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Bu çalışmada CDS değerleri ile döviz kuru arasındaki nedensellik ilişkisi Türkiye özelinde incelenmektedir. Çalışmada söz konusu nedensellik ilişkisi frekans alanı nedensellik yaklaşımı çerçevesinde kısa, orta ve uzun vadeli olarak test edilmektedir. 11/03/2020-14/04/2021 dönemine ait 5 yıllık CDS baz puanına göre belirlenen günlük CDS verileri ile döviz kurunu temsil eden ABD Dolar kuru verilerinin analiz edildiği çalışmada, döviz kurundan CDS’e doğru düşük frekanslarda diğer bir ifadeyle uzun dönemde bir nedensellik ilişkisi belirlenirken, CDS’ten döviz kuruna doğru herhangi bir dönemde nedensellik ilişkisi saptanmamıştır. Sonuçlar temel olarak uzun vadede ABD Dolar kurunun ülke riskini temsil eden CDS değerleri üzerinde etkili olduğunu, bir diğer ifadeyle döviz kurundaki değişimlerin uzun vadede Türkiye’nin risk algısını etkilediğini işaret etmektedir., In this study, the causality relationship between the exchange rate and CDS is examined for Turkey. In the study, the causality relationship in question is tested as short, medium and long term with the help of frequency domain causality approach. In the study in which daily 5 years CDS for the period 11/03/2020-14/04/2021 and daily data of exchange rate of Dollar representing the exchange rate are analyzed, a causal relationship is determined from the exchange rate to CDS at low frequencies, in other words, a long-term causality relationship is determined. However, no causality relationship was found from CDS to exchange rate in any term. The results basically imply that in the long run, the exchange rate of Dollar has an impact on CDS representing the country risk, in other words, the changes in the exchange rate affect risk perception about Turkey in the long run.

A study on varietal effects on the productivity of potato (Solanum tuberosum L.) was conducted during the 2017 and 2018 cropping seasons at the Research Farm of the National Root Crops Research Institute (NRCRI) Kuru, Jos in Plateau State, Nigeria. The study was aimed at assessing the effect of variety on productivity of potato. The treatments consisted of two varieties of potato (improved variety: Daimat, local variety). The experiment consisted of 4 that were laid out in a 2×2 split plot arrangement in a randomized complete block design (RCBD) and replicated three times. Crop data collected were percent germination, plant height, leaf area, number of leaves, number of branches, number of stems, stem girth, number of tubers per plant, number of seed tubers per plant, number of ware tubers per plant, weight of seed tubers per plant, weight of ware tubers per plant and total yield of potato (tons/ha). Although there was no significant effect of variety on the growth parameters of potato but the improved variety performed better than the local variety. The improved variety is here by recommended for adoption in the study area.

Seventy years ago we learned from Chris Anfinsen that the stereochemical code necessary to fold a protein is embedded into its amino acid sequence. In water, protein morphogenesis is a spontaneous reversible process leading from an ensemble of disordered structures to the ordered functionally competent protein; conforming to Aristotle's definition of substance, the synolon of matter and form. The overall process of folding is generally consistent with a two state transition between the native and the denatured protein: not only the denatured state is an ensemble of several structures, but also the native protein populates distinct functionally relevant conformational (sub)states. This two-state view should be revised, given that any globular protein can populate a peculiar third state called amyloid, characterized by an overall architecture that at variance with the native state, is by-and-large independent of the primary structure. In a nut shell, we should accept that beside the folded and unfolded states, any protein can populate a third state called amyloid which gained centre stage being the hallmark of incurable neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases as well as others. These fatal diseases are characterized by clear-cut clinical differences, yet display some commonalities such as the presence in the brain of amyloid deposits constituted by one misfolded protein specific for each disease. Some aspects of this complex problem are summarized here as an excursus from the prion's fibrils observed in the brain of aborigines who died of Kuru to the amyloid detectable in the cortex of Alzheimer's patients. This article is protected by copyright. All rights reserved.

The urge to bring a comprehensive explanation to the problems in the Middle East has consumed a plethora of intellectuals. Not only the western scholarship, but also the Muslim intelligentsia has g...

Ahmet T. Kuru, Islam, Authoritarianism and Underdevelopment: A Global and Historical Comparison (Cambridge University Press, 2019). pp. 323. ISBN: 9781108419093 paperback (£26.99).

Dental and oral health problems in pregnant women are caused by poor care behavior of dental and oral hygiene as well as the condition of dental and oral hygiene of pregnant women itself. Those can lead to an impact of premature birth and low weight of the baby at birth. Strategies for behavioral change in pregnant women were one achieved through dental and oral hygiene education in the form of counseling along with material delivered that was well received by the pregnant women as the subject of research. The modification of Kuru-Kuru as game model can improve skills, self-reliance and as a media of counseling to pregnant women. The aim of research is to create KuruKuru, a game model, as an effort to improve dental health treatment to pregnant women. Research and Development method (R & D) was adopted with model testing of quasy-experimental one-group pre-test posttest design for this research. OHI-S and the skills of pregnant women are the dependent variables. The expert validation used intra-class correlation coefficient, while for the normality test, it used Shapiro Wilk. In addition, variable of abnormal pregnant women used non-parametric test (Wilcoxon). The result of KuruKuru game model is either relevant or feasible as an effort to improve dental and oral hygiene of pregnant women shown by p-value less than 0.003. This game effectively improves the skills of dental and oral hygiene with pre-test result in 5.92±1.158 and post-test in 9.54±0.613 (p < 0,000) and lowers the score of OHI-S pregnant women with pre-test in 1.211±0.605 and posttest in 0.155±0.275 (p < 0,000). It can be concluded that Kuru-kuru game model is effective as an effort to shape the behavior of pregnant women in improving dental and oral hygiene.

Designa-se por “príon” a forma alterada de uma proteína da superfície neuronal. Os príons são notáveis pelo fato de serem capazes de induzirem sua contraparte normal a assumir a configuração patológica em uma espécie de reação em cadeia, podendo inclusive serem transmitidos de um indivíduo para outro e até mesmo entre espécies diferentes. Os príons são causadores de uma série de patologias neurodegenerativas que afetam o homem (doença de Creutzfeldt-Jakob, síndrome de Gerstmann-Straussler-Scheinker, insônia familar fatal, kuru) e animais como bovinos (encefalopatia espongiforme bovina ou “doença da vaca louca”), cervídeos (doença do esgotamento crônico) e ovinos (scrapie). No presente artigo, oferecemos uma visão geral à respeito da natureza dos príons, assim como uma breve discussão sobre as doenças provocadas por príons que afetam o homem. Palavras-chave: príon, doença de Creutzfeld-Jakob, encefalopatia espongiforme transmissível, síndrome de Gerstmann-Straussler-Scheiker, encefalopatia espongiforme bovina.

Ahmet Kuru takes on the ambitious task of explaining why Muslim-majority states have experienced political violence, authoritarianism, and economic underdevelopment at higher rates than other state...

There is much to appreciate in this detailed book. Ahmet Kuru takes up a question that has gained salience again in the context of the war on terror: why do Muslim countries exhibit high levels of ...

Islam, Authoritarianism and Underdevelopment: A Global and Historical Comparison, by Ahmet T. Kuru, Bruce E. Porteous Professor of Political Science at San Diego State University, is a recent book ...

Ahmet Kuru seeks to answer big questions. In Secularism and State Policies Toward Religion, he asked why secular states pursue different policies towards religion. In order to answer that question,...

Comprehensive analysis is required for the accurate diagnosis of MV2-type sporadic Creutzfeldt-Jakob disease (sCJD) because it shows a wide clinicopathological spectrum. Here, we describe the clinical findings and neuropathologic observations of an autopsy-confirmed MV2K-type sCJD case with extensive spongiform changes of the cerebral cortex. In the early disease stages, the patient exhibited gait disturbance with ataxia and gradually showed cognitive dysfunction. Diffusion-weighted magnetic resonance images revealed hyperintense regions in the cerebral cortex, basal ganglia, and particularly in the thalamus. Prion protein (PrP) gene analysis revealed no mutations, and polymorphic codon 129 exhibited methionine and valine heterozygosity. During the course of the disease, a startle reaction was observed, whereas myoclonus was not observed. Electroencephalography showed no periodic sharp wave complexes. The patient died at age 61 years with 13 months total disease duration and did not reach the akinetic mutism state. Pathologic investigation revealed extensive fine vacuole-type spongiform change in the cerebral cortex, and the appearance of vacuolation tended to be more pronounced in the deeper layers. Numerous kuru plaques were observed in the cerebellum. PrP immunostaining revealed extensive diffuse synaptic-type PrP deposition in the cerebral cortex, and the finding was prominent in the deeper layer with perineuronal-type PrP deposition. In the limbic system, basal ganglia, and thalamus, mixed small plaque-type PrP with synaptic-type PrP deposition was observed. In the cerebellar cortex, diffuse synaptic-type PrP depositions were observed with numerous strongly immunopositive plaques. Western blot analysis of examined brain samples revealed mixed type 2 PrPSc (scrapie type) and intermediate-type PrPSc .

The purpose of this study was to perform an updated reclassification of all definite prion disease cases with available fresh-frozen samples referred to the Danish Reference Center over the past 40 years, putting a special emphasis on the molecular characterization of novel disease subtypes. Investigation of the Danish prion diseases cohort revealed rare sporadic Creutzfeldt-Jakob disease cases with mixed subtypes and subtypes with previously uncharacterized white matter plaques, a new case of sporadic fatal insomnia, and 3 novel mutations, including 2 large octapeptide repeat insertions, and a point mutation in the prion protein gene. The evaluation of methionine and valine distribution at codon 129 among the prion disease patients in the cohort revealed the increased prevalence of methionine homozygotes compared to the general population. This observation was in line with the prevalence reported in other Caucasian prion disease cohort studies. Reclassification of the old prion diseases cohort revealed unique cases, the molecular characterization of which improves prion diseases classification, diagnostic accuracy, genetic counseling of affected families, and the understanding of disease biology.

The infectious protein or prion (PrPSC) is a transmissible and replicable polypeptide, which arises from an abnormal folding of the PrP protein, by unknown mechanisms and without changes in the primary sequence of its amino acids. Its new spatial disposition arises from the substitution of its alpha helices by beta bands, which increase its structural stability, avoiding its complete proteolysis, resulting in a residual accumulation of prions. These prions induce the misfolding of normal PrP protein, generating their exponential increase, leading to a disturbance of neuronal homeostasis which results in the development of the fatal spongiform encephalopathy of the Creutzfeldt-Jakob disease (CJD). This is the most prevalent human prion disease, and 90% of cases are sporadic, suggesting the endogenous genesis of prions. There are different types of prions, identified based on the genetic variance of codon 129 amino acids of the prion protein. Meteonin (M) and Valine (V)), associated with the result of their enzymatic proteolysis, define prions type 1 (21 kDa) and type 2 (19 kDa). The Classical form of CJD produced by MM1 prion occurs in 70% of the cases. The Cerebellar form originated by the VV2 prion occurs in 15% of cases, the form with Kuru plates, associated with the prion MV2 occurs in 5%, and the Vacuolar, related to the MM2 prion occurs in 4%. CJD is always characterized by behavioral, motor, cognitive, and vision alterations and by findings in magnetic resonance imaging, electroencephalogram and cerebrospinal fluid that define each clinical and neuropathological form.

MicroRNAs (miRNAs) are small non-coding RNA molecules able to post-transcriptionally regulate gene expression via base-pairing with partially complementary sequences of target transcripts. Prion diseases comprise a singular group of neurodegenerative conditions caused by endogenous, misfolded pathogenic (prion) proteins, associated with molecular aggregates. In humans, classical prion diseases include Creutzfeldt–Jakob disease, fatal familial insomnia, Gerstmann–Sträussler–Scheinker syndrome, and kuru. The aim of this review is to present the connections between miRNAs and prions, exploring how the interaction of both molecular actors may help understand the susceptibility, onset, progression, and pathological findings typical of such disorders, as well as the interface with some prion-like disorders, such as Alzheimer’s. Additionally, due to the inter-regulation of prions and miRNAs in health and disease, potential biomarkers for non-invasive miRNA-based diagnostics, as well as possible miRNA-based therapies to restore the levels of deregulated miRNAs on prion diseases, are also discussed. Since a cure or effective treatment for prion disorders still pose challenges, miRNA-based therapies emerge as an interesting alternative strategy to tackle such defying medical conditions.

The normal soluble cellular prion protein, PrPC, is responsible for many cellular processes in our body. It gets structurally transformed into a misfolded, insoluble protein called PrPSc. This misfolded protein is responsible for a variety of neurodegenerative diseases commonly known as prion disease. The cause of this structural change from the alpha helical-rich structure of PrPC to the beta sheet-rich structure of PrPSc is not known yet. The PrPSc causes prion amyloids to form and aggregate at different parts of the brain, making it spongy in nature. In humans, prion disease is known by many names, including kuru, Gerstmann-Straussler-Scheinker disease, and Creutzfeldt Jakob disease (CJD). In sheep, it is known as scrapie and in cattle, it is mad cow disease or bovine spongiform encephalopathy (BSE). There are many treatment strategies to control prion disease, such as agents that can dissociate the prion amyloids, small molecules that can target the diseased prion and dissociate it, interfering RNAs, antiprion antibodies, and stem cell therapy. Stem cell therapy deals with the different types of differentiated stem cell grafts incorporation in scrapie-induced mice models. Stem cells from different origins such as neural stem cells (NSCs), embryonic stem cells (ESCs), adult stem cells, fetal neural stem cells (fNSCs), mesenchymal stem cells derived from bone marrow, etc., have been used as grafts to repair the damaged neural cells in the brain of prion-induced mice. Many results have been promising in improving the survival of mice, but very few could indicate a complete cure of the disease. Moreover, the time of disease onset and graft injection plays an important role in obtaining effective results. The strains of prion proteins most commonly used for infecting mice are Chandler, Obihiro, or RML, and the grafting is done well before the onset of disease symptoms to improve mice survival. In this chapter, we will discuss the different stem cell therapeutic approaches so far identified in managing prion disease.

One of remarkable features of sporadic Creutzfeldt-Jakob disease (sCJD) is the great phenotypic variability. Understanding the molecular basis of this variability has important implications for the development of therapeutic approaches. It is well established that, in many cases, phenotypic heterogeneity of sCJD is under control of two determinants: the genotype at the methionine (M)/valine (V) polymorphic codon 129 of the human prion protein gene and the type, 1 or 2, of the pathogenic and disease-related form of the prion protein, PrPD. However, this scenario fails to explain the existence of distinct heterozygous sCJDMV2 subtypes, where heterogeneity occurs without any variation of the 129 allotype and PrPD type. One of these subtypes, denoted sCJDMV2C, associated with PrPD type 2, is characterized by widespread spongiform degeneration of the cerebral cortex (C). The second variant, denoted sCJDMV2K, features prominent deposition of PrPD amyloid forming kuru type (K) plaques. Here we used a mass spectrometry based approach to test the hypothesis that phenotypic variability within the sCJDMV2 subtype is at least partly determined by the abundance of 129 M and 129 V polymorphic forms of proteinase K-resistant PrPD (resPrPD). Consistent with this hypothesis, our data demonstrated a strong correlation of the MV2C and MV2K phenotypes with the relative populations of protease-resistant forms of the pathogenic prion proteins, resPrPD-129 M and resPrPD-129 V, where resPrPD-129 M dominated in the sCJDMV2C variant and resPrPD-129 V in the sCJDMV2K variant. This finding suggests an important, previously unrecognized mechanism for phenotypic determination in human prion diseases.

Resumen Desde el scrapie de la oveja a la encefalopatía espongiforme bovina y desde el kuru a la enfermedad de Creutzfeldt-Jakob, tenaces investigadores buscaron los misteriosos agentes de estos desórdenes neurológicos, hasta que Stanley Prusiner descubriera y describiera las priones en los ochenta, obteniendo el Premio Nobel en 1997. Pero, este no fue el final de esta fantástica historia de la increible proteina designada prion por Prusiner, porque ahora, la investigación en neurociencia ha encontrado proteínas prion-like jugando un importante papel en la génesis de la memoria a largo plazo.

During the past decades, prion proteins, the pathological agents causing sporadic, genetic and infectious neurodegenerative disorders, have constituted major concerns for public health authorities. Although the molecular mechanisms of these diseases are not completely understood, the invariably fatal outcome in humans [namely Kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker syndrome, fatal insomnia and new variant CJD (vCJD)] and animals (bovine spongiform encephalopathy and scrapie in sheep) has partly overshadowed the physiological action of prions. In fact, increasing evidence support the essential role of prion and prion-like proteins in reproductive physiology. This review examines the roles played by prion (PrPc), prion-like testis specific (Prt), Shadoo and Doppel genes and proteins, in reproductive physiology, and is supported by the expertise acquired by our group in this domain. This covers spermatogenesis, sperm motility, zona binding, fertilization, 3D NMR structure, as well as the evaluation of the genetic regulation of these genes in granulosa cells, using novel techniques of gene silencing (siRNAs) and epigenetic analysis (methylation). This review will thus appraise key issues concerning the biological characters and physiological functions of prion like family members in reproduction.

Although colocalization of amyloid β (Aβ) with prion protein (PrP) in the kuru plaque has previously been observed in the brain of prion diseases patients, the participating Aβ species has not been identified. Here, we present an immunohistochemical assessment of the brain and spinal cord of a 69-year-old Japanese female patient with Gerstmann-Sträussler-Scheinker disease with a P105L mutation on the PRNP gene (GSS-P105L). Immunohistochemical assessment of serial brain sections was performed using anti-PrP and -Aβ antibodies in the hippocampus, frontal and occipital lobes. She died 69 years after a 21-year clinical course. Immunohistochemistorical examination revealed that ~50% of the kuru plaques in the cerebrum were colocalized with Aβ, and Aβ42 was predominantly observed to be colocalized with PrP-plaques. The Aβ deposition patterns were unique, and distinct from diffuse plaques observed in the normal aging brain or Alzheimer's disease brain. The spinal cord exhibited degeneration in the lateral corticospinal tract, posterior horn, and fasciculus gracilis. We have demonstrated for the first time that Aβ42, rather than Aβ40, is the main Aβ component associated with PrP-plaques, and also the degeneration of the fasciculus gracilis in the spinal cord in GSS-P105L, which could be associated with specific clinical features of GSS-P105L.

It is now a decade since the last known case of Kuru died in Papua New Guinea.1 While it is a classic example of the synergy of public health, anthropology, and the laboratory sciences, Kuru is a disease that few will have heard of outside of public health and neuropathology circles...

We present an autopsied case of non-plaque-type dura mater graft-associated Creutzfeldt-Jakob disease (dCJD) with extensive amyloid-β (Aβ) deposition in the brain. A 39-year-old Japanese woman presented with memory disturbance and abnormal behavior. The patient had a history of craniotomy with dura matter-graft transplant for a head injury which occurred when she was 19 years old. Magnetic resonance imaging (MRI) showed hyperintensities in the cerebral cortex and striatum on diffusion-weighted images, particularly on the dura mater-grafted right side. Her clinical symptoms, including rapidly progressing cognitive impairment, myoclonus, and periodic sharp wave complexes on electroencephalogram, could not be distinguished from typical sporadic CJD cases. The patient died 11 months after symptom onset, and pathological investigations showed extensive spongiform degeneration with prion protein (PrP) deposition without Kuru plaques; these observations were essentially the same as those of typical sporadic CJD cases. Furthermore, Aβ immunohistochemistry showed extensive diffuse staining in the cerebral neocortex, plaque-type deposition, positive staining in the pia mater, and cerebral amyloid angiopathy. Although the MRI findings suggested that the pathological involvement originated from the dura mater-grafted right side, the PrP and Aβ depositions showed no apparent regionalization and laterality. Tau-pathology including neurofibrillary tangles was hardly identified. The proteins phosphorylated α-synuclein and phosphorylated transactivation response DNA-binding protein 43 kDa were not detected on immunostaining. Although this report describes only one case, various speculations were made based on detailed clinical and pathological observations in conjunction with previous reports of dCJD. In particular, this report provides significant insight into the characteristics and progression of dCJD pathology and its relationship with Aβ pathology.

Evaluation of transmission properties is important for the differential diagnosis of a subgroup of acquired Creutzfeldt-Jakob disease (CJD) with methionine homozygosity at polymorphic codon 129 of the PRNP gene, an intermediate type abnormal prion protein (PrP), and kuru plaques, denoted as acquired CJD-MMiK. The present study aimed to develop a quick evaluation system of the transmission properties of acquired CJD-MMiK. In the PrP-humanized mice intraperitoneally inoculated with brain homogenates from an acquired CJD-MMiK patient, accumulation of abnormal PrP was observed in follicular dendritic cells of the spleen at 75 days post-inoculation. The transmission properties of acquired CJD-MMiK were quite different from those of sporadic CJD with the same PRNP codon 129 genotype. Moreover, even at 14 days post-inoculation, the characteristic transmission properties of acquired CJD-MMiK could be detected. These findings suggest that the bioassay using follicular dendritic cells of the spleen, named as a FDC assay, can be an easy, time-saving, and useful method to distinguish acquired CJD-MMiK from sporadic CJD.

Tarımsal ürünler özellikle gelişmekte olan ülkeler için ödemeler dengesinde cari açığı telafi etmek için kullanılan en önemli ihracat çıktısı olarak karşımıza çıkmaktadır. Bu bağlamda, akademik literatürde sıkça ele alınmış olan tarım ürünleri ve onu etkileyen faktörler çalışmada ele alınmıştır. Bağımlı değişken olarak tarımsal ürünler ve bağımsız değişkenler olarak döviz kuru ve petrol fiyatları belirlenmiştir. Bu çalışmada döviz kurunun yanında petrol fiyatlarının tarımsal ürünlere olan etkisini ölçmek için çoklu regresyon analizi yapılmıştır. Veri seti aylık olarak Uluslararası Ticaret Merkezi (ITC) Trademap veri tabanından alınıp yapılmış olan tüm ekonometriksel analizlerde kullanılmıştır. Ayrıca, değişkenler arası uzun vadeli ilişkiyi tespit etmek için Johansen eşbütünleşme testi kullanılmıştır. VAR analizi durağan çıktıktan sonra varyans ayrıştırması analizi ile etki tepki analizi hangi bağımsız değişkenin diğer bağımsız değişkene göre bağımlı değişkeni daha fazla etkilediğini tespit etmek için kullanılmıştır. Bu çalışmada yapılan tüm ampirik bulgulara göre gerek petrol fiyatları gerekse döviz kurları tarım ürünlerini etkilemiştir ve aralarında uzun vadeli ilişki vardır. Sonuç olarak, tarımsal ürünler, uluslararası arenada rekabetin artması için enerji kaynaklarının stratejik önemini ve gerekliliğini açıkça ortaya koymaktadır. Tarımsal üretimin petrol kaynakları ile arttırılması, tarımın ülke ekonomisi için stratejik üstünlüğünü arttırıcı bir unsurdur. Dolayısıyla, petrol kaynakları bulunmayan tarımsal ürün ihracatçısı konumundaki ülkeler, petrole dayalı yakıtlar konusunda, tarımsal üretimi destekleyici sübvansiyon politikaları geliştirmelidir. Agricultural goods are so significant export output in order to compensate trade deficit in terms of balance of payments in developing countries. In this context, the impact of oil price and exchange rates on agricultural goods have been discussed in this paper. Agricultural good is determined as dependent variable and oil price and exchange rates are determined as independent variable. Multivariate regression test is implemented in order to reveal the effect of oil price and exchange rates on agricultural goods. Data are derived from International Trade Center as monthly and they all used in econometrical analysis. Besides, Johansen co-integration test is used to comprehend long-term relationship between relevant variables. After determining that the VAR analysis is stationary, both impulse response and variance decomposition analysis are implemented to reply which independent variable influences more the dependent variable comparing other independent variable. In this work, according to all empirical results, there is long-term relationship between variables and both oil price and exchange rates affect agricultural goods. To sum up, agricultural goods are essential by providing energy resources and its strategical importance to increase competition among international markets. The production of agricultural goods are so vital via petroleum resources which increases strategic advantage of its significance. Therefore, agricultural goods exporting countries should develop supportive policy for producing agricultural goods due to lack of petroleum resources.

Kuru granite is strong and brittle so that it is prone to strain burst. A series of laboratory tests were carried out to investigate the fracturing process in both pre- and post-peak stages under uniaxial compression. The progressive fracturing in the cylindrical specimens was monitored by acoustic emission (AE) technique. The specimens were loaded to different levels both in pre-peak and post-peak stages. After that, the load was removed and two thin sections, one parallel and the other perpendicular to the loading direction, were prepared from each specimen. The fractures in the specimens were microscopically observed. The geometry of each fracture was quantified by its length, opening and orientation. The results show that noticeable fracture propagation occurs mainly at the stress level above 80% of the Uniaxial Compressive Strength (UCS). In general, intergranular cracks dominate in the whole loading process, but after the peak stress the density of intragranular cracks becomes comparable to the intergranular cracks. The percentage of the intergranular first rises and then drops with an increase in the damage of the material. The variation in the number of intragranular cracks is opposite. The intergranular cracks dominate in the beginning of fracture initiation and during the stage of stable fracture propagation, but the intragranular cracks begin to flourish during the stage of unstable fracture propagation. The propagation of intragranular cracks consumes more energy than intergranular cracks. The fracture propagation in the loading direction becomes dominant with an increase in the damage of the rock and finally the specimen fails in splitting. The microscopic observations reveal the fracturing pattern of the burst-prone rock, which are useful data for the study of the physics of strain burst in rock.

We report here on the ultrastructure of amyloid plaques in chronic wasting disease (CWD) transmitted to Tg20 transgenic mice overexpressing prion protein (PrPc). We identified three main types of amyloid deposits in mCWD: large amyloid deposits, unicentric plaques similar to kuru plaques in human prion diseases and multicentric plaques reminiscent of plaques typical of GSS. The most unique type of plaques were large subpial amyloid deposits. They were composed of large areas of amyloid fibrils but did not form „star-like” appearances of unicentric plaques. All types of plaques were totally devoid of dystrophic neuritic elements. However, numerous microglial cells invaded them. The plaques observed by confocal laser microscope were of the same types as those analyzed by electron microscopy. Neuronal processes surrounding the plaques did not show typical features of neuroaxonal dystrophy.

Prion diseases are transmissible and fatal neurodegenerative diseases affecting humans and animals, in which the infectious agent is composed of misfolded and multimeric forms of cellular prion protein. These conditions can be sporadic, inherited or acquired. Rapidly progressive dementia and ataxia are the common themes in the clinical presentation, but these can be accompanied by a wide variety of neurological or psychiatric syndromes. Neuropathological examination of brain tissue remains the only way of making a definite diagnosis, but major advances in magnetic resonance brain imaging, such as diffusion-weighted sequences, and cerebrospinal fluid prion amplification assays have proved to be reliable ante mortem diagnostic tools. Prion protein gene (PRNP) analysis is also recommended, to rule out Mendelian forms and provide the codon 129 genotype, which has profound effects on incubation period, susceptibility, duration of illness, clinical phenotype and neuropathology. At present, there is no effective treatment for prion disease.

OBJECTIVES The island of New Guinea was settled by modern human over 50,000 years ago, and is currently characterized by a complex landscape and contains one-seventh of the world's languages. The Eastern Highlands of New Guinea were also the home to the devastating prion disease called kuru that primarily affected Fore-speaking populations, with some 68% of cases involving adult females. We characterized the mitochondrial DNA (mtDNA) diversity of highlanders from Papua New Guinea (PNG) to: (a) gain insight into the coevolution of genes and languages in situ over mountainous landscapes; and (b) evaluate the recent influence of kuru mortality on the pattern of female gene flow. MATERIALS AND METHODS We sequenced the mtDNA hypervariable segment 1 of 870 individuals from the Eastern and Southern Highlands of PNG using serums collected in the 1950s to 1960s. These highlanders were selected from villages representing 15 linguistic groups within the Trans-New Guinea phylum. Genetic, linguistic, and geographic distances were calculated separately and correlations among those distance matrices were assessed using the Mantel test. RESULTS Geographic, genetic, and linguistic patterns were independently correlated with each other (p

Mammalian prion diseases are a group of neurodegenerative conditions caused by infection of the central nervous system with proteinaceous agents called prions, including sporadic, variant, and iatrogenic Creutzfeldt-Jakob disease; kuru; inherited prion disease; sheep scrapie; bovine spongiform encephalopathy; and chronic wasting disease. Prions are composed of misfolded and multimeric forms of the normal cellular prion protein (PrP). Prion diseases require host expression of the prion protein gene ( PRNP) and a range of other cellular functions to support their propagation and toxicity. Inherited forms of prion disease are caused by mutation of PRNP, whereas acquired and sporadically occurring mammalian prion diseases are controlled by powerful genetic risk and modifying factors. Whereas some PrP amino acid variants cause the disease, others confer protection, dramatically altered incubation times, or changes in the clinical phenotype. Multiple mechanisms, including interference with homotypic protein interactions and the selection of the permissible prion strains in a host, play a role. Several non- PRNP factors have now been uncovered that provide insights into pathways of disease susceptibility or neurotoxicity.