@sakura.kudpc.kyoto-u.ac.jp; Kawakami, Takuo; Ishihara, Ryoko; Mizuno, Yutaka; Takeuchi, Tohru

    2004-07-01

    Trace metallic elements in human cells play important roles in various cell functions as metalloprotein, metalloenzyme or metallic ions. Diffuse neurofibrillary tangles with calcification (DNTC) is an atypical dementia and is characterized pathologically by diffuse neurofibrillary tangles without senile plaques. In this study, X-ray fluorescence (XRF) spectroscopy using synchrotron radiation (SR) was applied to determine the distribution and density of the ultra-trace elements in the brain tissues from DTNC patients. This method made it possible to determine trace metallic elements non-destructively. The trace metallic elements (such as Ca, Fe, Zn, and Pb) in the brain tissues were examined. Two-dimension imaging of the elements and relative quantification of the elements in the brains were performed. The lead concentrations were observed in the calcified blood vessel in the brains with DNTC.

  2. The Tangled Branches (Las Ramas Enredadas): Sexual Risk, Substance Abuse, and Intimate Partner Violence Among Hispanic Men who Have Sex with Men

    Science.gov (United States)

    De Santis, Joseph P.; Gonzalez-Guarda, Rosa; Provencio-Vasquez, Elias; Deleon, Diego A.

    2012-01-01

    Hispanic men who have sex with men (MSM) experience a number of health disparities including high rates of HIV infection from high risk sex, substance abuse, and intimate partner violence. Although some research is available to document the relationships of these health disparities in the literature, few studies have explored the intersection of these disparities and the factors that influence them. The purpose of this study was to explore the experiences that Hispanic MSM residing in South Florida have with high risk sex, substance abuse, and intimate partner violence. Focus groups were conducted and analyzed using grounded theory methodology until data saturation was reached (n = 20). Two core categories with subcategories emerged from the data: The Roots of Risk (Los raices del riesgo) and The Tangled Branches (Las Ramas Enredadas). The results of the study provided some important clinical implications as well as directions for future research with Hispanic MSM. PMID:24084703

  3. The Tangled Branches (Las Ramas Enredadas): sexual risk, substance abuse, and intimate partner violence among Hispanic men who have sex with men.

    Science.gov (United States)

    De Santis, Joseph P; Gonzalez-Guarda, Rosa; Provencio-Vasquez, Elias; Deleon, Diego A

    2014-01-01

    Hispanic men who have sex with men (MSM) experience a number of health disparities including high rates of HIV infection from high-risk sex, substance abuse, and intimate partner violence. Although some research is available to document the relationships of these health disparities in the literature, few studies have explored the intersection of these disparities and the factors that influence them. The purpose of this study was to explore the experiences that Hispanic MSM residing in South Florida have with high-risk sex, substance abuse, and intimate partner violence. Focus groups were conducted and analyzed using grounded theory methodology until data saturation was reached (n = 20). Two core categories with subcategories emerged from the data: The Roots of Risk (Los raices del riesgo) and The Tangled Branches (Las Ramas Enredadas). The results of the study provided some important clinical implications as well as directions for future research with Hispanic MSM.

  4. Correlation of Alzheimer Disease Neuropathologic Changes With Cognitive Status: A Review of the Literature

    Science.gov (United States)

    Nelson, Peter T.; Alafuzoff, Irina; Bigio, Eileen H.; Bouras, Constantin; Braak, Heiko; Cairns, Nigel J.; Castellani, Rudolph J.; Crain, Barbara J.; Davies, Peter; Del Tredici, Kelly; Duyckaerts, Charles; Frosch, Matthew P.; Haroutunian, Vahram; Hof, Patrick R.; Hulette, Christine M.; Hyman, Bradley T.; Iwatsubo, Takeshi; Jellinger, Kurt A.; Jicha, Gregory A.; Kövari, Enikö; Kukull, Walter A.; Leverenz, James B.; Love, Seth; Mackenzie, Ian R.; Mann, David M.; Masliah, Eliezer; McKee, Ann C.; Montine, Thomas J.; Morris, John C.; Schneider, Julie A.; Sonnen, Joshua A.; Thal, Dietmar R.; Trojanowski, John Q.; Troncoso, Juan C.; Wisniewski, Thomas; Woltjer, Randall L.; Beach, Thomas G.

    2013-01-01

    Clinicopathologic correlation studies are critically important for the field of Alzheimer disease (AD) research. Studies on human subjects with autopsy confirmation entail numerous potential biases that affect both their general applicability and the validity of the correlations. Many sources of data variability can weaken the apparent correlation between cognitive status and AD neuropathologic changes. Indeed, most persons in advanced old age have significant non-AD brain lesions that may alter cognition independently of AD. Worldwide research efforts have evaluated thousands of human subjects to assess the causes of cognitive impairment in the elderly, and these studies have been interpreted in different ways. We review the literature focusing on the correlation of AD neuropathologic changes (i.e. β-amyloid plaques and neurofibrillary tangles) with cognitive impairment. We discuss the various patterns of brain changes that have been observed in elderly individuals to provide a perspective for understanding AD clinicopathologic correlation and conclude that evidence from many independent research centers strongly supports the existence of a specific disease, as defined by the presence of Aβ plaques and neurofibrillary tangles. Although Aβ plaques may play a key role in AD pathogenesis, the severity of cognitive impairment correlates best with the burden of neocortical neurofibrillary tangles. PMID:22487856

  5. Longitudinal Assessment of Tau Pathology in Patients with Alzheimer's Disease Using [18F]THK-5117 Positron Emission Tomography.

    Directory of Open Access Journals (Sweden)

    Aiko Ishiki

    Full Text Available The formation of neurofibrillary tangles is believed to contribute to the neurodegeneration observed in Alzheimer's disease (AD. Postmortem studies have shown strong associations between the neurofibrillary pathology and both neuronal loss and the severity of cognitive impairment. However, the temporal changes in the neurofibrillary pathology and its association with the progression of the disease are not well understood. Tau positron emission tomography (PET imaging is expected to be useful for the longitudinal assessment of neurofibrillary pathology in the living brain. Here, we performed a longitudinal PET study using the tau-selective PET tracer [18F]THK-5117 in patients with AD and in healthy control subjects. Annual changes in [18F]THK-5117 binding were significantly elevated in the middle and inferior temporal gyri and in the fusiform gyrus of patients with AD. Compared to patients with mild AD, patients with moderate AD showed greater changes in the tau load that were more widely distributed across the cortical regions. Furthermore, a significant correlation was observed between the annual changes in cognitive decline and regional [18F]THK-5117 binding. These results suggest that the cognitive decline observed in patients with AD is attributable to the progression of neurofibrillary pathology. Longitudinal assessment of tau pathology will contribute to the assessment of disease progression and treatment efficacy.

  6. Apolipoprotein E in Guamanian amyotrophic lateral sclerosis/parkinsonism-dementia complex: genotype analysis and relationships to neuropathological changes.

    Science.gov (United States)

    Buée, L; Pérez-Tur, J; Leveugle, B; Buée-Scherrer, V; Mufson, E J; Loerzel, A J; Chartier-Harlin, M C; Perl, D P; Delacourte, A; Hof, P R

    1996-01-01

    Apolipoprotein E (Apo E) has been recently identified within amyloid deposits and neurofibrillary tangles in the brains of Alzheimer's disease (AD) patients. A strong association of the Apo E epsilon 4 allele with higher risk of developing AD has also been reported. In the present study, the distribution of Apo E and the possible relationship between Apo E alleles and neuropathological alterations were analyzed in a series of Guamanian amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) cases, a neurodegenerative condition characterized neuropathologically by widespread, severe neurofibrillary tangle formation but rare amyloid deposits. ApoE immunoreactivity was consistently observed in both type of lesions in these cases. Compared to tau protein immunoreactivity, there were generally fewer Apo E-immunoreactive neurofibrillary tangles, particularly in the deep layers of the neocortex and in the hippocampus. Genotype analysis revealed that the epsilon 4 allele frequency was 5.9%, the epsilon 3 allele frequency 88.2%, and the epsilon 2 allele frequency 5.9% in this series. Recent data suggest that the Apo E4 variant may induce amyloidogenesis, while E2 could have a neuroprotective role. However, the rare Guamanian patients with amyloid deposits in cortical areas were not related to the epsilon 4 allele, since all cases with senile plaques were epsilon 3/epsilon 3. In addition, compared to unaffected Guamanian cases and other Asian-Pacific populations previously reported, the observed low frequency of the epsilon 2 allele in the present cases, which may be consistent with the notion that this allele, may represent a neuroprotective factor in several neurodegenerative disorders. The present data indicate that there is a strong interaction between Apo E deposition and neurofibrillary changes in Guamanian ALS-PDC.

  7. Relationship between genetic risk factors and markers for Alzheimer's disease pathology

    NARCIS (Netherlands)

    Elias-Sonnenschein, L.S.; Bertram, L.; Visser, P.J.

    2012-01-01

    Alzheimers disease (AD) is a neurodegenerative disorder characterized by neuritic plaques (main constituent: -amyloid [A]) and neurofibrillary tangles (hyperphosphorylated tau protein) in the brain. Abnormalities in A and tau can be measured upon neuropathological examination, in cerebrospinal fluid

  8. Medline Plus

    Full Text Available In a person with Alzheimer disease, neurofibrillary tangles and plaques develop causing both structural and chemical problems in the brain. Alzheimer disease appears to disconnect areas ...

  9. Medline Plus

    Full Text Available In a person with Alzheimer disease, neurofibrillary tangles and plaques develop causing both structural and chemical problems in the brain. Alzheimer disease appears to disconnect areas of ...

  10. "A Complicated Tangle of Circumstances"

    Science.gov (United States)

    Miller, Carole; Saxton, Juliana

    2009-01-01

    The post-modern curriculum, drawing on chaos and complexity theory, recognises the realities of a world in flux and posits that the teacher and the class are always teetering "in the midst" of chaos, "not linked by chains of causality but [by] layers of meaning, recursive dynamics, non-linear effects and chance" (Osberg 2008,…

  11. The Tangle of Student Allowances.

    Science.gov (United States)

    Thomson, Norman J.

    1980-01-01

    A discussion of the distribution of student financial aid in Australia focuses on these issues: direct vs. indirect payment to students; inequality in living allowances given to secondary and postsecondary students; and distribution of expense allowances by state government and living allowances by the Commonwealth. (MSE)

  12. Hematopoietic Stem Cell and Its Growth Factor

    Science.gov (United States)

    1988-02-16

    senile dementia of the Alzheimer type share an antigenic deermi oclonsi antibody specific for Lactasyiceramide. J. fBo. Chem. nant with intermediate...erythroblast. Blood 63:1376, 1984. 10. Yen SH, Gaskin F, Fu SM: Neurofibrillary tangles in senile dementia of the Alzheimer type share an antigenic...and induced globin expression. Science 216:1233. 59 21. Yen SH, F Gaskin and SM Fu. 1983. Neurofibrillary tangles in senile dementia of the Alzheimer

  13. Tangent map intermittency as an approximate analysis of intermittency in a high dimensional fully stochastic dynamical system: The Tangled Nature model

    Science.gov (United States)

    Diaz-Ruelas, Alvaro; Jeldtoft Jensen, Henrik; Piovani, Duccio; Robledo, Alberto

    2016-12-01

    It is well known that low-dimensional nonlinear deterministic maps close to a tangent bifurcation exhibit intermittency and this circumstance has been exploited, e.g., by Procaccia and Schuster [Phys. Rev. A 28, 1210 (1983)], to develop a general theory of 1/f spectra. This suggests it is interesting to study the extent to which the behavior of a high-dimensional stochastic system can be described by such tangent maps. The Tangled Nature (TaNa) Model of evolutionary ecology is an ideal candidate for such a study, a significant model as it is capable of reproducing a broad range of the phenomenology of macroevolution and ecosystems. The TaNa model exhibits strong intermittency reminiscent of punctuated equilibrium and, like the fossil record of mass extinction, the intermittency in the model is found to be non-stationary, a feature typical of many complex systems. We derive a mean-field version for the evolution of the likelihood function controlling the reproduction of species and find a local map close to tangency. This mean-field map, by our own local approximation, is able to describe qualitatively only one episode of the intermittent dynamics of the full TaNa model. To complement this result, we construct a complete nonlinear dynamical system model consisting of successive tangent bifurcations that generates time evolution patterns resembling those of the full TaNa model in macroscopic scales. The switch from one tangent bifurcation to the next in the sequences produced in this model is stochastic in nature, based on criteria obtained from the local mean-field approximation, and capable of imitating the changing set of types of species and total population in the TaNa model. The model combines full deterministic dynamics with instantaneous parameter random jumps at stochastically drawn times. In spite of the limitations of our approach, which entails a drastic collapse of degrees of freedom, the description of a high-dimensional model system in terms of a low

  14. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2010-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming a partici......Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...... as the idea of the naïve observer becomes a void. Not recognizing and observing oneself as observer and co-producer of empirical data simply leaves the process of observation as the major unobserved absorber of contingency in data production based on participating observation....

  15. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2011-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming a partici......Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...... as the idea of the naïve observer becomes a void. Not recognizing and observing oneself as observer and co-producer of empirical data simply leaves the process of observation as the major unobserved absorber of contingency in data production based on participating observation....

  16. Lysosomal Fusion Dysfunction as a Unifying Hypothesis for Alzheimer's Disease Pathology

    Directory of Open Access Journals (Sweden)

    Kristen E. Funk

    2012-01-01

    Full Text Available Alzheimer's disease is characterized pathologically by extracellular senile plaques, intracellular neurofibrillary tangles, and granulovacuolar degeneration. It has been debated whether these hallmark lesions are markers or mediators of disease progression, and numerous paradigms have been proposed to explain the appearance of each lesion individually. However, the unfaltering predictability of these lesions suggests a single pathological nidus central to disease onset and progression. One of the earliest pathologies observed in Alzheimer's disease is endocytic dysfunction. Here we review the recent literature of endocytic dysfunction with particular focus on disrupted lysosomal fusion and propose it as a unifying hypothesis for the three most-studied lesions of Alzheimer's disease.

  17. GSK-3β, a pivotal kinase in Alzheimer disease

    Directory of Open Access Journals (Sweden)

    Maria eLLorens-Martin

    2014-05-01

    Full Text Available Alzheimer disease (AD is the most common form of age-related dementia. The etiology of AD is considered to be multifactorial as only a negligible percentage of cases have a familial or genetic origin. Glycogen synthase kinase-3 (GSK-3 is regarded as a critical molecular link between the two histopathological hallmarks of the disease, namely senile plaques and neurofibrillary tangles. In this review, we summarize current data regarding the involvement of this kinase in several aspects of AD development and progression, as well as key observations highlighting GSK-3 as one of the most relevant targets for AD treatment.

  18. γ-Aminobutyric Acid (GABA) Production and Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Fermented Soybean Containing Sea Tangle by the Co-Culture of Lactobacillus brevis with Aspergillus oryzae.

    Science.gov (United States)

    Jang, Eun Kyeong; Kim, Nam Yeun; Ahn, Hyung Jin; Ji, Geun Eog

    2015-08-01

    To enhance the γ-aminobutyric acid (GABA) content, the optimized fermentation of soybean with added sea tangle extract was evaluated at 30°C and pH 5.0. The medium was first inoculated with Aspergillus oryzae strain FMB S46471 and fermented for 3 days, followed by the subsequent inoculation with Lactobacillus brevis GABA 100. After fermentation for 7 days, the fermented soybean showed approximately 1.9 g/kg GABA and exhibited higher ACE inhibitory activity than the traditional soybean product. Furthermore, several peptides in the fraction containing the highest ACE inhibitory activity were identified. The novel fermented soybean enriched with GABA and ACE inhibitory components has great pharmaceutical and functional food values.

  19. Tau causes synapse loss without disrupting calcium homeostasis in the rTg4510 model of tauopathy.

    Directory of Open Access Journals (Sweden)

    Katherine J Kopeikina

    Full Text Available Neurofibrillary tangles (NFTs of tau are one of the defining hallmarks of Alzheimer's disease (AD, and are closely associated with neuronal degeneration. Although it has been suggested that calcium dysregulation is important to AD pathogenesis, few studies have probed the link between calcium homeostasis, synapse loss and pathological changes in tau. Here we test the hypothesis that pathological changes in tau are associated with changes in calcium by utilizing in vivo calcium imaging in adult rTg4510 mice that exhibit severe tau pathology due to over-expression of human mutant P301L tau. We observe prominent dendritic spine loss without disruptions in calcium homeostasis, indicating that tangles do not disrupt this fundamental feature of neuronal health, and that tau likely induces spine loss in a calcium-independent manner.

  20. The influence of phospho-tau on dendritic spines of cortical pyramidal neurons in patients with Alzheimer’s disease

    Science.gov (United States)

    Merino-Serrais, Paula; Benavides-Piccione, Ruth; Blazquez-Llorca, Lidia; Kastanauskaite, Asta; Rábano, Alberto; Avila, Jesús

    2013-01-01

    The dendritic spines on pyramidal cells represent the main postsynaptic elements of cortical excitatory synapses and they are fundamental structures in memory, learning and cognition. In the present study, we used intracellular injections of Lucifer yellow in fixed tissue to analyse over 19 500 dendritic spines that were completely reconstructed in three dimensions along the length of the basal dendrites of pyramidal neurons in the parahippocampal cortex and CA1 of patients with Alzheimer’s disease. Following intracellular injection, sections were immunostained for anti-Lucifer yellow and with tau monoclonal antibodies AT8 and PHF-1, which recognize tau phosphorylated at Ser202/Thr205 and at Ser396/404, respectively. We observed that the diffuse accumulation of phospho-tau in a putative pre-tangle state did not induce changes in the dendrites of pyramidal neurons, whereas the presence of tau aggregates forming intraneuronal neurofibrillary tangles was associated with progressive alteration of dendritic spines (loss of dendritic spines and changes in their morphology) and dendrite atrophy, depending on the degree of tangle development. Thus, the presence of phospho-tau in neurons does not necessarily mean that they suffer severe and irreversible effects as thought previously but rather, the characteristic cognitive impairment in Alzheimer’s disease is likely to depend on the relative number of neurons that have well developed tangles. PMID:23715095

  1. Diversity, distribution and floral specificity of tangle-veined flies (Diptera: Nemestrinidae in north west Patagonia, Argentina Diversidad, distribución y especificidad floral de nemestrínidos (Diptera en el noroeste de la Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    MARIANO DEVOTO

    2006-03-01

    Full Text Available Tangle-veined flies (Nemestrinidae constitute a primitive and rather widespread family among Diptera. The genus Trichophthalma occurs in Australia and South America and is the only one in the family with a typically Gondwanian, disjoint distribution. The ecology and distribution of most southern South American species of this genus remains virtually unknown. We studied the diversity, distribution and flower specificity of flower-visiting species of the genus Trichophthalma in the temperate forests of southern South America in ten sites along an east-west rainfall gradient (37-40°S on the eastern slope of the Andes. We recorded nine species of Trichophthalma, which showed an overlapped distribution along the gradient and different degrees of floral specificity. Three species are reported for Argentina for the first time and three are first recorded as flower visitors to the local flora. Our results show that while in southern Africa tangle-veined flies are engaged in highly specialized pollination interactions with long-tubed species, the Trichophthalma spp. of Patagonia share their flowers with a diverse and rather unspecialized visitor fauna among which several species of flies, bees and birds are presentLos nemestrínidos constituyen una familia de Dípteros primitiva y de amplia distribución. El género Trichophthalma se encuentra en Australia y Sudamérica y es el único en la familia con una distribución disjunta típicamente gondwánica. La ecología y distribución de la mayoría de las especies sudamericanas permanecen virtualmente desconocidas. Estudiamos la diversidad, distribución y especificidad floral de las especies del género Trichophthalma de los bosques templados del sur de Sudamérica en diez sitios ubicados a lo largo de un gradiente de precipitación este-oeste (37-40°S sobre la vertiente occidental de los Andes. Registramos nueve especies de Trichophthalma, las cuales mostraron una distribución superpuesta a lo largo

  2. Tangled skeins: a first report of non-captive mating behavior in the Southeast Asian Paradise Flying Snake (Reptilia: Squamata: Colubridae: Chrysopelea paradisi

    Directory of Open Access Journals (Sweden)

    Hinrich Kaiser

    2016-02-01

    Full Text Available We describe the courtship behavior of the Paradise Flying Snake, Chrysopelea paradisi, from a series of images taken near Sandakan, eastern Sabah, Borneo, Malaysia. During the episode observed, four males moved together with a female in various states of entanglement, traveling at ground level and into a series of bushes.  The observations took place over the course of a 30-min period until the snakes were lost to view.  Our report is the first direct observation of mating behavior in C. paradisi in the wild and provides another rare glimpse of the multi-male courtship in Southeast Asian colubrids. 

  3. An inconspicuous, conspicuous new species of Asian pipesnake, genus Cylindrophis (Reptilia: Squamata: Cylindrophiidae), from the south coast of Jawa Tengah, Java, Indonesia, and an overview of the tangled taxonomic history of C. ruffus (Laurenti, 1768).

    Science.gov (United States)

    Kieckbusch, Max; Mecke, Sven; Hartmann, Lukas; Ehrmantraut, Lisa; O'shea, Mark; Kaiser, Hinrich

    2016-03-20

    We describe a new species of Cylindrophis currently known only from Grabag, Purworejo Regency, Jawa Tengah Pro-vince (Central Java), Java, Indonesia. Cylindrophis subocularis sp. nov. can be distinguished from all congeners by the presence of a single, eponymous subocular scale between the 3rd and 4th or 4th and 5th supralabial, preventing contact between the 4th or 5th supralabial and the orbit, and by having the prefrontal in narrow contact with or separated from the orbit. We preface our description with a detailed account of the tangled taxonomic history of the similar and putatively wide-ranging species C. ruffus, which leads us to (1) remove the name Scytale scheuchzeri from the synonymy of C. ruffus, (2) list the taxon C. rufa var. javanica as species inquirenda, and (3) synonymize C. mirzae with C. ruffus. We provide additional evidence to confirm that the type locality of C. ruffus is Java. Cylindrophis subocularis sp. nov. is the second species of Asian pipesnake from Java.

  4. Oxidative Stress and Metabolic Syndrome: Cause or Consequence of Alzheimer's Disease?

    Directory of Open Access Journals (Sweden)

    Diana Luque-Contreras

    2014-01-01

    Full Text Available Alzheimer’s disease (AD is a major neurodegenerative disease affecting the elderly. Clinically, it is characterized by a progressive loss of memory and cognitive function. Neuropathologically, it is characterized by the presence of extracellular β-amyloid (Aβ deposited as neuritic plaques (NP and neurofibrillary tangles (NFT made of abnormal and hyperphosphorylated tau protein. These lesions are capable of generating the neuronal damage that leads to cell death and cognitive failure through the generation of reactive oxygen species (ROS. Evidence indicates the critical role of Aβ metabolism in prompting the oxidative stress observed in AD patients. However, it has also been proposed that oxidative damage precedes the onset of clinical and pathological AD symptoms, including amyloid-β deposition, neurofibrillary tangle formation, vascular malfunction, metabolic syndrome, and cognitive decline. This paper provides a brief description of the three main proteins associated with the development of the disease (Aβ, tau, and ApoE and describes their role in the generation of oxidative stress. Finally, we describe the mitochondrial alterations that are generated by Aβ and examine the relationship of vascular damage which is a potential prognostic tool of metabolic syndrome. In addition, new therapeutic approaches targeting ROS sources and metabolic support were reported.

  5. Tangled up in two: a burst of genome duplications at the end of the Cretaceous and the consequences for plant evolution.

    Science.gov (United States)

    Vanneste, Kevin; Maere, Steven; Van de Peer, Yves

    2014-08-05

    Genome sequencing has demonstrated that besides frequent small-scale duplications, large-scale duplication events such as whole genome duplications (WGDs) are found on many branches of the evolutionary tree of life. Especially in the plant lineage, there is evidence for recurrent WGDs, and the ancestor of all angiosperms was in fact most likely a polyploid species. The number of WGDs found in sequenced plant genomes allows us to investigate questions about the roles of WGDs that were hitherto impossible to address. An intriguing observation is that many plant WGDs seem associated with periods of increased environmental stress and/or fluctuations, a trend that is evident for both present-day polyploids and palaeopolyploids formed around the Cretaceous-Palaeogene (K-Pg) extinction at 66 Ma. Here, we revisit the WGDs in plants that mark the K-Pg boundary, and discuss some specific examples of biological innovations and/or diversifications that may be linked to these WGDs. We review evidence for the processes that could have contributed to increased polyploid establishment at the K-Pg boundary, and discuss the implications on subsequent plant evolution in the Cenozoic.

  6. Amyloid beta 1-42 and phoshorylated tau threonin 231 in brains of aged cynomolgus monkeys (Macaca fascicularis

    Directory of Open Access Journals (Sweden)

    Huda Shalahudin Darusman

    2014-11-01

    Full Text Available Pathological hallmarks indicative of Alzheimer’s disease, which are the plaques of Amyloid Beta 1-42 and neurofibrillary tangles, were found in brain of aged cynomolgus monkey. The aim of the study was to investigate if aged monkeys exhibiting spatial memory impairment and levels of biomarkers indicative of Alzheimer’s disease, had brain lesions similar to human patients suffering from senile dementia. Generating immunohistochemistry technique to biomarkers of Amyloid beta 1-42 and the phosphorylated tau 231, our study assessed the amyloidopathy, such as indicative to the senile plaques and cerebral amyloid angiopathy, and the tauopathy, to possible neurofibrillary tangles. Six aged monkeys were selected based on their spatial memory performance and profile of biomarkers of Alzheimer’s disease, divided equally to affected aged subject - with Memory-affected and low amyloid level, and aged with higher performance in memory and amyloid, as the age-matched subjects. Using immunohistochemistry, plaques of Amyloid Beta 1-42 were observed in two out of three brains of aged subjects with memory impairment and biomarkers indicative of Alzheimer’s disease. The cerebral amyloid angiopathy was observed in both aged monkey groups, and unlike in the human, the amyloids were found to deposit in the small veins and capillaries. In one of the affected individuals, phosphorylated tau was positively stained intracellularly of the neurons, indicating a possibility of an early stage of the formation of tangles. These findings add to the body of evidence of the utility of the aged cynomolgus monkeys as a spontaneous model for Alzheimer-related disease.

  7. New tangles in the auxin signaling web

    Science.gov (United States)

    Wright, R. Clay

    2015-01-01

    Plants use auxin to relay critical information that shapes their growth and development. Auxin perception and transcriptional activation are mediated by the degradation of Aux/IAA repressor proteins. Degradation of Aux/IAAs relieves repression on Auxin Response Factors (ARFs), which bind DNA sequences called Auxin Response Elements (AuxREs). In most higher plant genomes, multiple paralogs exist for each part of the auxin nuclear signaling pathway. This potential combinatorial diversity in signaling pathways likely contributes to the myriad of context-specific responses to auxin. Recent structures of several domains from ARF proteins have exposed new modes of ARF dimerization, new models for ARF-AuxRE specificity, and the strong likelihood of larger order complexes formed by ARF and Aux/IAA homo- and heteromultimerization. Preliminary experiments support a role for these novel interactions in planta, further increasing the potential architectural complexity of this seemingly simple pathway. PMID:25750737

  8. Cell competition: pirates on the tangled bank.

    Science.gov (United States)

    Green, Douglas R

    2010-04-02

    Competition by stem cells for occupation of a limited niche is a well-described phenomenon. Two recent studies highlight competition between hematopoietic stem cells based on p53. These findings have implications for both normal homeostasis and tumorigenesis. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  9. Intractable Tangles in the Bird Family Tree.

    Science.gov (United States)

    Roberts, Roland G

    2015-08-01

    Rapid sequential speciation events can outpace the fixation of genetic variants, resulting in a family tree that lacks clear branching patterns. A new study of bird genomes reveals such an explosive super-radiation that may coincide with the mass extinction at the end of the Cretaceous period.

  10. "It Takes at Least Two to Tangle"

    Science.gov (United States)

    Walker, Janice M.

    2010-01-01

    Despite past lessons, book-banning continues to exist at all levels within our democratic society. This case presents a realistic scenario when the school district, facing a book challenge by a concerned parent, responds by removing the book from the library. On the basis of a true story, the study features a parent of an elementary child…

  11. New tangles in the auxin signaling web.

    Science.gov (United States)

    Wright, R Clay; Nemhauser, Jennifer L

    2015-01-01

    Plants use auxin to relay critical information that shapes their growth and development. Auxin perception and transcriptional activation are mediated by the degradation of Aux/IAA repressor proteins. Degradation of Aux/IAAs relieves repression on Auxin Response Factors (ARFs), which bind DNA sequences called Auxin Response Elements (AuxREs). In most higher plant genomes, multiple paralogs exist for each part of the auxin nuclear signaling pathway. This potential combinatorial diversity in signaling pathways likely contributes to the myriad of context-specific responses to auxin. Recent structures of several domains from ARF proteins have exposed new modes of ARF dimerization, new models for ARF-AuxRE specificity, and the strong likelihood of larger order complexes formed by ARF and Aux/IAA homo- and heteromultimerization. Preliminary experiments support a role for these novel interactions in planta, further increasing the potential architectural complexity of this seemingly simple pathway.

  12. Gout and Metabolic Syndrome: a Tangled Web.

    Science.gov (United States)

    Thottam, Gabrielle E; Krasnokutsky, Svetlana; Pillinger, Michael H

    2017-08-26

    The complexity of gout continues to unravel with each new investigation. Gout sits at the intersection of multiple intrinsically complex processes, and its prevalence, impact on healthcare costs, and association with important co-morbidities make it increasingly relevant. The association between gout and type 2 diabetes, hypertension, hyperlipidemia, cardiovascular disease, renal disease, and obesity suggest that either gout, or its necessary precursor hyperuricemia, may play an important role in the manifestations of the metabolic syndrome. In this review, we analyze the complex interconnections between gout and metabolic syndrome, by reviewing gout's physiologic and epidemiologic relationships with its major co-morbidities. Increasing evidence supports gout's association with metabolic syndrome. More specifically, both human studies and animal models suggest that hyperuricemia may play a role in promoting inflammation, hypertension and cardiovascular disease, adipogenesis and lipogenesis, insulin and glucose dysregulation, and liver disease. Fructose ingestion is associated with increased rates of hypertension, weight gain, impaired glucose tolerance, and dyslipidemia and is a key driver of urate biosynthesis. AMP kinase (AMPK) is a central regulator of processes that tend to mitigate against the metabolic syndrome. Within hepatocytes, leukocytes, and other cells, a fructose/urate metabolic loop drives key inhibitors of AMPK, including AMP deaminase and fructokinase, that may tilt the balance toward metabolic syndrome progression. Preliminary evidence suggests that agents that block the intracellular synthesis of urate may restore AMPK activity and help maintain metabolic homeostasis. Gout is both an inflammatory and a metabolic disease. With further investigation of urate's role, the possibility of proper gout management additionally mitigating metabolic syndrome is an evolving and important question.

  13. Asthma and cystic fibrosis: A tangled web.

    LENUS (Irish Health Repository)

    Kent, Brian D

    2014-03-01

    Successfully diagnosing concomitant asthma in people with cystic fibrosis (CF) is a challenging proposition, and the utility of conventional diagnostic criteria of asthma in CF populations remains uncertain. Nonetheless, the accurate identification of individuals with CF and asthma allows appropriate tailoring of therapy, and should reduce the unnecessary use of asthma medication in broader CF cohorts. In this review, we discuss the diagnostic challenge posed by asthma in CF, both in terms of clinical evaluation, and of interpretation of pulmonary function testing and non-invasive markers of airway inflammation. We also examine how the role of cross-sectional thoracic imaging in CF and asthma can assist in the diagnosis of asthma in these patients. Finally, we critically appraise the evidence base behind the use of asthma medications in CF populations, with a particular focus on the use of inhaled corticosteroids and bronchodilators. As shall be discussed, the gaps in the current literature make further high-quality research in this field imperative. Pediatr Pulmonol. 2014; 49:205-213. © 2014 Wiley Periodicals, Inc.

  14. Tangled in a sparse spider web

    DEFF Research Database (Denmark)

    Dimitrov, Dimitar Stefanov; Lopardo, Lara; Giribet, Gonzalo

    2012-01-01

    In order to study the tempo and the mode of spider orb web evolution and diversification, we conducted a phylogenetic analysis using six genetic markers along with a comprehensive taxon sample. The present analyses are the first to recover the monophyly of orb-weaving spiders based solely on DNA ...

  15. Primary age-related tauopathy (PART): a common pathology associated with human aging.

    Science.gov (United States)

    Crary, John F; Trojanowski, John Q; Schneider, Julie A; Abisambra, Jose F; Abner, Erin L; Alafuzoff, Irina; Arnold, Steven E; Attems, Johannes; Beach, Thomas G; Bigio, Eileen H; Cairns, Nigel J; Dickson, Dennis W; Gearing, Marla; Grinberg, Lea T; Hof, Patrick R; Hyman, Bradley T; Jellinger, Kurt; Jicha, Gregory A; Kovacs, Gabor G; Knopman, David S; Kofler, Julia; Kukull, Walter A; Mackenzie, Ian R; Masliah, Eliezer; McKee, Ann; Montine, Thomas J; Murray, Melissa E; Neltner, Janna H; Santa-Maria, Ismael; Seeley, William W; Serrano-Pozo, Alberto; Shelanski, Michael L; Stein, Thor; Takao, Masaki; Thal, Dietmar R; Toledo, Jonathan B; Troncoso, Juan C; Vonsattel, Jean Paul; White, Charles L; Wisniewski, Thomas; Woltjer, Randall L; Yamada, Masahito; Nelson, Peter T

    2014-12-01

    We recommend a new term, "primary age-related tauopathy" (PART), to describe a pathology that is commonly observed in the brains of aged individuals. Many autopsy studies have reported brains with neurofibrillary tangles (NFTs) that are indistinguishable from those of Alzheimer's disease (AD), in the absence of amyloid (Aβ) plaques. For these "NFT+/Aβ-" brains, for which formal criteria for AD neuropathologic changes are not met, the NFTs are mostly restricted to structures in the medial temporal lobe, basal forebrain, brainstem, and olfactory areas (bulb and cortex). Symptoms in persons with PART usually range from normal to amnestic cognitive changes, with only a minority exhibiting profound impairment. Because cognitive impairment is often mild, existing clinicopathologic designations, such as "tangle-only dementia" and "tangle-predominant senile dementia", are imprecise and not appropriate for most subjects. PART is almost universally detectable at autopsy among elderly individuals, yet this pathological process cannot be specifically identified pre-mortem at the present time. Improved biomarkers and tau imaging may enable diagnosis of PART in clinical settings in the future. Indeed, recent studies have identified a common biomarker profile consisting of temporal lobe atrophy and tauopathy without evidence of Aβ accumulation. For both researchers and clinicians, a revised nomenclature will raise awareness of this extremely common pathologic change while providing a conceptual foundation for future studies. Prior reports that have elucidated features of the pathologic entity we refer to as PART are discussed, and working neuropathological diagnostic criteria are proposed.

  16. Pathology of the superior colliculus in chronic traumatic encephalopathy

    OpenAIRE

    Richard A. Armstrong; McKee, Ann C.; Cairns, Nigel J.

    2017-01-01

    PURPOSE: To investigate neuropathological changes in the superior colliculus in chronic traumatic encephalopathy. METHODS: The densities of the tau-immunoreactive neurofibrillary tangles, neuropil threads, dot-like grains, astrocytic tangles, and neuritic plaques, together with abnormally enlarged neurons, typical neurons, vacuolation, and frequency of contacts with blood vessels, were studied across the superior colliculus from pia mater to the periaqueductal gray in eight chronic traumatic ...

  17. Antisense-mediated Exon Skipping Decreases Tau Protein Expression: A Potential Therapy For Tauopathies

    OpenAIRE

    Sud, Reeteka; Geller, Evan T.; Schellenberg, Gerard D.

    2014-01-01

    In Alzheimer's disease, progressive supranuclear palsy, and a number of other neurodegenerative diseases, the microtubule associated protein tau aggregates to form intracellular neurofibrillary tangles and glial tangles, abnormal structures that are part of disease pathogenesis. Disorders with aggregated tau are called tauopathies. Presently, there are no disease-modifying treatments for this disease class. Tau is encoded by the MAPT gene. We propose that reducing MAPT expression and thus the...

  18. Observation Station

    Science.gov (United States)

    Rutherford, Heather

    2011-01-01

    This article describes how a teacher integrates science observations into the writing center. At the observation station, students explore new items with a science theme and use their notes and questions for class writings every day. Students are exposed to a variety of different topics and motivated to write in different styles all while…

  19. Observing nebulae

    CERN Document Server

    Griffiths, Martin

    2016-01-01

    This book enables anyone with suitable instruments to undertake an examination of nebulae and see or photograph them in detail. Nebulae, ethereal clouds of gas and dust, are among the most beautiful objects to view in the night sky. These star-forming regions are a common target for observers and photographers. Griffiths describes many of the brightest and best nebulae and includes some challenges for the more experienced observer. Readers learn the many interesting astrophysical properties of these clouds, which are an important subject of study in astronomy and astrobiology. Non-mathematical in approach, the text is easily accessible to anyone with an interest in the subject. A special feature is the inclusion of an observational guide to 70 objects personally observed or imaged by the author. The guide also includes photographs of each object for ease of identification along with their celestial coordinates, magnitudes and other pertinent information. Observing Nebulae provides a ready resource to allow an...

  20. Beta-Amyloid Deposition and Alzheimer's Type Changes Induced by Borrelia Spirochetes

    Energy Technology Data Exchange (ETDEWEB)

    Miklossy,J.; Kis, A.; Radenovic, A.; Miller, L.; Forro, L.; Martins, R.; Reiss, K.; Darbinian, N.; Darekar, P.; et al.

    2006-01-01

    The pathological hallmarks of Alzheimer's disease (AD) consist of {beta}-amyloid plaques and neurofibrillary tangles in affected brain areas. The processes, which drive this host reaction are unknown. To determine whether an analogous host reaction to that occurring in AD could be induced by infectious agents, we exposed mammalian glial and neuronal cells in vitro to Borrelia burgdorferi spirochetes and to the inflammatory bacterial lipopolysaccharide (LPS). Morphological changes analogous to the amyloid deposits of AD brain were observed following 2-8 weeks of exposure to the spirochetes. Increased levels of {beta}-amyloid presursor protein (A{beta}PP) and hyperphosphorylated tau were also detected by Western blots of extracts of cultured cells that had been treated with spirochetes or LPS. These observations indicate that, by exposure to bacteria or to their toxic products, host responses similar in nature to those observed in AD may be induced.

  1. Observational astrophysics

    CERN Document Server

    Léna, Pierre; Lebrun, François; Mignard, François; Pelat, Didier

    2012-01-01

    This is the updated, widely revised, restructured and expanded third edition of Léna et al.'s successful work Observational Astrophysics. It presents a synthesis on tools and methods of observational astrophysics of the early 21st century. Written specifically for astrophysicists and graduate students, this textbook focuses on fundamental and sometimes practical limitations on the ultimate performance that an astronomical system may reach, rather than presenting particular systems in detail. In little more than a decade there has been extraordinary progress in imaging and detection technologies, in the fields of adaptive optics, optical interferometry, in the sub-millimetre waveband, observation of neutrinos, discovery of exoplanets, to name but a few examples. The work deals with ground-based and space-based astronomy and their respective fields. And it also presents the ambitious concepts behind space missions aimed for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spec...

  2. Observable supertranslations

    Science.gov (United States)

    Bousso, Raphael; Porrati, Massimo

    2017-10-01

    We show that large gauge transformations in asymptotically flat spacetime can be implemented by sandwiching a shell containing the ingoing hard particles between two finite-width shells of soft gauge excitations. Integration of the graviton Dirac bracket implies that our observable soft degrees of freedom obey the algebra imposed by Strominger et al. on unobservable boundary degrees of freedom. Thus, we provide both a derivation and an observable realization of this algebra. We recently showed that soft charges fail to constrain the hard scattering problem, and so cannot be relevant to the black hole information paradox. By expressing the Bondi-van der Burg-Metzner-Sachs (BMS) algebra in terms of observable quantities, the present work shows that this conclusion was not an artifact of working with strictly zero frequency soft modes. The conservation laws associated with asymptotic symmetries are seen to arise physically from free propagation of infrared modes.

  3. Deltagende observation

    DEFF Research Database (Denmark)

    Warming, H.

    2007-01-01

    Artiklen er en introduktion til deltagende observation som samfundsvidenskabelig metode. I artiklen introduceres til de teorihistoriske rødder, forskellige tilgange til metoden, den konkrete fremgangsmåde og de dermed forbundne overvejelser. Endvidere eksemplificeres metoden, og der opstilles en...

  4. Flare Observations

    Directory of Open Access Journals (Sweden)

    Benz Arnold O.

    2008-02-01

    Full Text Available Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays at 100 MeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, and SOHO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections (CMEs, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting reconnection of magnetic field lines as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s lower ionosphere. While flare scenarios have slowly converged over the past decades, every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  5. Flare Observations

    Directory of Open Access Journals (Sweden)

    Arnold O. Benz

    2016-12-01

    Full Text Available Abstract Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1 GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth’s ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  6. Flare Observations

    Science.gov (United States)

    Benz, Arnold O.

    2017-12-01

    Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1 GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth's ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

  7. Amyloid beta1–42 and the phoshorylated tau threonine 231 in brains of aged cynomolgus monkeys (Macaca fascicularis)

    DEFF Research Database (Denmark)

    Darusman, Huda Shalahudin; Gjedde, Albert; Sajuthi, Dondin

    2014-01-01

    Pathological hallmarks indicative of Alzheimer's disease (AD), which are the plaques of amyloid beta1-42 and neurofibrillary tangles, were found in brain of aged cynomolgus monkey. The aim of this study was to investigate if aged monkeys exhibiting spatial memory impairment and levels of biomarke...

  8. Aberrant myelinated neurites in the anterior horns of a patient with amyotrophic lateral sclerosis

    NARCIS (Netherlands)

    Troost, D.; Louwerse, E. S.; de Jong, J. M.; van Leersum, G. S.; van Raalte, J. A.

    1989-01-01

    A case of amyotrophic lateral sclerosis revealed the classical pathologic features of ALS, i.e. neuronal loss in the anterior horns and pyramidal tract degeneration. In addition to the pathological hallmarks of Alzheimer's disease, senile plaques, neurofibrillary tangles and granulovacuolar changes

  9. Glia in Alzheimer's disease and aging: Molecular mechanisms underlying astrocyte and microglia reactivity

    NARCIS (Netherlands)

    Orre, A.M.

    2014-01-01

    Alzheimer’s disease (AD) is the most common form of dementia in our society. The disease is characterized by pathological hallmarks such as Amyloid beta (Aß) plaques and neurofibrillary tangles. These pathological changes are associated with neuronal dysfunction and severe cognitive impairment. In

  10. Relationship of aluminum to Alzheimer's disease.

    Science.gov (United States)

    Perl, D P

    1985-01-01

    Alzheimer's disease is a progressive degenerative brain disease of unknown etiology, characterized by the development of large numbers of neurofibrillary tangles and senile plaques in the brain. Aluminum salts may be used experimentally to produce lesions which are similar, but not identical, to the neurofibrillary tangle. Although some studies have reported increased amounts of aluminum in the brains of Alzheimer's disease victims, these bulk analysis studies have been difficult to replicate and remain controversial. Using scanning electron microscopy with X-ray spectrometry, we have investigated this question on the cellular level. We have identified abnormal accumulations of aluminum within neurons derived from Alzheimer's disease patients containing neurofibrillary tangles. Similar accumulations have been detected in the numerous neurofibrillary tangle-bearing neurons seen in the brains of the indigenous native population of the island of Guam who suffer from amyotrophic lateral sclerosis and parkinsonism with dementia. Epidemiologic evidence strongly suggests a causal role for local environmental conditions relating to availability of aluminum, calcium, and magnesium. In view of the fact that a major consequence of acid rain is the liberation of large amounts of aluminum in bioavailable forms, concerns are raised about possible human health risks of this environmental phenomenon. PMID:4076080

  11. Cardiovascular risk factors and future risk of Alzheimer's disease

    NARCIS (Netherlands)

    R.F.A.G. de Bruijn (Renée); M.A. Ikram (Arfan)

    2014-01-01

    textabstractAlzheimer's disease (AD) is the most common neurodegenerative disorder in elderly people, but there are still no curative options. Senile plaques and neurofibrillary tangles are considered hallmarks of AD, but cerebrovascular pathology is also common. In this review, we summarize

  12. Untangling the Mystery of Alzheimer's Disease-Understanding ...

    Indian Academy of Sciences (India)

    http://www.ias.ac.in/article/fulltext/reso/007/02/0033-0045. Keywords. Neurodegenerative disorder; senile dementia; -amyloid plaques; neurofibrillary tangles. Author Affiliations. Sovan Sarkar1 Anupam Choudhury T N Avinash. II MSc - Biotechnology School of Biotechnology Madurai Kamaraj University Madurai 625021, ...

  13. Les observables

    Directory of Open Access Journals (Sweden)

    Bergounioux Gabriel

    2014-07-01

    jacents ? Au cours de cette table ronde, la question des observables sera interrogée en partant d’une réflexion concernant les études qui se fondent sur l’inventaire empirique des données pour construire leurs analyses (statistique lexicale, Labphon, corpus-guided linguistics, sociolinguistique variationniste, linguistique cognitive… et en allant jusqu’aux théories qui postulent l’existence de formalismes préalables dont les discours et les textes ratifieraient, par l’actualisation et la distribution de leurs occurrences, la pertinence épistémologique.

  14. Characterization of TauC3 antibody and demonstration of its potential to block tau propagation.

    Directory of Open Access Journals (Sweden)

    Samantha B Nicholls

    Full Text Available The spread of neurofibrillary tangle (NFT pathology through the human brain is a hallmark of Alzheimer's disease (AD, which is thought to be caused by the propagation of "seeding" competent soluble misfolded tau. "TauC3", a C-terminally truncated form of tau that is generated by caspase-3 cleavage at D421, has previously been observed in NFTs and has been implicated in tau toxicity. Here we show that TauC3 is found in the seeding competent high molecular weight (HMW protein fraction of human AD brain. Using a specific TauC3 antibody, we were able to substantially block the HMW tau seeding activity of human AD brain extracts in an in vitro tau seeding FRET assay. We propose that TauC3 could contribute to the templated tau misfolding that leads to NFT spread in AD brains.

  15. A quantitative study of intracranial calcification in dementia of the Alzheimer type.

    Science.gov (United States)

    Friedland, R P; Luxenberg, J S; Koss, E

    1990-01-01

    Abnormalities in calcium homeostasis have been reported in Alzheimer's disease (AD) and in the neurofibrillary tangle disorders of amyotrophic lateral sclerosis and parkinsonism-dementia occurring in the Pacific. In order to more fully evaluate calcium physiology in AD, we analyzed the size of pineal and choroid plexus calcifications, using X-ray computed tomography, in 23 patients with probable AD and 18 healthy age-matched control subjects. The area occupied by calcification was measured from hard copies of the data by two independent observers who were blind to the diagnosis. There were no differences in the areas occupied by pineal or choroid plexus calcifications between the two groups. These data suggest that AD is not accompanied by alternations in intracranial calcium deposition in pineal gland or choroid plexus.

  16. The human pineal gland in aging and Alzheimer's disease: patterns of cytoskeletal antigen immunoreactivity.

    Science.gov (United States)

    Pardo, C A; Martin, L J; Troncoso, J C; Price, D L

    1990-01-01

    Patients with Alzheimer's disease (AD) and some aged controls may have diminished functions of the pineal gland. In this immunocytochemical study, we stained pineal glands from cases of AD and young and aged controls for cytoskeletal elements and amyloid. We found no evidence of neurofibrillary tangles (NFT) or the accumulation of neurofilaments, tau, A68, or beta/A4 amyloid deposition in pinealocytes or associated structures in cases of AD or controls. In both AD and controls, we observed dense immunoreactivity for phosphorylated neurofilaments in marginal plexuses associated with processes of pinealocytes, boutons, and knob-like endings. The accumulation of phosphorylated neurofilaments in the processes of pinealocytes appears to be a normal morphological characteristic of the pineal gland and may not represent a pathological change.

  17. Axonal accumulation of synaptic markers in APP transgenic Drosophila depends on the NPTY motif and is paralleled by defects in synaptic plasticity

    DEFF Research Database (Denmark)

    Rusu, Patricia; Jansen, Anna; Soba, Peter

    2007-01-01

    Alzheimer's disease (AD) is characterized by neurofibrillary tangles and extracellular plaques, which consist mainly of beta-amyloid derived from the beta-amyloid precursor protein (APP). An additional feature of AD is axonopathy, which might contribute to impairment of cognitive functions....... Specifically, axonal transport defects have been reported in AD animal models, including mice and flies that overexpress APP and tau. Here we demonstrate that the APP-induced traffic jam of vesicles in peripheral nerves of Drosophila melanogaster larvae depends on the four residues NPTY motif in the APP....... Together, our results show that overexpression of APP induces partial stalling of axonal transport vesicles, paralleled by abnormalities in synaptic plasticity, which may provide a functional link to the deterioration of cognitive functions observed in AD....

  18. Neuropathological Alterations in Alzheimer Disease

    Science.gov (United States)

    Serrano-Pozo, Alberto; Frosch, Matthew P.; Masliah, Eliezer; Hyman, Bradley T.

    2011-01-01

    The neuropathological hallmarks of Alzheimer disease (AD) include “positive” lesions such as amyloid plaques and cerebral amyloid angiopathy, neurofibrillary tangles, and glial responses, and “negative” lesions such as neuronal and synaptic loss. Despite their inherently cross-sectional nature, postmortem studies have enabled the staging of the progression of both amyloid and tangle pathologies, and, consequently, the development of diagnostic criteria that are now used worldwide. In addition, clinicopathological correlation studies have been crucial to generate hypotheses about the pathophysiology of the disease, by establishing that there is a continuum between “normal” aging and AD dementia, and that the amyloid plaque build-up occurs primarily before the onset of cognitive deficits, while neurofibrillary tangles, neuron loss, and particularly synaptic loss, parallel the progression of cognitive decline. Importantly, these cross-sectional neuropathological data have been largely validated by longitudinal in vivo studies using modern imaging biomarkers such as amyloid PET and volumetric MRI. PMID:22229116

  19. Early correlation of microglial activation with enhanced tumor necrosis factor-alpha and monocyte chemoattractant protein-1 expression specifically within the entorhinal cortex of triple transgenic Alzheimer's disease mice

    Directory of Open Access Journals (Sweden)

    LaFerla Frank M

    2005-10-01

    Full Text Available Abstract Background Alzheimer's disease is a complex neurodegenerative disorder characterized pathologically by a temporal and spatial progression of beta-amyloid (Aβ deposition, neurofibrillary tangle formation, and synaptic degeneration. Inflammatory processes have been implicated in initiating and/or propagating AD-associated pathology within the brain, as inflammatory cytokine expression and other markers of inflammation are pronounced in individuals with AD pathology. The current study examines whether inflammatory processes are evident early in the disease process in the 3xTg-AD mouse model and if regional differences in inflammatory profiles exist. Methods Coronal brain sections were used to identify Aβ in 2, 3, and 6-month 3xTg-AD and non-transgenic control mice. Quantitative real-time RT-PCR was performed on microdissected entorhinal cortex and hippocampus tissue of 2, 3, and 6-month 3xTg-AD and non-transgenic mice. Microglial/macrophage cell numbers were quantified using unbiased stereology in 3xTg-AD and non-transgenic entorhinal cortex and hippocampus containing sections. Results We observed human Aβ deposition at 3 months in 3xTg-AD mice which is enhanced by 6 months of age. Interestingly, we observed a 14.8-fold up-regulation of TNF-α and 10.8-fold up-regulation of MCP-1 in the entorhinal cortex of 3xTg-AD mice but no change was detected over time in the hippocampus or in either region of non-transgenic mice. Additionally, this increase correlated with a specific increase in F4/80-positive microglia and macrophages in 3xTg-AD entorhinal cortex. Conclusion Our data provide evidence for early induction of inflammatory processes in a model that develops amyloid and neurofibrillary tangle pathology. Additionally, our results link inflammatory processes within the entorhinal cortex, which represents one of the earliest AD-affected brain regions.

  20. The role of protein glycosylation in Alzheimer disease.

    Science.gov (United States)

    Schedin-Weiss, Sophia; Winblad, Bengt; Tjernberg, Lars O

    2014-01-01

    Glycosylation is one of the most common, and the most complex, forms of post-translational modification of proteins. This review serves to highlight the role of protein glycosylation in Alzheimer disease (AD), a topic that has not been thoroughly investigated, although glycosylation defects have been observed in AD patients. The major pathological hallmarks in AD are neurofibrillary tangles and amyloid plaques. Neurofibrillary tangles are composed of phosphorylated tau, and the plaques are composed of amyloid β-peptide (Aβ), which is generated from amyloid precursor protein (APP). Defects in glycosylation of APP, tau and other proteins have been reported in AD. Another interesting observation is that the two proteases required for the generation of amyloid β-peptide (Aβ), i.e. γ-secretase and β-secretase, also have roles in protein glycosylation. For instance, γ-secretase and β-secretase affect the extent of complex N-glycosylation and sialylation of APP, respectively. These processes may be important in AD pathogenesis, as proper intracellular sorting, processing and export of APP are affected by how it is glycosylated. Furthermore, lack of one of the key components of γ-secretase, presenilin, leads to defective glycosylation of many additional proteins that are related to AD pathogenesis and/or neuronal function, including nicastrin, reelin, butyrylcholinesterase, cholinesterase, neural cell adhesion molecule, v-ATPase, and tyrosine-related kinase B. Improved understanding of the effects of AD on protein glycosylation, and vice versa, may therefore be important for improving the diagnosis and treatment of AD patients. © 2013 FEBS.

  1. Tau deposition drives neuropathological, inflammatory and behavioral abnormalities independently of neuronal loss in a novel mouse model

    Science.gov (United States)

    Cook, Casey; Kang, Silvia S.; Carlomagno, Yari; Lin, Wen-Lang; Yue, Mei; Kurti, Aishe; Shinohara, Mitsuru; Jansen-West, Karen; Perkerson, Emilie; Castanedes-Casey, Monica; Rousseau, Linda; Phillips, Virginia; Bu, Guojun; Dickson, Dennis W.; Petrucelli, Leonard; Fryer, John D.

    2015-01-01

    Aberrant tau protein accumulation drives neurofibrillary tangle (NFT) formation in several neurodegenerative diseases. Currently, efforts to elucidate pathogenic mechanisms and assess the efficacy of therapeutic targets are limited by constraints of existing models of tauopathy. In order to generate a more versatile mouse model of tauopathy, somatic brain transgenesis was utilized to deliver adeno-associated virus serotype 1 (AAV1) encoding human mutant P301L-tau compared with GFP control. At 6 months of age, we observed widespread human tau expression with concomitant accumulation of hyperphosphorylated and abnormally folded proteinase K resistant tau. However, no overt neuronal loss was observed, though significant abnormalities were noted in the postsynaptic scaffolding protein PSD95. Neurofibrillary pathology was also detected with Gallyas silver stain and Thioflavin-S, and electron microscopy revealed the deposition of closely packed filaments. In addition to classic markers of tauopathy, significant neuroinflammation and extensive gliosis were detected in AAV1-TauP301L mice. This model also recapitulates the behavioral phenotype characteristic of mouse models of tauopathy, including abnormalities in exploration, anxiety, and learning and memory. These findings indicate that biochemical and neuropathological hallmarks of tauopathies are accurately conserved and are independent of cell death in this novel AAV-based model of tauopathy, which offers exceptional versatility and speed in comparison with existing transgenic models. Therefore, we anticipate this approach will facilitate the identification and validation of genetic modifiers of disease, as well as accelerate preclinical assessment of potential therapeutic targets. PMID:26276810

  2. Modeling familial Danish dementia in mice supports the concept of the amyloid hypothesis of Alzheimer's disease

    Science.gov (United States)

    Coomaraswamy, Janaky; Kilger, Ellen; Wölfing, Heidrun; Schäfer, Claudia; Kaeser, Stephan A.; Wegenast-Braun, Bettina M.; Hefendehl, Jasmin K.; Wolburg, Hartwig; Mazzella, Matthew; Ghiso, Jorge; Goedert, Michel; Akiyama, Haruhiko; Garcia-Sierra, Francisco; Wolfer, David P.; Mathews, Paul M.; Jucker, Mathias

    2010-01-01

    Familial Danish dementia (FDD) is a progressive neurodegenerative disease with cerebral deposition of Dan-amyloid (ADan), neuroinflammation, and neurofibrillary tangles, hallmark characteristics remarkably similar to those in Alzheimer's disease (AD). We have generated transgenic (tg) mouse models of familial Danish dementia that exhibit the age-dependent deposition of ADan throughout the brain with associated amyloid angiopathy, microhemorrhage, neuritic dystrophy, and neuroinflammation. Tg mice are impaired in the Morris water maze and exhibit increased anxiety in the open field. When crossed with TauP301S tg mice, ADan accumulation promotes neurofibrillary lesions, in all aspects similar to the Tau lesions observed in crosses between β-amyloid (Aβ)-depositing tg mice and TauP301S tg mice. Although these observations argue for shared mechanisms of downstream pathophysiology for the sequence-unrelated ADan and Aβ peptides, the lack of codeposition of the two peptides in crosses between ADan- and Aβ-depositing mice points also to distinguishing properties of the peptides. Our results support the concept of the amyloid hypothesis for AD and related dementias, and suggest that different proteins prone to amyloid formation can drive strikingly similar pathogenic pathways in the brain. PMID:20385796

  3. A Nanoflare-Based Cellular Automaton Model and the Observed Properties of the Coronal Plasma

    Science.gov (United States)

    Lopez-Fuentes, Marcelo; Klimchuk, James Andrew

    2016-01-01

    We use the cellular automaton model described in Lopez Fuentes and Klimchuk to study the evolution of coronal loop plasmas. The model, based on the idea of a critical misalignment angle in tangled magnetic fields, produces nanoflares of varying frequency with respect to the plasma cooling time. We compare the results of the model with active region (AR) observations obtained with the Hinode/XRT and SDOAIA instruments. The comparison is based on the statistical properties of synthetic and observed loop light curves. Our results show that the model reproduces the main observational characteristics of the evolution of the plasma in AR coronal loops. The typical intensity fluctuations have amplitudes of 10 percent - 15 percent both for the model and the observations. The sign of the skewness of the intensity distributions indicates the presence of cooling plasma in the loops. We also study the emission measure (EM) distribution predicted by the model and obtain slopes in log(EM) versus log(T) between 2.7 and 4.3, in agreement with published observational values.

  4. Aluminum involvement in the progression of Alzheimer's disease.

    Science.gov (United States)

    Walton, J R

    2013-01-01

    The neuroanatomic specificity with which Alzheimer's disease (AD) progresses could provide clues to AD etiopathology. Magnetic resonance imaging studies of AD clinical progression have confirmed general conclusions from earlier studies of AD neuropathological progression wherein neurofibrillary tangle pathology was observed to spread along a well-defined sequence of corticocortical and corticosubcortical connections, preferentially affecting certain cell types, while sparing others. Identical and non-identical twin studies have consistently shown AD has mixed (environmental and genetic) etiopathogenesis. The decades-long prodromal phase over which AD develops suggests slow but progressive accumulation of a toxic or infective agent over time. Major environmental candidates are reviewed to assess which best fits the profile of an agent that slowly accrues in susceptible cell types of AD-vulnerable brain regions to toxic levels by old age, giving rise to AD neuropathology without rapid neuronal lysis. Chronic aluminum neurotoxicity best matches this profile. Many humans routinely ingest aluminum salts as additives contained in processed foods and alum-treated drinking water. The physical properties of aluminum and ferric iron ions are similar, allowing aluminum to use mechanisms evolved for iron to enter vulnerable neurons involved in AD progression, accumulate in those neurons, and cause neurofibrillary damage. The genetic component of AD etiopathogenesis apparently involves a susceptibility gene, yet to be identified, that increases aluminum absorption because AD and Down syndrome patients have higher than normal plasma, and brain, aluminum levels. This review describes evidence for aluminum involvement in AD neuropathology and the clinical progression of sporadic AD.

  5. Aged chimpanzees exhibit pathologic hallmarks of Alzheimer's disease.

    Science.gov (United States)

    Edler, Melissa K; Sherwood, Chet C; Meindl, Richard S; Hopkins, William D; Ely, John J; Erwin, Joseph M; Mufson, Elliott J; Hof, Patrick R; Raghanti, Mary Ann

    2017-11-01

    Alzheimer's disease (AD) is a uniquely human brain disorder characterized by the accumulation of amyloid-beta protein (Aβ) into extracellular plaques, neurofibrillary tangles (NFT) made from intracellular, abnormally phosphorylated tau, and selective neuronal loss. We analyzed a large group of aged chimpanzees (n = 20, age 37-62 years) for evidence of Aβ and tau lesions in brain regions affected by AD in humans. Aβ was observed in plaques and blood vessels, and tau lesions were found in the form of pretangles, NFT, and tau-immunoreactive neuritic clusters. Aβ deposition was higher in vessels than in plaques and correlated with increases in tau lesions, suggesting that amyloid build-up in the brain's microvasculature precedes plaque formation in chimpanzees. Age was correlated to greater volumes of Aβ plaques and vessels. Tangle pathology was observed in individuals that exhibited plaques and moderate or severe cerebral amyloid angiopathy, a condition in which amyloid accumulates in the brain's vasculature. Amyloid and tau pathology in aged chimpanzees suggests these AD lesions are not specific to the human brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A Changing Perspective on the Role of Neuroinflammation in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Donna M. Wilcock

    2012-01-01

    Full Text Available Alzheimer's disease (AD is a complex, neurodegenerative disorder characterized by the presence of amyloid plaques and neurofibrillary tangles in the brain. Glial cells, particularly microglial cells, react to the presence of the amyloid plaques and neurofibrillary tangles producing an inflammatory response. While once considered immunologically privileged due to the blood-brain barrier, it is now understood that the glial cells of the brain are capable of complex inflammatory responses. This paper will discuss the published literature regarding the diverse roles of neuroinflammation in the modulation of AD pathologies. These data will then be related to the well-characterized macrophage phenotypes. The conclusion is that the glial cells of the brain are capable of a host of macrophage responses, termed M1, M2a, M2b, and M2c. The relationship between these states and AD pathologies remains relatively understudied, yet published data using various inflammatory stimuli provides some insight. It appears that an M1-type response lowers amyloid load but exacerbates neurofibrillary tangle pathology. In contrast, M2a is accompanied by elevated amyloid load and appears to ameliorate, somewhat, neurofibrillary pathology. Overall, it is clear that more focused, cause-effect studies need to be performed to better establish how each inflammatory state can modulate the pathologies of AD.

  7. Tau proteins in the cerebrospinal fluid of patients with subacute sclerosing panencephalitis.

    Science.gov (United States)

    Yuksel, Deniz; Yilmaz, Deniz; Uyar, Neval Y; Senbil, Nesrin; Gurer, Yavuz; Anlar, Banu

    2010-06-01

    Neurodegenerative diseases characterized by cytoskeletal deformation and neurofibrillary tangles are associated with altered levels of tau and related proteins in cerebrospinal fluid (CSF). Neuronal or glial fibrillary tangles have been shown in 20% of subacute sclerosing panencephalitis (SSPE) patients. We therefore investigated CSF samples from 60 newly diagnosed SSPE and 31 neurological control patients for total tau (t-tau), phosphorylated tau (p-tau), and S100-B levels by ELISA. There was no difference between patient and control groups in t-tau and S100-B levels. p-Tau was lower in the SSPE group (p=0.009). Past history of measles infection, measles immunization status, latent period between measles and onset of SSPE, duration of symptoms, frequency of myoclonia, neurological deficit index, stage and progression rate of the disease, CSF glucose levels and cell counts, CSF and serum measles IgG titer, distribution of lesions on brain magnetic resonance imaging were not related to t-tau, p-tau and S100-B levels. Mental status and age were negatively correlated with t-tau, and male gender and EEG abnormalities were associated with higher t-tau levels. The levels of tau proteins in our patients suggest there is no, or only scarce and immature, neurofibrillary tangle formation in SSPE. Autopsy studies showing neurofibrillary tangles might have examined older patients with longer disease and more parenchymal involvement. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  8. Clinicopathologic studies in cognitively healthy aging and Alzheimer's disease: relation of histologic markers to dementia severity, age, sex, and apolipoprotein E genotype.

    Science.gov (United States)

    Berg, L; McKeel, D W; Miller, J P; Storandt, M; Rubin, E H; Morris, J C; Baty, J; Coats, M; Norton, J; Goate, A M; Price, J L; Gearing, M; Mirra, S S; Saunders, A M

    1998-03-01

    To study differences between subjects with Alzheimer disease (AD) and cognitively intact control subjects, with respect to brain histologic markers of AD, and the relationship of those markers in the AD group to severity of dementia, age at death, sex, and apolipoprotein E genotype. Washington University Alzheimer's Disease Research Center, St Louis, Mo. Consecutive neuropathologic series of 224 prospectively studied volunteer research subjects, 186 with dementia of the Alzheimer type (DAT) or "incipient" DAT and confirmed to have AD by postmortem examination and 13 cognitively intact subjects, confirmed to lack postmortem findings of AD. Brain densities (number per square millimeter) of senile plaques and neurofibrillary tangles, extent of cerebral amyloid angiopathy, cortical Lewy bodies, and apolipoprotein E genotype. Neocortical neurofibrillary tangle densities were substantially correlated with dementia severity, and to a greater degree than was true for senile plaque densities. When infarcts, hemorrhages, and Parkinson disease changes coexisted with AD, neurofibrillary tangle and senile plaque densities were lower. Plaque-predominant AD was found in a greater proportion of subjects with milder than more severe dementia. Entorhinal cortical Lewy bodies were no more frequent in plaque-predominant AD than in the remaining AD cases. Increasing age at death was negatively correlated with dementia severity and densities of senile plaques and neurofibrillary tangles. The apolipoprotein E epsilon4 allele frequency was greater in AD than in control subjects but decreased with increasing age. After controlling for dementia severity, senile plaque densities were only weakly related to epsilon4 allele frequency, and only in hippocampus. However, the degree of cerebral amyloid angiopathy was clearly related to epsilon4 allele frequency. Among subjects diagnosed during life as having DAT or incipient DAT, only 7% were found to have a neuropathologic disorder other than AD

  9. An aluminum-based rat model for Alzheimer's disease exhibits oxidative damage, inhibition of PP2A activity, hyperphosphorylated tau, and granulovacuolar degeneration.

    Science.gov (United States)

    Walton, J R

    2007-09-01

    In Alzheimer's disease (AD), oxidative damage leads to the formation of amyloid plaques while low PP2A activity results in hyperphosphorylated tau that polymerizes to form neurofibrillary tangles. We probed these early events, using brain tissue from a rat model for AD that develops memory deterioration and AD-like behaviors in old age after chronically ingesting 1.6 mg aluminum/kg bodyweight/day, equivalent to the high end of the human dietary aluminum range. A control group consumed 0.4 mg aluminum/kg/day. We stained brain sections from the cognitively-damaged rats for evidence of amyloid plaques, neurofibrillary tangles, aluminum, oxidative damage, and hyperphosphorylated tau. PP2A activity levels measured 238.71+/-17.56 pmol P(i)/microg protein and 580.67+/-111.70 pmol P(i)/microg protein (paluminum-loading occurs in some aged rat neurons as in some aged human neurons; (2) aluminum-loading in rat neurons is accompanied by oxidative damage, hyperphosphorylated tau, neuropil threads, and granulovacuolar degeneration; and (3) amyloid plaques and neurofibrillary tangles were absent from all rat brain sections examined. Known species difference can reasonably explain why plaques and tangles are unable to form in brains of genetically-normal rats despite developing the same pathological changes that lead to their formation in human brain. As neuronal aluminum can account for early stages of plaque and tangle formation in an animal model for AD, neuronal aluminum could also initiate plaque and tangle formation in humans with AD.

  10. A FORAY INTO THE TANGLE OF GLOBALIZATION MEASUREMENT

    Directory of Open Access Journals (Sweden)

    PhD Iulia LUPU

    2013-06-01

    Full Text Available The concerns over globalization and its impact on the different aspects of life amplified over the recent years and generated the need to measure this phenomenon so as to know its effects and to get prepared to manage them. This paper makes a critical presentation of the main indicators that measure the phenomenon of globalization and selected one indicator, seemingly the most comprehensive, and applied it to Romania in order to see its rank when comparing with other countries, according to the values of the indicator and its components.

  11. Calculator programs guide directionally drilled wells through tangled Thums lease

    Energy Technology Data Exchange (ETDEWEB)

    Clark, D.D.; Barth, J.W.

    1983-10-01

    Over 900 wells have been directionally drilled in the Long Beach Unit of the East Wilmington field from four man-made islands and land-based drilling sites. As more wells are added to each site, the planning of new well courses has become more complex. The hand-held calculator, with Long Beach Unit-developed programs, has been an aid in laying out new wells which avoid existing cased bore holes. The hand-held calculator method also prevented unnecessary commercial computer runs of well plats from surface locations that prove impossible or impractical to drill. With the use of these programs the optimum well course can be designed, reducing drilling and design costs.

  12. The tangle of space and time in human cognition.

    Science.gov (United States)

    Núñez, Rafael; Cooperrider, Kensy

    2013-05-01

    Everyday concepts of duration, of sequence, and of past, present, and future are fundamental to how humans make sense of experience. In culture after culture, converging evidence from language, co-speech gesture, and behavioral tasks suggests that humans handle these elusive yet indispensable notions by construing them spatially. Where do these spatial construals come from and why do they take the particular, sometimes peculiar, spatial forms that they do? As researchers across the cognitive sciences pursue these questions on different levels--cultural, developmental--in diverse populations and with new methodologies, clear answers will depend upon a shared and nuanced set of theoretical distinctions. Time is not a monolith, but rather a mosaic of construals with distinct properties and origins. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Conservation through community: An attempt to untangle a tangled word.

    Directory of Open Access Journals (Sweden)

    Deeraj Koul

    2014-04-01

    Full Text Available Conservation is not something that can be thrust upon a community, and neither can it be labelled as a measure to take away a people’s rights and nor can it be used as a force to make others adhere to rules and laws from outside; by outside I mean you and me and your or my Government. I am not writing to highlight that conservation should not happen with the community but I do believe that older community bonds are broken or they have started to brake and the ways implied earlier no longer hold in the field. Most of us are still hanging on to older approaches to community conservation but the younger generation in a community has moved beyond, now it is rare to see a community come together for the sake of collective benefits and also when conservation measures take longer to deliver the fruits and the sustained release of impacts over a period of time it makes people forget the changes made to the immediate environment, except for a few visible ones. This too is forgotten with time until the cycle of destruction repeats itself. Previously, the community used to look at water, forests and other natural resources as common resources and they used to protect them, but the present generation does not understand common resources. In their terms it has to be yours or mine or else it is the Government’s. There is no fourth dimension, i.e. the common resource which used to be a main dimension of conservation. The vanishing concept of the common resource has brought about the biggest destruction ever. New ways of conservation have to be found as older traditional ways of conservation may still work in some places but they will be not adhered to by the majority. I am not saying this because community led work isn’t good enough, but because the community system was previously woven into social fabric and there was mutual dependence. However, the social fabric has changed a lot over recent years and so has traditional community bonding. The west lost it a long time ago but other regions are catching up very quickly; community bonds are getting weaker and weaker and other ways of social bonding are taking over and we all are still struggling to solve problems through our narrow prism of community. We need to broaden it. I don’t mean that community shouldn’t be involved, it is the only way, but we need to understand the psyche of the community and try new ways to involve it. I hope I have not confused you and that you will continue reading. For everyone the mantra of conservation is through community and almost all conservation activities revolve around one particular community. However, I feel there is a problem with the way it is projected and the percentage success rate is very low. In other words, in a world were two brothers do not have same level of thinking and the same approach to a single issue, how can we expect a community to work together on a single focused agenda and hold on to it for a long period at a time when people have started to weigh everything on a scale of personal gain. Also, since conservation is a time-consuming process it is quite likely that the efforts of a community and its initial enthusiasm will fade over time. On this point a lot of people will try to pounce on me and try to prove me wrong with data and by showcasing successful community level projects. I do not deny that there are lots of success stories but are we getting the percentage of results that should have been achieved by now with so many NGOs, aid agencies and government efforts coming together? What is the success rate of these projects? An officer from the forest department once told me that in the last 30 years in India so many plantations have been made through community that no space would be available for plantations if all the work had born results. He may have exaggerated or he may be referring to poor implementation but there might still be some truth to his word. Also, I do expect the same kind of results around the world with some variations, since so much money has been spent through reforestation, community forestry. There seems to be a huge difference in conservation through community available on paper records and the reality on the ground, meaning that no matter how much money is spent, conservation has a low success rate and we are still persisting with ideas that have a very low percentage of success. In a community project a lot of management committees are formed, a forest committee, a watershed committee, a management committee; people participate and committees are formed but most of the committees become defunct over a period of time or they remain but are inactive. What are the reasons behind this? Maybe there is very little personal stake or low interest due to the high probability of getting bad reputation in the eyes of people if a community member tries to ensure that the system is adhered to. As the needs of people are unlimited and resources are limited a conflict of interest is bound to arise. I agree that other factors such as local politics etc. are also responsible, and I also agree that we need to persist in conservation through community as any other option will be suicidal. Some will try to argue that for any project the work to be undertaken is decided by the community and even the priority of work is decided by the community, at each step the community is involved from initiation to completion. But how many of us see sustained community support and adherence from initiation to completion and beyond. As we know from the human tendency most times we humans get involved keenly only when we see direct benefits, and not through indirect benefits or co-benefits. Thus, in order to make everyone get involved each person has to see some kind of a personal stake in the project, otherwise only a few will persist and others will not. We as conservationists think that it is the duty of a community to protect itself. Conservation will not be successful because we think that the community should protect itself. Even within a community there are different views and they will come together but will only disintegrate with time. To see how well a project will work I believe that we first need to analyse how much the members of the community are dependent on each other, how much the community is woven into the social fabric and its bonds, how much the community is not affected by my political factionalism. And if the community lacks in the above then we have to change the way conservation is conducted. Community approaches like collective thinking but direct individual benefits need to be incorporated more into the programmes so that better results can be achieved, by direct benefit I don’t mean monetary benefit but giving every individual a sense of belief that whatever conservation effort he has done at his level is his own, it is his creation and he is the master of its destiny. I also trust that we are witnessing new social bonding’s which are independent of regional background, politics, colour, rich and poor differentiation, taking shape and blooming as social media groups, they have a power to evolve a new thinking, bring change and develop a new form of common resource concept which can take conservation of globalised community to a new platform. These are not the only ways but surely other ways of uniting a community need to be found in order to generate a truly participatory approach.

  14. The Tangled Web of Taliban and Associated Movements

    Directory of Open Access Journals (Sweden)

    Greg Smith

    2009-01-01

    Full Text Available Following the devastating terrorist attacks of September 11, 2001,worldwide attention became focused on the Taliban and al-Qaida forcesin Afghanistan. Prior to the attacks, many people had never heard of the Taliban or their shar'ia-law style of government. Since 2001, manysplinter groups have formed in response to the continual United Statespresence in the region. Today, the term Taliban has been used to envelop several groups such as the Tehrik-i-Taliban Pakistan (TTP, the Haqqani Network (HQN and the Tehrik-eNifaz-e-Shariat-e-Mohammadi(TNSM. These groups make up the majority of fighters along the Afghanistan-Pakistan border. Many of these groups have been historicrivals for control of the region, but have since joined a loose alliance in response to United States and Pakistani Government actions in the Federally Administered Tribal Areas (FATA. This article examines the origins and operations of the Pakistani Taliban and associated groups. Particular attention will be given as to how these groups receive funding and support from each other through state sponsors such as Pakistan's Inter-Services Intelligence (ISI agency and non-state sponsors such as al-Qaida and Wahhabi idealists in Saudi Arabia, as well as arms supplies from Iran and potentially China.

  15. Quantifying the tangling of trajectories using the topological entropy

    Science.gov (United States)

    Candelaresi, S.; Pontin, D. I.; Hornig, G.

    2017-09-01

    We present a simple method to efficiently compute a lower limit of the topological entropy and its spatial distribution for two-dimensional mappings. These mappings could represent either two-dimensional time-periodic fluid flows or three-dimensional magnetic fields, which are periodic in one direction. This method is based on measuring the length of a material line in the flow. Depending on the nature of the flow, the fluid can be mixed very efficiently which causes the line to stretch. Here, we study a method that adaptively increases the resolution at locations along the line where folds lead to a high curvature. This reduces the computational cost greatly which allows us to study unprecedented parameter regimes. We demonstrate how this efficient implementation allows the computation of the variation of the finite-time topological entropy in the mapping. This measure quantifies spatial variations of the braiding efficiency, important in many practical applications.

  16. Tangled up in grief: Bob Dylan's songs of separation.

    Science.gov (United States)

    Smith, Keverne

    This article argues that much can be learned about the ways in which individuals grieve through a careful analysis of the presentation of loss in creative fiction, especially in terms of unconscious and uncensored responses presented indirectly through figurative language and structural patterns. It takes Bob Dylan's collection of songs about the anguish caused by lost love, Blood on the Tracks, as an example. An examination of the songs included in, and some rejected for, the album reveals developing responses to grief resulting from relationship breakdown, including the search for the absent one and for reconciliation; the intrusion of deep pain into everyday situations; the problem of infidelity and guilt; the attempt to reach a more detached perspective; the consequences of the pain becoming unbearable; and the attempt at a kind of closure. Taken together, the songs reveal how complex and contradictory responses to the agony of loss can be.

  17. [Ecology of vector systems: a tangle of complexity].

    Science.gov (United States)

    Rodhain, F

    2008-06-01

    The long co-evolutionary process between arthropods and microorganisms has resulted in a wide variety of relationships. One such relationship involves a wide range of infectious agents (virus, bacteria, protozoa, helminthes) that use blood-feeding arthropods (insects and mites) as vectors for transmission from one vertebrate to another. Transmission involves three components, i.e., microorganism, vector(s), and vertebrate host(s). Study under natural conditions has shown that the underlying mechanisms are extremely complex with circulation of the infectious agents depending on numerous conditions linked not only to bioecology but also to genetic factors in all three component populations. The role of arthropods sometimes goes beyond that of a transmitter of disease. In some cases they also serve as reservoirs or disseminators. In addition changes in the environment whether due to natural causes or human activities (e.g. pollution, agropastoralism, urbanization, transportation network development, and climate change) can have profound and rapid effects on the mechanisms underlying these vector systems. In short the ecology of vector systems closely reflects the extreme complexity of epidemiological studies on diseases caused by infectious agents depending on this type of transmission. As a result prediction of infectious risks and planning of preventive action are difficult. It appears obvious that a good understanding of vector systems in their natural context will require a truly ecological approach to the diseases that must be the focus of extremely close epidemiologic surveillance. Achieving this goal will necessitate more than the skills of physicians and veterinarians. It will require the contribution of specialists from a variety of fields such as microbiology, entomology, systematics, climatology, ecology, urbanism, social sciences, economic development, and many others.

  18. Host and Parasite Evolution in a Tangled Bank.

    Science.gov (United States)

    Betts, Alex; Rafaluk, Charlotte; King, Kayla C

    2016-11-01

    Most hosts and parasites exist in diverse communities wherein they interact with other species, spanning the parasite-mutualist continuum. These additional interactions have the potential to impose selection on hosts and parasites and influence the patterns and processes of their evolution. Yet, host-parasite interactions are almost exclusively studied in species pairs. A wave of new research has incorporated a multispecies community context, showing that additional ecological interactions can alter components of host and parasite fitness, as well as interaction specificity and virulence. Here, we synthesize these findings to assess the effects of increased species diversity on the patterns and processes of host and parasite evolution. We argue that our understanding of host-parasite interactions would benefit from a richer biotic perspective. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Distribution of lead in the brain tissues from DNTC patients using synchrotron radiation microbeams

    Energy Technology Data Exchange (ETDEWEB)

    Ide-Ektessabi, Ari [International Innovation Center, Kyoto University, Kyoto (Japan); Ota, Yukihide [Department of Precision Engineering, Kyoto University, Yoshida Honnmachi, Sakyo-ku, Kyoto (Japan)]. E-mail: h51167@sakura.kudpc.kyoto-u.ac.jp; Ishihara, Ryoko [Department of Psychiatry, Nagoya University, Graduate School of Medicine, Nagoya (Japan); Mizuno, Yutaka [Obu Dementia Care Research and Training Center, Obu (Japan); Takeuchi, Tohru [Department of Psychiatry, Nagoya University, Graduate School of Medicine, Nagoya (Japan)

    2005-12-15

    Diffuse neurofibrillary tangles with calcification (DNTC) is a form of dementia with certain characteristics. Its pathology is characterized by cerebrum atrophy, calcification on globus pallidus and dentate nucleus and diffuse neurofibrillary tangles without senile plaques. In the present study brain tissues were prepared from patients with patients DNTC, calcified and non-calcified Alzheimer's disease (AD) patients. The brain tissues were examined non-destructively by X-ray fluorescence (XRF) spectroscopy using synchrotron radiation (SR) microbeams for trace metallic elements Ca, Fe, Cu, Zn and Pb. The XRF analysis showed that there were Pb concentrations in the calcified areas in the brain tissues with both DNTC and AD but there was none in those with non-calcified AD.

  20. Neurobiological pathways to Alzheimer's disease: Amyloid-beta, TAU protein or both?

    Directory of Open Access Journals (Sweden)

    Vanessa de Jesus R. de Paula

    Full Text Available Abstract Alzheimer's disease (AD is a neurodegenerative disease characterized by progressive cognitive decline, including memory loss, behavioral and psychological symptoms and personality changes. The neuropathological hallmarks of AD are the presence of neuritic (senile plaques (NP and neurofibrillary tangles (NFT, along with neuronal loss, dystrophic neurites, and gliosis. Neuritic plaques are extracellular lesions and their main constituent is the amyloid-b42 peptide (Ab42. Neurofibrillary tangles are intracellular lesions that are mainly composed of hyperphosphorylated TAU protein. In this article, we review the major hypotheses concerning the physiopathology of AD, focusing on the b-amyloid cascade as primary events (supported by the "baptists" and cytoskeletal abnormalities secondary to the hyperphosphorylation of protein TAU (as advocated by the "Tauists". We further provide an integrative view of the physiopathology of AD.

  1. Regulator of Calcineurin 1 (RCAN1) Facilitates Neuronal Apoptosis through Caspase-3 Activation*

    OpenAIRE

    Sun,, Xiucong; Wu, De; Chen, Bin; Zhang, Zhuohua; Zhou, Weihui; Tong,; Yuan, Junying; Xia, Kun; Gronemeyer, Hinrich; Flavell, Richard A.; Song

    2011-01-01

    Individuals with Down syndrome (DS) will inevitably develop Alzheimer disease (AD) neuropathology sometime after middle age, which may be attributable to genes triplicated in individuals with DS. The characteristics of AD neuropathology include neuritic plaques, neurofibrillary tangles, and neuronal loss in various brain regions. The mechanism underlying neurodegeneration in AD and DS remains elusive. Regulator of calcineurin 1 (RCAN1) has been implicated in the pathogenesis of DS. Our data s...

  2. Frontal Cortex Neuropathology in Dementia Pugilistica

    OpenAIRE

    Saing, Tommy; Dick, Malcolm; Nelson, Peter T.; Kim, Ronald C; Cribbs, David H.; Head, Elizabeth

    2012-01-01

    AbstractDementia pugilistica (DP) is associated with chronic traumatic brain injury (CTBI), and leads to a “punch drunk” syndrome characterized by impairments in memory and executive function, behavioral changes, and motor signs. Microscopic features include the accumulation of neurofibrillary tangles (NFTs), beta-amyloid (Aβ), and TAR DNA binding protein 43 (TDP-43) pathology. Here we describe detailed clinical and neuropathological data about a 55-year-old retired boxer (ApoE3/4), who prese...

  3. Model Hirano Bodies Protect against Tau-Independent and Tau-Dependent Cell Death Initiated by the Amyloid Precursor Protein Intracellular Domain

    OpenAIRE

    Furgerson, Matthew; Fechheimer, Marcus; Furukawa, Ruth

    2012-01-01

    The main pathological hallmarks of Alzheimer's disease are amyloid-beta plaques and neurofibrillary tangles, which are primarily composed of amyloid precursor protein (APP) and tau, respectively. These proteins and their role in the mechanism of neurodegeneration have been extensively studied. Hirano bodies are a frequently occurring pathology in Alzheimer's disease as well as other neurodegenerative diseases. However, the physiological role of Hirano bodies in neurodegenerative diseases has ...

  4. A local insult of okadaic acid in wild-type mice induces tau phosphorylation and protein aggregation in anatomically distinct brain regions

    OpenAIRE

    Baker, Si?n; G?tz, J?rgen

    2016-01-01

    In Alzheimer?s disease (AD), the distribution and density of neurofibrillary tangles, a histological hallmark comprised predominately of phosphorylated tau protein, follows a distinct pattern through anatomically connected brain regions. Studies in transgenic mice engineered to regionally confine tau expression have suggested spreading of tau within neural networks. Furthermore, injection of protein lysates isolated from brains of transgenic mice or patients with tauopathies, including AD, we...

  5. Role of PrPC Expression in Tau Protein Levels and Phosphorylation in Alzheimer¿s Disease Evolution

    OpenAIRE

    Vergara, Cristina; Ordóñez-Gutiérrez, Lara; Wandosell, Francisco; Ferrer, I. M; Río, J. A. del; Gavín, Rosalina

    2014-01-01

    Alzheimer's disease (AD) is characterized by the presence of amyloid plaques mainly consisting of hydrophobic -amyloid peptide (A) aggregates and neurofibrillary tangles (NFTs) composed principally of hyperphosphorylated tau. A oligomers have been described as the earliest effectors to negatively affect synaptic structure and plasticity in the affected brains, and cellular prion protein (PrPC) has been proposed as receptor for these oligomers. The most widely accepted theory holds that the to...

  6. Time-Course and Regional Analyses of the Physiopathological Changes Induced after Cerebral Injection of an Amyloid β Fragment in Rats

    OpenAIRE

    Zussy, Charleine; Brureau, Anthony; Delair, Brice; Marchal, Stephane; Keller, Emeline; Ixart, Guy; Naert, Gaelle; Meunier, Johann; Chevallier, Nathalie; Maurice, Tangui; Givalois, Laurent

    2011-01-01

    Alzheimer's disease (AD) is a neurodegenerative pathology characterized by the presence of senile plaques and neurofibrillary tangles, accompanied by synaptic and neuronal loss. The major component of senile plaques is an amyloid β protein (Aβ) formed by pathological processing of the Aβ precursor protein. We assessed the time-course and regional effects of a single intracerebroventricular injection of aggregated Aβ fragment 25–35 (Aβ25-35) in rats. Using a combined biochemical, behavioral, a...

  7. Modulation der Alzheimer-Pathologie in transgenen Mausmodellen

    OpenAIRE

    Duma, Carmen Cecilia

    2009-01-01

    Alzheimer’s disease (AD), a progressive neurodegenerative disorder, is the most common cause of dementia. The neuropathological hallmarks of AD include extracellular deposits of the amyloid-ß peptide (Aß) and neurofibrillary tangles, composed of filamentous aggregates of hyperphosphorylated tau protein. To study AD pathogenesis, transgenic mice that overexpress human mutated amyloid precursor protein (APP) and/or mutated presenilin1/2 (PS1/2) have been generated. These models exhibit age-r...

  8. Anti-Amyloidogenic and Anti-Apoptotic Role of Melatonin in Alzheimer Disease

    OpenAIRE

    He, Hongwen; Dong, Weiguo; Huang, Fang

    2010-01-01

    Alzheimer disease (AD) is an age-related neurodegenerative disorder characterized by the presence of senile plaques, neurofibrillary tangles and neuronal loss. Amyloid-β protein (Aβ) deposition plays a critical role in the development of AD. It is now generally accepted that massive neuronal death due to apoptosis is a common characteristic in the brains of patients suffering from neurodegenerative diseases, and apoptotic cell death has been found in neurons and glial cells in AD. Melatonin i...

  9. Oxidative stress in Alzheimer disease

    OpenAIRE

    Gella, Alejandro; Durany, Nuria

    2009-01-01

    Alzheimer disease (AD) is a progressive dementia affecting a large proportion of the aging population. The histopathological changes in AD include neuronal cell death, formation of amyloid plaques and neurofibrillary tangles. There is also evidence that brain tissue in patients with AD is exposed to oxidative stress (e.g., protein oxidation, lipid oxidation, DNA oxidation and glycoxidation) during the course of the disease. Advanced glycation endproducts (AGEs) are present in amyloid plaques ...

  10. Abstracts from the 7th Canadian Conference on Dementia (CCD) held in Vancouver, October 2013

    OpenAIRE

    Montgomery, S.; Wangsgaard, J.; Koenig, J.; Jeremy,; Pathak, K.; Jude, A.; Davidson, S.; Rice, J.; Cytryn, K.N.; Lungu, O.; Voyer, P.; Wilchesky, M.; Qian, W.; Schweizer, T.; Fischer, C.

    2013-01-01

    Background/Purpose: As of 2011, approximately 747,000 Canadians suffer from some form of dementia; Alzheimer?s disease (AD) is one such form. AD is a neurodegenerative disease characterized by significant neuronal death. Neuronal death has been associated with two pathophysiological features: 1) neurofibrillary tangles within the neurons, and 2) amyloid beta plaque formation between neurons. Excessive production of these two features is manifested by severe cognitive impairment. One of the mo...

  11. Efficacy and mechanism of action of novel synthetic fatty acids derivatives in a transgenic Drosophila melanogaster Model of a Alzheimer's disease

    OpenAIRE

    Mohaibes, Raheem J.

    2015-01-01

    - Introducció Alzheimer's disease (AD) is a neurodegenerative disorder characterized by early synaptic and late neuronal loss, affecting more than 26 million people worldwide. Among patients affected with dementia, more than half suffer from Alzheimer’s disease. The biggest risk factor for developing Alzheimer's disease is age. β-amyloid (Aβ) plaques and neurofibrillary p-Tau tangles accumulates in the brains of elderly patients playing a central role in the pathogenesis of ...

  12. Impact of antidiabetic substances to development of insulin resistance and neurodegenerative changes in mouse models of type 2 diabetes

    OpenAIRE

    Mikulášková, Barbora

    2014-01-01

    Numerous epidemiological and experimental studies have shown that patients suffering from metabolic disorders such as type 2 diabetes mellitus (TDM2), insulin resistance or obesity are at a higher risk of cognitive functions impairment and developing Alzheimer's disease (AD). Impairment of insulin signalling in the brain could contribute to two pathological changes which leads to AD development that include insoluble senile plaques and neurofibrillary tangles, containing an abnormally hyperph...

  13. Implications of Neuroimmunity in Alzheimer’s Disease: A Review

    OpenAIRE

    Katriel Lee

    2017-01-01

    AD is characterized cognitively by memory, problem-solving, and language difficulties. It is estimated that 5.4 million Americans currently have Alzheimer’s disease (AD). The cognitive difficulties in AD are reflected in the brain through the accumulation of amyloid-β (Aβ) in cerebral amyloid angiopathy (CAA), neurofibrillary tau tangles, neuronal tissue atrophy, and neuroinflammation, but the exact cause of AD is still in question. However, evidence suggests that differences in neuroimmune f...

  14. Brain-derived neurotrophic factor protects against tau-related neurodegeneration of Alzheimer's disease

    OpenAIRE

    Jiao, S-S; Shen, L-L; C. Zhu; Bu, X-L; Liu, Y-H; Liu, C-H; Yao, X-Q; Zhang, L-L; Zhou, H-D; Walker, D. G.; J. Tan; G?tz, J; Zhou, X-F; Wang, Y-J

    2016-01-01

    Reduced expression of brain-derived neurotrophic factor (BDNF) has a crucial role in the pathogenesis of Alzheimer's disease (AD), which is characterized with the formation of neuritic plaques consisting of amyloid-beta (A?) and neurofibrillary tangles composed of hyperphosphorylated tau protein. A growing body of evidence indicates a potential protective effect of BDNF against A?-induced neurotoxicity in AD mouse models. However, the direct therapeutic effect of BDNF supplement on tauopathy ...

  15. The Hsp70/Hsp90 Chaperone Machinery in Neurodegenerative Diseases

    OpenAIRE

    Rachel E. Lackie; Rachel E. Lackie; Andrzej Maciejewski; Andrzej Maciejewski; Valeriy G. Ostapchenko; Jose Marques-Lopes; Wing-Yiu Choy; Martin L. Duennwald; Vania F. Prado; Vania F. Prado; Vania F. Prado; Vania F. Prado; Marco A. M. Prado; Marco A. M. Prado; Marco A. M. Prado

    2017-01-01

    The accumulation of misfolded proteins in the human brain is one of the critical features of many neurodegenerative diseases, including Alzheimer's disease (AD). Assembles of beta-amyloid (Aβ) peptide—either soluble (oligomers) or insoluble (plaques) and of tau protein, which form neurofibrillary tangles, are the major hallmarks of AD. Chaperones and co-chaperones regulate protein folding and client maturation, but they also target misfolded or aggregated proteins for refolding or for degrada...

  16. Roles of Amyloid β-Peptide-Associated Oxidative Stress and Brain Protein Modifications in the Pathogenesis of Alzheimer's Disease and Mild Cognitive Impairment

    OpenAIRE

    Butterfield, D. Allan; Reed, Tanea; Newman, Shelley F.; Sultana, Rukhsana

    2007-01-01

    Oxidative stress has been implicated to play a crucial role in the pathogenesis of a number of diseases, including neurodegenerative disorders, cancer, and ischemia just to name a few. Alzheimer's disease (AD) is an age-related neurodegenerative disorder that is recognized as the most common form of dementia. AD is histopathologically characterized by the presence of extracellular amyloid plaques, intracellular neurofibrillary tangles, the presence of oligomers of amyloid β-peptide (Aβ), and ...

  17. Absence of chronic traumatic encephalopathy in retired football players with multiple concussions and neurological symptomatology

    OpenAIRE

    Lili-Naz eHazrati; Maria Carmela Tartaglia; Phedias eDiamandis; Karen eDavis; Green, Robin E. A.; Richard eWennberg; Wong, Janice C; Leo eEzerins; Tator, Charles H.

    2013-01-01

    Background: Chronic traumatic encephalopathy (CTE) is the term coined for the neurodegenerative disease often suspected in athletes with histories of repeated concussion and progressive dementia. Histologically, CTE is defined as a tauopathy with a distribution of tau-positive neurofibrillary tangles that is distinct from other tauopathies, and usually shows an absence of beta-amyloid deposits, in contrast to Alzheimer’s disease. Although the connection between repeated concussions and CTE-t...

  18. Absence of chronic traumatic encephalopathy in retired football players with multiple concussions and neurological symptomatology

    OpenAIRE

    Hazrati, Lili-Naz; Tartaglia, Maria C.; Diamandis, Phedias; Karen D Davis; Green, Robin E.; Wennberg, Richard; Wong, Janice C; Ezerins, Leo; Tator, Charles H.

    2013-01-01

    Background: Chronic traumatic encephalopathy (CTE) is the term coined for the neurodegenerative disease often suspected in athletes with histories of repeated concussion and progressive dementia. Histologically, CTE is defined as a tauopathy with a distribution of tau-positive neurofibrillary tangles (NFTs) that is distinct from other tauopathies, and usually shows an absence of beta-amyloid deposits, in contrast to Alzheimer's disease (AD). Although the connection between repeated concussion...

  19. Optimization of microtubule affinity regulating kinase (MARK) inhibitors with improved physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sloman, David L.; Noucti, Njamkou; Altman, Michael D.; Chen, Dapeng; Mislak, Andrea C.; Szewczak, Alexander; Hayashi, Mansuo; Warren, Lee; Dellovade, Tammy; Wu, Zhenhua; Marcus, Jacob; Walker, Deborah; Su, Hua-Poo; Edavettal, Suzanne C.; Munshi, Sanjeev; Hutton, Michael; Nuthall, Hugh; Stanton, Matthew G. (Merck)

    2016-09-01

    Inhibition of microtubule affinity regulating kinase (MARK) represents a potentially attractive means of arresting neurofibrillary tangle pathology in Alzheimer’s disease. This manuscript outlines efforts to optimize a pyrazolopyrimidine series of MARK inhibitors by focusing on improvements in potency, physical properties and attributes amenable to CNS penetration. A unique cylcyclohexyldiamine scaffold was identified that led to remarkable improvements in potency, opening up opportunities to reduce MW, Pgp efflux and improve pharmacokinetic properties while also conferring improved solubility.

  20. The Observation Scientist

    Science.gov (United States)

    O'Shaughnessy, Molly

    2016-01-01

    Once the reasons for habitual observation in the classroom have been established, and the intent to observe has been settled, the practical details of observation must be organized. In this article, O'Shaughnessy gives us a model for the implementation of observation. She thoroughly reviews Montessori's work curves and how they can be used to show…

  1. Connecting Participant Observation Positions

    DEFF Research Database (Denmark)

    McCurdy, Patrick; Uldam, Julie

    2014-01-01

    In this article, we argue for the importance of considering participant observation roles in relation to both insider/outsider and overt/covert roles. Through combining key academic debates on participant observation, which have separately considered insider/outsider and overt/covert participant...... observation, we develop a reflexive framework to assist researchers in (1) locating the type of participant observation research; (2) identifying implications of participant observation for both the research and the subjects under study; and (3) reflecting on how one’s role as participant observer shifts over...

  2. Lightship Daily Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations taken on board lightships along the United States coasts from 1936 - 1983. Generally 4-6 observations daily. Also includes deck logs, which give...

  3. JAPANSE LONGLINE OBSERVER JPLL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data that were collected by trained observers aboard Japanese pelagic longline vessels operating in the US EEZ. Observers collected...

  4. Uruguay - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface weather observation forms for 26 stations in Uruguay. Period of record 1896-2005, with two to eight observations per day. Files created through a...

  5. OBSCAN Observer Scanning System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Paper logs are the primary data collection tool used by observers of the Northeast Fisheries Observer Program deployed on commercial fishing vessels. After the data...

  6. Bottomfish Observer Database - Legacy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains data collected by at sea observers in the Bottomfish Observer Program in the Northwestern Hawaiian Islands from October 2003 - April 2006.

  7. Surface Weather Observations Hourly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard hourly observations taken at Weather Bureau/National Weather Service offices and airports throughout the United States. Hourly observations began during the...

  8. Regional National Cooperative Observer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA publication dedicated to issues, news and recognition of observers in the National Weather Service Cooperative Observer program. Issues published regionally...

  9. Cloning of observables

    OpenAIRE

    Ferraro, Alessandro; Galbiati, Matteo; Paris, Matteo G. A.

    2005-01-01

    We introduce the concept of cloning for classes of observables and classify cloning machines for qubit systems according to the number of parameters needed to describe the class under investigation. A no-cloning theorem for observables is derived and the connections between cloning of observables and joint measurements of noncommuting observables are elucidated. Relationships with cloning of states and non-demolition measurements are also analyzed.

  10. Being observed magnifies action

    NARCIS (Netherlands)

    Steinmetz, J.; Xu, Q.; Fishbach, A.; Zhang, Y.

    2016-01-01

    We test the hypothesis that people, when observed, perceive their actions as more substantial because they add the audience’s perspective to their own perspective. We find that participants who were observed while eating (Study 1) or learned they were observed after eating (Study 2) recalled eating

  11. Observation of online communities

    DEFF Research Database (Denmark)

    Nørskov, Sladjana V.; Rask, Morten

    2011-01-01

    This paper addresses the application of observation to online settings with a special focus on observer roles. It draws on a study of online observation of a virtual community, i.e. an open source software (OSS) community. The paper examines general and specific advantages and disadvantages...... of the observer roles in online settings by relating these roles to the same roles assumed in offline settings. The study suggests that under the right circumstances online and offline observation may benefit from being combined as they complement each other well. Quality issues and factors important to elicit...... trustworthy observational data from online study settings, such as OSS communities, are discussed. A proposition is made concerning how threats to credibility and transferability in relation to online observation (i.e. lack of richness and detail, risk of misunderstandings) can be diminished, while...

  12. BOOK REVIEW: Observational Cosmology Observational Cosmology

    Science.gov (United States)

    Howell, Dale Andrew

    2013-04-01

    Observational Cosmology by Stephen Serjeant fills a niche that was underserved in the textbook market: an up-to-date, thorough cosmology textbook focused on observations, aimed at advanced undergraduates. Not everything about the book is perfect - some subjects get short shrift, in some cases jargon dominates, and there are too few exercises. Still, on the whole, the book is a welcome addition. For decades, the classic textbooks of cosmology have focused on theory. But for every Sunyaev-Zel'dovich effect there is a Butcher-Oemler effect; there are as many cosmological phenomena established by observations, and only explained later by theory, as there were predicted by theory and confirmed by observations. In fact, in the last decade, there has been an explosion of new cosmological findings driven by observations. Some are so new that you won't find them mentioned in books just a few years old. So it is not just refreshing to see a book that reflects the new realities of cosmology, it is vital, if students are to truly stay up on a field that has widened in scope considerably. Observational Cosmology is filled with full-color images, and graphs from the latest experiments. How exciting it is that we live in an era where satellites and large experiments have gathered so much data to reveal astounding details about the origin of the universe and its evolution. To have all the latest data gathered together and explained in one book will be a revelation to students. In fact, at times it was to me. I've picked up modern cosmological knowledge through a patchwork of reading papers, going to colloquia, and serving on grant and telescope allocation panels. To go back and see them explained from square one, and summarized succinctly, filled in quite a few gaps in my own knowledge and corrected a few misconceptions I'd acquired along the way. To make room for all these graphs and observational details, a few things had to be left out. For one, there are few derivations

  13. Tau deposition drives neuropathological, inflammatory and behavioral abnormalities independently of neuronal loss in a novel mouse model.

    Science.gov (United States)

    Cook, Casey; Kang, Silvia S; Carlomagno, Yari; Lin, Wen-Lang; Yue, Mei; Kurti, Aishe; Shinohara, Mitsuru; Jansen-West, Karen; Perkerson, Emilie; Castanedes-Casey, Monica; Rousseau, Linda; Phillips, Virginia; Bu, Guojun; Dickson, Dennis W; Petrucelli, Leonard; Fryer, John D

    2015-11-01

    Aberrant tau protein accumulation drives neurofibrillary tangle (NFT) formation in several neurodegenerative diseases. Currently, efforts to elucidate pathogenic mechanisms and assess the efficacy of therapeutic targets are limited by constraints of existing models of tauopathy. In order to generate a more versatile mouse model of tauopathy, somatic brain transgenesis was utilized to deliver adeno-associated virus serotype 1 (AAV1) encoding human mutant P301L-tau compared with GFP control. At 6 months of age, we observed widespread human tau expression with concomitant accumulation of hyperphosphorylated and abnormally folded proteinase K resistant tau. However, no overt neuronal loss was observed, though significant abnormalities were noted in the postsynaptic scaffolding protein PSD95. Neurofibrillary pathology was also detected with Gallyas silver stain and Thioflavin-S, and electron microscopy revealed the deposition of closely packed filaments. In addition to classic markers of tauopathy, significant neuroinflammation and extensive gliosis were detected in AAV1-Tau(P301L) mice. This model also recapitulates the behavioral phenotype characteristic of mouse models of tauopathy, including abnormalities in exploration, anxiety, and learning and memory. These findings indicate that biochemical and neuropathological hallmarks of tauopathies are accurately conserved and are independent of cell death in this novel AAV-based model of tauopathy, which offers exceptional versatility and speed in comparison with existing transgenic models. Therefore, we anticipate this approach will facilitate the identification and validation of genetic modifiers of disease, as well as accelerate preclinical assessment of potential therapeutic targets. © The Author 2015. Published by Oxford University Press.

  14. Association of the apolipoprotein E {epsilon}4 allele with clinical subtypes of autopsy-confirmed Alzheimer`s Disease

    Energy Technology Data Exchange (ETDEWEB)

    Zubenko, G.S.; Stiffler, S.; Kopp, U. [Univ. of Pittsburgh School of Medicine, PA (United States)] [and others

    1994-09-15

    Consistent with previous reports, we observed a significant association of the APOE {epsilon}4 allele with Alzheimer`s Disease (AD) in a series of 91 autopsy-confirmed cases. The {epsilon}4 allele frequency was higher in cases with a family history of AD-like dementia (0.54 {+-} 0.07), although the {epsilon}4 allele frequency in the AD cases with a negative family history (0.38 {+-} 0.05) remained significantly greater than that for the non-AD control group (0.13 {+-} 0.03). A similar increase in {epsilon}4 allele frequency (0.54 {+-} 0.07) was observed in the AD cases with amyloid angiopathy, compared to those who did not have amyloid angiopathy (0.35 {+-} 0.04). Contrary to previous reports, no effect of the dosage of the {epsilon}4 allele was found on the age of onset of dementia among the AD cases and, contrary to reports suggesting an association of {epsilon}4 and atherosclerosis, the {epsilon}4 allele frequency was similar in cases with or without concurrent brain infarcts. Modest but consistent correlations were observed between the dosage of {epsilon}4 alleles and the cortical density of senile plaques, but not neurofibrillary tangles. The last finding suggests that the pathogenic events mediated by the {epsilon}4 allele may be more directly involved in the formation of senile plaques, the identifying lesions in AD, than neurofibrillary tangles. A robust association of both the presence of an {epsilon}4 allele and a family history of AD-like dementia with concurrent amyloid angiopathy occurred within our sample of AD cases. This association arose from an interaction of the {epsilon}4 allele with a separate familial factor for which a family history of dementia served as a surrogate. These results suggest that amyloid angiopathy may be a common or central feature of a form of familial AD that is associated with the transmission of the APOE {epsilon}4 allele. 22 refs., 2 figs., 5 tabs.

  15. Does Observation Influence Learning?

    OpenAIRE

    Olivier Armantier

    2001-01-01

    A common value auction experiment is run to compare the relative influence of observation and experience on learning. It is shown that the ex-post observation of opponents' actions and payoffs homogenizes behavior and accelerates learning toward the Nash equilibrium. Besides, experiential and observational learning are both relevant and of comparable magnitude. A general reinforcement model for continuous strategies, encompassing choice reinforcement learning, direction learning and payoff de...

  16. Observations in public settings

    Science.gov (United States)

    Robert G. Lee

    1977-01-01

    Straightforward observation of children in their everyday environments is a more appropriate method of discovering the meaning of their relationships to nature than complex methodologies or reductionist commonsense thinking. Observational study requires an explicit conceptual framework and adherence to procedures that allow scientific inference. Error may come from...

  17. Maximally incompatible quantum observables

    Energy Technology Data Exchange (ETDEWEB)

    Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)

    2014-05-01

    The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.

  18. The observer's sky atlas

    CERN Document Server

    Karkoschka, E

    2007-01-01

    This title includes a short introduction to observing, a thorough description of the star charts and tables, a glossary and much more. It is perfect for both the beginner and seasoned observer. It is fully revised edition of a best-selling and highly-praised sky atlas.

  19. Participation beyond observation

    DEFF Research Database (Denmark)

    Chimirri, Niklas Alexander

    , however, the researchers typically uphold the notion that all they methodically engage in is participant observation. The paper argues that important aspects of children’s living and understanding may be lost when considering them mere objects of one’s visual and verbal research practices. First I delve...... on investigating children’s perspectives through participant observation, but also ontological and political ones....

  20. Deltagende observation 2. udgave

    DEFF Research Database (Denmark)

    Kristiansen, Søren; Krogstrup, Hanne Kathrine

    Denne bog er en teoretisk og praktisk introduktion til deltagende observation, og giver konkrete anvisninger, som er nyttige for såvel erfarne som den uprøvede feltforsker.......Denne bog er en teoretisk og praktisk introduktion til deltagende observation, og giver konkrete anvisninger, som er nyttige for såvel erfarne som den uprøvede feltforsker....

  1. Status of memory loss.

    LENUS (Irish Health Repository)

    Iyer, Parameswaran Mahadeva

    2012-01-01

    A 72-year-old woman presented with first onset of seizure with no prior history of cognitive dysfunction. EEG revealed focal non-convulsive status epilepticus. MRI brain showed a left temporal non-enhancing lesion. Temporal pole biopsy showed acute neuronal necrosis and astrocyte hyperplasia together with extensive amyloid plaques and neurofibrillary tangles. Perivascular oligodendroglial hyperplasia was present. Postmortem examination revealed extensive plaque and tangle disease. Perivascular oligodendroglial hyperplasia was limited to the left temporal area. The presence of focal perivascular oligodendroglial hyperplasia in the left temporal cortex, combined with extensive plaque and tangle disease may have contributed to the focal status epilepticus in this patient. Although the presence of focal perivascular oligodendroglial hyperplasia has been reported in cases of temporal lobe epilepsy, it has not been reported as a cause of seizure in patients with Alzheimer\\'s disease previously. Further studies for clinical-pathologic correlation would be required to confirm this hypothesis.

  2. Observing Convective Aggregation

    Science.gov (United States)

    Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

    2017-11-01

    Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

  3. Observing Convective Aggregation

    Science.gov (United States)

    Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

    2017-06-01

    Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

  4. Propagation of tau pathology: hypotheses, discoveries, and yet unresolved questions from experimental and human brain studies.

    Science.gov (United States)

    Lewis, Jada; Dickson, Dennis W

    2016-01-01

    Tau is a microtubule-associated protein and a key regulator of microtubule stabilization as well as the main component of neurofibrillary tangles-a principle neuropathological hallmark of Alzheimer's disease (AD)-as well as pleomorphic neuronal and glial inclusions in neurodegenerative tauopathies. Cross-sectional studies of neurofibrillary pathology in AD reveal a stereotypic spatiotemporal pattern of neuronal vulnerability that correlates with disease severity; however, the relationship of this pattern to disease progression is less certain and exceptions to the typical pattern have been described in a subset of AD patients. The basis for the selective vulnerability of specific populations of neurons to tau pathology and cell death is largely unknown, although there have been a number of hypotheses based upon shared properties of vulnerable neurons (e.g., degree of axonal myelination or synaptic plasticity). A recent hypothesis for selective vulnerability takes into account the emerging science of functional connectivity based upon resting state functional magnetic resonance imaging, where subsets of neurons that fire synchronously define patterns of degeneration similar to specific neurodegenerative disorders, including various tauopathies. In the past 6 years, the concept of tau propagation has emerged from numerous studies in cell and animal models suggesting that tau moves from cell-to-cell and that this may trigger aggregation and region-to-region spread of tau pathology within the brain. How the spread of tau pathology relates to functional connectivity is an area of active investigation. Observations of templated folding and propagation of tau have prompted comparisons of tau to prions, the pathogenic proteins in transmissible spongiform encephalopathies. In this review, we discuss the most compelling studies in the field, discuss their shortcomings and consider their implications with respect to human tauopathies as well as the controversy that

  5. Astrolabe observations of Mars

    Science.gov (United States)

    Standish, E. M.; Debarbat, S.; Sanchez, M.

    1981-01-01

    A previously reported bias in the right ascension residuals of astrolabe observations of Mars is removed by correcting for equinox motion and relating the observations to the Jet Propulsion Laboratory's planetary ephemeris, DE111. The remaining residuals show a 'phase effect', the magnitude of which is solved for and compared with that previously found for meridian transit observations. The final residuals reveal no significant offset in either right ascension or declination. In modifying the residuals, use is also made of Fricke's (1980) correction for the motion of the FK 4 equinox.

  6. Biochemical assessment of precuneus and posterior cingulate gyrus in the context of brain aging and Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Chera L Maarouf

    Full Text Available Defining the biochemical alterations that occur in the brain during "normal" aging is an important part of understanding the pathophysiology of neurodegenerative diseases and of distinguishing pathological conditions from aging-associated changes. Three groups were selected based on age and on having no evidence of neurological or significant neurodegenerative disease: 1 young adult individuals, average age 26 years (n = 9; 2 middle-aged subjects, average age 59 years (n = 5; 3 oldest-old individuals, average age 93 years (n = 6. Using ELISA and Western blotting methods, we quantified and compared the levels of several key molecules associated with neurodegenerative disease in the precuneus and posterior cingulate gyrus, two brain regions known to exhibit early imaging alterations during the course of Alzheimer's disease. Our experiments revealed that the bioindicators of emerging brain pathology remained steady or decreased with advancing age. One exception was S100B, which significantly increased with age. Along the process of aging, neurofibrillary tangle deposition increased, even in the absence of amyloid deposition, suggesting the presence of amyloid plaques is not obligatory for their development and that limited tangle density is a part of normal aging. Our study complements a previous assessment of neuropathology in oldest-old subjects, and within the limitations of the small number of individuals involved in the present investigation, it adds valuable information to the molecular and structural heterogeneity observed along the course of aging and dementia. This work underscores the need to examine through direct observation how the processes of amyloid deposition unfold or change prior to the earliest phases of dementia emergence.

  7. Histopathological and molecular heterogeneity among individuals with dementia associated with Presenilin mutations

    Directory of Open Access Journals (Sweden)

    Kalback Walter M

    2008-11-01

    Full Text Available Abstract Background Mutations in the presenilin (PSEN genes are associated with early-onset familial Alzheimer's disease (FAD. Biochemical characterizations and comparisons have revealed that many PSEN mutations alter γ-secretase activity to promote accumulation of toxic Aβ42 peptides. In this study, we compared the histopathologic and biochemical profiles of ten FAD cases expressing independent PSEN mutations and determined the degradation patterns of amyloid-β precursor protein (AβPP, Notch, N-cadherin and Erb-B4 by γ-secretase. In addition, the levels of Aβ40/42 peptides were quantified by ELISA. Results We observed a wide variation in type, number and distribution of amyloid deposits and neurofibrillary tangles. Four of the ten cases examined exhibited a substantial enrichment in the relative proportions of Aβ40 over Aβ42. The AβPP N-terminal and C-terminal fragments and Tau species, assessed by Western blots and scanning densitometry, also demonstrated a wide variation. The Notch-1 intracellular domain was negligible by Western blotting in seven PSEN cases. There was significant N-cadherin and Erb-B4 peptide heterogeneity among the different PSEN mutations. Conclusion These observations imply that missense mutations in PSEN genes can alter a range of key γ-secretase activities to produce an array of subtly different biochemical, neuropathological and clinical manifestations. Beyond the broad common features of dementia, plaques and tangles, the various PSEN mutations resulted in a wide heterogeneity and complexity and differed from sporadic AD.

  8. An autopsied case of progressive supranuclear palsy presenting with cerebellar ataxia and severe cerebellar involvement.

    Science.gov (United States)

    Iwasaki, Yasushi; Mori, Keiko; Ito, Masumi; Tatsumi, Shinsui; Mimuro, Maya; Yoshida, Mari

    2013-10-01

    A Japanese male patient presented with gait disturbance at the age of 69 years. His principal symptom was cerebellar ataxia for several years. He was initially diagnosed as having olivopontocerebellar atrophy because dysarthria and ataxia gradually developed, and head CT scan showed apparent atrophy of the cerebellum and brainstem and dilatation of the fourth ventricle. Later, he showed vertical gaze palsy, dysphagia, retrocollis, parkinsonism, axial dominant rigidity and grasp reflex, and therefore, the diagnosis was modified to progressive supranuclear palsy (PSP). Progressive atrophy of the frontotemporal lobe, cerebellum and brainstem, and dilatation of the lateral, third and fourth ventricles were evident on MRI. Gastrostomy and tracheotomy were performed 9 and 10 years after onset, respectively, and the patient died after 11 years disease duration. At autopsy the brain weighed 1000 g and showed atrophy of the frontotemporal lobe, cerebellum and brainstem. Neurofibrillary tangles, mainly globose-type revealed by Gallyas-Braak silver staining, were extensively observed in the cerebral cortex and subcortical grey matter. Numerous glial fibrillary tangles, including tuft-shaped astrocytes and coiled bodies, and extensive argyrophilic threads were also recognized, particularly in the frontal lobe, basal ganglia, cerebellar white matter, brainstem and spinal cord. The Purkinje cell layer showed severe neuron loss with Bergmann's gliosis, and the dentate nucleus showed severe neuron loss with grumose degeneration. Tau-positive/Gallyas-positive inclusions in the Purkinje cells and the glial cells of the Purkinje cell layer were observed. Pathological findings of the present patient were consistent with the diagnosis of PSP, but the olivopontocerebellar involvement, particularly in the cerebellum, was generally more severe, and the quantity of tau-positive/Gallyas-positive structures were more abundant than in typical PSP cases. The existence of a distinct, rare PSP

  9. Land Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is the international standard code format for hourly surface weather observations. The acronym roughly translates from French as Aviation Routine Weather...

  10. Surface Weather Observations Monthly

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface Weather Observation 1001 Forms is a set of historical manuscript records for the period 1893-1948. The collection includes two very similar form types: Form...

  11. NWS Corrections to Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Form B-14 is the National Weather Service form entitled 'Notice of Corrections to Weather Records.' The forms are used to make corrections to observations on forms...

  12. Water Current Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tidal, river and ocean current observations collected by the U.S. Coast and Geodetic Survey. Period of record is late 1800s to mid-1980s.

  13. Oil Rig Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather observations taken at offshore platforms along the United States coastlines. The majority are located in oil-rich areas of the Gulf of Mexico, Gulf of...

  14. Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Surface Weather Observation Collection consists primarily of hourly, synoptic, daily, and monthly forms submitted to the archive by the National Weather Service...

  15. Longline Observer Data System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — LODS, the Hawaii Longline Observer Data System, is a complete suite of tools designed to collect, process, and manage quality fisheries data and information. Guided...

  16. Cooperative Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly logs include a daily account of temperature extremes and precipitation, along with snow data at some locations. U.S. Cooperative Observer Program (COOP)...

  17. Mexico - Surface Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Mexican Surface Daily Observations taken at 94 observatories located throughout Mexico, beginning in 1872 and going up through 1981. The data resided on paper...

  18. Coastal research: Observational challenge

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, M.R.

    applications to rapid response as well as climatic scale problems. Ships have played important roles in providing access to coastal observations since early expeditionary voyages begin ning several centuries ago. Today they are important for: (1) direct... observations and data collection and (2) deployment of other sampling platforms such as moor ings, drifters, and others described below. One of the ad vantages of ships is that advanced analytical instrumen tation, which cannot presently be deployed in situ...

  19. RADIO POLARIZATION OBSERVATIONS OF THE SNAIL: A CRUSHED PULSAR WIND NEBULA IN G327.1–1.1 WITH A HIGHLY ORDERED MAGNETIC FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y. K.; Ng, C.-Y. [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Bucciantini, N. [INAF—Osservatorio Astrofisico di Arcetri, L.go E. Fermi 5, I-50125 Firenze (Italy); Slane, P. O. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gaensler, B. M. [Dunlap Institute for Astronomy and Astrophysics, The University of Toronto, Toronto, ON M5S 3H4 (Canada); Temim, T., E-mail: ncy@bohr.physics.hku.hk [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-04-01

    Pulsar wind nebulae (PWNe) are suggested to be acceleration sites of cosmic rays in the Galaxy. While the magnetic field plays an important role in the acceleration process, previous observations of magnetic field configurations of PWNe are rare, particularly for evolved systems. We present a radio polarization study of the “Snail” PWN inside the supernova remnant G327.1−1.1 using the Australia Telescope Compact Array. This PWN is believed to have been recently crushed by the supernova (SN) reverse shock. The radio morphology is composed of a main circular body with a finger-like protrusion. We detected a strong linear polarization signal from the emission, which reflects a highly ordered magnetic field in the PWN and is in contrast to the turbulent environment with a tangled magnetic field generally expected from hydrodynamical simulations. This could suggest that the characteristic turbulence scale is larger than the radio beam size. We built a toy model to explore this possibility, and found that a simulated PWN with a turbulence scale of about one-eighth to one-sixth of the nebula radius and a pulsar wind filling factor of 50%–75% provides the best match to observations. This implies substantial mixing between the SN ejecta and pulsar wind material in this system.

  20. Observing Photons in Space

    Science.gov (United States)

    Huber, Martin C. E.; Pauluhn, Anuschka; Timothy, J. Gethyn

    This first chapter of the book "Observing Photons in Space" serves to illustrate the rewards of observing photons in space, to state our aims, and to introduce the structure and the conventions used. The title of the book reflects the history of space astronomy: it started at the high-energy end of the electromagnetic spectrum, where the photon aspect of the radiation dominates. Nevertheless, both the wave and the photon aspects of this radiation will be considered extensively. In this first chapter we describe the arduous efforts that were needed before observations from pointed, stable platforms, lifted by rocket above the Earth"s atmosphere, became the matter of course they seem to be today. This exemplifies the direct link between technical effort -- including proper design, construction, testing and calibration -- and some of the early fundamental insights gained from space observations. We further report in some detail the pioneering work of the early space astronomers, who started with the study of γ- and X-rays as well as ultraviolet photons. We also show how efforts to observe from space platforms in the visible, infrared, sub-millimetre and microwave domains developed and led to today"s emphasis on observations at long wavelengths.

  1. FuzzObserver

    Science.gov (United States)

    Howard, Ayanna; Bayard, David

    2006-01-01

    Fuzzy Feature Observation Planner for Small Body Proximity Observations (FuzzObserver) is a developmental computer program, to be used along with other software, for autonomous planning of maneuvers of a spacecraft near an asteroid, comet, or other small astronomical body. Selection of terrain features and estimation of the position of the spacecraft relative to these features is an essential part of such planning. FuzzObserver contributes to the selection and estimation by generating recommendations for spacecraft trajectory adjustments to maintain the spacecraft's ability to observe sufficient terrain features for estimating position. The input to FuzzObserver consists of data from terrain images, including sets of data on features acquired during descent toward, or traversal of, a body of interest. The name of this program reflects its use of fuzzy logic to reason about the terrain features represented by the data and extract corresponding trajectory-adjustment rules. Linguistic fuzzy sets and conditional statements enable fuzzy systems to make decisions based on heuristic rule-based knowledge derived by engineering experts. A major advantage of using fuzzy logic is that it involves simple arithmetic calculations that can be performed rapidly enough to be useful for planning within the short times typically available for spacecraft maneuvers.

  2. Diabetes mellitus accelerates Aβ pathology in brain accompanied by enhanced GAβ generation in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Sachi Okabayashi

    Full Text Available Growing evidence suggests that diabetes mellitus (DM is one of the strongest risk factors for developing Alzheimer's disease (AD. However, it remains unclear why DM accelerates AD pathology. In cynomolgus monkeys older than 25 years, senile plaques (SPs are spontaneously and consistently observed in their brains, and neurofibrillary tangles are present at 32 years of age and older. In laboratory-housed monkeys, obesity is occasionally observed and frequently leads to development of type 2 DM. In the present study, we performed histopathological and biochemical analyses of brain tissue in cynomolgus monkeys with type 2 DM to clarify the relationship between DM and AD pathology. Here, we provide the evidence that DM accelerates Aβ pathology in vivo in nonhuman primates who had not undergone any genetic manipulation. In DM-affected monkey brains, SPs were observed in frontal and temporal lobe cortices, even in monkeys younger than 20 years. Biochemical analyses of brain revealed that the amount of GM1-ganglioside-bound Aβ (GAβ--the endogenous seed for Aβ fibril formation in the brain--was clearly elevated in DM-affected monkeys. Furthermore, the level of Rab GTPases was also significantly increased in the brains of adult monkeys with DM, almost to the same levels as in aged monkeys. Intraneuronal accumulation of enlarged endosomes was also observed in DM-affected monkeys, suggesting that exacerbated endocytic disturbance may underlie the acceleration of Aβ pathology due to DM.

  3. Association of Parkinson disease-related protein PINK1 with Alzheimer disease and multiple sclerosis brain lesions.

    Science.gov (United States)

    Wilhelmus, Micha M M; van der Pol, Susanne M A; Jansen, Quentin; Witte, Maarten E; van der Valk, Paul; Rozemuller, Annemieke J M; Drukarch, Benjamin; de Vries, Helga E; Van Horssen, Jack

    2011-02-01

    Mitochondrial dysfunction and oxidative stress are hallmarks of various neurological disorders, including multiple sclerosis (MS), Alzheimer disease (AD), and Parkinson disease (PD). Mutations in PINK1, a mitochondrial kinase, have been linked to the occurrence of early onset parkinsonism. Currently, various studies support the notion of a neuroprotective role for PINK1, as it protects cells from stress-mediated mitochondrial dysfunction, oxidative stress, and apoptosis. Because information about the distribution pattern of PINK1 in neurological diseases other than PD is scarce, we here investigated PINK1 expression in well-characterized brain samples derived from MS and AD individuals using immunohistochemistry. In control gray matter PINK1 immunoreactivity was observed in neurons, particularly neurons in layers IV-VI. Astrocytes were the most prominent cell type decorated by anti-PINK1 antibody in the white matter. In addition, PINK1 staining was observed in the cerebrovasculature. In AD, PINK1 was found to colocalize with classic senile plaques and vascular amyloid depositions, as well as reactive astrocytes associated with the characteristic AD lesions. Interestingly, PINK1 was absent from neurofibrillary tangles. In active demyelinating MS lesions we observed a marked astrocytic PINK1 immunostaining, whereas astrocytes in chronic lesions were weakly stained. Taken together, we observed PINK1 immunostaining in both AD and MS lesions, predominantly in reactive astrocytes associated with these lesions, suggesting that the increase in astrocytic PINK1 protein might be an intrinsic protective mechanism to limit cellular injury. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Diabetes mellitus accelerates Aβ pathology in brain accompanied by enhanced GAβ generation in nonhuman primates.

    Science.gov (United States)

    Okabayashi, Sachi; Shimozawa, Nobuhiro; Yasutomi, Yasuhiro; Yanagisawa, Katsuhiko; Kimura, Nobuyuki

    2015-01-01

    Growing evidence suggests that diabetes mellitus (DM) is one of the strongest risk factors for developing Alzheimer's disease (AD). However, it remains unclear why DM accelerates AD pathology. In cynomolgus monkeys older than 25 years, senile plaques (SPs) are spontaneously and consistently observed in their brains, and neurofibrillary tangles are present at 32 years of age and older. In laboratory-housed monkeys, obesity is occasionally observed and frequently leads to development of type 2 DM. In the present study, we performed histopathological and biochemical analyses of brain tissue in cynomolgus monkeys with type 2 DM to clarify the relationship between DM and AD pathology. Here, we provide the evidence that DM accelerates Aβ pathology in vivo in nonhuman primates who had not undergone any genetic manipulation. In DM-affected monkey brains, SPs were observed in frontal and temporal lobe cortices, even in monkeys younger than 20 years. Biochemical analyses of brain revealed that the amount of GM1-ganglioside-bound Aβ (GAβ)--the endogenous seed for Aβ fibril formation in the brain--was clearly elevated in DM-affected monkeys. Furthermore, the level of Rab GTPases was also significantly increased in the brains of adult monkeys with DM, almost to the same levels as in aged monkeys. Intraneuronal accumulation of enlarged endosomes was also observed in DM-affected monkeys, suggesting that exacerbated endocytic disturbance may underlie the acceleration of Aβ pathology due to DM.

  5. Detection of hyperphosphorylated tau protein and α-synuclein in spinal cord of patients with Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Guo YJ

    2016-02-01

    Full Text Available Yanjun Guo,1,2 Luning Wang,2 Mingwei Zhu,2 Honghong Zhang,3 Yazhuo Hu,3 Zhitao Han,3 Jia Liu,4 Weiqin Zhao,1 Dexin Wang11Department of Neurology, Beijing Friendship Hospital, Capital Medical University, 2Department of Geriatric Neurology, PLA General Hospital, 3Institute of Geriatrics, Chinese PLA General Hospital & Chinese PLA Medical Academy, 4Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of ChinaAbstract: The aim of this study was to investigate the neuropathological features of the spinal cord in patients suffering with Alzheimer’s disease (AD. Spinal cord tissue collected from three AD patients and eight controls was selected for the study. Data were collected at T2, T8, T10, L4, and S2 spinal levels. The sections were subjected to hematoxylin and eosin and Gallyas–Braak staining methods and then were immunostained with antibodies such as phosphorylated tau protein (AT8, α-synuclein, Aβ, amyloid precursor protein , ubiquitin, and TDP-43. Pathological changes exhibited by the biomarkers were detected by microscopy. Neurofibrillary tangles (NFTs were detectable in spinal anterior horn motor neurons in two of the three AD patients. AT8-positive axons or axon-like structures and AT8 expression in glial cells were detected in all three AD cases. Hyperphosphorylation of tau protein was detected in spinal anterior horn cells, glial cells, and axons, and its severity was associated with NFTs in the brain tissue. α-Synuclein-positive Lewy bodies and scattered Lewy-like neuritis were detected in the medial horn of the thoracic spinal cord and ventral sacral gray matter, respectively, in one patient who had AD with Lewy bodies. Neither amyloid deposition nor amyloid precursor protein and TDP-43 expression was detected in the spinal cord of AD patients. Spinal cord of AD patients was observed to contain phosphorylated tau protein and α-synuclein immunoreactive structures, which may play a

  6. Presence of tau pathology within foetal neural allografts in patients with Huntington's and Parkinson's disease.

    Science.gov (United States)

    Cisbani, Giulia; Maxan, Alexander; Kordower, Jeffrey H; Planel, Emmanuel; Freeman, Thomas B; Cicchetti, Francesca

    2017-11-01

    Cell replacement has been explored as a therapeutic strategy to repair the brain in patients with Huntington's and Parkinson's disease. Post-mortem evaluations of healthy grafted tissue in such cases have revealed the development of Huntington- or Parkinson-like pathology including mutant huntingtin aggregates and Lewy bodies. An outstanding question remains if tau pathology can also be seen in patients with Huntington's and Parkinson's disease who had received foetal neural allografts. This was addressed by immunohistochemical/immunofluorescent stainings performed on grafted tissue of two Huntington's disease patients, who came to autopsy 9 and 12 years post-transplantation, and two patients with Parkinson's disease who came to autopsy 18 months and 16 years post-transplantation. We show that grafts also contain tau pathology in both types of transplanted patients. In two patients with Huntington's disease, the grafted tissue showed the presence of hyperphosphorylated tau [both AT8 (phospho-tau Ser202 and Thr205) and CP13 (pSer202) immunohistochemical stainings] pathological inclusions, neurofibrillary tangles and neuropil threads. In patients with Parkinson's disease, the grafted tissue was characterized by hyperphosphorylated tau (AT8; immunofluorescent staining) pathological inclusions, neurofibrillary tangles and neuropil threads but only in the patient who came to autopsy 16 years post-transplantation. Abundant tau-related pathology was observed in the cortex and striatum of all cases studied. While the striatum of the grafted Huntington's disease patient revealed an equal amount of 3-repeat and 4-repeat isoforms of tau, the grafted tissue showed elevated 4-repeat isoforms by western blot. This suggests that transplants may have acquired tau pathology from the host brain, although another possibility is that this was due to acceleration of ageing. This finding not only adds to the recent reports that tau pathology is a feature of these neurodegenerative

  7. Multifunctional Mesoscale Observing Networks.

    Science.gov (United States)

    Dabberdt, Walter F.; Schlatter, Thomas W.; Carr, Frederick H.; Friday, Elbert W. Joe; Jorgensen, David; Koch, Steven; Pirone, Maria; Ralph, F. Martin; Sun, Juanzhen; Welsh, Patrick; Wilson, James W.; Zou, Xiaolei

    2005-07-01

    More than 120 scientists, engineers, administrators, and users met on 8 10 December 2003 in a workshop format to discuss the needs for enhanced three-dimensional mesoscale observing networks. Improved networks are seen as being critical to advancing numerical and empirical modeling for a variety of mesoscale applications, including severe weather warnings and forecasts, hydrology, air-quality forecasting, chemical emergency response, transportation safety, energy management, and others. The participants shared a clear and common vision for the observing requirements: existing two-dimensional mesoscale measurement networks do not provide observations of the type, frequency, and density that are required to optimize mesoscale prediction and nowcasts. To be viable, mesoscale observing networks must serve multiple applications, and the public, private, and academic sectors must all actively participate in their design and implementation, as well as in the creation and delivery of value-added products. The mesoscale measurement challenge can best be met by an integrated approach that considers all elements of an end-to-end solution—identifying end users and their needs, designing an optimal mix of observations, defining the balance between static and dynamic (targeted or adaptive) sampling strategies, establishing long-term test beds, and developing effective implementation strategies. Detailed recommendations are provided pertaining to nowcasting, numerical prediction and data assimilation, test beds, and implementation strategies.

  8. Visually observing comets

    CERN Document Server

    Seargent, David A J

    2017-01-01

    In these days of computers and CCD cameras, visual comet observers can still contribute scientifically useful data with the help of this handy reference for use in the field. Comets are one of the principal areas for productive pro-amateur collaboration in astronomy, but finding comets requires a different approach than the observing of more predictable targets. Principally directed toward amateur astronomers who prefer visual observing or who are interested in discovering a new comet or visually monitoring the behavior of known comets, it includes all the advice needed to thrive as a comet observer. After presenting a brief overview of the nature of comets and how we came to the modern understanding of comets, this book details the various types of observations that can usefully be carried out at the eyepiece of a telescope. Subjects range from how to search for new comets to visually estimating the brightness of comets and the length and orientation of tails, in addition to what to look for in comet heads a...

  9. Solar Prominences: Observations

    Directory of Open Access Journals (Sweden)

    Susanna Parenti

    2014-03-01

    Full Text Available Solar prominences are one of the most common features of the solar atmosphere. They are found in the corona but they are one hundred times cooler and denser than the coronal material, indicating that they are thermally and pressure isolated from the surrounding environment. Because of these properties they appear at the limb as bright features when observed in the optical or the EUV cool lines. On the disk they appear darker than their background, indicating the presence of a plasma absorption process (in this case they are called filaments. Prominence plasma is embedded in a magnetic environment that lies above magnetic inversion lines, denoted a filament channel. This paper aims at providing the reader with the main elements that characterize these peculiar structures, the prominences and their environment, as deduced from observations. The aim is also to point out and discuss open questions on prominence existence, stability and disappearance. The review starts with a general introduction of these features and the instruments used for their observation. Section 2 presents the large scale properties, including filament morphology, thermodynamical parameters, magnetic fields, and the properties of the surrounding coronal cavity, all in stable conditions. Section 3 is dedicated to small-scale observational properties, from both the morphological and dynamical points of view. Section 4 introduces observational aspects during prominence formation, while Section 5 reviews the sources of instability leading to prominence disappearance or eruption. Conclusions and perspectives are given in Section 6.

  10. Observing workplace incivility.

    Science.gov (United States)

    Reich, Tara C; Hershcovis, M Sandy

    2015-01-01

    Interpersonal mistreatment at work often occurs in the presence of others; however, these "others" are rarely examined in empirical research despite their importance to the context of the negative interaction. We conducted 2 experiments to examine how witnessing incivility affects observer reactions toward instigators and targets. In Study 1, participants (N = 60) worked virtually with an ostensible instigator and target. In Study 2, participants (N = 48) worked in vivo with confederates (hired actors) on a job task. Across these 2 studies, we found that observers of incivility tend to punish instigators while their reactions to targets were generally unaffected. Further, the effect of witnessing incivility was mediated by observers' negative emotional reaction toward the instigator. (c) 2015 APA, all rights reserved.

  11. Observed Barium Emission Rates

    Science.gov (United States)

    Stenbaek-Nielsen, H. C.; Wescott, E. M.; Hallinan, T. J.

    1993-01-01

    The barium releases from the CRRES satellite have provided an opportunity for verifying theoretically calculated barium ion and neutral emission rates. Spectra of the five Caribbean releases in the summer of 1991 were taken with a spectrograph on board a U.S. Air Force jet aircraft. Because the line of sight release densities are not known, only relative rates could be obtained. The observed relative rates agree well with the theoretically calculated rates and, together with other observations, confirm the earlier detailed theoretical emission rates. The calculated emission rates can thus with good accuracy be used with photometric observations. It has been postulated that charge exchange between neutral barium and oxygen ions represents a significant source for ionization. If so. it should be associated with emissions at 4957.15 A and 5013.00 A, but these emissions were not detected.

  12. Observed climate change hotspots

    Science.gov (United States)

    Turco, M.; Palazzi, E.; Hardenberg, J.; Provenzale, A.

    2015-05-01

    We quantify climate change hotspots from observations, taking into account the differences in precipitation and temperature statistics (mean, variability, and extremes) between 1981-2010 and 1951-1980. Areas in the Amazon, the Sahel, tropical West Africa, Indonesia, and central eastern Asia emerge as primary observed hotspots. The main contributing factors are the global increase in mean temperatures, the intensification of extreme hot-season occurrence in low-latitude regions and the decrease of precipitation over central Africa. Temperature and precipitation variability have been substantially stable over the past decades, with only a few areas showing significant changes against the background climate variability. The regions identified from the observations are remarkably similar to those defined from projections of global climate models under a "business-as-usual" scenario, indicating that climate change hotspots are robust and persistent over time. These results provide a useful background to develop global policy decisions on adaptation and mitigation priorities over near-time horizons.

  13. Confronting theory with observations

    DEFF Research Database (Denmark)

    Bergström... [], Lars; Bjerrum-Bohr, N. Emil J.; Butt, Sharaz

    2011-01-01

    This workshop exposed theoretical cosmologists to some of the important observations that are being made of our universe. The goal was to encourage theorists to think concretely about the questions being raised by these new discoveries and also to acquire a sense of the realistic constaints on th...... on theoretical ideas and models that will be possible from the coming generation of cosmological observations. The atmosphere was kept lively and informal, with relatively few talks each day, which provided plenty of time for discussion and callaboration among the participants...

  14. Observations from Sarmizegetusa Sanctuary

    Science.gov (United States)

    Barbosu, M.

    2000 years ago, Sarmizegetusa Regia was the capital of ancient Dacia (today: Romania). It is known that the Dacian high priests used the Sanctuary of Sarmizegetusa not only for religious ceremonies, but also for astronomical observations. After having completed geodesic measurements, we analyzed the architecture of the sanctuary with its main points, directions and circles. We discuss here what kind of astronomical observations could have been made with the scientific knowledge of that time. The final section of this work is dedicated to the remarkable resemblance between Sarmizegztusa and Stonehenge.

  15. Observational Research: Formalized Curiosity

    Science.gov (United States)

    Skaggs, Paul

    2004-01-01

    Design research is a valuable tool to help the designer understand the problem that he/she needs to solve. The purpose of design research is to help state or understand the problems better, which will lead to better solutions. Observational research is a design research method for helping the designer understand and define the problem.…

  16. A Single Neonatal Exposure to BMAA in a Rat Model Produces Neuropathology Consistent with Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Laura Louise Scott

    2017-12-01

    Full Text Available Although cyanobacterial β-N-methylamino-l-alanine (BMAA has been implicated in the development of Alzheimer’s Disease (AD, Parkinson’s Disease (PD and Amyotrophic Lateral Sclerosis (ALS, no BMAA animal model has reproduced all the neuropathology typically associated with these neurodegenerative diseases. We present here a neonatal BMAA model that causes β-amyloid deposition, neurofibrillary tangles of hyper-phosphorylated tau, TDP-43 inclusions, Lewy bodies, microbleeds and microgliosis as well as severe neuronal loss in the hippocampus, striatum, substantia nigra pars compacta, and ventral horn of the spinal cord in rats following a single BMAA exposure. We also report here that BMAA exposure on particularly PND3, but also PND4 and 5, the critical period of neurogenesis in the rodent brain, is substantially more toxic than exposure to BMAA on G14, PND6, 7 and 10 which suggests that BMAA could potentially interfere with neonatal neurogenesis in rats. The observed selective toxicity of BMAA during neurogenesis and, in particular, the observed pattern of neuronal loss observed in BMAA-exposed rats suggest that BMAA elicits its effect by altering dopamine and/or serotonin signaling in rats.

  17. A Unified Hypothesis of Early- and Late-Onset Alzheimer's Disease Pathogenesis.

    Science.gov (United States)

    Atwood, Craig S; Bowen, Richard L

    2015-01-01

    Early-onset familial Alzheimer's disease (EOFAD) and late-onset sporadic AD (LOSAD) both follow a similar pathological and biochemical course that includes: neuron and synapse loss and dysfunction, microvascular damage, microgliosis, extracellular amyloid-β deposition, tau phosphorylation, formation of intracellular neurofibrillary tangles, endoreduplication and related cell cycle events in affected brain regions. Any mechanistic explanation of AD must accommodate these biochemical and neuropathological features for both forms of the disease. In this insight paper we provide a unifying hypothesis for EOFAD and LOSAD that proposes that the aberrant re-entry of terminally differentiated, post-mitotic neurons into the cell division cycle is a common pathway that explains both early and late-onset forms of AD. Cell cycle abnormalities appear very early in the disease process, prior to the appearance of plaques and tangles, and explain the biochemical (e.g. tau phosphorylation), neuropathological (e.g. neuron hypertrophy; polypoidy) and cognitive changes observed in EOFAD and LOSAD. Genetic mutations in AβPP, PSEN1, and PSEN2 that alter amyloid-β precursor protein and Notch processing drive reactivation of the cell cycle in EOFAD, while age-related reproductive endocrine dyscrasia that upregulates mitogenic TNF signaling and AβPP processing toward the amyloidogenic pathway drives reactivation of the cell cycle in LOSAD. In essence, AβPP and presenilin mutations initiate early, what endocrine dyscrasia initiates later: aberrant cell cycle re-entry of post-mitotic neurons leading to neurodegeneration and cognitive decline in AD. Inhibition of cell cycle re-entry in post-mitotic neurons may be a useful therapeutic strategy to prevent, slow or halt disease progression.

  18. Clustering of tau-immunoreactive pathology in chronic traumatic encephalopathy.

    Science.gov (United States)

    Armstrong, Richard A; McKee, Ann C; Alvarez, Victor E; Cairns, Nigel J

    2017-02-01

    Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder which may result from repetitive brain injury. A variety of tau-immunoreactive pathologies are present, including neurofibrillary tangles (NFT), neuropil threads (NT), dot-like grains (DLG), astrocytic tangles (AT), and occasional neuritic plaques (NP). In tauopathies, cellular inclusions in the cortex are clustered within specific laminae, the clusters being regularly distributed parallel to the pia mater. To determine whether a similar spatial pattern is present in CTE, clustering of the tau-immunoreactive pathology was studied in the cortex, hippocampus, and dentate gyrus in 11 cases of CTE and 7 cases of Alzheimer's disease neuropathologic change (ADNC) without CTE. In CTE: (1) all aspects of tau-immunoreactive pathology were clustered and the clusters were frequently regularly distributed parallel to the tissue boundary, (2) clustering was similar in two CTE cases with minimal co-pathology compared with cases with associated ADNC or TDP-43 proteinopathy, (3) in a proportion of cortical gyri, estimated cluster size was similar to that of cell columns of the cortico-cortical pathways, and (4) clusters of the tau-immunoreactive pathology were infrequently spatially correlated with blood vessels. The NFT and NP in ADNC without CTE were less frequently randomly or uniformly distributed and more frequently in defined clusters than in CTE. Hence, the spatial pattern of the tau-immunoreactive pathology observed in CTE is typical of the tauopathies but with some distinct differences compared to ADNC alone. The spread of pathogenic tau along anatomical pathways could be a factor in the pathogenesis of the disease.

  19. Saturn Ring Observer

    Science.gov (United States)

    Spilker, T. R.

    2001-01-01

    Answering fundamental questions about ring particle characteristics, and individual and group behavior, appears to require close-proximity (a few km) observations. Saturn's magnificent example of a ring system offers a full range of particle sizes, densities, and behaviors for study, so it is a natural choice for such detailed investigation. Missions implementing these observations require post-approach Delta(V) of approximately 10 km/s or more, so past mission concepts called upon Nuclear Electric Propulsion. The concept described here reduces the propulsive Delta(V) requirement to as little as 3.5 km/s, difficult but not impossible for high-performance chemical propulsion systems. Additional information is contained in the original extended abstract.

  20. Observing With NASA

    Science.gov (United States)

    Steel, Simon J.; Dussault, M. E.; Sienkiewicz, F. F.; Deutsch, F. S.; Reinfeld, E. L.; Gould, R. R.

    2009-01-01

    Observing With NASA (OWN) is a new NASA-funded e-learning project developed by the Harvard-Smithsonian Center for Astrophysics (CfA) in partnership with the Space Telescope Science Institute (STScI). The project will allow users to make their OWN astronomical observations and compare their images and data with that of NASA's orbiting telescopes and space probes. OWN will provide NASA's education and public outreach audiences with universal access to the CfA's MicroObservatory online network of robotic educational telescopes. Project staff are developing a customized online interface, curricular support materials, and professional development tutorials for both classroom and informal educators. OWN has the capacity to serve hundreds of thousands of student and public users during the 2009 International Year of Astronomy and beyond.

  1. GRBs: Recent Observational Results

    Science.gov (United States)

    Gehrels, Neil

    2009-01-01

    We are in an exciting period of discovery for gamma-ray bursts. The Swift observatory is detecting 100 bursts per year, providing arcsecond localizations and sensitive observations of the prompt and afterglow emission. The Fermi observatory is observing 250 bursts per year with its medium-energy ORB instrument and about 10 bursts per year with its high-energy LAT instrument. In addition, rapid-response telescopes on the ground are providing new capabilities to study optical emission during the prompt phase and spectral signatures of the host galaxies. The combined data set is enabling great advances in our understanding of GRBs including afterglow physics, short burst origin, and high energy emission. This talk will highlight recent findings.

  2. Special Observance Planning Guide

    Science.gov (United States)

    2015-11-01

    Appendix B Simple Timetable ……...……………………………………………………………..…. B – 2 Extensive Timetable …………………………………………………………………….. B – 3 Project Officer Planning... timetables , and other documents that can be tailored for use in developing a special observance event. What is the Observance Theme? The...milestones, and timetables can be found in this guide and can be tailored for unit use. • Funding – Adequate funding is critical. Without it

  3. Observations of Surfzone Albedo

    Science.gov (United States)

    Sinnett, G.; Feddersen, F.

    2014-12-01

    The surfzone environment (where waves break) contains several unique and previously unconsidered processes that affect the heat budget. Entering short-wave radiation is a dominant term in both shelf and surfzone heat budgets. In contrast to the shelf, however, depth limited wave breaking in the surfzone generates spray, whitewater and suspended sediments, elevating the surface albedo (ratio of reflected to incident short-wave radiation). Elevated albedo reduces the level of solar short-wave radiation entering the water, potentially resulting in less heating. Additionally, surfzone water quality is often impacted by fecal bacteria contamination. As bacteria mortality is related to short-wave solar radiation, elevated surfzone albedo could reduce pathogen mortality, impacting human health. Albedo in the open ocean has been frequently studied and parameterizations often consider solar zenith angle, wind speed and ocean chlorophyll concentration, producing albedo values typically near 0.06. However, surfzone albedo observations have been extremely sparse, yet show depth limited wave breaking may increase the albedo by nearly a factor of 10 up to 0.5. Here, we present findings from a field study at the Scripps Institution of Oceanography pier to observe the affect of waves on surfzone albedo. Concurrent measurements were taken with a four-way radiometer (to measure both downwelling and upwelling short-wave and long wave radiation) mounted above the surfzone. A co-located GoPro camera was used to relate visual aspects of the surfzone to measured reflectance, and wave height and period were observed with a bottom mounted pressure sensor in 5 m water depth just outside the surfzone. Wind speed and direction were observed on the pier 10 m above the water surface. Here, we will examine the surfzone albedo dependence on surfzone parameters, such as wave height.

  4. Southern hemisphere observations

    Science.gov (United States)

    Orchiston, Wayne

    Because of insurmountable problems associated with absolute dating, the non-literate cultures of the Southern Hemisphere can contribute little to Applied Historical Astronomy, although Maori traditions document a possible supernova dating to the period 1000-1770 AD. In contrast, the abundant nineteenth century solar, planetary, cometary and stellar observational data provided by Southern Hemisphere professional and amateur observatories can serve as an invaluable mine of information for present-day astronomers seeking to incorporate historical data in their investigations.

  5. AR Sco observing campaign

    Science.gov (United States)

    Waagen, Elizabeth O.

    2016-08-01

    Dr. Thomas Marsh (University of Warwick) and colleagues have requested AAVSO coverage of the intriguing binary AR Sco in support of upcoming Newton-XMM observations scheduled for 2016 September 10 15:41 - September 11 02:26 UT. This fascinating binary system is the subject of an exciting paper in the July 2016 issue of Nature (Marsh et al., 2016Natur.537..374M; pre-print version at arXiv (http://arxiv.org/abs/1607.08265). Marsh writes of their research on AR Sco: "...it was down to [the amateurs [who are co-authors] on the paper that we got onto it in the first place. Coverage immediately before, after and (especially) during [the XMM observations] would be great. The most challenging aspect is the time resolution: ideally one wants a cadence youtu.be). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  6. Geodetic Earth Observation

    Science.gov (United States)

    Rothacher, Markus

    2017-04-01

    Mankind is constantly threatened by a variety of natural disasters and global change phenomena. In order to be able to better predict and assess these catastrophic and disastrous events a continuous observation and monitoring of the causative Earth processes is a necessity. These processes may happen in time scales from extremely short (earthquakes, volcano eruptions, land slides, ...) to very long (melting of ice sheets, sea level change, plate tectonics, ...). Appropriate monitoring and early warning systems must allow, therefore, the detection and quantification of catastrophic events in (near) real-time on the one hand and the reliable identification of barely noticeable, but crucial long-term trends (e.g., sea level rise) on the other hand. The Global Geodetic Observing System (GGOS), established by the International Association of Geodesy (IAG) in 2003, already now contributes in a multitude of ways to meet this challenge, e.g., by providing a highly accurate and stable global reference frame, without which the measurement of a sea level rise of 2-3 mm/y would not be possible; by measuring displacements in near real-time and deformations over decades that offer valuable clues to plate tectonics, earthquake processes, tsunamis, volcanos, land slides, and glaciers dynamics; by observing the mass loss of ice sheets with gravity satellite missions; and by estimating essential variables such as the amount of water vapor in the troposphere relevant for weather predictions and climate and the content of free electrons in the ionosphere crucial for space weather.

  7. Observing with CHEOPS

    Science.gov (United States)

    Isaak, K. G.

    2017-09-01

    CHEOPS (CHaracterising ExOPlanet Satellite) is the first exoplanet mission dedicated to the search for transits of exoplanets by means of ultrahigh precision photometry (optical/near-IR) of bright stars already known to host planets, with launch readiness foreseen by the end of 2018. It is also the first S-class mission in ESA's Cosmic Vision 2015-2025. The mission is a partnership between Switzerland and ESA's science programme, with important contributions from 10 other member states. It will provide the unique capability of determining accurate radii for a subset of those planets in the super- Earth to Neptune mass range, for which the mass has already been estimated from ground- based spectroscopic surveys. 20% of the observing time in the 3.5 year nominal mission will be available to Guest Observers from the Community. Proposals will be requested through open calls from ESA that are foreseen to be every year, with the first 6 months before launch. In this poster I will provide an overview of how to obtain data from CHEOPS, with a particular focus on the CHEOPS Guest Observers Programme.

  8. NICER observation of magnetars

    Science.gov (United States)

    Enoto, Teruaki; Kaspi, Victoria M.; Arzoumanian, Zaven

    2016-04-01

    The Neutron Star Interior Composition ExploreR (NICER) is a NASA Explorer Misson of Opportunity as an attached payload aboard the International Space Station (ISS), launch in August 2016. The NICER is planned to study the interior composition and structure within neutron stars via high precise measurement of their stellar mass and radius, also to investigate dynamic and energetic behaviors of their activities. This mission will enable pulsar rotation-resolved spectroscopy in the 0.2--12 keV energy band with large collection area (about twice of the XMM-Newton observatory for soft X-ray timing), precise time-tagging resolution (~200 nsec, 25 times better than RXTE), and high sensitivity (about 2e-14 erg/s/cm2 in the 0.5--10 keV, 5-sigma for 10 ksec exposure). As one of prime goals of the mission, we will describe the science planning of the NICER magnetar observations. The NICER is expected to provide monitoring of fainter magnetar sources which cannot be performed by Swift due to its little collective area. Deep observations of quiescent magnetars and high-B radio pulsars can be also performed with the NICER to study their spectral similarity as a key to investigate the connection between these two sub-classes. Finally, ToO programs are suitable to follow-up the magnate outburst relaxation down to much fainter flux level. We will introduce the NICER strategy of the magnetar observation.

  9. R Aqr observing campaign

    Science.gov (United States)

    Waagen, Elizabeth O.

    2016-01-01

    Dr. George Wallerstein (University of Washington) has requested AAVSO coverage of the long period/symbiotic variable R Aquarii beginning immediately in support of high resolution spectroscopic observations planned for 2016 January 19 and 21. Several other astronomers, including Drs. Lee Anne Willson (Iowa State University), Ulisse Munari (INAF, Astronomical Observatory of Padua, Italy), and Fred Walter (Stony Brook University) are studying R Aqr closely and additional spectroscopic and other observations are planned for the near future. R Aqr is both a Mira (M) and a symbiotic (ZAND) - it is a close binary system consisting of a hot star and a late-type star (the Mira), both enveloped in nebulosity. As a result, the very interesting light curve shows not only the Mira pulsation but also complex eclipse behavior as the two stars interact. The period of Mira variation is 387.0 days; the eclipse period is 43.6-44 years. The cause of the eclipse is unknown; several theories h! ave been proposed, including a focused accretion stream, a disk or cloud around the secondary, and a triggered mass loss that produces an opaque cloud. Careful investigation of this upcoming event should help to resolve this question. The last eclipse of R Aqr was in 1978. The next eclipse is predicted for 2022, but may be early. The current behavior of R Aqr suggests that the eclipse, which lasts for several years, may either be beginning or its beginning may be imminent. R Aqr was at minimum in early December 2015 at magnitude V=11.4, and is currently at visual magnitude 11.0. During this phase of the approximately 44-year eclipse cycle, at maximum it may be as bright as V 6.0-6.5 but is not expected to become brighter. Beginning immediately, nightly BVRI CCD and DSLR photometry and visual observations are requested. As R Aqr brightens towards maximum and is in range, PEP observations are also requested. Ongoing spectroscopy over the next several years will be interesting to see as the system

  10. Application of neurite orientation dispersion and density imaging (NODDI) to a tau pathology model of Alzheimer's disease.

    LENUS (Irish Health Repository)

    Colgan, N

    2015-10-23

    Increased hyperphosphorylated tau and the formation of intracellular neurofibrillary tangles are associated with the loss of neurons and cognitive decline in Alzheimer\\'s disease, and related neurodegenerative conditions. We applied two diffusion models, diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI), to in vivo diffusion magnetic resonance images (dMRI) of a mouse model of human tauopathy (rTg4510) at 8.5months of age. In grey matter regions with the highest degree of tau burden, microstructural indices provided by both NODDI and DTI discriminated the rTg4510 (TG) animals from wild type (WT) controls; however only the neurite density index (NDI) (the volume fraction that comprises axons or dendrites) from the NODDI model correlated with the histological measurements of the levels of hyperphosphorylated tau protein. Reductions in diffusion directionality were observed when implementing both models in the white matter region of the corpus callosum, with lower fractional anisotropy (DTI) and higher orientation dispersion (NODDI) observed in the TG animals. In comparison to DTI, histological measures of tau pathology were more closely correlated with NODDI parameters in this region. This in vivo dMRI study demonstrates that NODDI identifies potential tissue sources contributing to DTI indices and NODDI may provide greater specificity to pathology in Alzheimer\\'s disease.

  11. Archview Lodge, Drumany, Letterkenny, Donegal.

    LENUS (Irish Health Repository)

    Colgan, N

    2015-10-23

    Increased hyperphosphorylated tau and the formation of intracellular neurofibrillary tangles are associated with the loss of neurons and cognitive decline in Alzheimer\\'s disease, and related neurodegenerative conditions. We applied two diffusion models, diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI), to in vivo diffusion magnetic resonance images (dMRI) of a mouse model of human tauopathy (rTg4510) at 8.5months of age. In grey matter regions with the highest degree of tau burden, microstructural indices provided by both NODDI and DTI discriminated the rTg4510 (TG) animals from wild type (WT) controls; however only the neurite density index (NDI) (the volume fraction that comprises axons or dendrites) from the NODDI model correlated with the histological measurements of the levels of hyperphosphorylated tau protein. Reductions in diffusion directionality were observed when implementing both models in the white matter region of the corpus callosum, with lower fractional anisotropy (DTI) and higher orientation dispersion (NODDI) observed in the TG animals. In comparison to DTI, histological measures of tau pathology were more closely correlated with NODDI parameters in this region. This in vivo dMRI study demonstrates that NODDI identifies potential tissue sources contributing to DTI indices and NODDI may provide greater specificity to pathology in Alzheimer\\'s disease.

  12. Alterations in protein phosphorylation in the amygdala of the 5XFamilial Alzheimer's disease animal model

    Directory of Open Access Journals (Sweden)

    Eun-Jeong Yang

    2017-04-01

    Full Text Available Alzheimer's disease is the most common disease underlying dementia in humans. Two major neuropathological hallmarks of AD are neuritic plaques primarily composed of amyloid beta peptide and neurofibrillary tangles primarily composed of hyperphosphorylated tau. In addition to impaired memory function, AD patients often display neuropsychiatric symptoms and abnormal emotional states such as confusion, delusion, manic/depressive episodes and altered fear status. Brains from AD patients show atrophy of the amygdala which is involved in fear expression and emotional processing as well as hippocampal atrophy. However, which molecular changes are responsible for the altered emotional states observed in AD remains to be elucidated. Here, we observed that the fear response as assessed by evaluating fear memory via a cued fear conditioning test was impaired in 5XFamilial AD (5XFAD mice, an animal model of AD. Compared to wild-type mice, 5XFAD mice showed changes in the phosphorylation of twelve proteins in the amygdala. Thus, our study provides twelve potential protein targets in the amygdala that may be responsible for the impairment in fear memory in AD.

  13. Alterations in protein phosphorylation in the amygdala of the 5XFamilial Alzheimer's disease animal model.

    Science.gov (United States)

    Yang, Eun-Jeong; Mahmood, Usman; Kim, Hyunju; Choi, Moonseok; Choi, Yunjung; Lee, Jean-Pyo; Chang, Moon-Jeong; Kim, Hye-Sun

    2017-04-01

    Alzheimer's disease is the most common disease underlying dementia in humans. Two major neuropathological hallmarks of AD are neuritic plaques primarily composed of amyloid beta peptide and neurofibrillary tangles primarily composed of hyperphosphorylated tau. In addition to impaired memory function, AD patients often display neuropsychiatric symptoms and abnormal emotional states such as confusion, delusion, manic/depressive episodes and altered fear status. Brains from AD patients show atrophy of the amygdala which is involved in fear expression and emotional processing as well as hippocampal atrophy. However, which molecular changes are responsible for the altered emotional states observed in AD remains to be elucidated. Here, we observed that the fear response as assessed by evaluating fear memory via a cued fear conditioning test was impaired in 5XFamilial AD (5XFAD) mice, an animal model of AD. Compared to wild-type mice, 5XFAD mice showed changes in the phosphorylation of twelve proteins in the amygdala. Thus, our study provides twelve potential protein targets in the amygdala that may be responsible for the impairment in fear memory in AD. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  14. Systemic inflammation, blood-brain barrier vulnerability and cognitive / non-cognitive symptoms in Alzheimer disease: Relevance to pathogenesis and therapy

    Directory of Open Access Journals (Sweden)

    Shuko eTakeda

    2014-07-01

    Full Text Available The incidence of dementia is increasing at an alarming rate, and has become a major public health concern. Alzheimer disease (AD is the most common form of dementia and is characterized by progressive cognitive impairment. In addition to classical neuropathological features such as amyloid plaques and neurofibrillary tangles, accumulation of activated immune cells has been documented in the AD brain, suggesting a contribution of neuroinflammation in the pathogenesis of AD. Besides cognitive deterioration, non-cognitive symptoms, such as agitation, aggression, depression and psychosis, are often observed in demented patients, including those with AD, and these neuropsychological symptoms place a heavy burden on caregivers. These symptoms often exhibit sudden onset and tend to fluctuate over time, and in many cases, they are triggered by an infection in peripheral organs, suggesting that inflammation plays an important role in the pathogenesis of these non-cognitive symptoms. However, there is no mechanistic explanation for the relationship between inflammation and neuropsychiatric symptoms. Observations from experimental mouse models indicate that alteration of brain blood vessels, especially blood-brain barrier dysfunction, may contribute to the relationship. The current review summarizes the results from recent studies on the relationship between inflammation and AD, while focusing on cerebrovascular alterations, which might provide an insight into the pathogenesis of cognitive / non-cognitive symptoms in AD patients and suggest a basis for the development of new therapeutic treatments for these conditions.

  15. Quantification of neuropathological findings by image data for the diagnosis of dementia in forensic autopsy cases.

    Science.gov (United States)

    Takayama, Mio; Kashiwagi, Masayuki; Matsusue, Aya; Waters, Brian; Hara, Kenji; Ikematsu, Natsuki; Kubo, Shin-ichi

    2016-01-01

    The aim of the present study was to quantify neuropathological findings using image analysis software for the diagnosis of dementia in deceased who underwent forensic autopsy. Of the autopsies performed within 48 hours of death and excluding those of patients with head injury, thermal injury, heat stroke, or intracranial lesions, 8 were of autopsy cases clinically diagnosed with dementia and thus included in the dementia group (D). The non-dementia group (non-D) consisted of 6 deceased without dementia. To compare the D and non-D groups, 6 regions and 7 types of pathological findings were observed semi-quantitatively using 4 conventional stainings. Quantitative analysis of collected image data was performed using image analysis software. Semiquantitative analysis of senile plaques and neurofibrillary tangles was performed with Bielschowsky-Hirano's silver staining image data. An easy, simple, and effective quantification method of the pathological findings was achieved. However, no significant differences were observed between the two groups, and diagnosis of dementia by the quantification of pathological findings was not successful. Diagnosis of dementia using image data may be possible in future studies with an increased number of autopsies, and by utilizing staining techniques with higher specificity and sensitivity, such as immunohistochemical staining.

  16. Caspase-6 Activation in Familial Alzheimer Disease Brains Carrying Amyloid Precursor Protein, Presenilin I or Presenilin II Mutations

    Science.gov (United States)

    Albrecht, Steffen; Bogdanovic, Nenad; Ghetti, Bernardino; Winblad, Bengt; LeBlanc, Andréa C.

    2010-01-01

    We previously demonstrated the activation of Caspase-6 in the hippocampus and cortex in cases of mild, moderate, severe and very severe Alzheimer disease (AD). To determine whether Caspase-6 is also activated in familial AD, we performed an immunohistochemical analysis of active Caspase-6 and Tau cleaved by Caspase-6 in temporal cortex and hippocampal tissue sections from cases of familial AD. The cases included 5 carrying the amyloid precursor protein K670N, M671L Swedish mutation, 1 carrying the amyloid precursor protein E693G Arctic mutation, 2 each carrying the Presenilin I M146V, F105L, A431E, V261F, Y115C mutations, and 1 with the Presenilin II N141I mutation. Active Caspase-6 immunoreactivity was found in all cases. Caspase-6 immunoreactivity was observed in neuritic plaques or cotton wool plaques in some cases, neuropil threads and neurofibrillary tangles. These results indicate that Caspase-6 is activated in familial forms of AD, as previously observed in sporadic forms. Since sporadic and familial AD cases have similar pathological features, these results support a fundamental role of Caspase-6 in the pathophysiology of both familial and sporadic AD. PMID:19915487

  17. Age-Related Changes in the Central Nervous System in Selected Domestic Mammals and Primates

    Directory of Open Access Journals (Sweden)

    Maciej Firląg

    2013-04-01

    Full Text Available Aging is a process which operates at many levels of physiological, genetic and molecular organizationand leads inevitably to death [18]. Brain macroscopic changes by MRI investigation during aging were observed in humans and dogs but chimpanzees did not display significant changes. This suggestion led to the statement that brain aging is different in various species. Although human brain changes, e.g. β-amyloid storage, neurofibrillary tangle formation, lipofuscin, are relatively well known, we are still looking for a suitable animal model to study the mechanisms of aging and neurodegenerative diseases. Therefore, this paper presents a comparative analysis of the changes described in the brains of senile dog, horse and gorilla. In addition we present the latest, non-invasive methods that can be applied in the diagnosisof old age in mammals. Our considerations have shown that the best animal model for further studies and observations on aging is the dog. 

  18. Synaptic plasticity modulation by circulating peptides and metaplasticity: Involvement in Alzheimer's disease.

    Science.gov (United States)

    Peineau, Stéphane; Rabiant, Kevin; Pierrefiche, Olivier; Potier, Brigitte

    2018-02-06

    Synaptic plasticity is a cellular process involved in learning and memory whose alteration in its two main forms (Long Term Depression (LTD) and Long Term Potentiation (LTP)), is observed in most brain pathologies, including neurodegenerative disorders such as Alzheimer's disease (AD). In humans, AD is associated at the cellular level with neuropathological lesions composed of extracellular deposits of β-amyloid (Aβ) protein aggregates and intracellular neurofibrillary tangles, cellular loss, neuroinflammation and a general brain homeostasis dysregulation. Thus, a dramatic synaptic environment perturbation is observed in AD patients, involving changes in brain neuropeptides, cytokines, growth factors or chemokines concentration and diffusion. Studies performed in animal models demonstrate that these circulating peptides strongly affect synaptic functions and in particular synaptic plasticity. Besides this neuromodulatory action of circulating peptides, other synaptic plasticity regulation mechanisms such as metaplasticity are altered in AD animal models. Here, we will review new insights into the study of synaptic plasticity regulatory/modulatory mechanisms which could influence the process of synaptic plasticity in the context of AD with a particular attention to the role of metaplasticity and peptide dependent neuromodulation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Observing with CHEOPS

    Science.gov (United States)

    Isaak, Kate

    2017-04-01

    CHEOPS (CHaracterising ExOPlanet Satellite) is the first exoplanet mission dedicated to the search for transits of exoplanets by means of ultrahigh precision photometry of bright stars already known to host planets, with launch readiness foreseen by the end of 2018. It is also the first S-class mission in ESA's Cosmic Vision 2015-2025. The mission is a partnership between Switzerland and ESA's science programme, with important contributions from 10 other member states. It will provide the unique capability of determining accurate radii for a subset of those planets in the super- Earth to Neptune mass range, for which the mass has already been estimated from ground- based spectroscopic surveys. It will also provide precision radii for new planets discovered by the next generation of ground-based transits surveys (Neptune-size and smaller). The high photometric precision of CHEOPS will be achieved using a photometer covering the 0.35 - 1.1um waveband, designed around a single frame-transfer CCD which is mounted in the focal plane of a 30 cm equivalent aperture diameter, f/5 on-axis Ritchey-Chretien telescope. 20% of the observing time in the 3.5 year nominal mission will be available to Guest Observers from the Community. Proposals will be requested through open calls from ESA that are foreseen to be every year, with the first 6 months before launch. In this poster I will provide an overview of how to obtain data from CHEOPS, with a particular focus on the CHEOPS Guest Observers Programme.

  20. Observing farming systems

    DEFF Research Database (Denmark)

    Noe, Egon; Alrøe, Hugo Fjelsted

    2012-01-01

    of analysis from individual farmers to communication and social relations. This is where Luhmann’s social systems theory can offer new insights. Firstly, it can help observe and understand the operational closure and system logic of a farming system and how this closure is produced and reproduced. Secondly......In Denmark, agriculture is becoming increasingly specialised, and more and more actors are becoming involved in farm decision making. These trends are more or less pronounced in other European countries as well. We therefore find that to understand modern farming systems, we have to shift the focus...

  1. Automation of interferometric observations

    Science.gov (United States)

    Bester, M.; Degiacomi, C. G.; Danchi, W. C.; Greenhill, L. J.; Townes, C. H.

    The Infrared Spatial Interferometer (ISI) is a heterodyne interferometer that operates in the 9-12 micron atmospheric window. It is located at Mount Wilson and consists of two 1.65-m Pfund-type telescopes. Presently baselines range up to 35 m. Lately the performance of the ISI was improved significantly, providing higher quality interferometric data. The improvements include all-reflective front-end optics, larger bandwidth and higher quantum efficiency heterodyne detectors, a fringe calibration system, a CCD autoguiding system, and a more advanced computer control system. The newly developed control software allows the observations to be largely automated.

  2. Mars Observer Camera

    OpenAIRE

    Malin, M. C.; Danielson, G. E.; Ingersoll, A. P.; Masursky, H.; J. Veverka(Massachusetts Institute of Technology, Cambridge, U.S.A.); Ravine, M. A.; Soulanille, T.A.

    1992-01-01

    The Mars Observer camera (MOC) is a three-component system (one narrow-angle and two wide-angle cameras) designed to take high spatial resolution pictures of the surface of Mars and to obtain lower spatial resolution, synoptic coverage of the planet's surface and atmosphere. The cameras are based on the “push broom” technique; that is, they do not take “frames” but rather build pictures, one line at a time, as the spacecraft moves around the planet in its orbit. MOC is primarily a telescope f...

  3. Autocorrelation of wind observations

    Science.gov (United States)

    Wylie, D. P.; Hinton, B. B.; Howland, M. R.; Lord, R. J.

    1985-01-01

    Autocorrelation and variance statistics are calculated for cloud motion measurements from four different sources, rawinsonde wind reports, synoptic land station reports, ship reports, aircraft reports, automatic aircraft reports gathered during the Global Weather Experiment, and Seasat scatterometer winds from September 1978. The last of these data sources exhibited the highest autocorrelations and lowest standard deviations over short distances. Structure function plots of autocovariances against separation distance between observations indicated that Seasat was most sensitive to wind field structure by having low autovariance at short distances.

  4. Mars Observer spacecraft

    Science.gov (United States)

    Potts, Dennis L.

    1989-01-01

    The technical aspects of the spacecraft for the Mars Observer mission are discussed. The spacecraft development focuses on using existing flight subsystem designs and production techniques to offer a low-cost, reliable, production-type spacecraft. The scientific objectives of the mission and the scientific payloads of the spacecraft are considered. The spacecraft system and its performance are discussed. The subsystems are described in detail, including attitude and articulation control, electrical power supply, propulsion, structure, thermal control, command and data handling, telecommunications, mechanics, and flight software.

  5. Geomagnetic Observations and Models

    CERN Document Server

    Mandea, Mioara

    2011-01-01

    This volume provides comprehensive and authoritative coverage of all the main areas linked to geomagnetic field observation, from instrumentation to methodology, on ground or near-Earth. Efforts are also focused on a 21st century e-Science approach to open access to all geomagnetic data, but also to the data preservation, data discovery, data rescue, and capacity building. Finally, modeling magnetic fields with different internal origins, with their variation in space and time, is an attempt to draw together into one place the traditional work in producing models as IGRF or describing the magn

  6. Observing inflationary reheating.

    Science.gov (United States)

    Martin, Jérôme; Ringeval, Christophe; Vennin, Vincent

    2015-02-27

    Reheating is the epoch which connects inflation to the subsequent hot big-bang phase. Conceptually very important, this era is, however, observationally poorly known. We show that the current Planck satellite measurements of the cosmic microwave background (CMB) anisotropies constrain the kinematic properties of the reheating era for most of the inflationary models. This result is obtained by deriving the marginalized posterior distributions of the reheating parameter for about 200 models of slow-roll inflation. Weighted by the statistical evidence of each model to explain the data, we show that the Planck 2013 measurements induce an average reduction of the posterior-to-prior volume by 40%. Making some additional assumptions on reheating, such as specifying a mean equation of state parameter, or focusing the analysis on peculiar scenarios, can enhance or reduce this constraint. Our study also indicates that the Bayesian evidence of a model can substantially be affected by the reheating properties. The precision of the current CMB data is therefore such that estimating the observational performance of a model now requires incorporating information about its reheating history.

  7. Observations of cold antihydrogen

    CERN Document Server

    Tan, J N; Gabrielse, G; Oxley, P; Speck, A; Storry, C H; Wessels, M; Grzonka, D; Oelert, W; Schepers, G; Sefzick, T; Walz, J; Pittner, H; Hänsch, T W; Hessels, E A

    2004-01-01

    ATRAP's e/sup +/ cooling of p in a nested Penning trap has led to reports of cold H produced during such cooling by the ATHENA and ATRAP collaborations. To observe H, ATHENA uses coincident annihilation detection and ATRAP uses field ionization followed by p storage. Advantages of ATRAP's field ionization method include the complete absence of any background events, and the first way to measure which H states are produced. ATRAP enhances the H production rate by driving many cycles of e/sup +/ cooling in the nested trap, with more H counted in an hour than the sum of all the other antimatter atoms ever reported. The number of H counted per incident high energy p is also higher than ever observed. The first measured distribution of H states is made using a pre-ionizing electric field between separated production and detection regions. The high rate and the high Rydberg states suggest that the H is formed via three-body recombination, as expected. (22 refs).

  8. Coronal Mass Ejections: Observations

    Directory of Open Access Journals (Sweden)

    David F. Webb

    2012-06-01

    Full Text Available Solar eruptive phenomena embrace a variety of eruptions, including flares, solar energetic particles, and radio bursts. Since the vast majority of these are associated with the eruption, development, and evolution of coronal mass ejections (CMEs, we focus on CME observations in this review. CMEs are a key aspect of coronal and interplanetary dynamics. They inject large quantities of mass and magnetic flux into the heliosphere, causing major transient disturbances. CMEs can drive interplanetary shocks, a key source of solar energetic particles and are known to be the major contributor to severe space weather at the Earth. Studies over the past decade using the data sets from (among others the SOHO, TRACE, Wind, ACE, STEREO, and SDO spacecraft, along with ground-based instruments, have improved our knowledge of the origins and development of CMEs at the Sun and how they contribute to space weather at Earth. SOHO, launched in 1995, has provided us with almost continuous coverage of the solar corona over more than a complete solar cycle, and the heliospheric imagers SMEI (2003 – 2011 and the HIs (operating since early 2007 have provided us with the capability to image and track CMEs continually across the inner heliosphere. We review some key coronal properties of CMEs, their source regions and their propagation through the solar wind. The LASCO coronagraphs routinely observe CMEs launched along the Sun-Earth line as halo-like brightenings. STEREO also permits observing Earth-directed CMEs from three different viewpoints of increasing azimuthal separation, thereby enabling the estimation of their three-dimensional properties. These are important not only for space weather prediction purposes, but also for understanding the development and internal structure of CMEs since we view their source regions on the solar disk and can measure their in-situ characteristics along their axes. Included in our discussion of the recent developments in CME

  9. Spatial Standard Observer

    Science.gov (United States)

    Watson, Andrew B. (Inventor)

    2012-01-01

    The present invention relates to devices and methods for the measurement and/or for the specification of the perceptual intensity of a visual image, or the perceptual distance between a pair of images. Grayscale test and reference images are processed to produce test and reference luminance images. A luminance filter function is convolved with the reference luminance image to produce a local mean luminance reference image. Test and reference contrast images are produced from the local mean luminance reference image and the test and reference luminance images respectively, followed by application of a contrast sensitivity filter. The resulting images are combined according to mathematical prescriptions to produce a Just Noticeable Difference, JND value, indicative of a Spatial Standard Observer, SSO. Some embodiments include masking functions, window functions, special treatment for images lying on or near borders and pre-processing of test images.

  10. Observation of Bs mixing

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    A peculiar and most important property of Bs mesons is that they transform spontaneously into their own antiparticles, and back again. These transitions, known as flavor oscillations or mixing, are extremely rapid, rendering their measurement a very challenging experimental task. The determination of the Bs oscillation frequency is, at the same time, of great interest for constraining elements of the Standard Model CKM matrix and its unitarity. Large samples of Bs mesons collected by the CDF and D0 experiments operating at the Fermilab Tevatron have recently yielded unprecedented results, which are here reported. Emphasis is given to details of the analysis developed at CDF, presenting the observation of Bs mixing, the precise measurement of the oscillation frequency, and a discussion of its impact on the description of the flavor sector.

  11. Semantic Observation Integration

    Directory of Open Access Journals (Sweden)

    Werner Kuhn

    2012-09-01

    Full Text Available Although the integration of sensor-based information into analysis and decision making has been a research topic for many years, semantic interoperability has not yet been reached. The advent of user-generated content for the geospatial domain, Volunteered Geographic Information (VGI, makes it even more difficult to establish semantic integration. This paper proposes a novel approach to integrating conventional sensor information and VGI, which is exploited in the context of detecting forest fires. In contrast to common logic-based semantic descriptions, we present a formal system using algebraic specifications to unambiguously describe the processing steps from natural phenomena to value-added information. A generic ontology of observations is extended and profiled for forest fire detection in order to illustrate how the sensing process, and transformations between heterogeneous sensing systems, can be represented as mathematical functions and grouped into abstract data types. We discuss the required ontological commitments and a possible generalization.

  12. Phoebe - Voyager 2 observations

    Science.gov (United States)

    Thomas, P.; Veverka, J.; Morrison, D.; Davies, M.; Johnson, T. V.

    1983-01-01

    Voyager 2 images of Phoebe obtained over a period of 24 hours provide information on the size, rotation rate, surface markings, and photometric properties of this mysterious object. Phoebe is approximately equidimensional: its longest diameter, about 230 km, is only 10 percent greater than the shortest-diameter (about 210 km). A prograde-rotation period of 9.4 + or - 0.2 hours was determined from both the disk-integrated light curve and by tracking individual markings. Because of the limited resolution of the images (11 pixels across the disk) crater counts cannot be made. The geometric albedo of Phoebe is longitudinally variable from 0.046 to 0.060 (clear filter, lambda = 0.47 micron). The most prominent surface markings are brighter patches at high northern and southern latitudes that have reflectances as much as 50 percent greater than the dark, bland areas. These patches are scattered and do not appear to constitute polar caps. The Voyager color data agree with earlier ground-based spectra that show that Phoebe has a flatter spectrum than does the dark side of Iapetus; this observation is not consistent with simple contamination of Iapetus by debris from Phoebe.

  13. [Pierre Janet observes history].

    Science.gov (United States)

    Fischer-Homberger, Esther

    2014-01-01

    Janet, philosopher and physician, Freud's junior by three years, not only described traumatic dissociation and pathogenic subconscious ideas; he outlined a comprehensive system of psychology. Still, he considered his concepts to be mere linguistic tools, designed to grasp mental phenomena as precisely as possible. His prime interest was in observations - his own and those of others, whether his contemporaries at home and abroad or predecessors of all kinds. Janet never regarded himself as a historian, but his works as well as his way of thinking are most interesting from a historiographical point of view. His three-volume Médications psychologiques of 1919 contains a wealth of material about the history of psychotherapy. Furthermore, he dealt with his sources in a critical and historically reflexive manner. The later Janet considered any explanation and theory to be "inventions", more or less useful and basically open to change. By working with the notion of "narration", he described scientific statements as narratives, different from lies, fairy-tales or novels only in their claim to be verifiable. Every narration, however, is placed in a social context: narrators always wish to evoke a particular image of the real in their audience. Thus Janet established the link between scientific edifices and individual motivation, an unsettling link in terms of the history of science and certainly alien, if not positively abhorrent to Freud.

  14. CMS tracker observes muons

    CERN Multimedia

    2006-01-01

    A computer image of a cosmic ray traversing the many layers of the TEC+ silicon sensors. The first cosmic muon tracks have been observed in one of the CMS tracker endcaps. On 14 March, a sector on one of the two large tracker endcaps underwent a cosmic muon run. Since then, thousands of tracks have been recorded. These data will be used not only to study the tracking, but also to exercise various track alignment algorithms The endcap tested, called the TEC+, is under construction at RWTH Aachen in Germany. The endcaps have a modular design, with silicon strip modules mounted onto wedge-shaped carbon fibre support plates, so-called petals. Up to 28 modules are arranged in radial rings on both sides of these plates. One eighth of an endcap is populated with 18 petals and called a sector. The next major step is a test of the first sector at CMS operating conditions, with the silicon modules at a temperature below -10°C. Afterwards, the remaining seven sectors have to be integrated. In autumn 2006, TEC+ wil...

  15. Rheoencephalographic observations in migraine

    Directory of Open Access Journals (Sweden)

    B. G. L. Von Almay

    1971-12-01

    Full Text Available The pathophysiological concept of migraine presently held attributes the major changes to vascular factors. Therefore, it seemed appropriate to use rheoencephalography to test cerebral hemodynamics in cases of migraine. This very harmless and well suited method revealed: (1 on routine tracings during the painless intervall only 1/7 of the cases showed significant changes, while more than 2/3 could be classified with the help of an orthostatic stress test under REG-observation; (2 REG is more often correct for diagnosis than EEG and this does not surprise since REG monitors cerebral hemodynamics directly while EEG records activity for parenchyma and thus only secondarily depends on circulation; (3 similar conditions were previously seen in Meniere's disease where EEG also is less efficient than REG. According to the results of this study, it should be interesting to include REG in the work-up of migrainous patients. In these and under similar conditions, REG will be of diagnostic value.

  16. The constellation observing Atlas

    CERN Document Server

    Privett, Grant

    2013-01-01

    Designed for anyone who wishes to learn the constellations or observe the best and brightest deep sky objects and double stars, this book contains an alphabetical list of constellations complete with star maps, historical background, and highlights of deep sky objects. Each entry contains position and physical information on enough stars to support astronomers in star-hopping, swinging the telescope from star to star to star to arrive at a faint target. It provides a carefully selected list of accessible and rewarding deep sky objects. Full-color maps show the constellations, with star types (spectral and physical) indicated by the colors used on the map. Extended objects such as galaxies and nebulae are shown with the approximate apparent size in the sky. With unmatched thoroughness and accessibility, this is a constellation atlas that makes the ideal companion to a night's telescope viewing, for novices and expert amateur astronomers alike. Easy to navigate and refer to, it is the key that unlocks the do...

  17. Precisely predictable Dirac observables

    CERN Document Server

    Cordes, Heinz Otto

    2006-01-01

    This work presents a "Clean Quantum Theory of the Electron", based on Dirac’s equation. "Clean" in the sense of a complete mathematical explanation of the well known paradoxes of Dirac’s theory, and a connection to classical theory, including the motion of a magnetic moment (spin) in the given field, all for a charged particle (of spin ½) moving in a given electromagnetic field. This theory is relativistically covariant, and it may be regarded as a mathematically consistent quantum-mechanical generalization of the classical motion of such a particle, à la Newton and Einstein. Normally, our fields are time-independent, but also discussed is the time-dependent case, where slightly different features prevail. A "Schroedinger particle", such as a light quantum, experiences a very different (time-dependent) "Precise Predictablity of Observables". An attempt is made to compare both cases. There is not the Heisenberg uncertainty of location and momentum; rather, location alone possesses a built-in uncertainty ...

  18. Decreased presence of perforated synapses in a triple-transgenic mouse model of Alzheimer's disease.

    Science.gov (United States)

    Bertoni-Freddari, Carlo; Sensi, Stefano L; Giorgetti, Belinda; Balietti, Marta; Di Stefano, Giuseppina; Canzoniero, Lorella M T; Casoli, Tiziana; Fattoretti, Patrizia

    2008-04-01

    Transgenic mouse models of Alzheimer's disease (AD) are useful tools to further our understanding of AD genotype-phenotype interaction. The triple transgenic mice harboring mutant forms of APP/PS1/Tau (3xTg-AD) exhibit beta-amyloid (Abeta) plaques (by 6 months of age) as well as neurofibrillary tangles (by 10-12 months of age). In this study, we characterized morphological alterations of hippocampal synapses obtained from 13-month-old 3xTg-AD and age-matched control (PS1-KI) mice. Numeric density of synapses (Nv, number of junctions/microm(3) of tissue), average synaptic contact area (S), and synaptic surface density (Sv, total synaptic contact area/microm(3) of tissue) were investigated by morphometric methods in the AD vulnerable CA1 pyramidal cell layer. Comparisons between 3xTg-AD and control mice showed no statistically significant differences in any of the three parameters; however, a significant decrease (by 28.5%) in the fraction of perforated junctional areas (PS) was observed in the 3xTg-AD mice. As PS is a reliably indirect index of synaptic plasticity, a decreased PS number might represent a subtle and early sign of synaptic dysfunction occurring in the 3xTg-AD mice, and lend support to the hypothesis that altered synaptic function is a critical feature of AD.

  19. Neuropathological correlates of late-life depression in older people.

    Science.gov (United States)

    Tsopelas, Christos; Stewart, Robert; Savva, George M; Brayne, Carol; Ince, Paul; Thomas, Alan; Matthews, Fiona E

    2011-02-01

    Depression is common in old age and is associated with risk of dementia, but its neuropathological correlates in the community are unknown. To investigate for the first time in a population-representative sample of people with no dementia the association between depression observed during life and neurofibrillary tangles, diffuse and neuritic plaques, Lewy bodies, brain atrophy and cerebrovascular disease found in the brain at post-mortem. Out of 456 donations to a population-based study, 153 brains were selected where donors had no dementia measured in life. Alzheimer and vascular pathology measures, Lewy bodies and neuronal loss were compared between those with (n = 36) and without (n = 117) depression ascertained using a fully structured diagnostic interview during life. Brain areas examined included frontal, parietal, temporal and occipital cortical areas as well as the entorhinal cortex, hippocampus and brain-stem monoaminergic nuclei. Depression was significantly associated with the presence of subcortical Lewy bodies. No association was found between depression and cerebrovascular or Alzheimer pathology in cortical or subcortical areas, although depression was associated with neuronal loss in the hippocampus as well as in some of the subcortical structures investigated (nucleus basalis, substantia nigra, raphe nucleus). Late-life depression was associated with subcortical and hippocampal neuronal loss but not with cerebrovascular or Alzheimer pathology.

  20. The 2,6-disubstituted naphthalene derivative FDDNP labeling reliably predicts Congo red birefringence of protein deposits in brain sections of selected human neurodegenerative diseases.

    Science.gov (United States)

    Smid, Lojze M; Vovko, Tomaz D; Popovic, Mara; Petric, Andrej; Kepe, Vladimir; Barrio, Jorge R; Vidmar, Gaj; Bresjanac, Mara

    2006-04-01

    Deposition of conformationally altered proteins prominently characterizes pathogenesis and pathomorphology of a number of neurodegenerative disorders. 2-(1-{6-[(2-[F-18]fluoroethyl) (methyl)amino]-2-naphthyl} ethylidene) malononitrile ([F-18]FDDNP), a hydrophobic, viscosity-sensitive, solvent-sensitive, fluorescent imaging probe has been used with positron emission tomography to visualize brain pathology in the living brain of Alzheimer disease (AD) patients. Its non-radiofluorinated analog FDDNP was shown to label senile plaques and neurofibrillary tangles (NFTs) in brain tissue sections. This work aimed at evaluating FDDNP labeling of various protein deposits in fixed, paraffin-embedded brain tissue sections of selected neurodegenerative disorders: AD, cerebral amyloid angiopathy (CAA), transmissible spongiform encephalopathies, progressive supranuclear palsy (PSP), Pick disease (PiD), Parkinson disease, dementia with Lewy bodies, multiple system atrophy (MSA). Cerebral hypertensive vascular hyalinosis (HVH) was used as negative control. Significant agreement between amyloid histochemical properties and FDDNP labeling of the deposits was established. FDDNP labeling showed high positive predictive value for birefringence in senile plaques and NFTs in AD, prion plaques and amyloid deposits in CAA. No FDDNP labeled structures were observed in HVH, PSP, PiD or MSA tissue sections. Our findings may be of significant value for the detection of neuropathological aggregates with [F-18]FDDNP in some of these disorders in the living brain of human subjects.

  1. Influence of Water Quality on Cholesterol-Induced Tau Pathology: Preliminary Data

    Directory of Open Access Journals (Sweden)

    D. Larry Sparks

    2011-01-01

    Full Text Available The studies employed the cholesterol-fed rabbit model of Alzheimer's disease (AD to investigate the relationship between AD-like neurofibrillary tangle (NFT neuropathology and tau protein levels as the main component of NFT. We measured brain and plasma tau levels and semiquantified NFT-like neuropathology in cholesterol-fed rabbits administered drinking water of varying quality (distilled, tap, and distilled+copper compared to animals receiving normal chow and local tap water. Total tau levels in plasma were increased in all cholesterol-fed rabbits compared to animals on normal chow, regardless of quality of water. In contrast, increased tau in brain and increased AT8 immunoreactive NFT-like lesions were greatest in cholesterol-fed rabbits administered distilled water. A substantial decrease in brain tau and incidence and density of AT8 immunoreactive NFT-like lesions occurred in cholesterol-fed rabbits administered copper water, and an even greater decrease was observed in cholesterol-fed animals on local tap water. These studies suggest the possibility that circulating tau could be the source of the tau accumulating in the brain.

  2. Alpha-synuclein lesions in normal aging, Parkinson disease, and Alzheimer disease: evidence from the Baltimore Longitudinal Study of Aging (BLSA).

    Science.gov (United States)

    Mikolaenko, Irina; Pletnikova, Olga; Kawas, Claudia H; O'Brien, Richard; Resnick, Susan M; Crain, Barbara; Troncoso, Juan C

    2005-02-01

    Alpha-synuclein (alpha-synuclein) lesions are characteristic of idiopathic Parkinson disease (PD) and other alpha-synucleinopathies. To study the frequency of alpha-synuclein lesions in normal aging and how frequently they coexist with lesions of Alzheimer disease (AD), we examined the autopsy brains from normal and demented subjects in the Baltimore Longitudinal Study of Aging (BLSA) (n = 117). We found that the overall frequency of alpha-synuclein lesions was 25%, with 100% in 7 cases of PD, 31.5% in 56 cases with AD lesions, and 8.3% among 36 older control brains. Among brains with AD lesions, the frequency of alpha-synuclein pathology was higher in those with higher scores for neuritic plaques, but not in those with higher scores for neurofibrillary tangles. Our observations indicate that alpha-synuclein lesions are uncommon in aged control subjects. Finally, the coexistence of Abeta amyloid and alpha-synuclein pathology in AD brains suggests that the pathogenic mechanism/s leading to the accumulation of Abeta and alpha-synuclein may be similar.

  3. Combined administration of D-galactose and aluminium induces Alzheimer-like lesions in brain.

    Science.gov (United States)

    Xiao, Fei; Li, Xiao-Guang; Zhang, Xiao-Yu; Hou, Jun-Dai; Lin, Lian-Feng; Gao, Qin; Luo, Huan-Min

    2011-06-01

    It has been reported that D-galactose (D-gal) can model subacute aging, and aluminum (Al) acts as a neurotoxin, but combined effects of them have not been reported. The present work aimed to reveal the effect of combined administration of D-gal and Al in mice and compare the effect of D-gal treatment with that of Al treatment. Al was intragastrically administered and D-gal was subcutaneously injected into Kunming mice for 10 consecutive weeks. Learning and memory, cholinergic systems, as well as protein levels of amyloid β (Aβ) and hyperphosphorylated tau were determined using Morri water maze test, biochemical assays and immunohistochemical staining, respectively. The mice with combined treatment had obvious learning and memory deficits, and showed decreases in brain acetylcholine (ACh) level and in activities of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE). Formation of senile plaque (SP)-like and neurofibrillary tangle (NFT)-like structures was also observed. The behavioral and pathological changes persisted for at least 6 weeks after withdrawal of D-gal and Al. Combined use of D-gal and Al is an effective way to establish the non-transgenic Alzheimer's disease (AD) animal model, and is useful for studies of AD pathogenesis and therapeutic evaluation.

  4. Aluminum in hippocampal neurons from humans with Alzheimer's disease.

    Science.gov (United States)

    Walton, J R

    2006-05-01

    Using a staining technique developed in 2004, we examined hippocampal tissue from autopsy-confirmed cases of Alzheimer's disease (AD) and controls. The stain disclosed aluminum in cells and subcellular structure. All pyramidal neurons in these aged specimens appeared to exhibit at least some degree of aluminum staining. Many displayed visible aluminum only in their nucleolus. At the other extreme were neurons that stained for aluminum throughout their nucleus and cytoplasm. The remainder exhibited intermediate degrees of staining. On the basis of their aluminum staining patterns, all pyramidal neurons could be classified into stages that indicated two distinct neuropathological processes, either (1) progressive increase of nuclear aluminum (often accompanied by granulovacuolar degeneration with granules that stain for aluminum) or (2) formation of neurofibrillary tangles (NFTs) in regions of aluminum-rich cytoplasm, especially in AD brain tissue. In the latter process, intraneuronal NFTs appeared to displace nuclei and then enucleate the affected neurons during the course of their transformation into extracellular NFTs. Given that the NFTs we observed in human neurons always developed in conjunction with cytoplasmic aluminum, we hypothesize that aluminum plays an important role in their formation and should therefore be reconsidered as a causative factor for AD.

  5. Doubly Phosphorylated Peptide Vaccines to Protect Transgenic P301S Mice against Alzheimer’s Disease Like Tau Aggregation

    Directory of Open Access Journals (Sweden)

    Monique Richter

    2014-07-01

    Full Text Available Intracellular neurofibrillary tangles and extracellular senile plaques are potential targets for active and passive immunotherapies. In this study we used the transgenic mouse model P301S for active immunizations with peptide vaccines composed of a double phosphorylated tau neoepitope (pSer202/pThr205, pThr212/pSer214, pThr231/pSer235 and an immunomodulatory T cell epitope from the tetanus toxin or tuberculosis antigen Ag85B. Importantly, the designed vaccine combining Alzheimer’s disease (AD specific B cell epitopes with foreign (bacterial T cell epitopes induced fast immune responses with high IgG1 titers after prophylactic immunization that subsequently decreased over the observation period. The effectiveness of the immunization was surveyed by evaluating the animal behavior, as well as the pathology in the brain by biochemical and histochemical techniques. Immunized mice clearly lived longer with reduced paralysis than placebo-treated mice. Additionally, they performed significantly better in rotarod and beam walk tests at the age of 20 weeks, indicating that the disease development was slowed down. Forty-eight weeks old vaccinated mice passed the beam walk test significantly better than control animals, which together with the increased survival rates undoubtedly prove the treatment effect. In conclusion, the data provide strong evidence that active immune therapies can reduce toxic effects of deposits formed in AD.

  6. Intracerebroventricular administration of okadaic acid induces hippocampal glucose uptake dysfunction and tau phosphorylation.

    Science.gov (United States)

    Broetto, Núbia; Hansen, Fernanda; Brolese, Giovana; Batassini, Cristiane; Lirio, Franciane; Galland, Fabiana; Dos Santos, João Paulo Almeida; Dutra, Márcio Ferreira; Gonçalves, Carlos-Alberto

    2016-06-01

    Intraneuronal aggregates of neurofibrillary tangles (NFTs), together with beta-amyloid plaques and astrogliosis, are histological markers of Alzheimer's disease (AD). The underlying mechanism of sporadic AD remains poorly understood, but abnormal hyperphosphorylation of tau protein is suggested to have a role in NFTs genesis, which leads to neuronal dysfunction and death. Okadaic acid (OKA), a strong inhibitor of protein phosphatase 2A, has been used to induce dementia similar to AD in rats. We herein investigated the effect of intracerebroventricular (ICV) infusion of OKA (100 and 200ng) on hippocampal tau phosphorylation at Ser396, which is considered an important fibrillogenic tau protein site, and on glucose uptake, which is reduced early in AD. ICV infusion of OKA (at 200ng) induced a spatial cognitive deficit, hippocampal astrogliosis (based on GFAP increment) and increase in tau phosphorylation at site 396 in this model. Moreover, we observed a decreased glucose uptake in the hippocampal slices of OKA-treated rats. In vitro exposure of hippocampal slices to OKA altered tau phosphorylation at site 396, without any associated change in glucose uptake activity. Taken together, these findings further our understanding of OKA neurotoxicity, in vivo and vitro, particularly with regard to the role of tau phosphorylation, and reinforce the importance of the OKA dementia model for studying the neurochemical alterations that may occur in AD, such as NFTs and glucose hypometabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Roles of tau pathology in the locus coeruleus (LC) in age-associated pathophysiology and Alzheimer's disease pathogenesis: Potential strategies to protect the LC against aging.

    Science.gov (United States)

    Satoh, Akiko; Iijima, Koichi M

    2017-12-21

    The locus coeruleus (LC) is the noradrenaline (norepinephrine, NE)-containing nucleus in the brainstem and innervates into widespread brain regions. This LC-NE system plays a critical role in a variety of brain functions, including attention, arousal, emotion, cognition, and the sleep-wake cycle. The LC is one of the brain regions vulnerable to the occurrence of neurofibrillary tangles (NFTs), which is associated with "primary age-related tauopathy (PART)" that describes the pathology commonly observed in the brains of aged individuals. In Alzheimer's disease (AD), the LC is one of the first places to develop NFTs, which may act as a seed for subsequent spreading of the pathology throughout the brain upon amyloid-β (Aβ) accumulation. As AD progresses, significant neuron loss occurs in the LC. Moreover, LC neurodegeneration is not only a consequence of AD, but also drives clinical and pathological manifestations of AD, such as microglial dysregulation, sleep disturbance, cognitive decline, and neurovascular dysfunction. Therefore, prevention of NFT pathology and neuron loss in the LC-NE system is critical for suppressing the progression of AD. We propose that targeting aging itself may be a proactive intervention against age-associated changes in the LC. Such an approach could open the way for novel interventions against age-associated neurodegenerative disorders, in particular, AD. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Brain pathologies in extreme old age.

    Science.gov (United States)

    Neltner, Janna H; Abner, Erin L; Jicha, Gregory A; Schmitt, Frederick A; Patel, Ela; Poon, Leonard W; Marla, Gearing; Green, Robert C; Davey, Adam; Johnson, Mary Ann; Jazwinski, S Michal; Kim, Sangkyu; Davis, Daron; Woodard, John L; Kryscio, Richard J; Van Eldik, Linda J; Nelson, Peter T

    2016-01-01

    With an emphasis on evolving concepts in the field, we evaluated neuropathologic data from very old research volunteers whose brain autopsies were performed at the University of Kentucky Alzheimer's Disease Center, incorporating data from the Georgia Centenarian Study (n = 49 cases included), Nun Study (n = 17), and University of Kentucky Alzheimer's Disease Center (n = 11) cohorts. Average age of death was 102.0 (range: 98-107) years overall. Alzheimer's disease pathology was not universal (62% with "moderate" or "frequent" neuritic amyloid plaque densities), whereas frontotemporal lobar degeneration was absent. By contrast, some hippocampal neurofibrillary tangles (including primary age-related tauopathy) were observed in every case. Lewy body pathology was seen in 16.9% of subjects and hippocampal sclerosis of aging in 20.8%. We describe anatomic distributions of pigment-laden macrophages, expanded Virchow-Robin spaces, and arteriolosclerosis among Georgia Centenarians. Moderate or severe arteriolosclerosis pathology, throughout the brain, was associated with both hippocampal sclerosis of aging pathology and an ABCC9 gene variant. These results provide fresh insights into the complex cerebral multimorbidity, and a novel genetic risk factor, at the far end of the human aging spectrum. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Discovery of the first dual GSK3β inhibitor/Nrf2 inducer. A new multitarget therapeutic strategy for Alzheimer’s disease

    Science.gov (United States)

    Gameiro, Isabel; Michalska, Patrycja; Tenti, Giammarco; Cores, Ángel; Buendia, Izaskun; Rojo, Ana I.; Georgakopoulos, Nikolaos D.; Hernández-Guijo, Jesús M.; Teresa Ramos, María; Wells, Geoffrey; López, Manuela G.; Cuadrado, Antonio; Menéndez, J. Carlos; León, Rafael

    2017-03-01

    The formation of neurofibrillary tangles (NFTs), oxidative stress and neuroinflammation have emerged as key targets for the treatment of Alzheimer’s disease (AD), the most prevalent neurodegenerative disorder. These pathological hallmarks are closely related to the over-activity of the enzyme GSK3β and the downregulation of the defense pathway Nrf2-EpRE observed in AD patients. Herein, we report the synthesis and pharmacological evaluation of a new family of multitarget 2,4-dihydropyrano[2,3-c]pyrazoles as dual GSK3β inhibitors and Nrf2 inducers. These compounds are able to inhibit GSK3β and induce the Nrf2 phase II antioxidant and anti-inflammatory pathway at micromolar concentrations, showing interesting structure-activity relationships. The association of both activities has resulted in a remarkable anti-inflammatory ability with an interesting neuroprotective profile on in vitro models of neuronal death induced by oxidative stress and energy depletion and AD. Furthermore, none of the compounds exhibited in vitro neurotoxicity or hepatotoxicity and hence they had improved safety profiles compared to the known electrophilic Nrf2 inducers. In conclusion, the combination of both activities in this family of multitarget compounds confers them a notable interest for the development of lead compounds for the treatment of AD.

  10. Original article. Protective effect of resveratrol against neuronal damage through oxidative stress in cerebral hemisphere of aluminum and fluoride treated rats

    Directory of Open Access Journals (Sweden)

    Nalagoni Chandra Shakar Reddy

    2016-06-01

    Full Text Available Aluminum has no defined biological function and it is potentially involved in the pathogenesis of neurodegenerative disorders. Furthermore, the presence of fluoride causes more aluminum to accumulate in the brain, resulting in increased neuronal damage. In recent years, resveratrol through its ameliorative effects was found to be a neuroprotectant. This study reports the protective effects of resveratrol on combined aluminum and fluoride induced neuronal damage through oxidative stress in rats. Protective effects of resveratrol (30 mg/kg b.w on markers of oxidative stress were determined in rats exposed to aluminum chloride (100 mg/kg b.w along with sodium fluoride (10 mg/kg b.w for 8 weeks. The results showed a statistically significant (p<0.05 increase in lipid peroxidation (LPx as well as a significant (p<0.05 decrease in superoxide dismutase and catalase activity. Enlarged cells, neurofibrillary tangles, and vacuolar spaces showing oxidative stress in the cerebral cortex were also observed in hematoxylin and eosin stained sections in aluminum and fluoride treated rats. Administration of resveratrol along with aluminum + fluoride showed significant reversal of oxidative stress and neuronal damage in rats. Thus resveratrol potentially acts as a neuroprotectant against aluminum chloride + sodium fluoride induced neuronal damage through its anti-oxidant efficacy.

  11. Promoting brain health through exercise and diet in older adults: a physiological perspective.

    Science.gov (United States)

    Jackson, Philippa A; Pialoux, Vincent; Corbett, Dale; Drogos, Lauren; Erickson, Kirk I; Eskes, Gail A; Poulin, Marc J

    2016-08-15

    The rise in incidence of age-related cognitive impairment is a global health concern. Ageing is associated with a number of changes in the brain that, collectively, contribute to the declines in cognitive function observed in older adults. Structurally, the ageing brain atrophies as white and grey matter volumes decrease. Oxidative stress and inflammation promote endothelial dysfunction thereby hampering cerebral perfusion and thus delivery of energy substrates and nutrients. Further, the development of amyloid plaques and neurofibrillary tangles contributes to neuronal loss. Of interest, there are substantial inter-individual differences in the degree to which these physical and functional changes impact upon cognitive function as we grow older. This review describes how engaging in physical activity and cognitive activities and adhering to a Mediterranean style diet promote 'brain health'. From a physiological perspective, we discuss the effects of these modifiable lifestyle behaviours on the brain, and how some recent human trials are beginning to show some promise as to the effectiveness of lifestyle behaviours in combating cognitive impairment. Moreover, we propose that these lifestyle behaviours, through numerous mechanisms, serve to increase brain, cerebrovascular and cognitive reserve, thereby preserving and enhancing cognitive function for longer. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  12. Role of miR-211 in Neuronal Differentiation and Viability: Implications to Pathogenesis of Alzheimer’s Disease

    Science.gov (United States)

    Fan, Chunying; Wu, Qi; Ye, Xiaoyang; Luo, Hongxue; Yan, Dongdong; Xiong, Yi; Zhu, Haili; Diao, Yarui; Zhang, Wei; Wan, Jun

    2016-01-01

    Alzheimer’s disease (AD) is an age-related irreversible neurodegenerative disorder characterized by extracellular β Amyloid(Aβ) deposition, intracellular neurofibrillary tangles and neuronal loss. The dysfunction of neurogenesis and increased degeneration of neurons contribute to the pathogenesis of AD. We now report that miR-211-5p, a small non-coding RNA, can impair neurite differentiation by directly targeting NUAK1, decrease neuronal viability and accelerate the progression of Aβ-induced pathologies. In this study, we observed that during embryonic development, the expression levels of miR-211-5p were down-regulated in the normal cerebral cortexes of mice. However, in APPswe/PS1ΔE9 double transgenic adult mice, it was up-regulated from 9 months of age compared to that of the age-matched wild type mice. Studies in primary cortical neuron cultures demonstrated that miR-211-5p can inhibit neurite growth and branching via NUAK1 repression and decrease mature neuron viability. The impairments were more obvious under the action of Aβ. Our data showed that miR-211-5p could inhibit cortical neuron differentiation and survival, which may contribute to the synaptic failure, neuronal loss and cognitive dysfunction in AD. PMID:27458373

  13. The model Caenorhabditis elegans in diabetes mellitus and Alzheimer's disease.

    Science.gov (United States)

    Morcos, Michael; Hutter, Harald

    2009-01-01

    Diabetes mellitus, with its complications, and Alzheimer's disease (AD) share many similarities. Both are age-related and associated with enhanced formation of advanced glycation endproducts (AGEs) and oxidative stress, factors that can be observed during the normal aging process as well. AGE deposits can be found in areas of atherosclerotic lesions in diabetes and in senile plaques and neurofibrillary tangles in AD. A classical model organism in aging research is the nematode Caenorhabditis elegans (C. elegans). Though C. elegans lacks a vascular system, it has been introduced in diabetes and AD research since it shares many similarities at the molecular level to pathological processes found in humans. AGEs accumulate in C. elegans, and increased AGE-formation and mitochondrial AGE-modification are responsible for increased oxidative stress and limiting life span. Moreover, C. elegans has an accessible and well characterized nervous system and features several genes homologous to human genes implicated in AD like amyloid-beta protein precursor, presenilins and tau. In addition, human genes linked to AD, such as amyloid-beta or tau, can be expressed and studied in C. elegans. So far, C. elegans research has contributed to a better understanding of the function of AD-related genes and the development of this disease.

  14. Elevated risk of type 2 diabetes for development of Alzheimer disease: a key role for oxidative stress in brain.

    Science.gov (United States)

    Butterfield, D Allan; Di Domenico, Fabio; Barone, Eugenio

    2014-09-01

    Alzheimer disease (AD) is the most common form of dementia among the elderly and is characterized by progressive loss of memory and cognition. Epidemiological data show that the incidence of AD increases with age and doubles every 5 years after 65 years of age. From a neuropathological point of view, amyloid-β-peptide (Aβ) leads to senile plaques, which, together with hyperphosphorylated tau-based neurofibrillary tangles and synapse loss, are the principal pathological hallmarks of AD. Aβ is associated with the formation of reactive oxygen (ROS) and nitrogen (RNS) species, and induces calcium-dependent excitotoxicity, impairment of cellular respiration, and alteration of synaptic functions associated with learning and memory. Oxidative stress was found to be associated with type 2 diabetes mellitus (T2DM), which (i) represents another prevalent disease associated with obesity and often aging, and (ii) is considered to be a risk factor for AD development. T2DM is characterized by high blood glucose levels resulting from increased hepatic glucose production, impaired insulin production and peripheral insulin resistance, which close resemble to the brain insulin resistance observed in AD patients. Furthermore, growing evidence suggests that oxidative stress plays a pivotal role in the development of insulin resistance and vice versa. This review article provides molecular aspects and the pharmacological approaches from both preclinical and clinical data interpreted from the point of view of oxidative stress with the aim of highlighting progresses in this field. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Palmitoylethanolamide Dampens Reactive Astrogliosis and Improves Neuronal Trophic Support in a Triple Transgenic Model of Alzheimer’s Disease: In Vitro and In Vivo Evidence

    Directory of Open Access Journals (Sweden)

    Maria Rosanna Bronzuoli

    2018-01-01

    Full Text Available Alzheimer’s disease (AD is a neurodegenerative disorder responsible for the majority of dementia cases in elderly people. It is widely accepted that the main hallmarks of AD are not only senile plaques and neurofibrillary tangles but also reactive astrogliosis, which often precedes detrimental deposits and neuronal atrophy. Such phenomenon facilitates the regeneration of neural networks; however, under some circumstances, like in AD, reactive astrogliosis is detrimental, depriving neurons of the homeostatic support, thus contributing to neuronal loss. We investigated the presence of reactive astrogliosis in 3×Tg-AD mice and the effects of palmitoylethanolamide (PEA, a well-documented anti-inflammatory molecule, by in vitro and in vivo studies. In vitro results revealed a basal reactive state in primary cortical 3×Tg-AD-derived astrocytes and the ability of PEA to counteract such phenomenon and improve viability of 3×Tg-AD-derived neurons. In vivo observations, performed using ultramicronized- (um- PEA, a formulation endowed with best bioavailability, confirmed the efficacy of this compound. Moreover, the schedule of treatment, mimicking the clinic use (chronic daily administration, revealed its beneficial pharmacological properties in dampening reactive astrogliosis and promoting the glial neurosupportive function. Collectively, our results encourage further investigation on PEA effects, suggesting it as an alternative or adjunct treatment approach for innovative AD therapy.

  16. Frontotemporal dementia with parkinsonism linked to chromosome 17 with the MAPT R406W mutation presenting with a broad distribution of abundant senile plaques.

    Science.gov (United States)

    Ishida, Chiho; Kobayashi, Katsuji; Kitamura, Tatsuru; Ujike, Hiroshi; Iwasa, Kazuo; Yamada, Masahito

    2015-02-01

    We report the autopsy results of a patient with familial dementia who was diagnosed as having frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17) with an R406W mutation in the microtubule-associated protein tau (MAPT) gene. This patient showed Alzheimer's disease (AD)-like clinical manifestations from the age of 59, with reduced β-amyloid1-42 (Aβ42 ) and elevated total and phosphorylated tau levels in the cerebrospinal fluid. He did not present with any apparent parkinsonism throughout the disease course. His autopsy at age 73 showed atrophy and neurodegeneration in many brain regions, particularly in the antero-medial temporal cortex and hippocampus, followed by the frontal lobes, with abundant neurofibrillary tangles. In addition, a diffuse distribution of Aβ-positive senile plaques, including many neuritic plaques, was observed and classified as stage C according to the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria. These results suggest that analyzing of the MAPT gene is essential for diagnosing familial dementia, even if amyloid markers such as Aβ42 in the cerebrospinal fluid and amyloid imaging are positive, or if neuropathological findings indicate a diagnosis of AD. © 2014 Japanese Society of Neuropathology.

  17. Alzheimer's disease: An alternative approach

    Directory of Open Access Journals (Sweden)

    Sadanandavalli Retnaswami Chandra

    2017-01-01

    Full Text Available Alzheimer's disease (AD is the most common neurodegenerative cortical dementia. It starts with memory loss, spatial disorientation in people above the age of 65 yr with a preference to females. Its incidence is expected to increase threefold by 2050. It affects almost one out of ten persons above the age of 65 years. Majority of patients are sporadic, but a very small percentage is autosomal dominant. The pathomechanisms postulated include amyloid cascade hypothesis according to which mutation in amyloid precursor protein causes Aβ aggregation. The next hypothesis is signal transducer and activation of transcription 3 (STAT3 causing aberration in intracellular signalling pathways. Senile plaques and neurofibrillary tangles are other important pathological changes reported. It is observed that dementia research has not yielded the expected result world over, and therefore, the pitfalls with reference to known facts about diagnosis, clinical features, pathogenic mechanisms, assessment of progression, biomarkers, treatment and prevention, as well as brief information on our experiments with relatively inexpensive methods of differentiating the most common types of dementia AD and frontotemporal dementia are discussed.

  18. Alzheimer's Disease and the Eye

    Directory of Open Access Journals (Sweden)

    Richard A. Armstrong

    2009-01-01

    Full Text Available Dementia, including Alzheimer's disease (AD, is a major disorder causing visual problems in the elderly population. The pathology of AD includes the deposition in the brain of abnormal aggregates of β-amyloid (Aβ in the form of senile plaques (SP and abnormally phosphorylated tau in the form of neurofibrillary tangles (NFT. A variety of visual problems have been reported in patients with AD including loss of visual acuity (VA, colour vision and visual fields; changes in pupillary response to mydriatics, defects in fixation and in smooth and saccadic eye movements; changes in contrast sensitivity and in visual evoked potentials (VEP; and disturbances of complex visual functions such as reading, visuospatial function, and in the naming and identification of objects. Many of these changes are controversial with conflicting data in the literature and no ocular or visual feature can be regarded as particularly diagnostic of AD. In addition, some pathological changes have been observed to affect the eye, visual pathway, and visual cortex in AD. The optometrist has a role in helping a patient with AD, if it is believed that signs and symptoms of the disease are present, so as to optimize visual function and improve the quality of life.

  19. Alzheimer's disease: is a vaccine possible?

    Energy Technology Data Exchange (ETDEWEB)

    Alves, R.P.S. [Universidade de São Paulo, Instituto de Ciências Biomédicas II, Departamento de Microbiologia, Laboratório de Desenvolvimento de Vacinas, São Paulo, SP, Brasil, Laboratório de Desenvolvimento de Vacinas, Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, SP (Brazil); Yang, M.J. [Instituto Butantan, Laboratório de Genética, São Paulo, SP, Brasil, Laboratório de Genética, Instituto Butantan, São Paulo, SP (Brazil); Batista, M.T.; Ferreira, L.C.S. [Universidade de São Paulo, Instituto de Ciências Biomédicas II, Departamento de Microbiologia, Laboratório de Desenvolvimento de Vacinas, São Paulo, SP, Brasil, Laboratório de Desenvolvimento de Vacinas, Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-05-09

    The cause of Alzheimer's disease is still unknown, but the disease is distinctively characterized by the accumulation of β-amyloid plaques and neurofibrillary tangles in the brain. These features have become the primary focus of much of the research looking for new treatments for the disease, including immunotherapy and vaccines targeting β-amyloid in the brain. Adverse effects observed in a clinical trial based on the β-amyloid protein were attributed to the presence of the target antigen and emphasized the relevance of finding safer antigen candidates for active immunization. For this kind of approach, different vaccine formulations using DNA, peptide, and heterologous prime-boost immunization regimens have been proposed. Promising results are expected from different vaccine candidates encompassing B-cell epitopes of the β-amyloid protein. In addition, recent results indicate that targeting another protein involved in the etiology of the disease has opened new perspectives for the effective prevention of the illness. Collectively, the evidence indicates that the idea of finding an effective vaccine for the control of Alzheimer's disease, although not without challenges, is a possibility.

  20. Air pollution and brain damage.

    Science.gov (United States)

    Calderón-Garcidueñas, Lilian; Azzarelli, Biagio; Acuna, Hilda; Garcia, Raquel; Gambling, Todd M; Osnaya, Norma; Monroy, Sylvia; DEL Tizapantzi, Maria Rosario; Carson, Johnny L; Villarreal-Calderon, Anna; Rewcastle, Barry

    2002-01-01

    Exposure to complex mixtures of air pollutants produces inflammation in the upper and lower respiratory tract. Because the nasal cavity is a common portal of entry, respiratory and olfactory epithelia are vulnerable targets for toxicological damage. This study has evaluated, by light and electron microscopy and immunohistochemical expression of nuclear factor-kappa beta (NF-kappaB) and inducible nitric oxide synthase (iNOS), the olfactory and respiratory nasal mucosae, olfactory bulb, and cortical and subcortical structures from 32 healthy mongrel canine residents in Southwest Metropolitan Mexico City (SWMMC), a highly polluted urban region. Findings were compared to those in 8 dogs from Tlaxcala, a less polluted, control city. In SWMMC dogs, expression of nuclear neuronal NF-kappaB and iNOS in cortical endothelial cells occurred at ages 2 and 4 weeks; subsequent damage included alterations of the blood-brain barrier (BBB), degenerating cortical neurons, apoptotic glial white matter cells, deposition of apolipoprotein E (apoE)-positive lipid droplets in smooth muscle cells and pericytes, nonneuritic plaques, and neurofibrillary tangles. Persistent pulmonary inflammation and deteriorating olfactory and respiratory barriers may play a role in the neuropathology observed in the brains of these highly exposed canines. Neurodegenerative disorders such as Alzheimer's may begin early in life with air pollutants playing a crucial role.

  1. Clinical and pathological study on 10 cases of cerebral lobe hemorrhage related with cerebral amyloid angiopathy

    Directory of Open Access Journals (Sweden)

    Xiao-qi LI

    2015-07-01

    Full Text Available Objective To summarize the clinical data and pathological features of 10 cases of cerebral lobar hemorrhage related with cerebral amyloid angiopathy (CAA diagnosed pathologically, thereby to improve the knowledge and diagnosis of the disease. Methods The clinical data of 10 cases of cerebral lobar hemorrhage related with CAA, collected in the General Hospital of Shenyang Command from 1983 up to now, were retrospectively analyzed, and the clinical and neuropathological features of these cases were summarized. Results Of the 10 patients, 2 suffered from single lobar hemorrhage and 8 multiple lobar hemorrhage, all of them were confirmed pathologically to have ruptured into the subarachnoid space. Pathological examination revealed microaneurysm in 2 cases, "double barrel" change in 4 cases, multiple arteriolar clusters in 5 cases, obliterative onion-liked intima change in 4 cases, and fibrinoid necrosis of vessel wall in 7 cases. In addition, neurofibrillary tangles were found in 8 cases, and senile plaque was observed in 5 cases. Conclusions Cerebral lobar hemorrhage related with CAA is mainly located in the parietal, temporal and occipital lobes, readily breaking into the subarachnoid space, and it is often multiple and recurrent. The CAA associated microvasculopathy was found frequently in the autopsy sample of CAA related cerebral lobar hemorrhage, and it may contribute to the pathogenesis of cerebral hemorrhage. DOI: 10.11855/j.issn.0577-7402.2015.07.04

  2. [Alzheimer's disease cerebro-spinal fluid biomarkers: A clinical research tool sometimes useful in daily clinical practice of memory clinics for the diagnosis of complex cases].

    Science.gov (United States)

    Magnin, E; Dumurgier, J; Bouaziz-Amar, E; Bombois, S; Wallon, D; Gabelle, A; Lehmann, S; Blanc, F; Bousiges, O; Hannequin, D; Jung, B; Miguet-Alfonsi, C; Quillard, M; Pasquier, F; Peoc'h, K; Laplanche, J-L; Hugon, J; Paquet, C

    2017-04-01

    The role of biomarkers in clinical research was recently highlighted in the new criteria for the diagnosis of Alzheimer's disease. Cerebro-spinal fluid (CSF) biomarkers (total Tau protein, threonine 181 phosphorylated Tau protein and amyloid Aβ1-42 peptide) are associated with cerebral neuropathological lesions observed in Alzheimer's disease (neuronal death, neurofibrillary tangle with abnormal Tau deposits and amyloid plaque). Aβ1-40 amyloid peptide dosage helps to interpret Aβ1-42 results. As suggested in the latest international criteria and the French HAS (Haute Autorité de santé) recommendations, using theses CSF biomarkers should not be systematic but sometimes could be performed to improve confidence about the diagnostic of Alzheimer's disease in young subjects or in complex clinical situations. Future biomarkers actually in development will additionally help in diagnostic process (differential diagnosis) and in prognostic evaluation of neurodegenerative diseases. Copyright © 2016 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  3. A Systems Model of Parkinson's Disease Using Biochemical Systems Theory.

    Science.gov (United States)

    Sasidharakurup, Hemalatha; Melethadathil, Nidheesh; Nair, Bipin; Diwakar, Shyam

    2017-08-01

    Parkinson's disease (PD), a neurodegenerative disorder, affects millions of people and has gained attention because of its clinical roles affecting behaviors related to motor and nonmotor symptoms. Although studies on PD from various aspects are becoming popular, few rely on predictive systems modeling approaches. Using Biochemical Systems Theory (BST), this article attempts to model and characterize dopaminergic cell death and understand pathophysiology of progression of PD. PD pathways were modeled using stochastic differential equations incorporating law of mass action, and initial concentrations for the modeled proteins were obtained from literature. Simulations suggest that dopamine levels were reduced significantly due to an increase in dopaminergic quinones and 3,4-dihydroxyphenylacetaldehyde (DOPAL) relating to imbalances compared to control during PD progression. Associating to clinically observed PD-related cell death, simulations show abnormal parkin and reactive oxygen species levels with an increase in neurofibrillary tangles. While relating molecular mechanistic roles, the BST modeling helps predicting dopaminergic cell death processes involved in the progression of PD and provides a predictive understanding of neuronal dysfunction for translational neuroscience.

  4. Inflammatory Process in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    MARCO ANTONIO eMERAZ RIOS

    2013-08-01

    Full Text Available Alzheimer Disease (AD is a neurodegenerative disorder and the most common form of dementia. Histopathologically is characterized by the presence of two major hallmarks, the intracellular neurofibrillary tangles (NFTs and extracellular neuritic plaques (NPs surrounded by activated astrocytes and microglia. NFTs consist of paired helical filaments of truncated tau protein that is abnormally hyperphosphorylated. The main component in the NP is the amyloid-β peptide (Aβ, a small fragment of 40-42 amino acids with a molecular weight of 4kD. It has been proposed that the amyloid aggregates and microglia activation are able to favor the neurodegenerative process observed in AD patients. However, the role of inflammation in AD is controversial, because in early stages the inflammation could have a beneficial role in the pathology, since it has been thought that the microglia and astrocytes activated could be involved in Aβ clearance. Nevertheless the chronic activation of the microglia has been related with an increase of Aβ and possibly with tau phosphorylation. Studies in AD brains have shown an upregulation of complement molecules, pro-inflammatory cytokines, acute phase reactants and other inflammatory mediators that could contribute with the neurodegenerative process. Clinical trials and animal models with nonsteroidal anti-inflammatory drugs (NSAIDs indicate that these drugs may decrease the risk of developing AD and apparently reduce Aβ deposition. Finally, further studies are needed to determine whether treatment with anti-inflammatory strategies, may decrease the neurodegenerative process that affects these patients.

  5. PET Imaging of Epigenetic Influences on Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Paul J. Couto

    2015-01-01

    Full Text Available The precise role of environment-gene interactions (epigenetics in the development and progression of Alzheimer’s disease (AD is unclear. This review focuses on the premise that radiotracer-specific PET imaging allows clinicians to visualize epigenetically influenced events and that such imaging may provide new, valuable insights for preventing, diagnosing, and treating AD. Current understanding of the role of epigenetics in AD and the principles underlying the use of PET radiotracers for in vivo diagnosis are reviewed. The relative efficacies of various PET radiotracers for visualizing the epigenetic influences on AD and their use for diagnosis are discussed. For example, [18F]FAHA demonstrates sites of differential HDAC activity, [18F]FDG indirectly illuminates sites of neuronal hypomethylation, and the carbon-11 isotope-containing Pittsburgh compound B ([11C]PiB images amyloid-beta plaque deposits. A definitive AD diagnosis is currently achievable only by postmortem histological observation of amyloid-beta plaques and tau neurofibrillary tangles. Therefore, reliable in vivo neuroimaging techniques could provide opportunities for early diagnosis and treatment of AD.

  6. Familial motor neuron disease with prominent onion-bulb-like structures and axonal swelling restricted to the spinal ventral root: autopsy findings in two siblings.

    Science.gov (United States)

    Tokuyama, Wataru; Yagishita, Saburo; Ryo, Masafuchi; Kusunoki, Junichi; Hasegawa, Kazuko; Yoshida, Tsutomu; Mikami, Tetuo; Okayasu, Isao

    2010-02-01

    We report autopsy cases of two siblings who developed muscular atrophy and dementia, clinically considered to be familial motor neuron disease (MND). They presented with motor neuron signs predominantly in the distal limbs without sensory impairment. At autopsy, severe neuronal loss in the anterior horn consistent with MND was found, but histopathological hallmarks like Bunina bodies and skein-like inclusions were absent. Surprisingly, numerous huge axonal swellings (about 30 microm in diameter) and onion-bulb-like structures were found in the spinal ventral roots. These changes were not observed in spinal dorsal roots or peripheral nerves. However, obvious segmental demyelination of the ventral root was not found. In addition, neurofibrillary tangles (NFTs) and neuritic plaques were present in the frontal cortex, temporal cortex and hippocampus, and to a lesser degree, in the amygdala, substantia nigra and thalamus. Our two cases are a hitherto unreported type of MND, which shows focal giant axonopathy and prominent formation of onion-bulb-like structures due to Schwann cell proliferation restricted to the spinal ventral roots.

  7. Effects of dietary supplementation of carnosine on mitochondrial dysfunction, amyloid pathology, and cognitive deficits in 3xTg-AD mice.

    Directory of Open Access Journals (Sweden)

    Carlo Corona

    Full Text Available BACKGROUND: The pathogenic road map leading to Alzheimer's disease (AD is still not completely understood; however, a large body of studies in the last few years supports the idea that beside the classic hallmarks of the disease, namely the accumulation of amyloid-β (Aβ and neurofibrillary tangles, other factors significantly contribute to the initiation and the progression of the disease. Among them, mitochondria failure, an unbalanced neuronal redox state, and the dyshomeostasis of endogenous metals like copper, iron, and zinc have all been reported to play an important role in exacerbating AD pathology. Given these factors, the endogenous peptide carnosine may be potentially beneficial in the treatment of AD because of its free-radical scavenger and metal chelating properties. METHODOLOGY: In this study, we explored the effect of L-carnosine supplementation in the 3xTg-AD mouse, an animal model of AD that shows both Aβ- and tau-dependent pathology. PRINCIPAL FINDINGS: We found that carnosine supplementation in 3xTg-AD mice promotes a strong reduction in the hippocampal intraneuronal accumulation of Aβ and completely rescues AD and aging-related mitochondrial dysfunctions. No effects were found on tau pathology and we only observed a trend toward the amelioration of cognitive deficits. CONCLUSIONS AND SIGNIFICANCE: Our data indicate that carnosine can be part of a combined therapeutic approach for the treatment of AD.

  8. CCD Camera Observations

    Science.gov (United States)

    Buchheim, Bob; Argyle, R. W.

    One night late in 1918, astronomer William Milburn, observing the region of Cassiopeia from Reverend T.H.E.C. Espin's observatory in Tow Law (England), discovered a hitherto unrecorded double star (Wright 1993). He reported it to Rev. Espin, who measured the pair using his 24-in. reflector: the fainter star was 6.0 arcsec from the primary, at position angle 162.4 ^{circ } (i.e. the fainter star was south-by-southeast from the primary) (Espin 1919). Some time later, it was recognized that the astrograph of the Vatican Observatory had taken an image of the same star-field a dozen years earlier, in late 1906. At that earlier epoch, the fainter star had been separated from the brighter one by only 4.8 arcsec, at position angle 186.2 ^{circ } (i.e. almost due south). Were these stars a binary pair, or were they just two unrelated stars sailing past each other? Some additional measurements might have begun to answer this question. If the secondary star was following a curved path, that would be a clue of orbital motion; if it followed a straight-line path, that would be a clue that these are just two stars passing in the night. Unfortunately, nobody took the trouble to re-examine this pair for almost a century, until the 2MASS astrometric/photometric survey recorded it in late 1998. After almost another decade, this amateur astronomer took some CCD images of the field in 2007, and added another data point on the star's trajectory, as shown in Fig. 15.1.

  9. Les observations à Grenade (Espagne).

    Science.gov (United States)

    Valtier, J.-C.; Le Contel, J.-M.; Sareyan, J.-P.

    A team of observers of short period variable stars used their telescope and photometer for the successful observations of some mutual phenomena. The observations were made at Granada Observatory (Spain).

  10. Spectropolarimetric Imaging Observations

    Science.gov (United States)

    Bradley, Christine Lavella

    The capability to map anthropogenic aerosol quantities and properties over land can provide significant insights for climate and environmental studies on global and regional scales. One of the primary challenges in aerosol information monitoring is separating two signals measured by downward-viewing airborne or spaceborne instruments: the light scattered from the aerosols and light reflected from the Earth's surface. In order to study the aerosols independently, the surface signal needs to be subtracted out from the measurements. Some observational modalities, such as multispectral and multiangle, do not provide enough information to uniquely define the Earth's directional reflectance properties for this task due to the high magnitude and inhomogeneity of albedo for land surface types. Polarization, however, can provide additional information to define surface reflection. To improve upon current measurement capabilities of aerosols over urban areas, Jet Propulsion Laboratory developed the Multiangle SpectroPolarimetric Imager (MSPI) that can accurately measure the Degree of Linear Polarization to 0.5%. In particular, data acquired by the ground-based prototype, GroundMSPI, is used for directional reflectance studies of outdoor surfaces in this dissertation. This work expands upon an existing model, the microfacet model, to characterize the polarized bidirectional reflectance distribution function (pBRDF) of surfaces and validate an assumption, the Spectral Invariance Hypothesis, on the surface pBRDF that is used in aerosol retrieval algorithms. The microfacet model is commonly used to represent the pBRDF of Earth's surface types, such as ocean and land. It represents a roughened surface comprised of randomly oriented facets that specularly reflect incoming light into the upward hemisphere. The analytic form of the pBRDF for this model assumes only a single reflection of light from the microfaceted surface. If the incoming illumination is unpolarized, as it is with

  11. Peer Observation of Teaching: Perceptions of the Observer and the Observed

    Science.gov (United States)

    Kohut, Gary F.; Burnap, Charles; Yon, Maria G.

    2007-01-01

    While peer observation of teaching is regarded as an important part of a faculty member's promotion and tenure portfolio, little has been reported on its usefulness. Results from this study indicate that both observers and observees value the peer observation process, are neutral about the adequacy of observer training, use a variety of…

  12. Observations

    DEFF Research Database (Denmark)

    Rossiter, John R.; Percy, Larry

    2013-01-01

    This article is a commentary on the theme of the 2012 ICORIA Conference held in Stockholm, which was about 'the changing role of advertising'. We propose that the role of advertising has not changed. the role of advertising has always been, and will continue to be, to sell more of the branded...... product or service or to achieve a higher price that consumers are willing to pay than would obtain in the absence of advertising. What has changed in recent years is the notable worsening of the academic-practitioner divide, which has seen academic advertising researchers pursuing increasingly...... as requiring a new model of how advertising communicates and persuades, which, as the authors' textbooks explain, is sheer nonsense and contrary to the goal of integrated marketing. We provide in this article a translation of practitioners' jargon into more scientifically acceptable terminology as well...

  13. YZ Cnc Chandra observing campaign

    Science.gov (United States)

    Waagen, Elizabeth O.

    2016-12-01

    Dr. Christian Knigge (University of Southampton) and colleagues have requested AAVSO coverage of the SU UMa-type dwarf nova YZ Cnc in support of Chandra X-ray observations to be carried out via a Target of Opportunity (TOO) triggering when the system is in a suitable outburst. YZ Cnc has normal outbursts about every 7-10 days, and superoutbursts about every 100-110 days. The astronomers are planning to use a superoutburst to time the trigger of the TOO observations to cover not only the superoutburst but also the following normal outburst; the superoutburst must occur at a time favorable for observing with Chandra. Once the TOO observations have been triggered, coverage will need to continue through at least one normal outburst after the Chandra observations have been completed. Good coverage of YZ Cnc from AAVSO observers this season is essential; your observations will be used to decide when to trigger the TOO observations. When the TOO observations are triggered, observers will be notified and revised observing instructions will likely be issued via an AAVSO Special Notice and/or via the discussion thread on this campaign on the AAVSO Campaigns and Observation Reports forum on the AAVSO website. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  14. OBPRELIM Observer Preliminary Data System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Paper logs are the primary data collection tool used by observers of the Northeast Fisheries Observer Program and Industry Funded Scallop Program deployed on...

  15. US Daily Pilot Balloon Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pilot Balloon observational forms for the United States. Taken by Weather Bureau and U.S. Army observers. Period of record 1918-1960. Records scanned from the NCDC...

  16. Central American and Caribbean Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Weather and soil temperature observations from foreign countries, taken by foreign and American observers. Includes NOAA forms collected and archived at NCDC, and...

  17. Lightship Daily Observations - NARA Collection

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations taken on board lightships along the United States coasts from 1893 - 1943. Generally 4-6 observations daily. Also includes deck logs, which give...

  18. Ship Observations - VOS and Navy

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Combination of Voluntary Observing Ship (VOS) and US Navy Ship weather observations. Obs generally taken 2-4 times daily at 00, 06, 12, and 18z.

  19. US Naval Observatory Hourly Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly observations journal from the National Observatory in Washington DC. The observatory is the first station in the United States to produce hourly observations...

  20. US Air Force Base Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hourly observations taken by U.S. Air Force personnel at bases in the United States and around the world. Foreign observations concentrated in the Middle East and...

  1. Mechanisms of aluminum-induced neurodegeneration in animals: Implications for Alzheimer's disease.

    Science.gov (United States)

    Savory, John; Herman, Mary M; Ghribi, Othman

    2006-11-01

    For four decades the controversial question concerning a possible role for aluminum neurotoxicity in contributing to the pathogenesis of Alzheimer's disease has been debated, and studies by different investigators have yielded contradictory results. The lack of sensitivity to aluminum neurotoxicity in transgenic mouse models of Alzheimer's disease has not allowed the system to be used to explore important aspects of this toxicity. Rabbits are particularly sensitive to aluminum neurotoxicity and they develop severe neurological changes that are dependent on dose, age and route of administration. The most prominent feature induced by aluminum in rabbit brain is a neurofibrillary degeneration that shares some similarity with the neurofibrillary tangles found in Alzheimer's disease patients. In the present review we discuss data from our laboratory and others, on the effects of aluminum on behaviour, neurologic function and morphology, using aluminum administered to rabbits via different routes. Finally, we will examine data on the possible cellular mechanisms underlying aluminum neurotoxicity, and potential neuroprotective strategies against aluminum toxicity.

  2. JWST NIRCam Time Series Observations

    Science.gov (United States)

    Greene, Tom; Schlawin, E.

    2017-01-01

    We explain how to make time-series observations with the Near-Infrared camera (NIRCam) science instrument of the James Webb Space Telescope. Both photometric and spectroscopic observations are described. We present the basic capabilities and performance of NIRCam and show examples of how to set its observing parameters using the Space Telescope Science Institute's Astronomer's Proposal Tool (APT).

  3. Fault detection using (PI) observers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.; Shafai, B.

    The fault detection and isolation (FDI) problem in connection with Proportional Integral (PI) Observers is considered in this paper. A compact formulation of the FDI design problem using PI observers is given. An analysis of the FDI design problem is derived with respectt to the time domain...... properties. A method for design of PI observers applied to FDI is given....

  4. State observer for synchronous motors

    Science.gov (United States)

    Lang, Jeffrey H.

    1994-03-22

    A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

  5. Deregulated Cdk5 Activity Is Involved in Inducing Alzheimer’s Disease

    Science.gov (United States)

    Shukla, Varsha; Skuntz, Susan; Pant, Harish C.

    2012-01-01

    Alzheimer’s disease (AD), the most devastating chronic neurodegenerative disease in adults, causes dementia and eventually, death of the affected individuals. Clinically, AD is characterized as late-onset, age-dependent cognitive decline due to loss of neurons in cortex and hippocampus. The pathologic corollary of these symptoms is the formation of senile plaques and neurofibrillary tangles. Senile plaques are formed due to accumulation of oligomeric amyloid beta (Aβ) forming fibrillary plaques. This occurs due to the amyloidogenic processing of the amyloid precursor protein (APP) by various secretases. On the other hand, neurofibrillary tangles are formed due to hyperphosphorylation of cytoskeleton proteins like tau and neurofilament. Both are hyperphosphorylated by cyclin-dependent kinase-5 (Cdk5) and are part of the paired helical filament (PHF), an integral part of neurofibrillary tangles. Unlike other cyclin-dependent kinases, Cdk5 plays a very important role in the neuronal development. Cdk5 gets activated by its neuronal activators p35 and p39. Upon stress, p35 and p39 are cleaved by calpain resulting in truncated products as p25 and p29. Association of Cdk5/p25 is longer and uncontrolled causing aberrant hyperphosphorylation of various substrates of Cdk5 like APP, tau and neurofilament, leading to neurodegenerative pathology like AD. Additionally recent evidence has shown increased levels of p25, Aβ, hyperactivity of Cdk5, phosphorylated tau and neurofilament in human AD brains. This review briefly describes the above-mentioned aspects of involvement of Cdk5 in the pathology of AD and at the end summarizes the advances in Cdk5 as a therapeutic target. PMID:23142263

  6. [The application of Gallyas-Braak stainings in pathologic diagnosis of neurodegenerative diseases].

    Science.gov (United States)

    Wang, Luning; Zhu, Mingwei; Li, Xianghong; Gui, Qiuping

    2002-02-01

    To evaluate the role of Gallyas silver staining in the diagnosis of neurodegenerative diseases. Modified Gallyas-Braak staining method was used to investigate samples of the brain and spinal cord of 22 cases with neurodegenerative disease including Alzheimer's disease (AD), Parkinson's diseas (PD), Pick's disease, diffuse Lewy body disease (DLBD), progressive supranuclear palsy (PSP), diagnosed by clinical and routine pathologic method. 10 cases without clinical symptoms and pathologic abnormalities of the nervous system served as control. As compared with Bodian staining, Gallyas-Braak staining demonstrated clearly neurofibrillary tangles in the hippocampus and the cortex of frontal and temperal lobe in all the cases with Alzheimer's disease, 6 cases with dementia of other causes and 3 normal aged. However, global neurofibrillary tangles in the midbrain and the basal ganglia were found only with Gallyas-Braak staining in 4 cases with both dementia and extrapyramidal features. In addition, tuft-shaped astrocytes were shown with this method in the motor cortex, basal ganglia, midbrain of the above 4 cases and astrocytic plaques in the same area in 2 cases of the 4 cases. In this connexion, pathologic findings in 2 of the 4 cases corresponded to PSP and those of the other two cases fufiled the diagnostic criteria of corticobasal degeneration (CBD) Oligodendroglial cytoplasmic inclusions in the white matter of the brain and the spinal cord were founded in 3 of the 4 cases with multiple system atrophy (MSA). This silver staining demonstrated as well a lot of argyrophilic grains in the neuropil of the temporal lobe and the hippocampus in one case with AD. Gallyas silver staining could better reveal not only Alzheimer-like neurofibrillary tangles but also different glial inclusions in other neurodegenerative diseases such as PSP, CBD and MSA. Consequently, it is of great value in the pathologic diagnosis and study of such degenerative diseases.

  7. Sequence learning by action, observation and action observation.

    Science.gov (United States)

    Bird, Geoffrey; Osman, Magda; Saggerson, Anna; Heyes, Cecilia

    2005-08-01

    The serial reaction time (SRT) task was used to compare learning of a complex sequence by action (participants responded to sequential stimuli), by observation (participants watched but did not respond to sequential stimuli), and by action-observation (participants watched an expert model responding to sequential stimuli). Each of these groups was compared with an untrained control group. Experiment 1 indicated that both observation and action-observation were sufficient to support learning of a 12-item second-order conditional (SOC) sequence. Experiment 2 confirmed these findings, and showed that, as indexed by reaction time (RT), the extent of learning by observation and by action-observation was comparable to that of action-based learning. Using a recognition test, Experiment 2 and 3 also provided evidence that, whereas learning by stimulus observation was explicit, learning by action-observation was implicit. These findings are consistent with a connection between motor systems and implicit learning, but do not support the hypothesis that overt action is necessary for implicit learning.

  8. NS&T Management Observations

    Energy Technology Data Exchange (ETDEWEB)

    Gianotto, David [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-09-01

    The INL Management Observation Program (MOP) is designed to improve managers and supervisors understanding of work being performed by employees and the barriers impacting their success. The MOP also increases workers understanding of managements’ expectations as they relate to safety, security, quality, and work performance. Management observations (observations) are designed to improve the relationship and trust between employees and managers through increased engagement and interactions between managers and researchers in the field. As part of continuous improvement, NS&T management took initiative to focus on the participation and quality of observations in FY 14. This quarterly report is intended to (a) summarize the participation and quality of management’s observations, (b) assess observations for commonalities or trends related to facility or process barriers impacting research, and (c) provide feedback and make recommendations for improvements NS&T’s MOP.

  9. Is the Aluminum Hypothesis Dead?

    Science.gov (United States)

    2014-01-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust. PMID:24806729

  10. Is the Aluminum Hypothesis dead?

    Science.gov (United States)

    Lidsky, Theodore I

    2014-05-01

    The Aluminum Hypothesis, the idea that aluminum exposure is involved in the etiology of Alzheimer disease, dates back to a 1965 demonstration that aluminum causes neurofibrillary tangles in the brains of rabbits. Initially the focus of intensive research, the Aluminum Hypothesis has gradually been abandoned by most researchers. Yet, despite this current indifference, the Aluminum Hypothesis continues to attract the attention of a small group of scientists and aluminum continues to be viewed with concern by some of the public. This review article discusses reasons that mainstream science has largely abandoned the Aluminum Hypothesis and explores a possible reason for some in the general public continuing to view aluminum with mistrust.

  11. An 85-year old male with levodopa-responsive parkinsonism followed by dementia and supranuclear ophthalmoplegia caused by alzheimer-type pathology without Lewy bodies.

    Science.gov (United States)

    Kasahata, Naoki; Hagiwara, Mariko; Kato, Hiroyuki; Nakamura, Ayako; Uchihara, Toshiki

    2014-01-01

    An 85-year-old man developed l-dopa responsive parkinsonism indistinguishable from Parkinson's disease and subsequent dementia, followed by supranuclear ophthalmoplegia and neck dorsiflexion at the terminal stage. Midbrain tegmentum and medial temporal lobe were atrophic on magnetic resonance imaging, while decreased blood flow was predominant in frontotemporal lobes, detected by 3D-SSP of 123I- IMP SPECT. Alzheimer-type pathology without Lewy body pathology was confirmed at autopsy. Substantia nigra showed mild degeneration and several neurofibrillary tangles without Lewy body pathology or progressive supranuclear palsy cytopathology. L-dopa responsive parkinsonism could be an initial manifestation of Alzheimer's disease, which should be included in the differential diagnosis.

  12. Microglia-Synapse Pathways: Promising Therapeutic Strategy for Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Jingdun Xie

    2017-01-01

    Full Text Available The main hallmarks of Alzheimer’s disease (AD are extracellular deposits of amyloid plaques and intracellular accumulation of hyperphosphorylated neurofibrillary tangles (tau. However, the mechanisms underlying these neuropathological changes remain largely unclear. To date, plenty of studies have shown that microglia-mediated neuroinflammation contributes to the pathogenesis of AD, and the microglia-synapse pathways have been repeatedly identified as the crucial factor in the disease process. In this review, evidences from microglia and synapse studies are presented, and the role of microglia in the pathogenesis of AD, the contributing factors to synapse dysfunction, and the role and mechanisms of microglia-synapse pathways will be discussed.

  13. Alzheimer's 100th anniversary of death and his contribution to a better understanding of Senile dementia.

    Science.gov (United States)

    Engelhardt, Eliasz; Gomes, Marleide da Mota

    2015-02-01

    Initially the trajectory of the historical forerunners and conceptions of senile dementia are briefly presented, being highlighted the name of Alois Alzheimer who provided clinical and neuropathological indicators to differentiate a group of patients with Senile dementia. Alzheimer's examination of Auguste D's case, studied by him with Bielschowsky's silver impregnation technique, permitted to identify a pathological marker, the intraneuronal neurofibrillary tangles, characterizing a new disease later named after him by Kraepelin - Alzheimer's disease. Over the time this disorder became one of the most important degenerative dementing disease, reaching nowadays a status that may be considered as epidemic.

  14. Evaluation of regional cerebral blood flow in patient with atypical senile dementia with asymmetrical calcification.

    Science.gov (United States)

    Shoyama, Masaru; Ukai, Satoshi; Shinosaki, Kazuhiro

    2015-12-01

    We report an 83-year-old woman with atypical senile dementia with Fahr-type calcification. Brain computed tomography demonstrated asymmetrical calcification predominant in the basal ganglia on the right side and pronounced diffuse cortical atrophy in the frontotemporal areas. The patient was clinically diagnosed with diffuse neurofibrillary tangles with calcification. Brain single photon emission computed tomography findings revealed that cerebral blood flow was reduced on the right side, as compared with the left side, in widespread areas. Hemispheric asymmetry in both calcification and cerebral blood flow suggests a relationship between calcification and vascular changes. © 2015 The Authors. Psychogeriatrics © 2015 Japanese Psychogeriatric Society.

  15. Alzheimer's 100th anniversary of death and his contribution to a better understanding of Senile dementia

    Directory of Open Access Journals (Sweden)

    Eliasz Engelhardt

    2015-02-01

    Full Text Available Initially the trajectory of the historical forerunners and conceptions of senile dementia are briefly presented, being highlighted the name of Alois Alzheimer who provided clinical and neuropathological indicators to differentiate a group of patients with Senile dementia. Alzheimer's examination of Auguste D’s case, studied by him with Bielschowsky’s silver impregnation technique, permitted to identify a pathological marker, the intraneuronal neurofibrillary tangles, characterizing a new disease later named after him by Kraepelin – Alzheimer’s disease. Over the time this disorder became one of the most important degenerative dementing disease, reaching nowadays a status that may be considered as epidemic.

  16. ImmunoPEGliposome-mediated reduction of blood and brain amyloid levels in a mouse model of Alzheimer's disease is restricted to aged animals

    DEFF Research Database (Denmark)

    Ordóñez-Gutiérrez, Lara; Posado-Fernández, Adrián; Ahmadvand, Davoud

    2017-01-01

    The accumulation of extracellular amyloid-beta (Aβ) and intracellular neurofibrillary tangles (hyper-phosphorylated Tau) in the brain are two major neuropathological hallmarks of Alzheimer's disease (AD). Active and passive immunotherapy may limit cerebral Aβ deposition and/or accelerate its...... clearance. With the aid of a newly characterized monoclonal anti-Aβ antibody we constructed immunoPEGliposomes with high avidity for capturing Aβ in the periphery. The functionality of these vesicles in modulating Aβ uptake by both human brain capillary endothelial hCMEC/D3 cells (suppressing uptake...

  17. Observations of Novae From ROAD

    Science.gov (United States)

    Hambsch, F.-J.

    2014-12-01

    The author discusses observations of galactic novae and some extragalactic supernovae from his remote observatory ROAD (Remote Observatory Atacama Desert) he commenced in August 2011 with Nova Lupi 2011 (PR Lup). The observed novae are mainly chosen according to AAVSO Alert Notices and AAVSO Special Notices as published on their website. Examples of dense observations of different novae are presented. The focus goes to the different behaviors of their light curves. It also demonstrates the capability of the remote observatory ROAD.

  18. Alzheimer’s Disease: Mechanism and Approach to Cell Therapy

    Directory of Open Access Journals (Sweden)

    Takashi Amemori

    2015-11-01

    Full Text Available Alzheimer’s disease (AD is the most common form of dementia. The risk of AD increases with age. Although two of the main pathological features of AD, amyloid plaques and neurofibrillary tangles, were already recognized by Alois Alzheimer at the beginning of the 20th century, the pathogenesis of the disease remains unsettled. Therapeutic approaches targeting plaques or tangles have not yet resulted in satisfactory improvements in AD treatment. This may, in part, be due to early-onset and late-onset AD pathogenesis being underpinned by different mechanisms. Most animal models of AD are generated from gene mutations involved in early onset familial AD, accounting for only 1% of all cases, which may consequently complicate our understanding of AD mechanisms. In this article, the authors discuss the pathogenesis of AD according to the two main neuropathologies, including senescence-related mechanisms and possible treatments using stem cells, namely mesenchymal and neural stem cells.

  19. The Alzheimer myth and biomarker research in dementia.

    Science.gov (United States)

    Richard, Edo; Schmand, Ben; Eikelenboom, Piet; Westendorp, Rudi G; Van Gool, Willem A

    2012-01-01

    The focus of most of the research on Alzheimer's disease in the last decades has been on senile plaques and neurofibrillary tangles. The vast majority of patients with Alzheimer's disease are over 75 years of age, whereas most of the research focuses on younger subjects. To consider old-age dementia as a homogenous well-defined condition ignores the complexity of this condition and limits the development of new diagnostic methods, preventive strategies, or treatment strategies that could be widely applicable in daily practice in the majority of the older patients. The current research on biomarkers focuses on correlates of plaques and tangles, which are poor markers in older dementia subjects. Acknowledging that dementia in old age is an essentially different condition from dementia at relatively younger age is needed and should lead to new approaches in dementia research.

  20. Apparent diffusion coefficient measurements in progressive supranuclear palsy

    Energy Technology Data Exchange (ETDEWEB)

    Ohshita, T.; Oka, M.; Imon, Y.; Yamaguchi, S.; Mimori, Y.; Nakamura, S. [Hiroshima Univ. (Japan). School of Medicine

    2000-09-01

    We measured the apparent diffusion coefficient (ADC), using diffusion-weighted imaging (DWI) and signal intensity on T2-weighted MRI in the cerebral white matter of patients with progressive supranuclear palsy (PSP) and age-matched normal subjects. In PSP, ADC in the prefrontal and precentral white matter was significantly higher than in controls. There was no significant difference in signal intensity on T2-weighted images. The ADC did correlate with signal intensity. The distribution of the elevation of ADC may be the consequence of underlying pathological changes, such as neurofibrillary tangles or glial fibrillary tangles in the cortex. Our findings suggest that ADC measurement might be useful for demonstrating subtle neuropathological changes. (orig.)

  1. Observation of Persons and Contexts.

    Science.gov (United States)

    Gump, Paul V.

    Observational approaches used by ecological psychologists can focus on the behavior of persons or on their settings. The options for subject-centered observation are diary methods, specimen records, time sampling, and event sampling or critical incident recording. Serious limitations correlated to the time interval method, as it is often applied,…

  2. Loop quantum gravity and observations

    CERN Document Server

    Barrau, A

    2014-01-01

    Quantum gravity has long been thought to be completely decoupled from experiments or observations. Although it is true that smoking guns are still missing, there are now serious hopes that quantum gravity phenomena might be tested. We review here some possible ways to observe loop quantum gravity effects either in the framework of cosmology or in astroparticle physics.

  3. The INTEGRAL Core Observing Programme

    DEFF Research Database (Denmark)

    Winkler, C.; Gehrels, N.; Lund, Niels

    1999-01-01

    The Core Programme of the INTEGRAL mission is defined as the portion of the scientific programme covering the guaranteed time observations for the INTEGRAL Science Working Team. This paper describes the current status of the Core Programme preparations and summarizes the key elements...... of the observing programme....

  4. Observable Effects of Quantum Gravity

    CERN Document Server

    Chang, Lay Nam; Sun, Chen; Takeuchi, Tatsu

    2016-01-01

    We discuss the generic phenomenology of quantum gravity and, in particular, argue that the observable effects of quantum gravity, associated with new, extended, non-local, non-particle-like quanta, and accompanied by a dynamical energy-momentum space, are not necessarily Planckian and that they could be observed at much lower and experimentally accessible energy scales.

  5. Observer Effects on Teacher Behavior.

    Science.gov (United States)

    Samph, Thomas

    A study was designed to determine whether the presence or absence of a classroom observer and the prior knowledge or lack of knowledge that an observation was to occur would affect the verbal behavior of teachers as measured by the Flanders System of Interaction Analysis. The variables were dichotomized yielding a 2 x 2 x 2 experimental design…

  6. Mars Observer Orbit Insertion Briefing

    Science.gov (United States)

    1993-01-01

    Steve Wall is the host of this video entitled, "Return to the Red Planet". Live animation of the Mars Observer orbiting Mars is presented. Steve Wall explains the spacecraft insertion maneuver and also explains the purpose for the Mars Observer launch. Live coverage of the Cape Canaveral launch of the Mars Observer is also presented. Suzanne Dodd, Chief of the Mission Planning team describes the burn start and how the spacecraft will be captured by Mars' gravity. Glenn Cunningham, Mars Observer Project Manager, gives background information on the Mars Observer and describes the organizations behind the Mars Observer Spacecraft, such as the Deep Space Network, the Mission Operation Support Office, Science Investigators, the Flight Engineering Office, Operations Office, and the Ground Data System Office. Dr. William Piotrowski, Acting Director, Solar System Exploration Division, NASA, talks about the purpose of the Mars Pathfinder which is to develop the technology and systems for landing small science packages on Mars. Mr. Roger Gibbs, Former Mars Observer Spacecraft Systems Engineer, tells us how the Mars Observer was built and describes the structural elements on the Mars Observer. The 11-month cruise period for the spacecraft is given by Joseph Beerer, Manager of the Engineering office. The thrust for the Mars Orbit Insertion is described by Ronald Klemetson, Technical Manager, Propulsion Subsystem Jet Propulsion Laboratory (JPL). George Chen, Lead Engineer Attitude and Articulation Subsystem Spacecraft Team, explains the importance of the attitude control engines on the Spacecraft. Marvin Traxler, Manager of Tracking and Data Acquisition, describes how searching for a signal from the Mars Observer works. See NONP-NASA-VT-2000081555 for a continuation of this discussion with Marvin Traxler.

  7. Global Mercury Observation System (GMOS) surface observation data.

    Data.gov (United States)

    U.S. Environmental Protection Agency — GMOS global surface elemental mercury (Hg0) observations from 2013 & 2014. This dataset is associated with the following publication: Sprovieri, F., N. Pirrone,...

  8. Observability of global rivers with future SWOT observations

    Science.gov (United States)

    Fisher, Colby; Pan, Ming; Wood, Eric

    2017-04-01

    The Surface Water and Ocean Topography (SWOT) mission is designed to provide global observations of water surface elevation and slope from which river discharge can be estimated using a data assimilation system. This mission will provide increased spatial and temporal coverage compared to current altimeters, with an expected accuracy for water level elevations of 10 cm on rivers greater than 100 m wide. Within the 21-day repeat cycle, a river reach will be observed 2-4 times on average. Due to the relationship between the basin orientation and the orbit, these observations are not evenly distributed in time, which will impact the derived discharge values. There is, then, a need for a better understanding of how the mission will observe global river basins. In this study, we investigate how SWOT will observe global river basins and how the temporal and spatial sampling impacts the discharge estimated from assimilation. SWOT observations can be assimilated using the Inverse Streamflow Routing (ISR) model of Pan and Wood [2013] with a fixed interval Kalman smoother. Previous work has shown that the ISR assimilation method can be used to reproduce the spatial and temporal dynamics of discharge within many global basins: however, this performance was strongly impacted by the spatial and temporal availability of discharge observations. In this study, we apply the ISR method to 32 global basins with different geometries and crossing patterns for the future orbit, assimilating theoretical SWOT-retrieved "gauges". Results show that the model performance varies significantly across basins and is driven by the orientation, flow distance, and travel time in each. Based on these properties, we quantify the "observability" of each basin and relate this to the performance of the assimilation. Applying this metric globally to a large variety of basins we can gain a better understanding of the impact that SWOT observations may have across basin scales. By determining the

  9. Observational methodology in sport sciences

    Directory of Open Access Journals (Sweden)

    M. Teresa Anguera

    2013-11-01

    Full Text Available This paper reviews the conceptual framework, the key literature and the methods (observation tools, such as category systems and field formats, and coding software, etc. that should be followed when conducting research from the perspective of observational methodology. The observational designs used by the authors’ research group over the last twenty years are discussed, and the procedures for analysing data and assessing their quality are described. Mention is also made of the latest methodological trends in this field, such as the use of mixed methods.

  10. Sliding mode control and observation

    CERN Document Server

    Shtessel, Yuri; Fridman, Leonid; Levant, Arie

    2014-01-01

    The sliding mode control methodology has proven effective in dealing with complex dynamical systems affected by disturbances, uncertainties and unmodeled dynamics. Robust control technology based on this methodology has been applied to many real-world problems, especially in the areas of aerospace control, electric power systems, electromechanical systems, and robotics. Sliding Mode Control and Observation represents the first textbook that starts with classical sliding mode control techniques and progresses toward newly developed higher-order sliding mode control and observation algorithms and their applications. The present volume addresses a range of sliding mode control issues, including: *Conventional sliding mode controller and observer design *Second-order sliding mode controllers and differentiators *Frequency domain analysis of conventional and second-order sliding mode controllers *Higher-order sliding mode controllers and differentiators *Higher-order sliding mode observers *Sliding mode disturbanc...

  11. Mobile Source Observation Database (MSOD)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Mobile Source Observation Database (MSOD) is a relational database being developed by the Assessment and Standards Division (ASD) of the US Environmental...

  12. Observational Calculi and Association Rules

    CERN Document Server

    Rauch, Jan

    2013-01-01

    Observational calculi were introduced in the 1960’s as a tool of logic of discovery. Formulas of observational calculi correspond to assertions on analysed data. Truthfulness of suitable assertions can lead to acceptance of new scientific hypotheses. The general goal was to automate the process of discovery of scientific knowledge using mathematical logic and statistics. The GUHA method for producing true formulas of observational calculi relevant to the given problem of scientific discovery was developed. Theoretically interesting and practically important results on observational calculi were achieved. Special attention was paid to formulas - couples of Boolean attributes derived from columns of the analysed data matrix. Association rules introduced in the 1990’s can be seen as a special case of such formulas. New results on logical calculi and association rules were achieved. They can be seen as a logic of association rules. This can contribute to solving contemporary challenging problems of data minin...

  13. The Sprite 2005 Observation Campaign

    DEFF Research Database (Denmark)

    Chanrion, Olivier Arnaud; Crosby, Norma; Armone, Enrico

    2007-01-01

    and outreach programmes for the young scientists hired. Educational activities were based on the following elements: national PhD programmes, activities at CAL and other meetings, a dedicated summer school, and two European sprite observational campaigns. The young scientists were strongly involved...... in the latter and, as an example, the "EuroSprite2005" observational campaign is presented in detail. Some of the young scientists participated in the instrument set-up, others in the campaign logistics, some coordinated the observations, and others gathered the results to build a catalogue. During the four......-month duration of this campaign, all of them took turns in operating the system and making their own night observations. The ongoing campaign activities were constantly advertised and communicated via an Internet blog. In summary the campaign required all the CAL young scientists to embark on experimental work...

  14. COOP Wind and Radiation Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Wind and radiation data from stations in the National Weather Service Cooperative Observers Network. Some precipitation and pressure forms are mistakenly placed in...

  15. An introduction to observational astrophysics

    CERN Document Server

    Gallaway, Mark

    2016-01-01

    Observational Astrophysics follows the general outline of an astrophysics undergraduate curriculum targeting practical observing information to what will be covered at the university level. This includes the basics of optics and coordinate systems to the technical details of CCD imaging, photometry, spectography and radio astronomy.  General enough to be used by students at a variety of institutions and advanced enough to be far more useful than observing guides targeted at amateurs, the author provides a comprehensive and up-to-date treatment of observational astrophysics at undergraduate level to be used with a university’s teaching telescope.  The practical approach takes the reader from basic first year techniques to those required for a final year project. Using this textbook as a resource, students can easily become conversant in the practical aspects of astrophysics in the field as opposed to the classroom.

  16. Window observers for linear systems

    Directory of Open Access Journals (Sweden)

    Utkin Vadim

    2000-01-01

    Full Text Available Given a linear system x ˙ = A x + B u with output y = C x and a window function ω ( t , i.e., ∀ t , ω ( t ∈ {0,1 }, and assuming that the window function is Lebesgue measurable, we refer to the following observer, x ˆ = A x + B u + ω ( t L C ( x − x ˆ as a window observer. The stability issue is treated in this paper. It is proven that for linear time-invariant systems, the window observer can be stabilized by an appropriate design under a very mild condition on the window functions, albeit for linear time-varying system, some regularity of the window functions is required to achieve observer designs with the asymptotic stability. The corresponding design methods are developed. An example is included to illustrate the possible applications

  17. Observers Design for Biotechnological Processes

    National Research Council Canada - National Science Library

    Popova, S

    2008-01-01

    New method for design of observers for biotechnological processes is proposed. The method consists of analytical derivation of the first integrals of the differential system, which describes the process...

  18. CalNex Observational Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Observations made during the 2010 CalNex measurement campaign. This dataset is associated with the following publication: Woody , M., K. Baker , P. Hayes, J....

  19. US Monthly Pilot Balloon Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly winds aloft summary forms summarizing Pilot Balloon observational data for the United States. Generally labeled as Form 1114, and then transitioning to Form...

  20. Observability transition in real networks

    Science.gov (United States)

    Yang, Yang; Radicchi, Filippo

    2016-09-01

    We consider the observability model in networks with arbitrary topologies. We introduce a system of coupled nonlinear equations, valid under the locally treelike ansatz, to describe the size of the largest observable cluster as a function of the fraction of directly observable nodes present in the network. We perform a systematic analysis on 95 real-world graphs and compare our theoretical predictions with numerical simulations of the observability model. Our method provides almost perfect predictions in the majority of the cases, even for networks with very large values of the clustering coefficient. Potential applications of our theory include the development of efficient and scalable algorithms for real-time surveillance of social networks, and monitoring of technological networks.

  1. Observations afield on Alaskan wolves

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Widespread observations of wolves and their habits in Alaska during the period 1948-1954 generally confirm published reports of these phenomena elsewhere....

  2. Bulletin of International Simultaneous Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The publication of the Bulletin of International Simultaneous Observations, began July 1, 1875, with daily maps added in 1877. It was published for distribution...

  3. Mobile Source Observation Database (MSOD)

    Science.gov (United States)

    The Mobile Source Observation Database (MSOD) is a relational database developed by the Assessment and Standards Division (ASD) of the U.S. EPA Office of Transportation and Air Quality (formerly the Office of Mobile Sources).

  4. Modern Asteroid Occultation Observing Methods

    Science.gov (United States)

    Lucas, G. A.

    2004-05-01

    This presentation reviews current working methods for asteroid occultations developed by the International Occultation Timing Association (IOTA). Reduc- tion of multiple tracks or "chords" observed during stellar occultations pro- vides valuable measures of the relative sizes and shapes of asteroids. Tradi- tionally, predictions for asteroid occultations were prepared by regional IOTA computors, distributed annually in "hard copy" format to IOTA subscrib- ers and in publications such as Sky & Telescope magazine and the annual RASC Observers Handbook. IOTA - like many other organizations - is now using worldwide internet services and e-mail to distribute frequently-updated pre- dictions based upon the latest astrometry. The IOTA web pages provide an easily accessible, centralized source of information on lunar and solar sys- tem occultation events. IOTA's web pages feature a variety of articles on current activities, plans for observing campaigns and expeditions, and "how to do it" information on the latest technology and techniques. The latest up- dated predictions for asteroid events are made available as they are pro- duced, providing more accurate observing tracks and efficient coordination of observers. The IOTA e-mail list provides a dynamic forum for the exchange of technical information and com-munication of observing plans in a timely man- ner. Individuals may now generate customized occultation predictions using the WinOccult software package. The author presents some examples of recent occultation events, showing the benefits of coordinated observations. Also described are some of the latest innovations, featuring low-cost video camera equipment, devices for time insertion based on Global Positioning Satellite (GPS) technology, and a new approach using unattended secondary field station equipment to multiply the number of tracks observed.

  5. Observations at large zenith angles

    CERN Document Server

    Schroeder, F

    2000-01-01

    Cherenkov telescope observations at zenith angles >70 deg. are capable of providing large collection areas for high energy gamma-induced air showers. In order to provide a full Monte Carlo simulation of the large zenith angle observations the air shower simulation code CORSIKA was modified to treat particles in a curved geometry. First results of studies with the stand alone telescope HEGRA CT1 are presented.

  6. Earth observation for rangeland monitoring

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2012-10-01

    Full Text Available for the methodology is presented in Figure 1. Figure 1: Conceptual framework for the development of grass nutrient estimation models, using remote sensing at various scales Earth Observation for Rangeland Monitoring DR A RAMOELO, DR M CHO AND DR R MATHIEU CSIR... and canopy N conforms to the underlying geology (Figure 2). ACKNOWLEDGEMENT The authors would like to thank the Department of Science and Technology which contributed financially to this work through the grant ?Earth Observation Application Development...

  7. Observational biases for transiting planets

    Science.gov (United States)

    Kipping, David M.; Sandford, Emily

    2016-12-01

    Observational biases distort our view of nature, such that the patterns we see within a surveyed population of interest are often unrepresentative of the truth we seek. Transiting planets currently represent the most informative data set on the ensemble properties of exoplanets within 1 au of their star. However, the transit method is inherently biased due to both geometric and detection-driven effects. In this work, we derive the overall observational biases affecting the most basic transit parameters from first principles. By assuming a trapezoidal transit and using conditional probability, we infer the expected distribution of these terms both as a joint distribution and in a marginalized form. These general analytic results provide a baseline against which to compare trends predicted by mission-tailored injection/recovery simulations and offer a simple way to correct for observational bias. Our results explain why the observed population of transiting planets displays a non-uniform impact parameter distribution, with a bias towards near-equatorial geometries. We also find that the geometric bias towards observed planets transiting near periastron is attenuated by the longer durations which occur near apoastron. Finally, we predict that the observational bias with respect to ratio-of-radii is super-quadratic, scaling as (RP/R⋆)5/2, driven by an enhanced geometric transit probability and modestly longer durations.

  8. Inhomogeneous distribution of Alzheimer pathology along the isocortical relief. Are cortical convolutions an Achilles heel of evolution?

    Science.gov (United States)

    Arendt, Thomas; Morawski, Markus; Gärtner, Ulrich; Fröhlich, Nadine; Schulze, Falko; Wohmann, Nils; Jäger, Carsten; Eisenlöffel, Christian; Gertz, Hermann-Josef; Mueller, Wolf; Brauer, Kurt

    2017-09-01

    Alzheimer's disease (AD) is neuropathologically characterized by neuritic plaques and neurofibrillary tangles. Progression of both plaques and tangles throughout the brain follows a hierarchical distribution which is defined by intrinsic cytoarchitectonic features and extrinsic connectivity patterns. What has less well been studied is how cortical convolutions influence the distribution of AD pathology. Here, the distribution of both plaques and tangles within subsulcal gyral components (fundi) to components forming their top regions at the subarachnoidal brain surface (crowns) by stereological methods in seven different cortical areas was systematically compared. Further, principle differences in cytoarchitectonic organization of cortical crowns and fundi that might provide the background for regionally selective vulnerability were attempted to identify. It was shown that both plaques and tangles were more prominent in sulcal fundi than gyri crowns. The differential distribution of pathology along convolutions corresponds to subgyral differences in the vascular network, GFAP-positive astrocytes and intracortical and subcortical connectivity. While the precise mechanisms accounting for these differences remain open, the presence of systematic inhomogeneities in the distribution of AD pathology along cortical convolutions indicates that the phylogenetic shaping of the cortex is associated with features that render the human brain vulnerable to AD pathology. © 2016 International Society of Neuropathology.

  9. Tactile perception during action observation.

    Science.gov (United States)

    Vastano, Roberta; Inuggi, Alberto; Vargas, Claudia D; Baud-Bovy, Gabriel; Jacono, Marco; Pozzo, Thierry

    2016-09-01

    It has been suggested that tactile perception becomes less acute during movement to optimize motor control and to prevent an overload of afferent information generated during action. This empirical phenomenon, known as "tactile gating effect," has been associated with mechanisms of sensory feedback prediction. However, less attention has been given to the tactile attenuation effect during the observation of an action. The aim of this study was to investigate whether and how the observation of a goal-directed action influences tactile perception as during overt action. In a first experiment, we recorded vocal reaction times (RTs) of participants to tactile stimulations during the observation of a reach-to-grasp action. The stimulations were delivered on different body parts that could be either congruent or incongruent with the observed effector (the right hand and the right leg, respectively). The tactile stimulation was contrasted with a no body-related stimulation (an auditory beep). We found increased RTs for tactile congruent stimuli compared to both tactile incongruent and auditory stimuli. This effect was reported only during the observation of the reaching phase, whereas RTs were not modulated during the grasping phase. A tactile two-alternative forced-choice (2AFC) discrimination task was then conducted in order to quantify the changes in tactile sensitivity during the observation of the same goal-directed actions. In agreement with the first experiment, the tactile perceived intensity was reduced only during the reaching phase. These results suggest that tactile processing during action observation relies on a process similar to that occurring during action execution.

  10. The Global Geodetic Observing System

    Science.gov (United States)

    Plag, H.-P.; Rothacher, M.; Pearlman, M.; Neilan, R.; Ma, C.

    2009-03-01

    The Global Geodetic Observing System (GGOS) was established by the International Association of Geodesy (IAG) in July 2003. In April 2004 the IAG, represented by GGOS, became a participating organization of the Group on Earth Observation (GEO) and in May 2006 GGOS was accepted as a member of the Integrated Global Observation Strategy Partnership (IGOS-P). GGOS is the contribution of geodesy to the Global Earth Observation System of Systems (GEOSS). It provides the reference systems and frames, which are crucial for Earth observing systems. GGOS is built on the IAG Services (IGS, IVS, ILRS, IDS, IERS, IGFS, etc.) and the products they derive on an operational basis for Earth monitoring, making use of space- and ground-based geodetic techniques such as Very Long Baseline Interferometry (VLBI), Satellite and Lunar Laser Ranging (SLR/LLR), Global Navigation Satellite Systems (GNSS), Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), altimetry, InSAR (Interferometric Synthetic Aperture Radar), gravity satellite missions, and gravimetry, etc. All these observation techniques are considered integral parts of GGOS, allowing the monitoring of the Earth's shape and deformation (including water surface), the Earth's orientation and rotation, and the Earth's gravity field and its temporal variations with an unprecedented accuracy. The observed parameters give direct evidence of many global processes that have a crucial impact on human society such as earthquakes, volcanism, floods, sea-level change, climate change, groundwater redistribution, mass balance of the polar ice sheets, etc. GGOS relies on the observing systems and analysis capabilities already in place in the IAG Services and envisions the continued development of innovative technologies, methods, and models to improve our understanding of global change processes. GGOS provides a framework that ranges from the acquisition, transfer, and processing of a tremendous amount of observational data

  11. The AUSTRAL VLBI observing program

    Science.gov (United States)

    Plank, L.; Lovell, J. E. J.; McCallum, J. N.; Mayer, D.; Reynolds, C.; Quick, J.; Weston, S.; Titov, O.; Shabala, S. S.; Böhm, J.; Natusch, T.; Nickola, M.; Gulyaev, S.

    2017-07-01

    The AUSTRAL observing program was started in 2011, performing geodetic and astrometric very long baseline interferometry (VLBI) sessions using the new Australian AuScope VLBI antennas at Hobart, Katherine, and Yarragadee, with contribution from the Warkworth (New Zealand) 12 m and Hartebeesthoek (South Africa) 15 m antennas to make a southern hemisphere array of telescopes with similar design and capability. Designed in the style of the next-generation VLBI system, these small and fast antennas allow for a new way of observing, comprising higher data rates and more observations than the standard observing sessions coordinated by the International VLBI Service for Geodesy and Astrometry (IVS). In this contribution, the continuous development of the AUSTRAL sessions is described, leading to an improvement of the results in terms of baseline length repeatabilities by a factor of two since the start of this program. The focus is on the scheduling strategy and increased number of observations, aspects of automated operation, and data logistics, as well as results of the 151 AUSTRAL sessions performed so far. The high number of the AUSTRAL sessions makes them an important contributor to VLBI end-products, such as the terrestrial and celestial reference frames and Earth orientation parameters. We compare AUSTRAL results with other IVS sessions and discuss their suitability for the determination of baselines, station coordinates, source coordinates, and Earth orientation parameters.

  12. Timed Testing under Partial Observability

    DEFF Research Database (Denmark)

    David, Alexandre; Larsen, Kim Guldstrand; Li, Shuhao

    2009-01-01

    To steer model-based conformance testing of real-time systems towards certain test purposes or test coverage, many testing methods need (to be enhanced with) the assumption of full observability of the System Under Test (SUT), which means that the tester can observe precisely what state or config......To steer model-based conformance testing of real-time systems towards certain test purposes or test coverage, many testing methods need (to be enhanced with) the assumption of full observability of the System Under Test (SUT), which means that the tester can observe precisely what state...... framework, define a partial observation-based conformance relation, present the test execution algorithms, and prove the soundness and completeness of this test method (i.e., a detected error is really an error, and if the SUT violates the test purpose, then a test case can be generated to detect...... this violation). Experiments on some non-trivial examples show that this method yields encouraging results....

  13. Observing Projects in Introductory Astronomy

    Science.gov (United States)

    Taylor, M. Suzanne

    2016-01-01

    Introductory astronomy classes without laboratory components face a unique challenge of how to expose students to the process of science in the framework of a lecture course. As a solution to this problem small group observing projects are incorporated into a 40 student introductory astronomy class composed primarily of non-science majors. Students may choose from 8 observing projects such as graphing the motion of the moon or a planet, measuring daily and seasonal motions of stars, and determining the rotation rate of the Sun from sunspots. Each group completes two projects, requiring the students to spend several hours outside of class making astronomical observations. Clear instructions and a check-list style observing log help students with minimal observing experience to take accurate data without direct instructor assistance. Students report their findings in a lab report-style paper, as well as in a formal oral or poster presentation. The projects serve a double purpose of allowing students to directly experience concepts covered in class as well as providing students with experience collecting, analyzing, and presenting astronomical data.

  14. Juno Waves observations at Jupiter

    Science.gov (United States)

    Kurth, W. S.; Hospodarsky, G. B.; Imai, M.; Tetrick, S. S.; Gurnett, D. A.; Ye, S.-Y.; Louarn, P.; Valek, P.; Allegrini, F.; Connerney, J. E. P.; Mauk, B. H.; Bolton, S. J.; Levin, S. M.; Adriani, A.; Gladstone, G. R.; McComas, D. J.; Zarka, P.

    2017-09-01

    The Juno spacecraft successfully entered Jupiter orbit on 5 July 2016. One of Juno's primary objectives is to explore Jupiter's polar magnetosphere. An obvious major aspect of this exploration includes remote and in situ observations of Jupiter's auroras and the processes responsible for them. To this end, Juno carries a suite of particle, field, and remote sensing instruments. One of these instruments is a radio and plasma wave instrument called Waves, designed to detect one electric field component of waves in the frequency range of 50 Hz to 41 MHz and one magnetic field component of waves in the range of 50 Hz to 20 kHz. Juno has now made scientific observations on several perijove passes beginning with Perijove 1 on 27 August 2016. This paper presents some of the early observations of the Juno Waves instrument.

  15. Is Observation Mathematically-Laden?

    Directory of Open Access Journals (Sweden)

    Thomas Michael Muller

    2013-04-01

    Full Text Available In this article, we will defend the epistemological claim that observation is mathematically- laden. A well-known thesis in the philosophy of science is that observation is theory-laden. The claim that observation is mathematically laden can be similarly justified. The first part of the paper focuses on the definition of mathematically-ladeness and its relations to the best-known problem of theory-ladeness. The second part of the paper presents some explicit examples and outlines the consequences and the difficulties of this epistemological limit. Finally, a specific context for this problem is discussed in detail: we will analyze the question of deterministic chaos as a paradigmatic example of mathematically-ladeness and show that the deterministic or indeterministic nature of chaos is strongly linked to the choice of a particular mathematical description.

  16. GROUNDWATER QUALITY AND OBSERVATION WELLS

    Directory of Open Access Journals (Sweden)

    Mladen Zelenika

    1997-12-01

    Full Text Available Groundwater in the aquifers in river valleys is the mot important resource for supply of drinking water in many regions. There are intensive human activities, such as construction and operation hydroelectric power and industrial plants, forest clearance, irrigation and cropping of land, water supply and sanitation works, and particularly the accidental pollution in one town or country can reduce water availability to itself, and to another (downstream town or country. Observation wells are not commonly used for sampling of groundwater, but in many instances it may still be the only way to collect sample of groundwater. This paper deals with the construction of observation wells installed and developed in confined or unconfined aquifer to observe and monitor time depending data, such as water level, groundwater quality and indications of contaminant transport in groundwater flow.

  17. Theoretical and observational planetary physics

    Science.gov (United States)

    Caldwell, J.

    1986-01-01

    This program supports NASA's deep space exploration missions, particularly those to the outer Solar System, and also NASA's Earth-orbital astronomy missions, using ground-based observations, primarily with the NASA IRTF at Mauna Kea, Hawaii, and also with such instruments as the Kitt Peak 4 meter Mayall telescope and the NRAO VLA facility in Socorro, New Mexico. An important component of the program is the physical interpretation of the observations. There were two major scientific discoveries resulting from 8 micrometer observations of Jupiter. The first is that at that wavelength there are two spots, one near each magnetic pole, which are typically the brightest and therefore warmest places on the planet. The effect is clearly due to precipitating high energy magnetospheric particles. A second ground-based discovery is that in 1985, Jupiter exhibited low latitude (+ or - 18 deg.) stratospheric wave structure.

  18. Incremental Observer Relative Data Extraction

    DEFF Research Database (Denmark)

    Bukauskas, Linas; Bøhlen, Michael Hanspeter

    2004-01-01

    or a Panorama, where an observer is data space this approach is far from optimal. A more scalable approach is to make the observer-aware database system and to restrict the communication between the database and visualization systems to the relevant data. In this paper VR-tree, an extension of the R......The visual exploration of large databases calls for a tight coupling of database and visualization systems. Current visualization systems typically fetch all the data and organize it in a scene tree that is then used to render the visible data. For immersive data explorations in a Cave......-tree, is used to index visibility ranges of objects. We introduce a new operator for incremental Observer Relative data Extraction (iORDE). We propose the Volatile Access STructure (VAST), a lightweight main memory structure that is created on the fly and is maintained during visual data explorations. VAST...

  19. Window Observational Research Facility (WORF)

    Science.gov (United States)

    Pelfrey, Joseph; Sledd, Annette

    2007-01-01

    This viewgraph document concerns the Window Observational Research Facility (WORF) Rack, a unique facility designed for use with the US Lab Destiny Module window. WORF will provide valuable resources for Earth Science payloads along with serving the purpose of protecting the lab window. The facility can be used for remote sensing instrumentation test and validation in a shirt sleeve environment. WORF will also provide a training platform for crewmembers to do orbital observations of other planetary bodies. WORF payloads will be able to conduct terrestrial studies utilizing the data collected from utilizing WORF and the lab window.

  20. The Global Geodetic Observing System

    Science.gov (United States)

    Neilan, Ruth

    2017-04-01

    Global Geodetic Observing System GGOS - 2017 until 2019 International Association of Geodesy (IAG) Ruth Neilan Vice Chair GGOS NASA/Caletch/Jet Propulsion Laboratory, California USA This talk will provide an update on the status of the Global Geodetic Observing System (GGOS) and plans for the next years, until 2020. A summary of relationships of GGOS to other relevant international organizations will be defined. For this background, GGOS components work with the the International Association of Geodesy (IAG) and their IAG Scientific Services for integration of applications and their timely provision of data and products for geodesy and geoscience. Please see: http://www.iag-aig.org http://ggos.org

  1. Power laws for nuclear observables

    Science.gov (United States)

    Peterson, R. J.

    2018-01-01

    Often mass-dependent nuclear observables are summarized by fits to a power law in the nuclear mass A , as proportional to Aα. In this work a simple justification of this usage is presented, also providing a simple expression for the exponent α , with one known parameter being the beam-nucleon total cross section and another parameter being a nuclear size r0A1 /3 . Measured power-law exponents α for total and reaction cross sections are near this simple formulation using r0=1.6 fm , whereas quasifree observables are near the simple expression using r0=1.2 fm .

  2. Observation af kritisk syge patienter

    DEFF Research Database (Denmark)

    Fuhrmann, Lone; Hesselfeldt, Rasmus; Lippert, Anne

    2009-01-01

    . MATERIAL AND METHODS: Prospective observational study at Herlev Hospital, Copenhagen, Denmark. Study personnel measured vital signs on all patients present on five wards during the evening and night and interviewed nursing staff about patients with abnormal vital signs. Subsequently, patient records were...... vital signs measured by study personnel. A total of 77% of patients had vital signs documented in their records on the day of the observation. The previous day, vital signs were documented in 70% of records and on the day after in 66%. The documentation of vital signs was significantly higher when staff...

  3. $0^{++}$ Resonances Observed at BES

    OpenAIRE

    Zou, B. S.; Collaboration, for BES

    2008-01-01

    In last 10 years, $0^{++}$ resonances have been observed and studied at BES in many processes, such as $J/\\psi\\to\\gamma\\pi^+\\pi^-\\pi^+\\pi^-$, $\\gamma\\pi^+\\pi^-$, $\\gamma\\pi^0\\pi^0$, $\\gamma K^+K^-$, $\\gamma K_SK_S$, $\\gamma\\omega\\phi$, $\\omega\\pi^+\\pi^-$, $\\omega K^+K^-$, $\\phi\\pi^+\\pi^-$, $\\phi K^+K^-$, $\\psi(2S)\\to J/\\psi\\pi^+\\pi^-$, $\\chi_{c0}\\to\\pi^+\\pi^-K^+K^-$, $\\pi^+\\pi^-\\pi^+\\pi^-$ etc.. The results on $0^{++}$ resonances observed at BES are reviewed.

  4. Moving Observer Support for Databases

    DEFF Research Database (Denmark)

    Bukauskas, Linas

    . The thesis discusses the VR-tree, an extension of the R-tree that enables observer relative data extraction. To support incremental observer position relative data extraction the thesis proposes the Volatile Access Structure (VAST). VAST is a main memory structure that caches nodes of the VR-tree. VAST......Interactive visual data explorations impose rigid requirements on database and visualization systems. Systems that visualize huge amounts of data tend to request large amounts of memory resources and heavily use the CPU to process and visualize data. Current systems employ a loosely coupled...

  5. Observational Research Opportunities and Limitations

    Science.gov (United States)

    Boyko, Edward J.

    2013-01-01

    Medical research continues to progress in its ability to identify treatments and characteristics associated with benefits and adverse outcomes. The principle engine for the evaluation of treatment efficacy is the randomized controlled trial (RCT). Due to the cost and other considerations, RCTs cannot address all clinically important decisions. Observational research often is used to address issues not addressed or not addressable by RCTs. This article provides an overview of the benefits and limitations of observational research to serve as a guide to the interpretation of this category of research designs in diabetes investigations. The potential for bias is higher in observational research but there are design and analysis features that can address these concerns although not completely eliminate them. Pharmacoepidemiologic research may provide important information regarding relative safety and effectiveness of diabetes pharmaceuticals. Such research must effectively address the important issue of confounding by indication in order to produce clinically meaningful results. Other methods such as instrumental variable analysis are being employed to enable stronger causal inference but these methods also require fulfillment of several key assumptions that may or may not be realistic. Nearly all clinical decisions involve probabilistic reasoning and confronting uncertainly, so a realistic goal for observational research may not be the high standard set by RCTs but instead the level of certainty needed to influence a diagnostic or treatment decision. PMID:24055326

  6. Kepler observations of Am stars

    DEFF Research Database (Denmark)

    Balona, L. A.; Ripepi, V.; Cantanzaro, G.

    2011-01-01

    on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fondación Galileo Galilei of the Istituto Nazionale di Astrofisica (INAF), at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, and with the Mercator...

  7. The problem of passive observation

    NARCIS (Netherlands)

    Boumans, M.

    2010-01-01

    Trygve Haavelmo's methodological manifesto "The Probability Approach in Econometrics" not only laid down the paradigm for the research pursued at the Cowles Commission, but also sets out a strategy for measurement outside the laboratory. His conceptualization of "passive observation" is still very

  8. Sky Observations by the Book

    Science.gov (United States)

    Trundle, Kathy Cabe; Sackes, Mesut

    2008-01-01

    The "National Science Education Standards (NSES)" state that students in grades K-4 are expected to understand that astronomical objects in the sky, including the Sun, Moon, and stars--have properties, locations, and patterns of movement that can be observed and described. They further suggest using an inquiry-based approach to teach…

  9. Photometric Observations of 1969 Alain

    Science.gov (United States)

    Hayes-Gehrke, Melissa N.; Leffler, Taylor; Hampton, Karley; Chavis, Jacob; Fong, Josef; Wang, Yu; Hung, Andrew; Mahoney, James; Rizal, Muhammad Haziq Aiman Saiful Rizal

    2018-01-01

    CCD photometric observations of minor planet 1969 Alain by the T17 Telescope in Siding Spring, Australia in March and April 2017 were combined for lightcurve analysis. The combined data set led to a rotation period of P = 32.4 ± 0.4 h.

  10. Lookback Time: Observing Cosmic History.

    Science.gov (United States)

    Corwin, Mike; Wachowiak, Dale

    1989-01-01

    The difference in time between the emission and reception of light is called the "lookback" time. This article explores implications of lookback time and explains some of the puzzling questions posed by the scientific observation of cosmic history. Provides several pictures and diagrams. (YP)

  11. Tools for Observing our Universe

    Science.gov (United States)

    Wollack, Ed

    2008-01-01

    A selection of hands on demonstrations related to the detection of light will be presented to middle students. The primary emphasis of the talk will be on conveying how scientists use light to remotely observe and understand the properties of astrophysical systems.

  12. Observational Effects of Strange Stars

    OpenAIRE

    Lu, T.

    1998-01-01

    In this talk, after briefly reviewing some historical remarks concerning strange stars, the achievements in physics and dynamical behavior of strange stars are discussed. Especially, various observational effects in distinguishing strange stars from neutron stars such as mechanical effects, cooling effects, phase transition and related interesting phenomena are stressed.

  13. Trends in Classroom Observation Scores

    Science.gov (United States)

    Casabianca, Jodi M.; Lockwood, J. R.; McCaffrey, Daniel F.

    2015-01-01

    Observations and ratings of classroom teaching and interactions collected over time are susceptible to trends in both the quality of instruction and rater behavior. These trends have potential implications for inferences about teaching and for study design. We use scores on the Classroom Assessment Scoring System-Secondary (CLASS-S) protocol from…

  14. Spitzer Observations Of IC 2118

    Science.gov (United States)

    2010-09-01

    YSOs, it 14 Some of our high school students, trained in observational techniques using the Sloan Digital Sky Survey Galaxy Zoo , participated in this...Strasbourg, France . This research has made use of data products from the Two Micron All-Sky Sur- vey (2MASS), which is a joint project of the

  15. Participant observation in risk problems

    NARCIS (Netherlands)

    Andriessen, H.; Kluin, M.H.A.; Van Gulijk, C.; Ale, B.J.M.

    2012-01-01

    Participant observation is a method to collect information through active participation in the social world that is under study, in this case two different risk-related working areas where confidentiality and secrecy are paramount. In reality there is a difference between what people do and say they

  16. Observation of relativistic antihydrogen atoms

    Energy Technology Data Exchange (ETDEWEB)

    Blanford, Glenn DelFosse

    1998-01-01

    An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

  17. Complexity of infimal observable superlanguages

    Czech Academy of Sciences Publication Activity Database

    Masopust, Tomáš

    2018-01-01

    Roč. 63, č. 1 (2018), s. 249-254 ISSN 0018-9286 Institutional support: RVO:67985840 Keywords : discrete event systems * observable language * complexity Subject RIV: BA - General Mathematics Impact factor: 4.270, year: 2016 http://ieeexplore.ieee.org/document/7962165/

  18. Bose-Einstein Condensation Observed

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. Bose-Einstein Condensation Observed. Rajaram Nityananda. Research News Volume 1 Issue 2 February 1996 pp 111-114. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/02/0111-0114 ...

  19. Observation, Serendipity, and Climatic Change

    Science.gov (United States)

    Schaefer, Vincent J.

    1974-01-01

    Provides an illustration of the contribution of serendipitous happenings to scientific information and relates this to a consideration of social and technical problems confronting mankind. The author decries an unfortunate tendency in science today: that of discarding observational aspects of field activities which cannot easily be made…

  20. Observation of $W \\to \\mu \

    Energy Technology Data Exchange (ETDEWEB)

    Westhusing, Thomas Kevin [Univ. of Illinois, Urbana-Champaign, IL (United States)

    1988-12-01

    The production and subsequent decay to muon and neutrino of the W intermediate vector boson has been observed in $\\bar{p}$p collisions at a center of mass energy of 1.8 TeV at the Fermilab Tevatron collider.

  1. Optical Observations of Space Debris

    Science.gov (United States)

    Seitzer, Patrick; Abercromby, Kira; Rodriquez, Heather; Barker, Edwin S.; Kelecy, Thomas

    2008-01-01

    This viewgraph presentation reviews the use of optical telescopes to observe space debris. .It will present a brief review of how the survey is conducted, and what some of the significant results encompass. The goal is to characterize the population of debris objects at GEO, with emphasis on the faint object population. Because the survey observations extend over a very short arc (5 minutes), a full six parameter orbit can not be determined. Recently we have begun to use a second telescope, the 0.9-m at CTIO, as a chase telescope to do follow-up observations of potential GEO debris candidates found by MODEST. With a long enough sequence of observations, a full six-parameter orbit including eccentricity can be determined. The project has used STK since inception for planning observing sessions based on the distribution of bright cataloged objects and the anti-solar point (to avoid eclipse). Recently, AGI's Orbit Determination Tool Kit (ODTK) has been used to determine orbits, including the effects of solar radiation pressure. Since an unknown fraction of the faint debris at GEO has a high area-to-mass ratio (A/M), the orbits are perturbed significantly by solar radiation. The ODTK analysis results indicate that temporal variations in the solar perturbations, possibly due to debris orientation dynamics, can be estimated in the OD process. Additionally, the best results appear to be achieved when solar forces orthogonal to the object-Sun line are considered. Determining the A/M of individual objects and the distribution of A/M values of a large sample of debris is important to understanding the total population of debris at GEO

  2. Herschel Observations of Interstellar Chloronium

    Science.gov (United States)

    Neufeld, David A.; Roueff, Evelyne; Snell, Ronald L.; Lis, Dariusz; Benz, Arnold O.; Bruderer, Simon; Black, John H.; De Luca, Massimo; Gerin, Maryvonne; Goldsmith, Paul F.; Gupta, Harshal; Indriolo, Nick; Le Bourlot, Jacques; Le Petit, Franck; Larsson, Bengt; Melnick, Gary J.; Menten, Karl M.; Monje, Raquel; Nagy, Zsófia; Phillips, Thomas G.; Sandqvist, Aage; Sonnentrucker, Paule; van der Tak, Floris; Wolfire, Mark G.

    2012-03-01

    Using the Herschel Space Observatory's Heterodyne Instrument for the Far-Infrared, we have observed para-chloronium (H2Cl+) toward six sources in the Galaxy. We detected interstellar chloronium absorption in foreground molecular clouds along the sight lines to the bright submillimeter continuum sources Sgr A (+50 km s-1 cloud) and W31C. Both the para-H35 2Cl+ and para-H37 2Cl+ isotopologues were detected, through observations of their 111-000 transitions at rest frequencies of 485.42 and 484.23 GHz, respectively. For an assumed ortho-to-para ratio (OPR) of 3, the observed optical depths imply that chloronium accounts for ~4%-12% of chlorine nuclei in the gas phase. We detected interstellar chloronium emission from two sources in the Orion Molecular Cloud 1: the Orion Bar photodissociation region and the Orion South condensation. For an assumed OPR of 3 for chloronium, the observed emission line fluxes imply total beam-averaged column densities of ~2 × 1013 cm-2 and ~1.2 × 1013 cm-2, respectively, for chloronium in these two sources. We obtained upper limits on the para-H35 2Cl+ line strengths toward H2 Peak 1 in the Orion Molecular cloud and toward the massive young star AFGL 2591. The chloronium abundances inferred in this study are typically at least a factor ~10 larger than the predictions of steady-state theoretical models for the chemistry of interstellar molecules containing chlorine. Several explanations for this discrepancy were investigated, but none has proven satisfactory, and thus the large observed abundances of chloronium remain puzzling. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  3. Observational consequences of a landscape

    Science.gov (United States)

    Freivogel, Ben; Kleban, Matthew; Rodríguez Martínez, María; Susskind, Leonard

    2006-03-01

    In this paper we consider the implications of the ``landscape" paradigm [1], [2] for the large scale properties of the universe. The most direct implication of a rich landscape is that our local universe was born in a tunnelling event from a neighboring vacuum. This would imply that we live in an open FRW universe with negative spatial curvature. We argue that the ``overshoot" problem, which in other settings would make it difficult to achieve slow roll inflation, actually favors such a cosmology. We consider anthropic bounds on the value of the curvature and on the parameters of inflation. When supplemented by statistical arguments these bounds suggest that the number of inflationary efolds is not very much larger than the observed lower bound. Although not statistically favored, the likelihood that the number of efolds is close to the bound set by observations is not negligible. The possible signatures of such a low number of efolds are briefly described.

  4. Solar System Observations with JWST

    Science.gov (United States)

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; hide

    2014-01-01

    The James Webb Space Telescope will enable a wealth of new scientific investigations in the near- and mid- infrared, with sensitivity and spatial-spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010 (Lunine et al., 2010). It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV in 2012.

  5. INTEGRAL Observations of GW170104

    DEFF Research Database (Denmark)

    Savchenko, V.; Ferrigno, C.; Bozzo, E.

    2017-01-01

    We used data from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) to set upper limits on the γ-ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration...... the INTEGRAL observations range from F γ = 1.9 × 10−7 erg cm−2 to F γ = 10−6 erg cm−2 (75 keV–2 MeV energy range). This translates into a ratio between the prompt energy released in γ-rays along the direction to the observer and the gravitational-wave energy of E γ /E GW

  6. Identifying Causality from Alarm Observations

    DEFF Research Database (Denmark)

    Kirchhübel, Denis; Zhang, Xinxin; Lind, Morten

    on an abstracted model of the mass and energy flows in the system. The application of MFM for root cause analysis based alarm grouping has been demonstrated and can be extended to reason about the direction of causality considering the entirety of the alarms present in the system for more comprehensive decision...... and consequences. This extended analysis results in causal paths from likely root causes to tentative consequences, providing the operator with a comprehensive tool to not only identify but also rank the criticality of a large number of concurrent alarms in the system....... support. This contribution presents the foundation for combining the cause and consequence propagation of multiple observations from the system based on an MFM model. The proposed logical reasoning matches actually observed alarms to the propagation analysis in MFM to distinguish plausible causes...

  7. Chaos problems in observer's mathematics

    Science.gov (United States)

    Khots, Boris; Khots, Dmitriy

    This work considers the solution of Cauchy problem (initial value problem) in a setting of arithmetic, algebra, and topology provided by Observer's Mathematics (see www.mathrelativity.com) and applies this solution to free wave equation, the linear (time-dependent) Schrodinger equation, the (time-dependent) Airy equation, the Korteweg-de Vries (KdV) equation, and quantum theory of two-slit interference. Certain results and communications pertaining to these problems are provided.

  8. Physics observables for color transparency

    OpenAIRE

    Pire, Bernard

    1997-01-01

    The physics observables dedicated to the study of color transparency are diverse. After a brief pedagogical introduction, we emphasize the complementarity of the nuclear filtering and color transparency concepts. The importance of quantum interferences leads to suspect pictures based on the preparation of a squeezed state of small transverse size leading to a rapid transverse expansion. The different roles of heavy and light nuclei are emphasized. The possibility of color transparency tests i...

  9. Satellite Observations of Tropospheric Ammonia

    Science.gov (United States)

    Shephard, M. W.; Luo, M.; Rinsland, C. P.; Cady-Pereira, K. E.; Beer, R.; Pinder, R. W.; Henze, D.; Payne, V. H.; Clough, S.; Rodgers, C. D.; Osterman, G. B.; Bowman, K. W.; Worden, H. M.

    2008-12-01

    Global high-spectral resolution (0.06 cm-1) nadir measurements from TES-Aura enable the simultaneous retrieval of a number of tropospheric pollutants and trace gases in addition to the TES standard operationally retrieved products (e.g. carbon monoxide, ozone). Ammonia (NH3) is one of the additional species that can be retrieved in conjunction with the TES standard products, and is important for local, regional, and global tropospheric chemistry studies. Ammonia emissions contribute significantly to several well-known environmental problems, yet the magnitude and seasonal/spatial variability of the emissions are poorly constrained. In the atmosphere, an important fraction of fine particulate matter is composed of ammonium nitrate and ammonium sulfate. These particles are statistically associated with health impacts. When deposited to ecosystems in excess, nitrogen, including ammonia can cause nutrient imbalances, change in ecosystem species composition, eutrophication, algal blooms and hypoxia. Ammonia is also challenging to measure in-situ. Observations of surface concentrations are rare and are particularly sparse in North America. Satellite observations of ammonia are therefore highly desirable. We recently demonstrated that tropospheric ammonia is detectable in the TES spectra and presented some corresponding preliminary retrievals over a very limited range of conditions (Beer et al., 2008). Presented here are results that expand upon these initial TES ammonia retrievals in order to evaluate/validate the retrieval results utilizing in-situ surface observations (e.g. LADCO, CASTNet, EPA /NC State) and chemical models (e.g. GEOS-Chem and CMAQ). We also present retrievals over regions of interest that have the potential to help further understand air quality and the active nitrogen cycle. Beer, R., M. W. Shephard, S. S. Kulawik, S. A. Clough, A. Eldering, K. W. Bowman, S. P. Sander, B. M. Fisher, V. H. Payne, M. Luo, G. B. Osterman, and J. R. Worden, First

  10. Observations of Local Seychelles Circulation

    Science.gov (United States)

    2015-09-30

    for numerical modeling. A nominal observational array is illustrated in Figure 2. Available components will include: • ADCP + thermistor chain...star, 2 locations): bottom-mounted 600 kHz ADCP with a nearby thermistor chain (8-10 SBE 56s with 1 SBE37 CT) to enable resolution of currents...locations with bottom moored ADCPs to resolve currents, stratification and internal wave energy fluxes. • PUV array (triangles, 2 location): bottom

  11. Observing urban forests in Australia

    Science.gov (United States)

    E.G. McPherson

    2009-01-01

    From February 13 to 28, 2009 I had the good fortune of visiting Australia, and touring urban forests in Sydney, Canberra, Brisbane, and Melbourne. My visits were only a day or two in each city, so in no case did I get an in-depth view of the urban forest resource or its management. The following observations are based on rather superficial field assessments and brief...

  12. Early BHs: simulations and observations

    Science.gov (United States)

    Cappelluti, Nico; di-Matteo, Tiziana; Schawinski, Kevin; Fragos, Tassos

    We report recent investigations in the field of Early Black Holes. We summarize recent theoretical and observational efforts to understand how Black Holes formed and eventually evolved into Super Massive Black Holes at high-z. This paper makes use of state of the art computer simulations and multiwavelength surveys. Although non conclusive, we present results and hypothesis that pose exciting challenges to modern astrophysics and to future facilities.

  13. [Observation of critically ill patients

    DEFF Research Database (Denmark)

    Fuhrmann, L.; Hesselfeldt, R.; Lippert, A.

    2009-01-01

    . MATERIAL AND METHODS: Prospective observational study at Herlev Hospital, Copenhagen, Denmark. Study personnel measured vital signs on all patients present on five wards during the evening and night and interviewed nursing staff about patients with abnormal vital signs. Subsequently, patient records were...... not measured. In two out of three patients, staff decided to intervene because of abnormal vital signs measured by study personnel, indicating a need to reevaluate monitoring routines at general wards Udgivelsesdato: 2009/2/9...

  14. Observation af kritisk syge patienter

    DEFF Research Database (Denmark)

    Fuhrmann, Lone; Hesselfeldt, Rasmus; Lippert, Anne

    2009-01-01

    . MATERIAL AND METHODS: Prospective observational study at Herlev Hospital, Copenhagen, Denmark. Study personnel measured vital signs on all patients present on five wards during the evening and night and interviewed nursing staff about patients with abnormal vital signs. Subsequently, patient records were...... not measured. In two out of three patients, staff decided to intervene because of abnormal vital signs measured by study personnel, indicating a need to reevaluate monitoring routines at general wards. Udgivelsesdato: 2009-Feb...

  15. Observation Predicates in Flow Logic

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Sun, Hongyan

    2003-01-01

    in such a way that the hard constraints are satisfi ed exactly when the observation predicates report no violations. The development is carried out in a large fragment of a first order logic with negation and also takes care of the transformations necessary in order to adhere to the stratification restrictions...... inherent in Alternation-free Least Fixed Point Logic and similar formalisms such as Datalog....

  16. β-Amyloid1-42, HIV-1Ba-L (clade B infection and drugs of abuse induced degeneration in human neuronal cells and protective effects of ashwagandha (Withania somnifera and its constituent Withanolide A.

    Directory of Open Access Journals (Sweden)

    Kesava Rao Venkata Kurapati

    Full Text Available Alzheimer's disease (AD is characterized by progressive dysfunction of memory and higher cognitive functions with abnormal accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles throughout cortical and limbic brain regions. Withania somnifera (WS also known as 'ashwagandha' (ASH is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer. However, there is paucity of data on potential neuroprotective effects of ASH against β-Amyloid (1-42 (Aβ induced neuropathogenesis. In the present study, we have tested the neuroprotective effects of Methanol: Chloroform (3:1 extract of ASH and its constituent Withanolide A (WA against Aβ induced toxicity, HIV-1(Ba-L (clade B infection and the effects of drugs of abuse using a human neuronal SK-N-MC cell line. Aβ when tested individually, induced cytotoxic effects in SK-N-MC cells as shown by increased trypan blue stained cells. However, when ASH was added to Aβ treated cells the toxic effects were neutralized. This observation was supported by cellular localization of Aβ, MTT formazan exocytosis, and the levels of acetylcholinesterase activity, confirming the chemopreventive or protective effects of ASH against Aβ induced toxicity. Further, the levels of MAP2 were significantly increased in cells infected with HIV-1(Ba-L (clade B as well as in cells treated with Cocaine (COC and Methamphetamine (METH compared with control cells. In ASH treated cells the MAP2 levels were significantly less compared to controls. Similar results were observed in combination experiments. Also, WA, a purified constituent of ASH, showed same pattern using MTT assay as a parameter. These results suggests that neuroprotective properties of ASH observed in the present study may provide some explanation for the ethnopharmacological uses of ASH in traditional medicine for cognitive and other HIV associated neurodegenerative disorders and further ASH could be a potential novel drug to

  17. [An autopsy case of senile dementia suspected to be influenced by cerebral amyloid angiopathy with multiple cortical microinfarcts].

    Science.gov (United States)

    Iwasaki, Yasushi; Mori, Keiko; Ito, Masumi; Deguchi, Akira; Shiraishi, Taizo; Mimuro, Maya; Yoshida, Mari; Hashizume, Yoshio

    2010-09-01

    A Japanese male showed gradually progressing dementia with psychiatric symptoms including abnormal behavior, night and day reversal, nocturnal delirium, loud shouting, agitation, resistance to care, and loud soliloquy. The patient had a history of right cerebral embolism due to atrial fibrillation 1 month before the onset of dementia. Head CT revealed widespread cerebral infarction in the right cerebral hemisphere with bilateral lateral ventricular dilatation. The patient died at the age of 83, 10 months after the onset of cerebral embolism. The clinical diagnosis was mixed-type dementia. On autopsy the brain weighed 1,160 g. Widespread cerebral amyloid angiopathy (CAA) was observed, with distribution most severe in the cerebral cortical vessels and slightly milder in the leptomeningial and subarachnoid vessels. The artery, arteriole, and capillary walls were thickened by the deposition of amorphous, eosinophilic and beta-protein immunopositive amyloid. Abeta-deposition was more severe in capillaries and CAA tended to be more severe in the occipital regions. Multiple cortical microinfarcts were found, particularly in the crests of the cerebral gyri of watershed zones. Cerebral white matter, basal ganglia, thalamus, brainstem and spinal cord were relatively preserved from CAA. Infarction was not apparent, except for an embolic lesion in the right cerebral hemisphere and the cortical microinfarcts. We did not observe fibrinoid necrosis, granulomatous angiitis or giant cell reaction associated with CAA-vasculopathies. Rare instances were observed of neurofibrillary tangles and senile plaques corresponding to Braak stages II and A, respectively. We thought the multiple cortical microinfarcts occurred due to chronic hypoperfusion associated with CAA-associated vasculopathies of capillaries in the cerebral cortex. We suspected that the dementia was influenced by the CAA with multiple cortical microinfarcts. Pathologic findings of the patient suggest that CAA without AD

  18. Brain lesions at autopsy in older Japanese-American men as related to cognitive impairment and dementia in the final years of life: a summary report from the Honolulu-Asia aging study.

    Science.gov (United States)

    White, Lon

    2009-01-01

    This report summarizes findings from 443 autopsies on Japanese-American men followed as active participants in the Honolulu-Asia Aging Study from 1991 through 2003. Five distinct neuropathological lesion types were found to have strong, partially, or completely independent associations with cognitive impairment and/or dementia in the final years of life. They were: Alzheimer lesions (neocortical neurofibrillary tangles and neuritic plaques), microvascular infarcts (microinfarcts and lacunar infarcts), neocortical Lewy bodies, hippocampal sclerosis, and generalized brain atrophy. Atrophy was strongly associated with both Alzheimer lesions and microvascular infarcts, but was also observed in decedents with negligible levels of these and the other lesions. About half of the hippocampal sclerosis cases appeared to be linked to Alzheimer lesions. A weak association of hippocampal sclerosis with microvascular infarcts was also noted. Comparable 3-level indices were defined for each of the five lesion types to facilitate comparisons of associations with cognitive impairment and dementia. Multiple combinations of the five lesion types were observed. The development of dementia in the final years of life was more closely correlated with their combined numbers and severities than with specific lesion types. In this autopsy panel, microvascular infarcts were identified as the sole or dominant lesion in 33.8% of the demented or definitely impaired decedents, compared with Alzheimer lesions in 18.6% and co-dominant lesions (most often Alzheimer and microvascular) in 14.2%. These or one or more of the other lesion types were observed in 87.9% of the demented or definitely impaired decedents.

  19. β-Amyloid1-42, HIV-1Ba-L (clade B) infection and drugs of abuse induced degeneration in human neuronal cells and protective effects of ashwagandha (Withania somnifera) and its constituent Withanolide A.

    Science.gov (United States)

    Kurapati, Kesava Rao Venkata; Samikkannu, Thangavel; Atluri, Venkata Subba Rao; Kaftanovskaya, Elena; Yndart, Adriana; Nair, Madhavan P N

    2014-01-01

    Alzheimer's disease (AD) is characterized by progressive dysfunction of memory and higher cognitive functions with abnormal accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles throughout cortical and limbic brain regions. Withania somnifera (WS) also known as 'ashwagandha' (ASH) is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer. However, there is paucity of data on potential neuroprotective effects of ASH against β-Amyloid (1-42) (Aβ) induced neuropathogenesis. In the present study, we have tested the neuroprotective effects of Methanol: Chloroform (3:1) extract of ASH and its constituent Withanolide A (WA) against Aβ induced toxicity, HIV-1(Ba-L) (clade B) infection and the effects of drugs of abuse using a human neuronal SK-N-MC cell line. Aβ when tested individually, induced cytotoxic effects in SK-N-MC cells as shown by increased trypan blue stained cells. However, when ASH was added to Aβ treated cells the toxic effects were neutralized. This observation was supported by cellular localization of Aβ, MTT formazan exocytosis, and the levels of acetylcholinesterase activity, confirming the chemopreventive or protective effects of ASH against Aβ induced toxicity. Further, the levels of MAP2 were significantly increased in cells infected with HIV-1(Ba-L) (clade B) as well as in cells treated with Cocaine (COC) and Methamphetamine (METH) compared with control cells. In ASH treated cells the MAP2 levels were significantly less compared to controls. Similar results were observed in combination experiments. Also, WA, a purified constituent of ASH, showed same pattern using MTT assay as a parameter. These results suggests that neuroprotective properties of ASH observed in the present study may provide some explanation for the ethnopharmacological uses of ASH in traditional medicine for cognitive and other HIV associated neurodegenerative disorders and further ASH could be a potential novel drug to reduce

  20. THE EARTH OBSERVATION TECHNOLOGY CLUSTER

    Directory of Open Access Journals (Sweden)

    P. Aplin

    2012-07-01

    Full Text Available The Earth Observation Technology Cluster is a knowledge exchange initiative, promoting development, understanding and communication about innovative technology used in remote sensing of the terrestrial or land surface. This initiative provides an opportunity for presentation of novel developments from, and cross-fertilisation of ideas between, the many and diverse members of the terrestrial remote sensing community. The Earth Observation Technology Cluster involves a range of knowledge exchange activities, including organisation of technical events, delivery of educational materials, publication of scientific findings and development of a coherent terrestrial EO community. The initiative as a whole covers the full range of remote sensing operation, from new platform and sensor development, through image retrieval and analysis, to data applications and environmental modelling. However, certain topical and strategic themes have been selected for detailed investigation: (1 Unpiloted Aerial Vehicles, (2 Terrestrial Laser Scanning, (3 Field-Based Fourier Transform Infra-Red Spectroscopy, (4 Hypertemporal Image Analysis, and (5 Circumpolar and Cryospheric Application. This paper presents general activities and achievements of the Earth Observation Technology Cluster, and reviews state-of-the-art developments in the five specific thematic areas.

  1. Hue discrimination in Iberoamerican Observers

    Science.gov (United States)

    Carranza, Jazmín; Medina, Juana

    2008-04-01

    In this work we analyze the Farnsworth Munsell 100 Hue Test results, this test offers a simple method for testing color discrimination and was applied to a sample of 129 observers, with natural daylight in the same conditions (the observers were men and women), all of these were participants in colorimetric training courses, and aged 20 to 76, with two to twenty five years experience in the color control manufacturer laboratories (of plastics, rugs, dyes, textiles, and paints). Their job titles included mixers, inspectors, shaders, matchers, passers, and dyers. The test was applied twice and the results here presented are the comparison between both tests, taking into account errors by mistakes incidence in each hue position, as well as the redeeming of each participant in both test. The comparison shows us that most of the mistakes are in the green hue in both tests, but in the second test, approximately 20 percent of the observers reduced those. Also we can to separate persons with normal color vision of those which have zones of color confusion. In this work it is show some ones results of the comparison between men and women.

  2. Observation of geo-neutrinos

    Science.gov (United States)

    Bellini, G.; Benziger, J.; Bonetti, S.; Avanzini, M. Buizza; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Chavarria, A.; Dalnoki-Veress, F.; D'Angelo, D.; Davini, S.; de Kerret, H.; Derbin, A.; Etenko, A.; Fiorentini, G.; Fomenko, K.; Franco, D.; Galbiati, C.; Gazzana, S.; Ghiano, C.; Giammarchi, M.; Goeger-Neff, M.; Goretti, A.; Guardincerri, E.; Hardy, S.; Ianni, Aldo; Ianni, Andrea; Joyce, M.; Kobychev, V. V.; Koshio, Y.; Korga, G.; Kryn, D.; Laubenstein, M.; Leung, M.; Lewke, T.; Litvinovich, E.; Loer, B.; Lombardi, P.; Ludhova, L.; Machulin, I.; Manecki, S.; Maneschg, W.; Manuzio, G.; Meindl, Q.; Meroni, E.; Miramonti, L.; Misiaszek, M.; Montanari, D.; Muratova, V.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Perasso, S.; Pocar, A.; Raghavan, R. S.; Ranucci, G.; Razeto, A.; Re, A.; Ricci, B.; Risso, P.; Romani, A.; Rountree, D.; Sabelnikov, A.; Saldanha, R.; Salvo, C.; Schönert, S.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Vignaud, D.; Vogelaar, R. B.; von Feilitzsch, F.; Winter, J.; Wojcik, M.; Wright, A.; Wurm, M.; Xu, J.; Zaimidoroga, O.; Zavatarelli, S.; Zuzel, G.; Borexino Collaboration

    2010-04-01

    Geo-neutrinos, electron anti-neutrinos produced in β decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet's interior. We report the first observation at more than 3σ C.L. of geo-neutrinos, performed with the Borexino detector at Laboratori Nazionali del Gran Sasso. Anti-neutrinos are detected through the neutron inverse β decay reaction. With a 252.6 ton yr fiducial exposure after all selection cuts, we detected 9.9+4.1-3.4(+14.6-8.2) geo-neutrino events, with errors corresponding to a 68.3% (99.73%) C.L. From the ln L profile, the statistical significance of the Borexino geo-neutrino observation corresponds to a 99.997% C.L. Our measurement of the geo-neutrinos rate is 3.9+1.6-1.3(+5.8-3.2) events/(100 ton yr). The observed prompt positron spectrum above 2.6 MeV is compatible with that expected from European nuclear reactors (mean base line of approximately 1000 km). Our measurement of reactor anti-neutrinos excludes the non-oscillation hypothesis at 99.60% C.L. This measurement rejects the hypothesis of an active geo-reactor in the Earth's core with a power above 3 TW at 95% C.L.

  3. INTEGRAL Observations of GW170104

    Science.gov (United States)

    Savchenko, V.; Ferrigno, C.; Bozzo, E.; Bazzano, A.; Brandt, S.; Chenevez, J.; Courvoisier, T. J.-L.; Diehl, R.; Hanlon, L.; von Kienlin, A.; Kuulkers, E.; Laurent, P.; Lebrun, F.; Lutovinov, A.; Martin-Carillo, A.; Mereghetti, S.; Roques, J. P.; Sunyaev, R.; Ubertini, P.

    2017-09-01

    We used data from the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) to set upper limits on the γ-ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration. The unique omnidirectional viewing capability of the instruments on board INTEGRAL allowed us to examine the full 90% confidence level localization region of the LIGO trigger. Depending on the particular spectral model assumed and the specific position within this region, the upper limits inferred from the INTEGRAL observations range from F γ = 1.9 × 10-7 erg cm-2 to F γ = 10-6 erg cm-2 (75 keV-2 MeV energy range). This translates into a ratio between the prompt energy released in γ-rays along the direction to the observer and the gravitational-wave energy of E γ /E GW relatively limited portion of the sky where the sensitivity of the INTEGRAL instruments was not optimal and the lowest-allowed fluence estimated for E2 would still be compatible with the INTEGRAL results. This region was also observed independently by Fermi/Gamma-ray Burst Monitor and AstroSAT, from which, as far as we are aware, there are no reports of any significant detection of a prompt high-energy event.

  4. Observer perspective imagery with stuttering.

    Science.gov (United States)

    Lowe, Robyn; Menzies, Ross; Packman, Ann; O'Brian, Sue; Onslow, Mark

    2015-01-01

    Adults who stutter are at risk of developing a range of psychological conditions. Social anxiety disorder is the most common anxiety disorder associated with stuttering. Observer perspective imagery is one cognitive process involved in the maintenance of some anxiety disorders. This involves viewing images as if looking at the self from the perspective of another. In contrast, the field perspective involves looking out from the self at the surrounding environment. The purpose of this study was to assess the presence of observer perspective imagery with stuttering. The authors administered the Hackmann, Surawy and Clark (1998) semi-structured interview to 30 adults who stutter and 30 controls. Group images and impressions were compared for frequency, perspective recalled and emotional valence. The stuttering group was significantly more likely than controls to recall images and impressions from an observer rather than a field perspective for anxious situations. It is possible the present results could reflect the same attentional processing bias that occurs with anxiety disorders in the non-stuttering population. These preliminary results provide an explanation for the persistence of conditions such as social anxiety disorder with stuttering. Clinical implications are discussed.

  5. Observations of 44i Bootis

    Science.gov (United States)

    Jurgenson, C.; Price, M. E.; Pereira, M.; Macinnes, D.; Snodgrass, H. B.

    1999-05-01

    Seven times of minimum were obtained for the W Ursae Majoris type system 44i Bootis; three primary and four secondary. These observations were taken using a 10-inch Newtonian reflector and 1P21 photomultiplier at Lewis & Clark College. Our times of minimum are used with previously observed minimum times for plotting an (o-c) curve to generate a function that describes how the system's ~ 6.5 hr. period is changing over time. After applying a parabolic least squares fit to the (o-c) curve we obtain a quadratic function F(E), where E is the eclipse number. Adding this to the 1991 ephemeris of Oprescu, we obtain a corrected non-linear ephemeris JD 2443604.5919 + 0.26781665 E + 5.9 x10(-11) E(2) . From this we find, in agreement with past observations, that the period of 44i Bootis is increasing over time, and determine the rate of increase. This work was supported by Partners in Science Grant HS0485, an M. J. Murdock Charitable Trust Award of Research Corporation.

  6. Biologic relativity: Who is the observer and what is observed?

    Science.gov (United States)

    Torday, John S; Miller, William B

    2016-05-01

    When quantum physics and biological phenomena are analogously explored, it emerges that biologic causation must also be understood independently of its overt appearance. This is similar to the manner in which Bohm characterized the explicate versus the implicate order as overlapping frames of ambiguity. Placed in this context, the variables affecting epigenetic inheritance can be properly assessed as a key mechanistic principle of evolution that significantly alters our understanding of homeostasis, pleiotropy, and heterochrony, and the purposes of sexual reproduction. Each of these become differing manifestations of a new biological relativity in which biologic space-time becomes its own frame. In such relativistic cellular contexts, it is proper to question exactly who has observer status, and who and what are being observed. Consideration within this frame reduces biology to cellular information sharing through cell-cell communication to resolve ambiguities at every scope and scale. In consequence, it becomes implicit that eukaryotic evolution derives from the unicellular state, remaining consistently adherent to it in a continuous evolutionary arc based upon elemental, non-stochastic physiologic first principles. Furthermore, the entire cell including its cytoskeletal apparatus and membranes that participate in the resolution of biological uncertainties must be considered as having equivalent primacy with genomes in evolutionary terms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Observations of a Windy Star

    Science.gov (United States)

    Kohler, Susanna

    2017-06-01

    Hubble view of the Homunculus Nebula surrounding Eta Carinae [NASA Hubble Space Telescope/Jon Morse (University of Colorado)]The incredibly luminous massive star Eta Carinae has long posed a challenge for astronomers to model. New observations are now in so were our models correct?Dramatic TargetThe massive evolved star Eta Carinae, located 7,500 light-years away in the constellation Carina, is the most luminous star in the Milky Way. Eta Carinae has a quite a reputation for drama: it has been very unstable in the past, exhibiting repeated eruptions that have created the spectacular Homunculus Nebula surrounding it. Its present-day wind has the highest mass-loss rate of any hot star weve observed.Picture of Stellar WindTop panel: February 2017 observations of Eta Carinae in continuum (left) and H-alpha. Middle panel: the normalized radial profile for H-alpha and continuum emission. Bottom panel: the full width at half maximum for H-alpha and continuum emission of Eta Carinae. The H-alpha is about 2.5 to 3 milliarcseconds wider than the continuum. [Adapted from Wu et al. 2017]In our goal to understand the late evolutionary phases of very massive stars, weve developed radiative-transfer models to explain the behavior of Eta Carinae. One of the most well-known models, developed by John Hillier and collaborators in 2001, describes Eta Carinaes mass loss via stellar winds. With the right observations, this model is testable, since it predicts observable locations for different types of emission. In particular, one prediction of the Hillier et al. model is that the dense, ionized winds surrounding the star should emit in H-alpha at distances between 6 and 60 AU, with a peak around 20 AU.This nicely testable hypothesis is rendered less convenient by the fact that its hard to get resolved images of Eta Carinaes H-alpha emission. Its distance from us and the fact that its shrouded in the complex nebula it created have thus far prevented us from resolving the H

  8. Remote Observational Techniques in Education

    Science.gov (United States)

    Thieman, J.; Mayo, L.

    2002-09-01

    The ability to observe celestial objects remotely is making a major impact into classroom access to astronomical instrumentation previously impossible to encorporate into curriculum. Two programs, Radio Jove and Telescopes In Education have made important contributions in this field. Radio JOVE is an interactive, hands-on, educational activity for learning the scientific method through the medium of radio observations of Jupiter, the Sun, and the galactic radio background. Students build radio receivers from relatively inexpensive non-profit kits (about \\$125 plus shipping) and use them to record data, analyze the data, and share the results with others. Alternatively, for no cost, the students can record and analyze data from remote radio receivers connected to the web. The projects are useful adjuncts to activities in optical observing since students should recognize that we learn about the universe through more than just the optical spectrum. The projects are mini-electronics courses and also teach about charged particles and magnetic fields. The Radio JOVE web site (http://radiojove.gsfc.nasa.gov) should be consulted for further information. The NASA-sponsored Telescopes In Education (TIE) network (http://tie.jpl.nasa.gov) has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. These telescopesare integrated seamlessly into one virtual observatory providing the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J

  9. INTEGRAL Observations of GW170104

    Energy Technology Data Exchange (ETDEWEB)

    Savchenko, V.; Ferrigno, C.; Bozzo, E.; Courvoisier, T. J.-L. [ISDC, Department of Astronomy, University of Geneva, chemin d’Écogia, 16 CH-1290 Versoix (Switzerland); Bazzano, A. [INAF-Institute for Space Astrophysics and Planetology, Via Fosso del Cavaliere 100, I-00133-Rome (Italy); Brandt, S.; Chenevez, J.; Ubertini, P. [DTU Space—National Space Institute Elektrovej, Building 327, DK-2800 Kongens Lyngby (Denmark); Diehl, R.; Von Kienlin, A. [Max-Planck-Institut für Extraterrestrische Physik, Garching (Germany); Hanlon, L.; Martin-Carillo, A. [Space Science Group, School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Kuulkers, E. [European Space Research and Technology Centre (ESA/ESTEC), Keplerlaan 1, 2201 AZ Noordwijk (Netherlands); Laurent, P. [APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris Sorbonne Paris Cité, 10 rue Alice Domont et Léonie Duquet, F-75205 Paris Cedex 13 (France); Lebrun, F. [DSM/Irfu/Service d’Astrophysique, Bat. 709 Orme des Merisiers CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France); Lutovinov, A.; Sunyaev, R. [Space Research Institute of Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Mereghetti, S. [INAF, IASF-Milano, via E.Bassini 15, I-20133 Milano (Italy); Roques, J. P. [Université Toulouse, UPS-OMP, CNRS, IRAP, 9 Av. Roche, BP 44346, F-31028 Toulouse (France)

    2017-09-10

    We used data from the International Gamma-Ray Astrophysics Laboratory ( INTEGRAL ) to set upper limits on the γ -ray and hard X-ray prompt emission associated with the gravitational-wave event GW170104, discovered by the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo collaboration. The unique omnidirectional viewing capability of the instruments on board INTEGRAL allowed us to examine the full 90% confidence level localization region of the LIGO trigger. Depending on the particular spectral model assumed and the specific position within this region, the upper limits inferred from the INTEGRAL observations range from F {sub γ} = 1.9 × 10{sup −7} erg cm{sup −2} to F {sub γ} = 10{sup −6} erg cm{sup −2} (75 keV–2 MeV energy range). This translates into a ratio between the prompt energy released in γ -rays along the direction to the observer and the gravitational-wave energy of E {sub γ} / E {sub GW} < 2.6 × 10{sup −5}. Using the INTEGRAL results, we cannot confirm the γ -ray proposed counterpart to GW170104 by the Astro—Rivelatore Gamma a Immagini Leggero (AGILE) team with the mini-Calorimeter (MCAL) instrument. The reported flux of the AGILE/MCAL event, E2, is not compatible with the INTEGRAL upper limits within most of the 90% LIGO localization region. There is only a relatively limited portion of the sky where the sensitivity of the INTEGRAL instruments was not optimal and the lowest-allowed fluence estimated for E2 would still be compatible with the INTEGRAL results. This region was also observed independently by Fermi /Gamma-ray Burst Monitor and AstroSAT, from which, as far as we are aware, there are no reports of any significant detection of a prompt high-energy event.

  10. APR-2 Tropical Cyclone Observations

    Science.gov (United States)

    Durden, S. L.; Tanelli, S.

    2011-01-01

    The Second Generation Airborne Precipitation Radar (APR-2) participated in the Genesis and Rapid Intensification Processes (GRIP) experiment in August and September of 2010, collecting a large volume of data in several tropical systems, including Hurricanes Earl and Karl. Additional measurements of tropical cyclone have been made by APR-2 in experiments prior to GRIP (namely, CAMEX-4, NAMMA, TC4); Table 1 lists all the APR-2 tropical cyclone observations. The APR-2 observations consist of the vertical structure of rain reflectivity at 13.4 and 35.6 GHz, and at both co-polarization and crosspolarization, as well as vertical Doppler measurements and crosswind measurements. APR-2 normally flies on the NASA DC-8 aircraft, as in GRIP, collecting data with a downward looking, cross-track scanning geometry. The scan limits are 25 degrees on either side of the aircraft, resulting in a roughly 10-km swath, depending on the aircraft altitude. Details of the APR-2 observation geometry and performance can be found in Sadowy et al. (2003).The multiparameter nature of the APR-2 measurements makes the collection of tropical cyclone measurements valuable for detailed studies of the processes, microphysics and dynamics of tropical cyclones, as well as weaker systems that are associated with tropical cyclone formation. In this paper, we give a brief overview of how the APR-2 data are processed. We also discuss use of the APR-2 cross-track winds to estimate various quantities of interest in in studies of storm intensification. Finally, we show examples of the standard products and derived information.

  11. Observing the Anthropocene from Space

    Science.gov (United States)

    Dittus, Hansjörg

    2016-07-01

    Influence of mankind on Earth's climate is evident. The growing population using the resources available, especially by burning goal, oil and gas, changes the composition of the Earth's atmosphere with the result of a continuously increasing temperature. Effects are not limited to the regional scale but are evident on the whole planet, meanwhile named Anthropocene. According to this global influence, it's necessary to also extend monitoring to the entire planet. Space-based observation systems are not limited by any artificial borders and are in principle able, to cover the whole Earth. In principle, two different ways of observation can be selected: Either a dedicated spacecraft will be send into low earth orbit (LEO) or existing platforms are used. Advantages of satellites are the more or less freely selectable orbit (with orbits covering also the polar regions) and the possible adaption of spacecraft platform for the dedicated instrument. On the other hand platforms like the ISS space station enable continuous long term coverage with different instruments. The drawback of an only limited coverage based on the orbit inclination is made up by the possibility to service systems on the station. Furthermore different generations of sensors can be run in parallel and therefore cross calibrated if needed. This paper reviews the currently available sensors types and discusses potential future needs. Included in this discussion is the international space station as an already available platform for earth observation. Furthermore, discussion should also take into account, that an increasing number of constellations with dozens or even thousand satellites are planned. Are these constellations also an option for an increased temporal and spatial monitoring of the Earth?

  12. Nucleon structure observables with PANDA

    Science.gov (United States)

    Mora EspÍ, MarÍa Carmen

    2017-12-01

    The PANDA detector will be built as a part of the future FAIR facility in Darmstadt. The availability of an antiproton beam with beam momenta up to 15 GeV/c will make possible a broad nuclear physics program. Topics like hadron spectroscopy in the charmonium mass region, the property of hadrons inside nuclear matter, hypernuclear physics, or nucleon properties using electromagnetic processes are part of the physics program of PANDA. The main part of this contribution concentrates on the feasibility of measurement of nucleon structure observables, such as electromagnetic form factors or transition distribution amplitudes, via experiments using electromagnetic processes in PANDA.

  13. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J.S. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impedance. This paper discusses three aspects of broadband impedance modelling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f. cavity. The last is a discussion of requirements for the mathematical form of an impedance which follow from the general properties of impedances. (author)

  14. Chronic rhinosinusitis: observation or treatment.

    Science.gov (United States)

    Prokopakis, Emmanuel; Vlastos, Ioannis; Pant, Harshita; Ferguson, Berrylin J

    2013-02-01

    Several treatment options have been proposed for chronic rhinosinusitis (CRS). Our purpose is to present a protocol/tool to treat patient symptoms, which is initially independent of assessment for presence of CRS. This protocol is called the Rational Patient Experiment (RPE), and its concept is largely based on the fact that CRS is overrepresented in incidence based on surveys, because symptoms of CRS are nonspecific and overlap multiple other disorders. Patients whose symptoms persist, despite the RPE, require further objective assessment of CRS with endoscopy and computed tomography. This review outlines the RPE and the evidence base for observation versus treatment with saline washes, steroids, or antibiotics.

  15. Observable heavy Higgs dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Keus, Venus [Department of Physics and Helsinki Institute of Physics,Gustaf Hallstromin katu 2, FIN-00014 University of Helsinki (Finland); School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); King, Stephen F. [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Moretti, Stefano [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Sokolowska, Dorota [University of Warsaw, Faculty of Physics, Pasteura 5,02-093 Warsaw (Poland)

    2015-11-04

    Dark Matter (DM), arising from an Inert Higgs Doublet, may either be light, below the W mass, or heavy, above about 525 GeV. While the light region may soon be excluded, the heavy region is known to be very difficult to probe with either Direct Detection (DD) experiments or the Large Hadron Collider (LHC). We show that adding a second Inert Higgs Doublet helps to make the heavy DM region accessible to both DD and the LHC, by either increasing its couplings to the observed Higgs boson, or lowering its mass to 360 GeV≲m{sub DM}, or both.

  16. Submillimeter Continuum Observations of Comets

    Science.gov (United States)

    Jewitt, David

    1998-01-01

    The aim of this proposal was to study the submillimeter continuum emission from comets. The study was based mainly on the exploitation of the world's leading submillimeter telescope, the JCMT (James Clerk Maxwell Telescope) on Mauna Kea. Submillimeter wavelengths provide a unique view of cometary physics for one main reason. The cometary size distribution is such that the scattering cross-section is dominated by small dust grains, while the mass is dominated by the largest particles. Submillimeter continuum radiation samples cometary particles much larger than those sampled by more common observations at shorter (optical and infrared) wavelengths and therefore provides a nearly direct measure of the cometary dust mass.

  17. Korea Earth Observation Satellite Program

    Science.gov (United States)

    Baek, Myung-Jin; Kim, Zeen-Chul

    via Korea Aerospace Research Institute (KARI) as the prime contractor in the area of Korea earth observation satellite program to enhance Korea's space program development capability. In this paper, Korea's on-going and future earth observation satellite programs are introduced: KOMPSAT- 1 (Korea Multi Purpose Satellite-1), KOMPSAT-2 and Communication, Broadcasting and Meteorological Satellite (CBMS) program. KOMPSAT-1 satellite successfully launched in December 1999 with Taurus launch vehicle. Since launch, KOMPSAT-1 is downlinking images of Korea Peninsular every day. Until now, KOMPSAT-1 has been operated more than 2 and half years without any major hardware malfunction for the mission operation. KOMPSAT-1 payload has 6.6m panchromatic spatial resolution at 685 km on-orbit and the spacecraft bus had NASA TOMS-EP (Total Ozone Mapping Spectrometer-Earth Probe) spacecraft bus heritage designed and built by TRW, U.S.A.KOMPSAT-1 program was international co-development program between KARI and TRW funded by Korean Government. be launched in 2004. Main mission objective is to provide geo-information products based on the multi-spectral high resolution sensor called Multi-Spectral Camera (MSC) which will provide 1m panchromatic and 4m multi-spectral high resolution images. ELOP of Israel is the prime contractor of the MSC payload system and KARI is the total system prime contractor including spacecraft bus development and ground segment. KARI also has the contract with Astrium of Europe for the purpose of technical consultation and hardware procurement. Based on the experience throughout KOMPSAT-1 and KOMPSAT-2 space system development, Korea is expecting to establish the infrastructure of developing satellite system. Currently, KOMPSAT-2 program is in the critical design stage. are scheduled to launch in 2008 and in 2014, respectively. The mission of CBMS consists of two areas. One is of space technology test for the communications mission, and the other is of a real

  18. First observation of 15Be

    Science.gov (United States)

    Snyder, J.; Baumann, T.; Christian, G.; Haring-Kaye, R. A.; DeYoung, P. A.; Kohley, Z.; Luther, B.; Mosby, M.; Mosby, S.; Simon, A.; Smith, J. K.; Spyrou, A.; Stephenson, S.; Thoennessen, M.

    2013-09-01

    The neutron-unbound nucleus 15Be was observed for the first time. It was populated using neutron transfer from a deuterated polyethylene target with a 59 MeV/u 14Be beam. Neutrons were measured in coincidence with outgoing 14Be particles and the reconstructed decay energy spectrum exhibits a resonance at 1.8(1) MeV. This corresponds to 15Be being unbound by 0.45 MeV more then 16Be thus significantly hindering the sequential two-neutron decay of 16Be to 14Be through this state.

  19. Recent SETI observations at Arecibo

    Science.gov (United States)

    Tarter, J. C.; Duquet, R. T.; Clark, T. A.; Lesyna, L.

    1983-05-01

    During 1980 and 1981, the 305-m radio telescope at the Arecibo Observatory in Puerto Rico was used to conduct a high resolution search for narrowband signals from the direction of 210 nearby solar type stars and 5 OH masers. For each star at least 4 MHz of bandwidth surrounding the 21-cm HI line and/or the 18-cm OH lines was studied with a spectral resolution of 5.5 Hz in both right and left circular polarization. The formal limit of sensitivity achieved during the course of this search varied depending upon the particular receivers available. In all cases the search could have detected a narrow band transmitter of power comparable to the Arecibo planetary radar, had any such been transmitting on the frequencies searched during the time of observation out to the distance of the farthest target star. As in previous searches, the number of "false alarms" encountered was far greater than predicted on the basis of Gaussian noise statistics. A small number of stars have exhibited signals which cannot immediately be explained in terms of astrophysical or man-made sources and deserve re-observation. This is typical of the results of previous non-real-time searches and does not yet constitute the detection of an ETI.

  20. Observations of substorm fine structure

    Directory of Open Access Journals (Sweden)

    L. L. Lazutin

    1998-07-01

    Full Text Available Particle and magnetic field measurements on the CRRES satellite were used, together with geosynchronous satellites and ground-based observations, to investigate the fine structure of a magnetospheric substorm on February 9, 1991. Using the variations in the electron fluxes, the substorm activity was divided into several intensifications lasting about 3–15 minutes each. The two main features of the data were: (1 the intensifications showed internal fine structure in the time scale of about 2 minutes or less. We call these shorter periods activations. Energetic electrons and protons at the closest geosynchronous spacecraft (1990 095 were found to have comparable activation structure. (2 The energetic (>69 keV proton injections were delayed with respect to electron injections, and actually coincided in time with the end of the intensifications and partial returns to locally more stretched field line configuration. We propose that the energetic protons could be able to control the dynamics of the system locally be quenching the ongoing intensification and possibly preparing the final large-scale poleward movement of the activity. It was also shown that these protons originated from the same intensification as the preceeding electrons. Therefore, the substorm instability responsible for the intensifications could introduce a negative feedback loop into the system, creating the observed fine structure with the intensification time scales.Key words. Magnetospheric Physics (Storms and substorms.

  1. Polarimetric observations of Hungaria asteroids

    Science.gov (United States)

    Gil-Hutton, R.; Lazzaro, D.; Benavidez, P.

    2007-06-01

    Aims:We present the results of a polarimetric program at Complejo Astronómico El Leoncito (Casleo), San Juan, Argentina. The aim of this campaign is to estimate the polarimetric properties of asteroids belonging to the Hungaria dynamical group. Methods: The data were obtained with the Casprof polarimeter at the 2.15 m telescope. The Casprof polarimeter is a two-hole aperture polarimeter with rapid modulation. The campaign began in 2000, and data on a sample of 24 members of the Hungaria group were obtained. We use the slope - albedo or P_min - albedo relationships to get polarimetric albedos for 18 of these objects. Results: Only two Xe-type objects, 434 Hungaria and 3447 Burkhalter, shown a polarimetric behavior compatible with a high albedo object. The A-type asteroid 1600 Vyssotsky has a polarimetric behavior similar to what was observed by Fornasier et al. (2006) for 863 Benkolea, and four objects show P_min values consistent with dark surfaces. Based on observations carried out at the Complejo Astronómico El Leoncito, operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba, and San Juan.

  2. Observation of Pollution from Space

    Science.gov (United States)

    Burrows, J. P.; Richter, A.; Bovensmann, H.; Buchwitz, M.; Andrés Hernández, M. D.; Hilboll, A.; Schoenhardt, A.; Blechschmidt, A.; Alvarado, L.; Wittrock, F.

    2016-12-01

    The rapid growth of population since the industrial revolution has led to large changes in surface emissions and land use change. It is now over 30 years since the SCIAMACHY project was initiated. This project has led to the GOME (ESA ERS-2 1995-2011), SCIAMACHY (ESA Envisat 2002 to 2011) GOME-2 (EUMETSAT/ESA Metop A, 2006 to present, Metop B 2012 to present, Metop C planned launch 2018) and the spin offs OMI (NASA AURA 2004-present) . This presentation addresses observations of tropospheric trace gas pollutants retrieved these instruments with a focus on recent studies of the ozone precursors NO2, HCHO and CHO.CHO, the halogen oxides BrO, IO and CH4 and CO2. It will discuss the objectives of the DLR HALO EMeRGe mission. The latter is research mission combining satelltie and aircraft observations, whihc aims to study pollution from major pollution centers in Europe and Asia, and is planned to take palce in 2017 and 2018.

  3. Observation of the Top Quark

    Science.gov (United States)

    Kim, S. B.

    1995-08-01

    Top quark production is observed in{bar p}p collisions at{radical}s= 1.8 TeV at the Fermilab Tevatron. The Collider Detector at Fermilab (CDF) and D{O} observe signals consistent with t{bar t} to WWb{bar b}, but inconsistent with the background prediction by 4.8{sigma} (CDF), 4.6a (D{O}). Additional evidence for the top quark Is provided by a peak in the reconstructed mass distribution. The kinematic properties of the excess events are consistent with the top quark decay. They measure the top quark mass to be 176{plus_minus}8(stat.){plus_minus}10(sys.) GeV/c{sup 2} (CDF), 199{sub -21}{sup+19}(stat.){plus_minus}22(sys.) GeV/c{sup 2} (D{O}), and the t{bar t} production cross section to be 6.8{sub -2.4}{sup+3.6}pb (CDF), 6.4{plus_minus}2.2 pb (D{O}).

  4. Committed warming inferred from observations

    Science.gov (United States)

    Mauritsen, Thorsten; Pincus, Robert

    2017-09-01

    Due to the lifetime of CO2, the thermal inertia of the oceans, and the temporary impacts of short-lived aerosols and reactive greenhouse gases, the Earth’s climate is not equilibrated with anthropogenic forcing. As a result, even if fossil-fuel emissions were to suddenly cease, some level of committed warming is expected due to past emissions as studied previously using climate models. Here, we provide an observational-based quantification of this committed warming using the instrument record of global-mean warming, recently improved estimates of Earth’s energy imbalance, and estimates of radiative forcing from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Compared with pre-industrial levels, we find a committed warming of 1.5 K (0.9-3.6, 5th-95th percentile) at equilibrium, and of 1.3 K (0.9-2.3) within this century. However, when assuming that ocean carbon uptake cancels remnant greenhouse gas-induced warming on centennial timescales, committed warming is reduced to 1.1 K (0.7-1.8). In the latter case there is a 13% risk that committed warming already exceeds the 1.5 K target set in Paris. Regular updates of these observationally constrained committed warming estimates, although simplistic, can provide transparent guidance as uncertainty regarding transient climate sensitivity inevitably narrows and the understanding of the limitations of the framework is advanced.

  5. Tangled ruptures: discursive changes in Danish psychiatric nursing 1965-75

    DEFF Research Database (Denmark)

    Buus, N

    2001-01-01

    Psychiatric nursing and psychiatric nurses have been referred to in various ways over the course of history. These articulations reflect and constitute the ways in which nursing is comprehended during specific periods. A rupture in these descriptions and conceptions of Danish psychiatric nursing...... over the period 1965--75 is identified using a discourse analytical framework, inspired primarily by Foucault. This rupture influenced all aspects of psychiatric nursing: the perception of the psychiatric patient, the expertise and knowledge of the nurse and the care given by the nurse. The study...

  6. Tangled roots: Kalenda and other neo-African dances in the circum-Caribbean

    Directory of Open Access Journals (Sweden)

    Julian Gerstin

    2004-01-01

    Full Text Available Investigates descriptions of Afro-Caribbean dances in early chronicles and historical material. Author focuses on choreography, as well as on musical instruments and their use. He pays special attention to descriptions of the Martinican kalenda dance. He discusses descriptions from the 18th c. of black Caribbean dance in French and other colonies, by priests and others, of the kalenda as a couple dance within a ring, and descriptions of other widespread early dances in the Caribbean, such as chica. Author notes that in these early descriptions the authors focus obsessively on eroticism, thus simplifying and exaggerating the dances as sexual, and ignoring their variety. Further, he analyses early chronicles on other widespread dances in the circum-Caribbean, such as stick-fighting dances, bamboula, djouba, and belair, comparing with present-day Caribbean dances, and on "challenge dancing" involving a dance soloist "challenged" by a lead drummer, found, for instance, in kalenda and rumba. In addition, the author focuses on the dances' musical accompaniment by drums, and the drum types and methods, specifically transverse drumming and drumming with sticks on the side of the drum, found today in kalenda, and other Caribbean styles. He points at the inaccuracy of some chronicles, mixing up dance names, and recurring superficiality and stereotypes. He nonetheless concludes from them that slaves from the Congo/Angola region probably played a crucial role in forming these early dance styles, and that their spread was connected with French colonialism and slavery and migrations from (once French colonies. He describes probable Congolese/Angolan influences, such as pelvic isolation, challenge dances, couple dancing within a circle, and transverse drumming, but indicates that these are over time combined with other African and other influences.

  7. Inhomogeneous vortex tangles in counterflow superfluid turbulence: flow in convergent channels

    Directory of Open Access Journals (Sweden)

    Saluto Lidia

    2016-06-01

    Full Text Available We investigate the evolution equation for the average vortex length per unit volume L of superfluid turbulence in inhomogeneous flows. Inhomogeneities in line density L andincounterflowvelocity V may contribute to vortex diffusion, vortex formation and vortex destruction. We explore two different families of contributions: those arising from asecondorder expansionofthe Vinenequationitself, andthose whichare notrelated to the original Vinen equation but must be stated by adding to it second-order terms obtained from dimensional analysis or other physical arguments.

  8. Sensitive Judges – How to Resolve the Tangle of Legal Decision-Making and Emotion?

    NARCIS (Netherlands)

    Hamer, Jurriën

    2012-01-01

    According to traditional legal thought, emotions should have no influence on legal decision-making. The general assumption is that emotions interfere with clear rational thinking, and cause decisions to be biased and imbalanced. However, in modern philosophical thought, a different thesis has been

  9. "Mississippi Trial, 1955": Tangling with Text through Reading, Discussion, and Writing

    Science.gov (United States)

    Grierson, Sirpa; Thursby, Jacqueline S.; Dean, Deborah; Crowe, Chris

    2007-01-01

    The authors proffer practical critical-reading strategies for teaching "Mississippi Trial, 1955" to increase students' vocabulary, comprehension, and background knowledge of historical eras. They use nonfiction, a PBS documentary, the Web, folklore, and picture books among other tools for inciting thoughtful discussion and writing.

  10. T helper 17 cells and Regulatory T cells in Pulmonary Sarcoidosis : It takes two to tangle

    NARCIS (Netherlands)

    C.E. Broos (Caroline)

    2017-01-01

    markdownabstractSarcoidosis is an intriguingly complex immunological disorder. It is characterized by the formation of non-necrotizing granulomas that are most commonly found in the mediastinal lymph nodes and lungs of patients. Gaps in knowledge on sarcoidosis disease etiology and determinants of

  11. Pedagogy Meets Digital Media: A Tangle of Teachers, Strategies, and Tactics

    Science.gov (United States)

    Rust, Julie

    2017-01-01

    Although increasingly encouraged to incorporate digital media into classrooms to prepare students for engaged participation in a digital world, teachers are often taken by surprise when paradigm clashes arise between traditional school expectations and the affordances of these new spaces. Through data gathered from ethnographic methodologies…

  12. Progression from chronic atrophic gastritis to gastric cancer; tangle, toggle, tackle with Korea red ginseng.

    Science.gov (United States)

    Kim, Yoon Jae; Chung, Jun Won; Lee, So Jung; Choi, Ki Seok; Kim, Ju Hyun; Hahm, Ki Baik

    2010-05-01

    Key molecular players that link inflammation to carcinogenesis are prostaglandins, cytokines, nuclear factor-kappaB (NF-kappaB), chemokines, angiogenic growth factors, and free radicals, all of which lead to increased mutations and altered functions of important enzymes and proteins, for example, activation of oncogenic products and/or inhibition of tumor suppressor proteins, in inflamed tissues, thus contributing to multi-stage carcinogenesis process. Interpreted reversely, the identification of the molecular mechanisms by which chronic inflammation increases cancer risk or optimal intervention of targeted drugs or agents during the inflammation-associated carcinogenic process could be a necessary basis for developing new strategy of cancer prevention at many sites. In this review, we discuss the possibilities for cancer prevention by controlling inflammation process in Helicobacter pylori (H. pylori)-associated inflamed stomach with Korea red ginseng. Korea red ginseng is a good example of a natural herb that has ubiquitous properties that are conductive to stop inflammatory carcinogenesis that is un wanted outcome of H. pylori infection, rendering rejuvenation of chronic atrophic gastritis.

  13. Tangled history of the European uses of Sphagnum moss and sphagnol.

    Science.gov (United States)

    Drobnik, Jacek; Stebel, Adam

    2017-09-14

    Sphagnum mosses and peat could have been utilized as wound dressings for centuries, however reliable data on this subject are ambiguous; sometimes even no distinction between peat moss (Sphagnum spp.) and peat is made or these terms become confused. The first scientific account on surgical use of peat comes from 1882: a peat digger who successfully, by himself and in the way unknown to the then medicine, cured an open fracture of his forearm with peat. The peat, and very soon the peat moss itself (which is the major constituent of peat) drew attention of the 19th-century surgeons. We search for reliable information on: (1) inspirations for Sphagnum usage for medical purposes and its beginnings in the 19th century, (2) substances or products named sphagnol and their connections with (1); (3) on the origin of this name, (4) and on the occurrence of this name in medical sources. We have identified and studied published sources on the uses of peat-based and Sphagnum-based preparations and products of any processing level (including herbal stock, distillate, isolated pure or impure active principle, or a mixture of such) in surgery, pharmacy or cosmetics. A special attention was paid to the name sphagnol, which appeared many a time, in more than one context since 1899. Source publications were critically analysed from the taxonomical, pharmacognostical and ethnopharmacological points of view. Gathered data were cross-checked with the modern knowledge of the biologically active principles of Sphagnum and the prospects of their medical use. The application of peat in surgery started 1882. The use of peat moss as dressings was developed in the 1880's. It returned to surgical practice during WW1. The name sphagnol has two meanings: (1) A chemical substance isolated from the cell walls of Sphagnum mosses in 1899. A post-1950 research showed it to be a mixture of phenols dominated by sphagnum acid. (2) A product of dry distillation of peat contains solid and liquid fractions and was applied in skin diseases due to antiseptic properties. It was added to ointments and medicated soaps manufactured up to the late 1960's. Today none of these two sphagnols is in use. Surgical application of peat had an ethnopharmacological origin: a case of wound treatment with peat as a remedy rather than a dressing (1880, published 1882) shortly shifted the surgeons' attention to peat moss as an absorptive dressing. The 1880's tests of antiseptic properties of peat and peat moss failed, the sterilization methods overrode the physiological effects of Sphagnum dressings. Sphagnan, a polysaccharide from Sphagnum cell walls, discovered 1983, inhibits microbial growth, tans the collagen and removes ammonia from microbial environments. Portions of raw peat could be sterile. The isolation of sphagnol (1899) from Sphagnum cell walls was not inspired by old surgery. Main component of sphagnol, the sphagnic acid, was used clinically during WW2, but was proved a weak antimicrobial agent. A homonymous name sphagnol appeared independently for a product of dry distillation of peat, introduced commercially probably about 1899, too, which gave rise to confusions: a) the commercial, "distilled" sphagnol was not the crystalline principle of Sphagnum cell walls. 2) the "distilled" sphagnol was hardly defined technologically or pharmacologically, never standardized in terms of the substrate (a variety of peat rather than Sphagnum herb) and the production process. This sphagnol, resembling pitch or tar, was an additive to medicated soaps and ointments for skin treatment and care. It must have been a low-scale product although advertised worldwide. Neither sphagnum acid nor sphagnan are used medicinally today. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  14. Untangling the Tangled Webs We Weave: A Team Approach to Cyberspace.

    Science.gov (United States)

    Broidy, Ellen; And Others

    Working in a cooperative team environment across libraries and job classifications, librarians and support staff at the University of California at Irvine (UCI) have mounted several successful web projects, including two versions of the Libraries' home page, a virtual reference collection, and Science Library "ANTswer Machine." UCI's…

  15. The Tangled Web: Investigating Academics' Views of Plagiarism at the University of Cape Town

    Science.gov (United States)

    de Jager, Karin; Brown, Cheryl

    2010-01-01

    This article considers the problematic question of student plagiarism, its causes and manifestations, and how it is addressed in academic environments. A literature survey was conducted to establish how higher education institutions approach these issues, and a twofold investigation was conducted at the University of Cape Town. Data was gathered…

  16. The Tangled Web of Agricultural Insurance: Evaluating the Impacts of Government Policy

    OpenAIRE

    Jason Pearcy; Vincent Smith

    2015-01-01

    This paper examines the effects of changes in major elements of the U.S. federal crop insurance program on the structure of the agricultural insurance industry. We model the interactions between farmers, insurance agents and insurance companies. Two symmetric equilibria are determined: one with competitive insurance companies and one where insurance companies form a collusive monopsony. We evaluate how marginal changes in government policy (changes in the premium subsidy rate, A&O subsidy rat...

  17. Tangled roots: Kalenda and other neo-African dances in the circum-Caribbean

    OpenAIRE

    Julian Gerstin

    2004-01-01

    Investigates descriptions of Afro-Caribbean dances in early chronicles and historical material. Author focuses on choreography, as well as on musical instruments and their use. He pays special attention to descriptions of the Martinican kalenda dance. He discusses descriptions from the 18th c. of black Caribbean dance in French and other colonies, by priests and others, of the kalenda as a couple dance within a ring, and descriptions of other widespread early dances in the Caribbean, such as ...

  18. Tangled up in Blue: Boosting Mental Health Services at Community Colleges

    Science.gov (United States)

    Finkel, Ed

    2016-01-01

    In a recent survey of 4,000 community college students, half reported experiencing a mental health condition. American College Counseling Association's (ACCA) fifth annual survey of personal and mental health counseling at community colleges provides some data from 159 professionals at two-year colleges in 41 states and Puerto Rico. Among the…

  19. Net-based information on varicose vein treatments: a tangled web.

    Science.gov (United States)

    Ching, Thida; Roake, Justin A; Lewis, David R

    2010-09-24

    30-40% of individuals will be affected by varicose veins during their lifetime. Many will contemplate treatment and will access the (Inter)net for information. The aim of this study is to determine whether New Zealand-based websites are an accurate source of information for the public. Inclusion criteria were New Zealand based websites that contained information on varicose vein treatments. These websites were identified using the search-engines Google and Yahoo. The first 60 websites from each were evaluated and subdivided into 4 groups based on web-site ownership: (1) Vein clinic/hospital; (2) Appearance medicine; (3) Online stores; (4) Health editorials; and (5) Medical resources. 46 of the 120 websites satisfied the inclusion criteria. 18 websites (39%) explained what varicose veins were. Information about treatment options was most comprehensive in the "Vein clinic/hospital" group. The "Appearance medicine" group mostly contained information on outpatient interventional therapies. "Health editorial" sites had lifestyle modification options. All the online herbal/health stores mentioned herbal treatment options. Few websites fully informed patients about treatment options while some simply advertised non-evidence based treatments. This study suggests that the Internet is not a reliable source of information and does not accurately inform patients about varicose veins and the treatment options.

  20. Potential contribution of exosomes to the prion-like propagation of lesions in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Valerie eVingtdeux

    2012-07-01

    Full Text Available Since the discovery of prion diseases, the concept that a transmissible pathogen could be a protein has emerged. As such, this transmissible protein agent can transfer its pathological mis-folded shape to the same but normally folded protein thus leading to the propagation of a disease. This idea is now extrapolate to several neurological diseases associated with protein mis-folding and aggregation, such as Alzheimer’s disease. Alzheimer’s disease (AD is a slowly developing dementing disease characterized by the coexistence of two types of lesions: the parenchymal amyloid deposits and the intraneuronal neurofibrillary tangles (NFT. Amyloid deposits are composed of amyloid-beta peptides that derive from sequential cleavages of its precursor named amyloid protein precursor. Neurofibrillary tangle is characterized by intraneuronal aggregation of abnormally modified microtubule-associated Tau proteins. A synergistic relationship between the two lesions may trigger the progression of the disease. Thus, starting in the medial temporal lobe and slowly progressing through temporal, frontal, parietal and occipital cortex, the progression of NFT is well correlated with clinical expression of the disease. However, little is known about the mechanism driving the spatiotemporal propagation of these lesions ultimately leading to the disease. A growing number of studies suggest a prion-like diffusion of amyloid deposits and NFT. In the present chapter, we will develop the current hypotheses regarding the molecular and cellular mechanisms driving the development and spreading of Alzheimer disease lesions from the window of multivesicular bodies and exosomes.

  1. Modeling non-hereditary mechanisms of Alzheimer disease during apoptosis in yeast.

    Science.gov (United States)

    Braun, Ralf J; Sommer, Cornelia; Leibiger, Christine; Gentier, Romina J; Dumit, Verónica I; Paduch, Katrin; Eisenberg, Tobias; Habernig, Lukas; Trausinger, Gert; Magnes, Christoph; Pieber, Thomas; Sinner, Frank; Dengjel, Jörn; Leeuwen, Fred W V; Kroemer, Guido; Madeo, Frank

    2015-03-20

    Impaired protein degradation and mitochondrial dysfunction are believed to contribute to neurodegenerative disorders, including Alzheimer disease (AD). In patients suffering from non-hereditary AD, UBB +1 , the frameshift variant of ubiquitin B, accumulated in neurons affected by neurofibrillary tangles, which is a pathological hallmark. We established a yeast model expressing high levels of UBB +1 , and could demonstrate that UBB +1 interfered with both the ubiquitin-proteasome system (UPS) and mitochondrial function. More precisely, UBB +1 promoted the mitochondrion-localized production of the basic amino acids arginine, ornithine, and lysine, which we identified as the decisive toxic event culminating in apoptosis. Inducing the UPS activity at mitochondria prevented the lethal basic amino acid accumulation and avoided UBB +1 -triggered cell loss. The arginine/ornithine metabolism is altered in brains of AD patients, and VMS1, the mitochondrion-specific UPS component, co-existed with UBB +1 in neurofibrillary tangles. Therefore, our data suggest that aberrant basic amino acid synthesis is a crucial link between UPS dysfunction and mitochondrial damage during AD progression.

  2. Alzheimer disease pathology in subjects without dementia in 2 studies of aging: the Nun Study and the Adult Changes in Thought Study.

    Science.gov (United States)

    SantaCruz, Karen S; Sonnen, Joshua A; Pezhouh, Maryam Kherad; Desrosiers, Mark F; Nelson, Peter T; Tyas, Suzanne L

    2011-10-01

    Individuals with antemortem preservation of cognition who show autopsy evidence of at least moderate Alzheimer disease (AD) pathology suggest the possibility of brain reserve, that is, functional resistance to structural brain damage. This reserve would, however, only be relevant if the pathologic markers correlate well with dementia. Using data from the Nun Study (n = 498) and the Adult Changes in Thought (ACT) Study (n = 323), we show that Braak staging correlates strongly with dementia status. Moreover, participants with severe(Braak stage V-VI) AD pathology who remained not demented represent only 12% (Nun Study) and 8% (ACT study) of nondemented subjects. Comparison of these subjects to those who were demented revealed that the former group was often significantly memory-impaired despite not being classified as demented. Most of these nondemented participants showed only stage V neurofibrillary pathology and frontal tangle counts that were slightly lower than a comparable (Braak stage V) dementia group. In summary, these data indicate that, in individuals with AD-type pathology who do not meet criteria for dementia, neocortical neurofibrillary tangles are somewhat reduced and incipient cognitive decline is present. Our data provide a foundation for helping to define additional factors that may impair, or be protective of, cognition in older adults.

  3. N epsilon-carboxymethyllysine in brain aging, diabetes mellitus, and Alzheimer's disease.

    Science.gov (United States)

    Gironès, Xavier; Guimerà, Arantxa; Cruz-Sánchez, Celia-Z; Ortega, Arantxa; Sasaki, Noboyuki; Makita, Zenji; Lafuente, José Vivente; Kalaria, Raj; Cruz-Sánchez, Félix F

    2004-05-15

    Oxidative stress has been implicated in the pathophysiology of Alzheimer's disease (AD) and diabetes mellitus (DM). N epsilon-carboxymethyllysine (CML) is an advanced glycation end product (AGE) recently found to be associated with oxidative stress mechanisms. Using immunocytochemical methods we examined the distribution of CML in brain tissue from AD and DM subjects and aging controls. CML reactivity was present in the cytoplasm of neurons, but there were marked differences in the intensity of expression, number of cells, and topographical distribution. CML expression was higher in hippocampus than in frontal and temporal cortex. In the hippocampus, neuronal and, to an extent, glial expression was more marked in CA3 and CA4 than in CA1 and CA2. In AD, CML was found to be coexpressed with tau protein, showing the similar neurofibrillary tangle shape, as well as in neuritic plaques but not in the core of amyloid plaques. We noted an increasing degree of CML expression such that the highest reactivity was evident in those with both AD and DM, followed by AD, DM, and aging controls. There was an inverse relationship between Braak staging and topography of CML expression. Although DM cases did not show Abeta deposition or neurofibrillary tangles, these findings suggest increased CML expression is not limited to AD. Nonetheless, high CML expression in AD with coexistent DM suggests there are additive effects compared with AD alone. It is plausible that the microangiopathy also associated with DM could worsen AD pathogenesis.

  4. Chronic Traumatic Encephalopathy in Athletes: Progressive Tauopathy following Repetitive Head Injury

    Science.gov (United States)

    McKee, Ann C.; Cantu, Robert C.; Nowinski, Christopher J.; Hedley-Whyte, E. Tessa; Gavett, Brandon E.; Budson, Andrew E.; Santini, Veronica E.; Lee, Hyo-Soon; Kubilus, Caroline A.; Stern, Robert A.

    2009-01-01

    Since the 1920s, it has been known that the repetitive brain trauma associated with boxing may produce a progressive neurological deterioration, originally termed “dementia pugilistica” and more recently, chronic traumatic encephalopathy (CTE). We review the 47 cases of neuropathologically verified CTE recorded in the literature and document the detailed findings of CTE in 3 professional athletes: one football player and 2 boxers. Clinically, CTE is associated with memory disturbances, behavioral and personality changes, Parkinsonism, and speech and gait abnormalities. Neuropathologically, CTE is characterized by atrophy of the cerebral hemispheres, medial temporal lobe, thalamus, mammillary bodies, and brainstem, with ventricular dilatation and a fenestrated cavum septum pellucidum. Microscopically, there are extensive tau-immunoreactive neurofibrillary tangles, astrocytic tangles, and spindle-shaped and threadlike neurites throughout the brain. The neurofibrillary degeneration of CTE is distinguished from other tauopathies by preferential involvement of the superficial cortical layers, irregular, patchy distribution in the frontal and temporal cortices, propensity for sulcal depths, prominent perivascular, periventricular and subpial distribution, and marked accumulation of tau-immunoreactive astrocytes. Deposition of beta amyloid, most commonly as diffuse plaques, occurs in fewer than half the cases. CTE is a neuropathologically distinct, slowly progressive tauopathy with a clear environmental etiology. PMID:19535999

  5. Chronic traumatic encephalopathy (CTE) in a National Football League Player: Case report and emerging medicolegal practice questions.

    Science.gov (United States)

    Omalu, Bennet I; Hamilton, Ronald L; Kamboh, M Ilyas; DeKosky, Steven T; Bailes, Julian

    2010-01-01

    We present a case of chronic traumatic encephalopathy (CTE) in a retired National Football League (NFL) Player with autopsy findings, apolipoprotein E genotype, and brain tissue evidence of chronic brain damage. This 44-year-old retired NFL player manifested a premortem history of cognitive and neuropsychiatric impairment, which included in part, chronic depression, suicide attempts, insomnia, paranoia, and impaired memory before he finally committed suicide. A full autopsy was performed with Polymerase Chain Reaction-based analyses of his blood to determine the apolipoprotein genotype. Histochemical and immunohistochemical analyses were performed on topographical gross sections of the brain. Autopsy confirmed a fatal gunshot wound of the head. The apolipoprotein E genotype was E3/E3 and the brain tissue revealed diffuse cerebral taupathy (Neurofibrillary Tangles and Neuritic Threads). This will be the third case of CTE in a national football player, which has been reported in the medical literature. Omalu et al., reported the first two cases in 2005 and 2006. This case series manifested similar premortem history of neuropsychiatric impairment with autopsy evidence of cerebral taupathy without any neuritic amyloidopathy. For a definitive diagnosis of CTE to be made, and for medicolegal purposes, a full autopsy must be performed with histochemical and immunohistochemical analyses of the brain to identify the presence of Neurofibrillary Tangles (NFTs) and Neuritic Threads (NTs). Further longitudinal prospective studies are required to confirm the common denominators and epidemiology of CTE in professional American football players, which have been identified by this case series.

  6. Early-onset familial lewy body dementia with extensive tauopathy: a clinical, genetic, and neuropathological study.

    Science.gov (United States)

    Clarimón, Jordi; Molina-Porcel, Laura; Gómez-Isla, Teresa; Blesa, Rafael; Guardia-Laguarta, Cristina; González-Neira, Anna; Estorch, Montserrat; Ma Grau, Josep; Barraquer, Lluís; Roig, Carles; Ferrer, Isidre; Lleó, Alberto

    2009-01-01

    We describe a Spanish family in which 3 of 4 siblings had dementia with Lewy bodies, 2 of them starting at age 26 years and the other at 29 years. The father has recently been diagnosed with Lewy body disease, with onset at 77 years. Neuropathological examination of the brain of the index patient disclosed unusual features characterized by diffuse Lewy body disease and generalized neurofibrillary tangle pathology but with no amyloid deposits in any region. Moreover, Lewy body pathology colocalized with neurofibrillary tangles in most affected neurons. Mutation screening that included all coding exons of presenilin 1 (PSEN1), presenilin 2 (PSEN2), alpha-synuclein (SNCA), beta-synuclein (SNCB), microtubule-associated protein tau (MAPT), leucine-rich repeat kinase 2 (LRRK2), glucocerebrosidase (GBA), and exons 16 and 17 of the amyloid precursor protein (APP) genes did not identify any mutation. Genome-wide single nucleotide polymorphism was performed in 4 family members and ruled out any pathogenic duplication or deletion in the entire genome. In summary, we report a unique family with pathologically confirmed early-onset dementia with Lewy bodies with widespread tau and alpha-synuclein deposition. The absence of mutations in genes known to cause Lewy body disease suggests that a novel locus or loci are implicated in this neurodegenerative disease.

  7. Age- and stage-dependent accumulation of advanced glycation end products in intracellular deposits in normal and Alzheimer's disease brains.

    Science.gov (United States)

    Lüth, Hans-Joachim; Ogunlade, Vera; Kuhla, Björn; Kientsch-Engel, Rosemarie; Stahl, Peter; Webster, Julie; Arendt, Thomas; Münch, Gerald

    2005-02-01

    In this immunohistochemical study, the age- and stage-dependent accumulation of advanced glycation end-products (AGEs) in Alzheimer's disease (AD) and their relation to the formation of neurofibrillary tangles and neuronal cell death was investigated. For this purpose, the distribution of AGEs in neurons and glia was analyzed in the auditory association area of superior temporal gyrus (Brodmann area 22) of young and old non-demented controls and compared with early- and late-stage AD. A possible co-localization of AGEs with typical hallmarks of AD, such as hyperphosphorylated tau (as a marker for disturbed kinase/phosphatase activity), nNOS (as a marker for nitroxidative stress) and caspase-3 (as a marker of apoptotic cell death), was also investigated. Our results show that the percentage of AGE-positive neurons (and astroglia) increase both with age and, in AD patients, with the progression of the disease (Braak stages). Interestingly, nearly all if those neurons which show diffuse cytosolic AGE immunoreactivity also contain hyperphosphoryated tau, suggesting a link between AGE accumulation and the formation of early neurofibrillary tangles. Many, but not all, neurons show a co-localization of AGEs with other markers of neurodegeneration, such as nNOS and caspase-3.

  8. Mass spectrometry assessment of ubiquitin carboxyl-terminal hydrolase L1 partitioning between soluble and particulate brain homogenate fractions.

    Science.gov (United States)

    Chen, Junjun; Huang, Richard Y-C; Turko, Illarion V

    2013-06-18

    Partitioning of specific proteins between soluble and insoluble forms because of aggregation, membrane attachment, and (or) association with senile plaques and neurofibrillary tangles is a major feature of several neurodegenerative disorders, including Alzheimer's disease (AD). Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is an example of a neuron-specific protein which displays two different dimerization-dependent catalytic activities and can be farnesylated for membrane attachment, oxidized, and truncated. Decreased levels of soluble UCH-L1 are inversely proportional to the number of neurofibrillary tangles. Further assessment of a link between UCH-L1 function and the pathogenesis of AD requires an analytical method to separately quantify different UCH-L1 forms. In the present study, we have developed a multiple reaction monitoring (MRM) assay to measure UCH-L1 in the high-speed supernatant and pellet of frontal cortex homogenate. The well-characterized (15)N-labeled quantification concatamer (QconCAT) carrying prototypic tryptic peptides of UCH-L1 was used as an internal standard. The composed protocol of frontal cortex processing includes solubilization and reduction/alkylation of proteins in the presence of 1% sodium dodecyl sulfate (SDS) and following with desalting/delipidation of the sample by chloroform/methanol precipitation with extra water washing of the protein pellet. The measurements were performed for frontal cortex samples from control and severe AD donors. The proposed workflow can be recommended for quantification of partitioning of other proteins of interest.

  9. Indoleamine 2,3-dioxygenase and 3-hydroxykynurenine modifications are found in the neuropathology of Alzheimer's disease.

    Science.gov (United States)

    Bonda, David J; Mailankot, Maneesh; Stone, Jeremy G; Garrett, Matthew R; Staniszewska, Magdalena; Castellani, Rudy J; Siedlak, Sandra L; Zhu, Xiongwei; Lee, Hyoung-gon; Perry, George; Nagaraj, Ram H; Smith, Mark A

    2010-01-01

    Tryptophan metabolism, through the kynurenine pathway, produces neurotoxic intermediates that are implicated in the pathogenesis of Alzheimer's disease. In particular, oxidative stress via 3-hydroxykynurenine (3-HK) and its cleaved product 3-hydroxyanthranilic acid (3-HAA) significantly damages neuronal tissue and may potentially contribute to a cycle of neurodegeneration through consequent amyloid-beta accumulation, glial activation, and up-regulation of the kynurenine pathway. To determine the role of the kynurenine pathway in eliciting and continuing oxidative stress within Alzheimer's diseased brains, we used immunocytochemical methods to show elevated levels of 3-HK modifications and the upstream, rate-limiting enzyme indoleamine 2,3-dioxygenase (IDO-1) in Alzheimer's diseased brains when compared to controls. Importantly, the association of IDO-1 with senile plaques was confirmed and, for the first time, IDO-1 was shown to be specifically localized in conjunction with neurofibrillary tangles. As senile plaques and neurofibrillary tangles are the pathological hallmarks of Alzheimer's disease, our study provides further evidence that the kynurenine pathway is involved with the destructive neurodegenerative pathway of Alzheimer's disease.

  10. Chronic traumatic encephalopathy in athletes: progressive tauopathy after repetitive head injury.

    Science.gov (United States)

    McKee, Ann C; Cantu, Robert C; Nowinski, Christopher J; Hedley-Whyte, E Tessa; Gavett, Brandon E; Budson, Andrew E; Santini, Veronica E; Lee, Hyo-Soon; Kubilus, Caroline A; Stern, Robert A

    2009-07-01

    Since the 1920s, it has been known that the repetitive brain trauma associated with boxing may produce a progressive neurological deterioration, originally termed dementia pugilistica, and more recently, chronic traumatic encephalopathy (CTE). We review 48 cases of neuropathologically verified CTE recorded in the literature and document the detailed findings of CTE in 3 profession althletes, 1 football player and 2 boxers. Clinically, CTE is associated with memory disturbances, behavioral and personality changes, parkinsonism, and speech and gait abnormalities. Neuropathologically, CTE is characterized by atrophy of the cerebral hemispheres, medial temporal lobe, thalamus, mammillary bodies, and brainstem, with ventricular dilatation and a fenestrated cavum septum pellucidum. Microscopically, there are extensive tau-immunoreactive neurofibrillary tangles, astrocytic tangles, and spindle-shaped and threadlike neurites throughout the brain. The neurofibrillary degeneration of CTE is distinguished from other tauopathies by preferential involvement of the superficial cortical layers, irregular patchy distribution in the frontal and temporal cortices, propensity for sulcal depths, prominent perivascular, periventricular, and subpial distribution, and marked accumulation of tau-immunoreactive astrocytes. Deposition of beta-amyloid, most commonly as diffuse plaques, occurs in fewer than half the cases. Chronic traumatic encephalopathy is a neuropathologically distinct slowly progressive tauopathy with a clear environmental etiology.

  11. Observing iodine monoxide from satellite

    Science.gov (United States)

    Schoenhardt, Anja; Richter, Andreas; Begoin, Mathias; Wittrock, Folkard; Burrows, John P.

    Iodine and iodine monoxide (IO) belong to the group of reactive halogen species, and they may impact on atmospheric chemical composition and the radiation budget. Vice versa, sur-rounding conditions may influence the emissions and pathways of iodine compounds. Although atmospheric amounts of iodine are typically fairly small, the impact may still be substantial. Iodine radicals are photolytically released from precursors and may then cause catalytic ozone depletion. In this reaction with ozone, IO is produced, a molecule which plays a central role in the iodine cycling. Via self reactions of IO, higher iodine oxides form and initiate the formation of new particles, which may change the atmospheric radiation balance. Apart from that, many living species, including human beings, vertebrates in general, but also micro-and macroalgae species, e.g., depend on the supply with iodine. Consequently, it is necessary to understand the cycling of iodine through the different components of the Earth system. Although increas-ing research effort in the form of field, laboratory and modeling studies has strongly improved our knowledge and understanding of iodine abundances and impact, still many open questions remain. The relevance of iodine on a global scale is not well known yet; sources are not well quantified and release processes are not fully understood. Since recently, IO may be observed from space by the SCIAMACHY instrument on the EN-VISAT satellite, which is in a near-polar, sun-synchronous orbit. Nadir observations from SCIAMACHY have been analysed for the IO absorption signature in the visible wavelength range for several mission years. IO amounts are typically close to the limit of detectability of SCIAMACHY. Detecting such small quantities, careful attention needs to be paid to system-atic errors, spectral correlations and resulting retrieval artefacts. Subsequently, appropriate temporal averaging is utilised to improve the signal-to-noise ratio. The resulting

  12. Amyloid-β peptides and tau protein as biomarkers in cerebrospinal and interstitial fluid following traumatic brain injury: A review of experimental and clinical studies

    Directory of Open Access Journals (Sweden)

    Parmenion P. Tsitsopoulos

    2013-06-01

    Full Text Available Traumatic brain injury (TBI survivors frequently suffer from life-long deficits in cognitive functions and a reduced quality of life. Axonal injury, observed in most severe TBI patients, results in accumulation of amyloid precursor protein (APP. Post-injury enzymatic cleavage of APP can generate amyloid-β (Aβ peptides, a hallmark finding in Alzheimer’s disease (AD. At autopsy, brains of AD and a subset of TBI victims display some similarities including accumulation of Aβ peptides and neurofibrillary tangles of hyperphosphorylated tau proteins. Most epidemiological evidence suggests a link between TBI and AD, implying that TBI has neurodegenerative sequelae. Aβ peptides and tau may be used as biomarkers in interstitial fluid (ISF using cerebral microdialysis and/or cerebrospinal fluid (CSF following clinical TBI. In the present review, the available clinical and experimental literature on Aβ peptides and tau as potential biomarkers following TBI is comprehensively analyzed. Elevated CSF and ISF tau protein levels have been observed following severe TBI and suggested to correlate with clinical outcome. Although Aβ peptides are produced by normal neuronal metabolism, high levels of long and/or fibrillary Aβ peptides may be neurotoxic. Increased CSF and/or ISF Aβ levels post-injury may be related to neuronal activity and/or the presence of axonal injury. The heterogeneity of animal models, clinical cohorts, analytical techniques and the complexity of TBI in available studies make the clinical value of tau and Aβ as biomarkers uncertain at present. Additionally, the link between early post-injury changes in tau and Aβ peptides and the future risk of developing AD remains unclear. Future studies using e.g. rapid biomarker sampling combined with enhanced analytical techniques and/or novel pharmacological tools could provide additional information on the importance of Aβ peptides and tau protein in both the acute pathophysiology and long

  13. Early-onset axonal pathology in a novel P301S-Tau transgenic mouse model of frontotemporal lobar degeneration.

    Science.gov (United States)

    van Eersel, Janet; Stevens, Claire H; Przybyla, Magdalena; Gladbach, Amadeus; Stefanoska, Kristie; Chan, Chesed Kai-Xin; Ong, Wei-Yi; Hodges, John R; Sutherland, Greg T; Kril, Jillian J; Abramowski, Dorothee; Staufenbiel, Matthias; Halliday, Glenda M; Ittner, Lars M

    2015-12-01

    Tau becomes hyperphosphorylated in Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD-tau), resulting in functional deficits of neurones, neurofibrillary tangle (NFT) formation and eventually dementia. Expression of mutant human tau in the brains of transgenic mice has produced different lines that recapitulate various aspects of FTLD-tau and AD. In this study, we characterized the novel P301S mutant tau transgenic mouse line, TAU58/2. Both young and aged TAU58/2 mice underwent extensive motor testing, after which brain tissue was analysed with immunohistochemistry, silver staining, electron microscopy and Western blotting. Tissue from various FTLD subtypes and AD patients was also analysed for comparison. TAU58/2 mice presented with early-onset motor deficits, which became more pronounced with age. Throughout the brains of these mice, tau was progressively hyperphosphorylated resulting in increased NFT formation with age. In addition, frequent axonal swellings that stained intensively for neurofilament (NF) were present in young TAU58/2 mice prior to NFT formation. Similar axonal pathology was also observed in human FTLD-tau and AD. Interestingly, activated microglia were found in close proximity to neurones harbouring transgenic tau, but were not associated with NF-positive axonal swellings. In TAU58/2 mice, early tau pathology induces functional deficits of neurones associated with NF pathology. This appears to be specific to tau, as similar changes are observed in FTLD-tau, but not in FTLD with TDP-43 inclusions. Therefore, TAU58/2 mice recapitulate aspects of human FTLD-tau and AD pathology, and will become instrumental in studying disease mechanisms and therapeutics in the future. © 2015 British Neuropathological Society.

  14. Observational Analysis of Coronal Fans

    Science.gov (United States)

    Talpeanu, D.-C.; Rachmeler, L; Mierla, Marilena

    2017-01-01

    Coronal fans (see Figure 1) are bright observational structures that extend to large distances above the solar surface and can easily be seen in EUV (174 angstrom) above the limb. They have a very long lifetime and can live up to several Carrington rotations (CR), remaining relatively stationary for many months. Note that they are not off-limb manifestation of similarly-named active region fans. The solar conditions required to create coronal fans are not well understood. The goal of this research was to find as many associations as possible of coronal fans with other solar features and to gain a better understanding of these structures. Therefore, we analyzed many fans and created an overview of their properties. We present the results of this statistical analysis and also a case study on the longest living fan.

  15. Nature of the Physical Observer

    Science.gov (United States)

    Osoroma, Drahcir S.

    2010-12-01

    The nature of the observer has long plagued physical science. Here we review the current status of cognitive science in the context of a cosmology of mind in an Anthropic Multiverse. The concept of an élan vital or life force has long been considered the elementary action principle driving the evolution of living-systems by theologically minded scientists and individuals. Sufficiently extending Einstein's original model of a Static Universe, to a Holographic Anthropic Multiverse (HAM), provides a context for solving this centuries old problem for introducing this type of teleological principle into Physics, Biology, Medicine and Psychology. This means the contemporary framework of biological mechanism should no longer be considered the formal philosophical basis for describing living systems and contemporary allopathic (scientific) medicine. The new noetic action principle has far reaching implications for medicine and transpersonal psychology.

  16. Trampoline Effect: Observations and Modeling

    Science.gov (United States)

    Guyer, R.; Larmat, C. S.; Ulrich, T. J.

    2009-12-01

    The Iwate-Miyagi earthquake at site IWTH25 (14 June 2008) had large, asymmetric at surface vertical accelerations prompting the sobriquet trampoline effect (Aoi et. al. 2008). In addition the surface acceleration record showed long-short waiting time correlations and vertical-horizontal acceleration correlations. A lumped element model, deduced from the equations of continuum elasticity, is employed to describe the behavior at this site in terms of a surface layer and substrate. Important ingredients in the model are the nonlinear vertical coupling between the surface layer and the substrate and the nonlinear horizontal frictional coupling between the surface layer and the substrate. The model produces results in qualitative accord with observations: acceleration asymmetry, Fourier spectrum, waiting time correlations and vertical acceleration-horizontal acceleration correlations. [We gratefully acknowledge the support of the U. S. Department of Energy through the LANL/LDRD Program for this work].

  17. Sky cover from MFRSR observations

    Directory of Open Access Journals (Sweden)

    E. Kassianov

    2011-07-01

    Full Text Available The diffuse all-sky surface irradiances measured at two nearby wavelengths in the visible spectral range and their modeled clear-sky counterparts are the main components of a new method for estimating the fractional sky cover of different cloud types, including cumuli. The performance of this method is illustrated using 1-min resolution data from a ground-based Multi-Filter Rotating Shadowband Radiometer (MFRSR. The MFRSR data are collected at the US Department of Energy Atmospheric Radiation Measurement (ARM Climate Research Facility (ACRF Southern Great Plains (SGP site during the summer of 2007 and represent 13 days with cumuli. Good agreement is obtained between estimated values of the fractional sky cover and those provided by a well-established independent method based on broadband observations.

  18. Observed properties of extrasolar planets.

    Science.gov (United States)

    Howard, Andrew W

    2013-05-03

    Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small planets between the sizes of Earth and Neptune substantially outnumber Jupiter-sized planets. The survey measurements support the core accretion model, in which planets form by the accumulation of solids and then gas in protoplanetary disks. The diversity of exoplanetary characteristics demonstrates that most of the gross features of the solar system are one outcome in a continuum of possibilities. The most common class of planetary system detectable today consists of one or more planets approximately one to three times Earth's size orbiting within a fraction of the Earth-Sun distance.

  19. Ice sheet hydrology from observations

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ-, Stockholm (Sweden))

    2010-11-15

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  20. Aerosol Observing System (AOS) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  1. Whatever Shines Should be Observed

    Science.gov (United States)

    McKenna-Lawlor, S. M. P.

    2003-08-01

    It is good to mark the new Millennium by looking back as well as forward. Whatever Shines should be Observed looks to the nineteenth century to celebrate the achievements of five distinguished women, four of whom were born in Ireland while the fifth married into an Irish family, who made pioneering contributions to photography, microscopy, astronomy and astrophysics. The women featured came from either aristocratic or professional families. Thus, at first sight, they had many material advantages among their peers. In the ranks of the aristocracy there was often a great passion for learning, and the mansions in which these families lived contained libraries, technical equipment (microscopes and telescopes) and collections from the world of nature. More modest professional households of the time were rich in books, while activities such as observing the stars, collecting plants etc. typically formed an integral part of the children's education. To balance this it was the prevailing philosophy that boys could learn, in addition to basic subjects, mathematics, mechanics, physics, chemistry and classical languages, while girls were channelled into 'polite' subjects like music and needlework. This arrangement allowed boys to progress to University should they so wish, where a range of interesting career choices (including science and engineering) was open to them. Girls, on the other hand, usually received their education at home, often under the tutelage of a governess who would not herself had had any serious contact with scientific or technical subjects. In particular, progress to University was not during most of the nineteenth century an option for women, and access to scientific libraries and institutions was also prohibited. Although those women with aristocratic and professional backgrounds were in a materially privileged position and had an opportunity to 'see' through the activities of their male friends and relatives how professional scientific life was lived

  2. Observing and Simulating Galaxy Evolution

    DEFF Research Database (Denmark)

    Olsen, Karen Pardos

    , but 50% smaller _CO factors, with the latter decreasing towards the center of each model galaxy. In a second study, SÍGAME is adapted to model the fine-structure line of singly ionized carbon, [CII] at 158 _m, the most powerful emission line of neutral ISM. Applying SÍGAME to the same type of galaxies......It remains a quest for modern astronomy to answer what main mechanisms set the star formation rate (SFR) of galaxies. Massive galaxies present a good starting point for such a quest due to their relatively easy detection at every redshift. Since stars form out of cold and dense gas, a comprehensive...... model for galaxy evolution should explain any observed connection between SFR and the amount and properties of the molecular gas of the interstellar medium (ISM). In proposed models of that kind, an active galactic nucleus (AGN) phase is often invoked as the cause for the decrease or cease of star...

  3. Juno JADE observations at Jupiter

    Science.gov (United States)

    Valek, P.; Allegrini, F.; Bagenal, F.; Bolton, S.; Connerney, J.; Ebert, R. W.; Gladstone, G. R.; Kim, T. K.; Kurth, W. S.; Levin, S.; Louran, P.; Mauk, B.; McComas, D. J.; Pollock, C.; Reno, M.; Szalay, J. R.; Thomsen, M. F.; Wilson, R. J.; Zink, J. L.

    2017-09-01

    Since the crossing of the Jovian bow shock on 24 June 2016 the Juno mission has performed measurements of the plasma environment across the Jovian magnetosphere. The large orbit - apojove 110 Rj with a 53.4 day period - allows the Juno spacecraft to measure the Jovian magnetosphere from the magnetosheath into the low altitude polar magnetosphere. In situ measurements of the plasma environment are performed by the Jovian Auroral Distributions Experiment (JADE). JADE measures electrons in the energy range from 100 eV to 100 keV, and composition separated ions from 10 eV / q to 50 eV / q. In this paper we present the range of JADE observations from the altitudes below 1 Rj out past the magnetopause.

  4. Dust in protoplanetary disks: observations*

    Directory of Open Access Journals (Sweden)

    Waters L.B.F.M.

    2015-01-01

    Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

  5. Optical MEMS for Earth observation

    Science.gov (United States)

    Liotard, Arnaud; Viard, Thierry; Noell, Wilfried; Zamkotsian, Frédéric; Freire, Marco; Guldimann, Benedikt; Kraft, Stefan

    2017-11-01

    Due to the relatively large number of optical Earth Observation missions at ESA, this area is interesting for new space technology developments. In addition to their compactness, scalability and specific task customization, optical MEMS could generate new functions not available with current technologies and are thus candidates for the design of future space instruments. Most mature components for space applications are the digital mirror arrays, the micro-deformable mirrors, the programmable micro diffraction gratings and tiltable micromirrors. A first selection of market-pull and techno-push concepts is done. In addition, some concepts are coming from outside Earth Observation. Finally two concepts are more deeply analyzed. The first concept is a programmable slit for straylight control for space spectro-imagers. This instrument is a push-broom spectroimager for which some images cannot be exploited because of bright sources in the field-of-view. The proposed concept consists in replacing the current entrance spectrometer slit by an active row of micro-mirrors. The MEMS will permit to dynamically remove the bright sources and then to obtain a field-of-view with an optically enhanced signal-to-noise ratio. The second concept is a push-broom imager for which the acquired spectrum can be tuned by optical MEMS. This system is composed of two diffractive elements and a digital mirror array. The first diffractive element spreads the spectrum. A micromirror array is set at the location of the spectral focal plane. By putting the micro-mirrors ON or OFF, we can select parts of field-of-view or spectrum. The second diffractive element then recombines the light on a push-broom detector. Dichroics filters, strip filter, band-pass filter could be replaced by a unique instrument.

  6. Vascular Disease and Dementias: Paradigm Shifts to Drive Research in New Directions

    Science.gov (United States)

    Kling, Mitchel A.; Trojanowski, John Q.; Wolk, David A.; Lee, Virginia M.-Y.; Arnold, Steven E.

    2012-01-01

    Vascular disease was once considered the principal cause of aging-related dementia. More recently, however, research emphasis has shifted to studies of progressive neurodegenerative disease processes such as those giving rise to neuritic plaques, neurofibrillary tangles, and Lewy bodies. While these studies have led to critical insights and potential therapeutic strategies, interest in the role of systemic and cerebrovascular disease mechanisms waned and has received relatively less attention and research support. Recent studies suggest that vascular disease mechanisms play an important role in the risk for aging-related cognitive decline and disorders. Vascular disease frequently coexists with cognitive decline in aging individuals, shares many risk factors with dementias considered to be of the “Alzheimer-type,” and is observed more frequently than expected in postmortem material from individuals manifesting “specific” disease stigmata such as abundant plaques and tangles. Considerable difficulties have emerged in attempting to classify dementias as being related to vascular vs. neurodegenerative causes, and several systems of criteria have been used. Despite multiple attempts, a lack of consensus remains regarding the optimal means of incorporating vascular disease into clinical diagnostic, neurocognitive, or neuropathologic classification schemes for dementias. We propose here an integrative, rather than a strictly taxonomic approach to the study and elucidation of how vascular disease mechanisms contribute to the development of dementias. We argue that, instead of discriminating between, e.g., “Alzheimer’s disease,” “vascular dementia,” and other diseases, there is a greater need to focus clinical and research efforts on elucidating specific pathophysiologic mechanisms that contribute to dementia phenotypes and neuropathologic outcomes. We outline a multi-tiered strategy, beginning with clinical and public health interventions that can be

  7. Starshade Observation Scheduling for WFIRST

    Science.gov (United States)

    Soto, Gabriel; Garrett, Daniel; Delacroix, Christian; Savransky, Dmitry

    2018-01-01

    An exoplanet direct imaging mission can employ an external starshade for starlight suppression to achieve higher contrasts and potentially higher throughput than with an internal coronagraph. This separately-launched starshade spacecraft is assumed to maintain a single, constant separation distance from the space telescope—for this study, the Wide Field Infrared Survey Telescope (WFIRST)—based on a designated inner working angle during integration times. The science yield of such a mission can be quantified using the Exoplanet Open-Source Imaging Simulator (EXOSIMS): this simulator determines the distributions of mission outcomes, such as the types and amount of exoplanet detections, based on ensembles of end-to-end simulations of the mission. This study adds a starshade class to the survey simulation module of EXOSIMS and outlines a method for efficiently determining observation schedules. The new starshade class solves boundary value problems using circular restricted three-body dynamics to find fast, high-accuracy estimates of the starshade motion while repositioning between WFIRST observations. Fuel usage dictates the mission lifetime of the starshade given its limited fuel supply and is dominated by the Δv used to reposition the starshade between the LOS of different targets; the repositioning time-of-flight is kept constant in this study. A starshade burns less fuel to reach certain target stars based on their relative projected positions on a skymap; other targets with costly transfers can be filtered out to increase the starshade mission duration. Because the initial target list can consist of nearly 2000 stars, calculating the Δv required to move the starshade to every other star on the target list would be too computationally expensive and renders running ensembles of survey simulations infeasible. Assuming the starshade begins its transfer at the LOS of a certain star, a Δv curve is approximated for the remaining target stars based on their right

  8. UV Observations of Hemispheric Asymmetry

    Science.gov (United States)

    Schaefer, R. K.; Paxton, L. J.; Wolven, B. C.; Zhang, Y.; Romeo, G.

    2015-12-01

    Asymmetry in the auroral patterns can be an important diagnostic for understanding the dynamics of solar wind interaction with the magnetosphere-ionosphere-thermosphere system (e.g., Newel and Meng, 1998; Fillingrim et al., 2005). Molecular nitrogen emission in the UV Lyman-Birge-Hopfield bands can be used to determine energy flux and electron mean energy (Sotirelis, et al, 2013) and thereby Hall and Pederson integrated conductances (Gjerloev, et al., 2014). UV imagery provided by the 4 SSUSI instruments on the Defense Meteorological Satellite Program (DMSP) F16-F19 spacecraft provide two dimensional maps of this emission at different local times. Often there are near simultaneous observations of both poles by some combination of the satellites. (see figure 1) The SSUSI auroral data products are well suited to this study, as they have the following features.: - dayglow has been subtracted on dayside aurora - electron energy flux and mean energy are pre-calculated - individual arcs have been identified through image processing. In order to intercompare data from multiple satellites, we must first ensure that the instrument calibrations are consistent. In this work we show that the instruments are consistently calibrated, and that results generated from the SSUSI data products can be trusted. Several examples of storm time asymmetries captured by the SSUSI instruments will be discussed. Fillingim, M. O., G. K. Parks, H. U. Frey, T. J. Immel, and S. B. Mende (2005), Hemispheric asymmetry of the afternoon electron aurora, Geophys. Res. Lett., 32, L03113, doi:10.1029/2004GL021635. Gjerloev, J., Schaefer, R., Paxton, L, and Zhang, Y. (2014), A comprehensive empirical model of the ionospheric conductivity derived from SSUSI/GUVI, SuperMAG and SuperDARN data, SM51G-4339, Fall 2014 AGU meeting, San Francisco. Newell, P. T., and C.-I. Meng (1988), Hemispherical asymmetry in cusp precipitation near solstices, J. Geophys. Res., 93(A4), 2643-2648, doi:10.1029/JA093iA04p02643

  9. What Catches the Eye in Class Observation? Observers' Perspectives in a Multidisciplinary Peer Observation of Teaching Program

    Science.gov (United States)

    Torres, Ana Cristina; Lopes, Amélia; Valente, Jorge M. S.; Mouraz, Ana

    2017-01-01

    Peer Observation of Teaching has raised a lot of interest as a device for quality enhancement of teaching. While much research has focused on its models, implementation schemes and feedback to the observed, little attention has been paid to what the observer actually sees and can learn from the observation. A multidisciplinary peer observation of…

  10. Space Debris and Observational Astronomy

    Science.gov (United States)

    Seitzer, Patrick

    2018-01-01

    Since the launch of Sputnik 1 in 1957, astronomers have faced an increasing number of artificial objects contaminating their images of the night sky. Currently almost 17000 objects larger than 10 cm are tracked and have current orbits in the public catalog. Active missions are only a small fraction of these objects. Most are inactive satellites, rocket bodies, and fragments of larger objects: all space debris. Several mega-constellations are planned which will increase this number by 20% or more in low Earth orbit (LEO). In terms of observational astronomy, this population of Earth orbiting objects has three implications: 1) the number of streaks and glints from spacecraft will only increase. There are some practical steps that can be taken to minimize the number of such streaks and glints in astronomical imaging data. 2) The risk to damage to orbiting astronomical telescopes will only increase, particularly those in LEO. 3) If you are working on a plan for an orbiting telescope project, then there are specific steps that must be taken to minimize space debris generation during the mission lifetime, and actions to safely dispose of the spacecraft at end of mission to prevent it from becoming space debris and a risk to other missions. These steps may involve sacrifices to mission performance and lifetime, but are essential in today's orbital environment.

  11. AEROSOL VARIABILITY OBSERVED WITH RPAS

    Directory of Open Access Journals (Sweden)

    B. Altstädter

    2013-08-01

    Full Text Available To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter. Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

  12. Cosmic Radiation Detection and Observations

    Science.gov (United States)

    Ramirez Chavez, Juan; Troncoso, Maria

    Cosmic rays consist of high-energy particles accelerated from remote supernova remnant explosions and travel vast distances throughout the universe. Upon arriving at earth, the majority of these particles ionize gases in the upper atmosphere, while others interact with gas molecules in the troposphere and producing secondary cosmic rays, which are the main focus of this research. To observe these secondary cosmic rays, a detector telescope was designed and equipped with two silicon photomultipliers (SiPMs). Each SiPM is coupled to a bundle of 4 wavelength shifting optical fibers that are embedded inside a plastic scintillator sheet. The SiPM signals were amplified using a fast preamplifier with coincidence between detectors established using a binary logic gate. The coincidence events were recorded with two devices; a digital counter and an Arduino micro-controller. For detailed analysis of the SiPM waveforms, a DRS4 sensory digitizer captured the waveforms for offline analysis with the CERN software package Physics Analysis Workstation in a Linux environment. Results from our experiments would be presented. Hartnell College STEM Internship Program.

  13. Chandra Observations of Hydra A

    Science.gov (United States)

    McNamara, Brian; Lavoie, Anthony R. (Technical Monitor)

    2000-01-01

    We present Chandra X-ray Observations of the Hydra A cluster of galaxies, and we report the discovery of structure in the central 80 kpc of the cluster's X-ray-emitting gas. The most remarkable structures are depressions in the X-ray surface brightness, approx. 25 - 35 kpc diameter, that are coincident with Hydra A's radio lobes. The depressions are nearly devoid of X-ray-emitting gas, and there is no evidence for shock-heated gas surrounding the radio lobes. We suggest the gas within the surface brightness depressions was displaced as the radio lobes expanded subsonically, leaving cavities in the hot atmosphere. The gas temperature declines from 4 keV at 70 kpc to 3 keV in the inner 20 kpc of the brightest cluster galaxy (BCG), and the cooling time of the gas is approx. 600 Myr in the inner 10 kpc. These properties are consistent with the presence of a approx. 34 solar mass/yr cooling flow within a 70 kpc radius. Bright X-ray emission is present in the BCG surrounding a recently-accreted disk of nebular emission and young stars. The star formation rate is commensurate with the cooling rate of the hot gas within the volume of the disk, although the sink for the material that may be cooling at larger radii remains elusive.

  14. Alma Polarimetric Observations Of Centaurus

    Science.gov (United States)

    Nagai, Hiroshi

    2017-10-01

    Synchrotron emission from the jets of nearby low luminosity AGNs show no or only little polarization at centimeter wavelengths and even at millimeter wavelengths. M87, M81, M84, and 3C 84 are typical example of weak polarization. The jet viewing angle to the line of sight is relatively large for all these sources. On the other hand, blazars which have a strongly beamed jet normally shows a strong polarization. This difference may arise from the jet viewing angle and properties of external environment around the emission region. We recently carried out polarization observations toward Centurus A, which is the representative of nearby LLAGNs, with the ALMA at 345 GHz. No significant polarized emission was detected at the level of greater than 0.1% throughout four different epochs. We give the lower limit of RM > 6 x 10^6 rad m^-2 with the assumption that the Cen A emission is intrinsically polarized but becomes unpolarized due to the extrinsic Faraday depolarization. If the emission region is very compact and located in the close vicinity of the black hole, we can give constraints on the accretion flow models. The derived lower limit of RM is roughly consistent with the RIAF models but place some limit to the radius where cold electrons can survive. We also discuss other possibilities for weak polarization of Cen A.

  15. Observer POD for radiographic testing

    Energy Technology Data Exchange (ETDEWEB)

    Kanzler, Daniel, E-mail: daniel.kanzler@bam.de, E-mail: uwe.ewert@bam.de, E-mail: christina.mueller@bam.de; Ewert, Uwe, E-mail: daniel.kanzler@bam.de, E-mail: uwe.ewert@bam.de, E-mail: christina.mueller@bam.de; Müller, Christina, E-mail: daniel.kanzler@bam.de, E-mail: uwe.ewert@bam.de, E-mail: christina.mueller@bam.de [Federal Institute for Materials Testing and Research, Berlin (Germany); Pitkänen, Jorma, E-mail: jorma.pitkanen@posiva.fi [Posiva Oy, Eurajoki (Finland)

    2015-03-31

    The radiographic testing (RT) is a non-destructive testing (NDT) method capable of finding volumetric and open planar defects depending on their orientation. The radiographic contrast is higher for larger penetrated length of the defect in a component. Even though, the detectability of defects does not only depend on the contrast, but also on the noise, the defect area and the geometry of the defect. The currently applied Probability of Detection (POD) approach uses a detection threshold that is only based on a constant noise level or on a constant contrast threshold. This does not reflect accurately the results of evaluations by human observers. A new approach is introduced, using the widely applied POD evaluation and additionally a detection threshold depending on the lateral area and shape of the indication. This work shows the process of calculating the POD curves with simulated data by the modeling software aRTist and with artificial reference data of different defect types, such as ASTM E 476 EPS plates, flat bottom holes and notches. Additional experiments with different operators confirm that the depth of a defect, the lateral area and shape of its indication contribute with different weight to the detectability of the defect if evaluated by human operators on monitors.

  16. Observer POD for radiographic testing

    Science.gov (United States)

    Kanzler, Daniel; Ewert, Uwe; Müller, Christina; Pitkänen, Jorma

    2015-03-01

    The radiographic testing (RT) is a non-destructive testing (NDT) method capable of finding volumetric and open planar defects depending on their orientation. The radiographic contrast is higher for larger penetrated length of the defect in a component. Even though, the detectability of defects does not only depend on the contrast, but also on the noise, the defect area and the geometry of the defect. The currently applied Probability of Detection (POD) approach uses a detection threshold that is only based on a constant noise level or on a constant contrast threshold. This does not reflect accurately the results of evaluations by human observers. A new approach is introduced, using the widely applied POD evaluation and additionally a detection threshold depending on the lateral area and shape of the indication. This work shows the process of calculating the POD curves with simulated data by the modeling software aRTist and with artificial reference data of different defect types, such as ASTM E 476 EPS plates, flat bottom holes and notches. Additional experiments with different operators confirm that the depth of a defect, the lateral area and shape of its indication contribute with different weight to the detectability of the defect if evaluated by human operators on monitors.

  17. Geotail observations of FTE velocities

    Directory of Open Access Journals (Sweden)

    G. I. Korotova

    2009-01-01

    Full Text Available We discuss the plasma velocity signatures expected in association with flux transfer events (FTEs. Events moving faster than or opposite the ambient media should generate bipolar inward/outward (outward/inward flow perturbations normal to the nominal magnetopause in the magnetosphere (magnetosheath. Flow perturbations directly upstream and downstream from the events should be in the direction of event motion. Flows on the flanks should be in the direction opposite the motion of events moving at subsonic and subAlfvénic speeds relative to the ambient plasma. Events moving with the ambient flow should generate no flow perturbations in the ambient plasma. Alfvén waves propagating parallel (antiparallel to the axial magnetic field of FTEs may generate anticorrelated (correlated magnetic field and flow perturbations within the core region of FTEs. We present case studies illustrating many of these signatures. In the examples considered, Alfvén waves propagate along event axes away from the inferred reconnection site. A statistical study of FTEs observed by Geotail over a 3.5-year period reveals that FTEs within the magnetosphere invariably move faster than the ambient flow, while those in the magnetosheath move both faster and slower than the ambient flow.

  18. Observation of a magnetoelectric aftereffect

    Science.gov (United States)

    Rado, G. T.; Ferrari, J. M.; Krishnan, R.

    1981-03-01

    The first observation of a magnetoelectric aftereffect is reported. Measurements were made of the electric polarization ΔP induced in the ''skin'' layer of lithium ferrite monocrystals by changes in an applied magnetic field H⃗. At temperatures, T, lower than 30°K, ΔP does not reach its equilibrium value until well after the changes in H⃗ are completed. In one experiment a sufficiently large H⃗ is rotated through an angle of π/2 from the principal axis of the crystal. In a second experiment H⃗ is applied along the principal axis. For both experiments the dependence of ΔP on t and T is successfully described by a newly proposed kinetic theory based on the superposition principle, a memory function, and a distribution of relaxation times τ = τ∞ exp (U/kT). Deduced from these experiments is the value U≃0.02eV, which suggests an electron hopping process, and a distribution of unexpectedly large values of τ∞ (10-4 to 10-2 sec), which may result from the ''skin'' layer inhomogeneity.

  19. Aerosol Variability Observed with Rpas

    Science.gov (United States)

    Altstädter, B.; Lampert, A.; Scholtz, A.; Bange, J.; Platis, A.; Hermann, M.; Wehner, B.

    2013-08-01

    To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS) Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter). Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

  20. Inhibition of Protein Phosphatase-2A (PP2A) by I1PP2A Leads to Hyperphosphorylation of Tau, Neurodegeneration, and Cognitive Impairment in Rats.

    Science.gov (United States)

    Wang, Xiaochuan; Blanchard, Julie; Tung, Yunn Chyn; Grundke-Iqbal, Inge; Iqbal, Khalid

    2015-01-01

    Protein phosphatase-2A (PP2A) deficiency is a cause of the abnormal hyperphosphorylation of tau, which composes neurofibrillary tangles (NFTs) in Alzheimer's disease (AD) brain. We previously reported that both mRNA and protein expression of inhibitor I of PP2A (I(1)(PP2A)) are elevated in AD brain and that this inhibitor induces a dose-dependent inhibition of PP2A activity and tau hyperphosphorylation in NIH3T3 cells. However, whether I(1)(PP2A) can induce AD neurofibrillary degeneration and cognitive impairment was not known. In the present study, we infected the brains of rat pups within 24 hours of birth with adeno-associated virus serotype 1 (AAV1) carrying I(1)(PP2A). In the adult AAV1-I(1)(PP2A) rats, we found a decrease in PP2A activity and abnormal hyperphosphorylation of tau in the brain. Immunohistochemistry showed a significant reduction of MAP2 and synapsin 1 in AAV1- I(1)(PP2A) animals, suggesting that I(1)(PP2A) can induce a loss of dendritic and synaptic plasticity markers. Behavioral tests revealed that infection with AAV1- I(1)(PP2A) induced deficits in exploratory activity, spatial reference memory, and memory consolidation in adult rats. These studies suggest that I(1)(PP2A) can inhibit PP2A activity, and in turn induce AD neurofibrillary degeneration and cognitive deficits in rats.