Showing papers by "University of Bergen published in 1998"
TL;DR: Transected axons are common in the lesions of multiple sclerosis, and axonal transection may be the pathologic correlate of the irreversible neurologic impairment in this disease.
Abstract: Background Multiple sclerosis is an inflammatory demyelinating disease of the central nervous system and is the most common cause of neurologic disability in young adults. Despite antiinflammatory or immunosuppressive therapy, most patients have progressive neurologic deterioration that may reflect axonal loss. We conducted pathological studies of brain tissues to define the changes in axons in patients with multiple sclerosis. Methods Brain tissue was obtained at autopsy from 11 patients with multiple sclerosis and 4 subjects without brain disease. Fourteen active multiple-sclerosis lesions, 33 chronic active lesions, and samples of normal-appearing white matter were examined for demyelination, inflammation, and axonal pathologic changes by immunohistochemistry and confocal microscopy. Axonal transection, identified by the presence of terminal axonal ovoids, was detected in all 47 lesions and quantified in 18 lesions. Results Transected axons were a consistent feature of the lesions of multiple sclerosis...
3,903 citations
TL;DR: In this article, an elevated level of total homocysteine (tHcy) in blood, denoted hyperhomocysteinemia, is emerging as a prevalent and strong risk factor for atherosclerotic vascular disease in the coronary, cerebral, and peripheral vessels, and for arterial and venous thromboembolism.
Abstract: An elevated level of total homocysteine (tHcy) in blood, denoted hyperhomocysteinemia, is emerging as a prevalent and strong risk factor for atherosclerotic vascular disease in the coronary, cerebral, and peripheral vessels, and for arterial and venous thromboembolism. The basis for these conclusions is data from about 80 clinical and epidemiological studies including more than 10,000 patients. Elevated tHcy confers a graded risk with no threshold, is independent of but may enhance the effect of the conventional risk factors, and seems to be a particularly strong predictor of cardiovascular mortality. Hyperhomocysteinemia is attributed to commonly occurring genetic and acquired factors including deficiencies of folate and vitamin B12. Supplementation with B-vitamins, in particular with folic acid, is an efficient, safe, and inexpensive means to reduce an elevated tHcy level. Studies are now in progress to establish whether such therapy will reduce cardiovascular risk.
2,099 citations
TL;DR: Objective measures of subclinical disease and disease severity were independent and joint predictors of 5-year mortality in older adults, along with male sex, relative poverty, physical activity, smoking, indicators of frailty, and disability.
Abstract: Context—Multiple factors contribute to mortality in older adults, but the extent
to which subclinical disease and other factors contribute independently to
mortality risk is not knownObjective—To determine the disease, functional, and personal characteristics that
jointly predict mortality in community-dwelling men and women aged 65 years
or olderDesign—Prospective population-based cohort study with 5 years of follow-up
and a validation cohort of African Americans with 425-year follow-upSetting—Four US communitiesParticipants—A total of 5201 and 685 men and women aged 65 years or older in the
original and African American cohorts, respectivelyMain Outcome Measures—Five-year mortalityResults—In the main cohort, 646 deaths (12%) occurred within 5 years Using
Cox proportional hazards models, 20 characteristics (of 78 assessed) were
each significantly (P<05) and independently associated
with mortality: increasing age, male sex, income less than $50000 per year,
low weight, lack of moderate or vigorous exercise, smoking for more than 50
pack-years, high brachial (>169 mm Hg) and low tibial (≤127 mm Hg) systolic
blood pressure, diuretic use by those without hypertension or congestive heart
failure, elevated fasting glucose level (>72 mmol/L [130 mg/dL]), low albumin
level (≤37 g/L), elevated creatinine level (≥106 µmol/L [12 mg/dL]),
low forced vital capacity (≤206 mL), aortic stenosis (moderate or severe)
and abnormal left ventricular ejection fraction (by echocardiography), major
electrocardiographic abnormality, stenosis of internal carotid artery (by
ultrasound), congestive heart failure, difficulty in any instrumental activity
of daily living, and low cognitive function by Digit Symbol Substitution test
score Neither high-density lipoprotein cholesterol nor low-density lipoprotein
cholesterol was associated with mortality After adjustment for other factors,
the association between age and mortality diminished, but the reduction in
mortality with female sex persisted Finally, the risk of mortality was validated
in the second cohort; quintiles of risk ranged from 2% to 39% and 0% to 26%
for the 2 cohortsConclusions—Objective measures of subclinical disease and disease severity were
independent and joint predictors of 5-year mortality in older adults, along
with male sex, relative poverty, physical activity, smoking, indicators of
frailty, and disability Except for history of congestive heart failure, objective,
quantitative measures of disease were better predictors of mortality than
was clinical history of disease
1,105 citations
TL;DR: In this article, the advantages and disadvantages of the preferred technique (weighted averaging partial least squares) are reviewed and the problems in model selection are discussed and the need for evaluation and validation of reconstructions is emphasised.
Abstract: In the last decade, palaeolimnology has shifted emphasis from being a predominantly qualitative, descriptive subject to being a quantitative, analytical science with the potential to address critical hypotheses concerning the impacts of environmental changes on limnic systems. This change has occurred because of (1) major developments in applied statistics, some of which have only become possible because of the extraordinary developments in computer technology, (2) increased concern about problem definition, research hypotheses, and project design, (3) the building up of high quality modern calibration data-sets, and (4) the narrowing of temporal resolution in palaeolimnological studies from centuries to decades or even single years or individual seasons. The most significant development in quantitative palaeolimnology has been the creation of many modern calibration data-sets of biotic assemblages and associated environmental data. Such calibration sets, when analysed by appropriate numerical procedures, have the potential to transform fossil biostratigraphical data into quantitative estimates of the past environment. The relevant numerical techniques are now well developed, widely tested, and perform remarkably well. The properties of these techniques are becoming better known as a result of simulation studies. The advantages and disadvantages of the preferred technique (weighted averaging partial least squares) are reviewed and the problems in model selection are discussed. The need for evaluation and validation of reconstructions is emphasised. Several statistical surprises have emerged from calibration studies. Outstanding problems remain the need for a detailed and consistent taxonomy in the calibration sets, the quality, representativeness, and inherent variability of the environmental variables of interest, and the inherent bias in the calibration models. Besides biological- environmental calibration sets, there is the potential to develop modern sediment-environment calibration sets to link sedimentary properties to catchment parameters. The adoption of a ‘dynamic calibration set’ approach may help to minimise the inherent bias in current calibration models. Modern regression techniques are available to explore the vast amount of unique ecological information about taxon-environment relationships in calibration data-sets. Hypothesis testing in palaeolimnology can be attempted directly by careful project design to take account of ‘natural experiments’ or indirectly by means of statistical testing, often involving computer- intensive permutation tests to evaluate specific null hypotheses. The validity of such tests depends on the type of permutation used in relation to the particular data-set being analysed, the sampling design, and the research questions being asked. Stratigraphical data require specific permutation tests. Several problems remain unsolved in devising permutation designs for fine-resolution stratigraphical data and for combined spatial and temporal data. Constrained linear or non-linear reduced rank regression techniques (e.g. redundancy analysis, canonical correspondence analysis and their partial counterparts) provide powerful tools for testing hypotheses in palaeolimnology. Work is needed, however, to extend their use to investigate and test for lag responses between biological assemblages and their environment. Having developed modern calibration data-sets, many palaeolimnologists are returning to the sedimentary record and are studying stratigraphical changes. In contrast to much palynological data, palaeolimnological data are often fine-resolution and as a result are often noisy, large, and diverse. Recent developments for detecting and summarising patterns in such data are reviewed, including statistical evaluation of zones, summarisation by detrended correspondence analysis, and non-parametric regression (e.g. LOESS). Techniques of time-series analysis that are free of many of the assumptions of conventional time-series analysis due to the development of permutation tests to assess statistical significance are of considerable potential in analysing fine-resolution palaeolimnological data. Such data also contain a wealth of palaeopopulation information. Robust statistical techniques are needed to help identify non-linear deterministic dynamics (chaos) from noise or random effects in fine-resolution palaeolimnological data.
846 citations
TL;DR: The FYVE finger, an evolutionarily conserved double-zinc-binding domain, is identified as a protein structure that binds to PtdIns(3)P with high specificity.
Abstract: The membrane lipid phosphatidylinositol-3-phosphate (PtdIns(3)P) is constitutively produced by yeast and higher eukaryotes through the phosphorylation of phosphatidylinositol by phosphatidylinositol-3-OH kinase1 (PI(3)K). PtdIns(3)P is important for vesicular transport1, but little is known about how it acts, and proteins that specifically recognize it have not yet been identified. Here we identify the FYVE finger2, an evolutionarily conserved double-zinc-binding domain (see Supplementary information), as a protein structure that binds to PtdIns(3)P with high specificity.
551 citations
TL;DR: Both the mother and the fetus contribute to the risk of pre-eclampsia, the contribution of the fetus being affected by paternal genes, and search for specific genes that predispose for pre- eClampsia should include the fetus as well as the mother.
Abstract: Objective: To use familial patterns of recurrence of pre-eclampsia to investigate whether paternal genes expressed in the fetus contribute to the mother9s risk of pre-eclampsia and whether mother9s susceptibility to pre-eclampsia is related to maternal inheritance by mitochondrial DNA. Design: Linked data on pregnancies of different women who had children with the same father, and subsequently linked data on pregnancies of half sisters who either had same mother and different fathers or had same father and different mothers. Setting: Population based data from the Medical Birth Registry of Norway covering all births since 1967 (about 1.7 million) and the Norwegian Central Population Register. Main outcome measures: Relative risk of pre-eclampsia after a previous pre-eclamptic pregnancy in the family. Relative risks approximated by odds ratios. Results: If a woman becomes pregnant by a man who has already fathered a pre-eclamptic pregnancy in a different woman her risk of developing pre-eclampsia is 1.8 (95% confidence interval 1.2 to 2.6). If the woman has a half sister who had pre-eclampsia and with whom she shares the same mother but different fathers the risk of pre-eclampsia is 1.6 (0.9 to2.6). If the two sisters have the same father but different mothers the risk is 1.8 (1.01 to 2.9). Conclusions: Both the mother and the fetus contribute to the risk of pre-eclampsia, the contribution of the fetus being affected by paternal genes. Mitochondrial genes, which are transmitted by mothers, do not seem to contribute to the risk. Key messages Paternal genes in the fetus may contribute substantially to a pregnant woman9s risk of pre-eclampsia The role of the fetus may be as important as that of the mother Purely maternal inheritance (specifically by mitochondrial DNA) is probably not involved in pre-eclampsia Search for specific genes that predispose for pre-eclampsia should include the fetus as well as the mother
461 citations
TL;DR: The mental models concept should be “unbundled” and the term “mental models” should be used more narrowly to initiate a dialogue through which the system dynamics community might achieve a shared understanding of mental models.
Abstract: Although “mental models” are of central importance to system dynamics research and practice, the field has yet to develop an unambiguous and agreed upon definition of them. To begin to address this problem, existing definitions and descriptions of mental models in system dynamics and several literatures related to cognitive science were reviewed and compared. Available definitions were found to be overly brief, general, and vague, and different authors were found to markedly disagree on the basic characteristics of mental models. Based on this review, we concluded that in order to reduce the amount of confusion in the literature, the mental models concept should be “unbundled” and the term “mental models” should be used more narrowly. To initiate a dialogue through which the system dynamics community might achieve a shared understanding of mental models, we propose a new definition of “mental models of dynamic systems” accompanied by an extended annotation that explains the definitional choices made and suggests terms for other cognitive structures left undefined by narrowing the mental model concept. Suggestions for future research that could improve the field's ability to further define mental models are discussed. © 1998 John Wiley & Sons, Ltd.
455 citations
TL;DR: In multivariate analysis, sex, age, folate intake, smoking status, and coffee consumption were the strongest determinants of tHcy concentration.
453 citations
01 Jan 1998
TL;DR: A new block cipher is proposed that uses S-boxes similar to those of DES in a new structure that simultaneously allows a more rapid avalanche, a more efficient bitslice implementation, and an easy analysis that enables it to be more secure than three-key triple-DES.
Abstract: We propose a new block cipher as a candidate for the Advanced Encryption Standard. Its design is highly conservative, yet still allows a very efficient implementation. It uses S-boxes similar to those of DES in a new structure that simultaneously allows a more rapid avalanche, a more efficient bitslice implementation, and an easy analysis that enables us to demonstrate its security against all known types of attack. With a 128-bit block size and a 256-bit key, it is as fast as DES on the market leading Intel Pentium/MMX platforms (and at least as fast on many others); yet we believe it to be more secure than three-key triple-DES.
433 citations
TL;DR: Using DNA reassociation analysis, it is demonstrated that bacterial communities in pristine soil and sediments may contain more than 10,000 different bacterial types, indicating that the culturing conditions select for a distinct subpopulation of the bacteria present in the environment.
431 citations
TL;DR: A portable, low mass device to measure linear acceleration of the trunk in a horizontal-vertical coordinate system during prolonged walking is of clinical interest and may give new information about balance in gait.
TL;DR: A log-linear method for analysis of case-parent-triad data, based on maximum likelihood with stratification on parental mating type, which generalizes easily to accommodate maternal effects on risk and produces powerful and orthogonal tests of the contribution of fetal versus maternal genetic factors.
Abstract: We describe a log-linear method for analysis of case-parent-triad data, based on maximum likelihood with stratification on parental mating type. The method leads to estimates of association parameters, such as relative risks, for a single allele, and also to likelihood ratio chi2 tests (LRTs) of linkage disequilibrium. Hardy-Weinberg equilibrium need not be assumed. Our simulations suggest that the LRT has power similar to that of the chi2 "score" test proposed by Schaid and Sommer and that both can outperform the transmission/disequilibrium test (TDT), although the TDT can perform better under an additive model of inheritance. Because a restricted version of the LRT is asymptotically equivalent to the TDT, the proposed test can be regarded as a generalization of the TDT. The method that we describe generalizes easily to accommodate maternal effects on risk and, in fact, produces powerful and orthogonal tests of the contribution of fetal versus maternal genetic factors. We further generalize the model to allow for effects of parental imprinting. Imprinting effects can be fitted by a simple, iterative procedure that relies on the expectation-maximization algorithm and that uses standard statistical software for the maximization steps. Simulations reveal that LRT tests for detection of imprinting have very good operating characteristics. When a single allele is under study, the proposed method can yield powerful tests for detection of linkage disequilibrium and is applicable to a broader array of causal scenarios than is the TDT.
TL;DR: Assessment of clinical findings can improve the rate of detection of mutations of DNA mismatch-repair genes in families suspected of having hereditary nonpolyposis colorectal cancer.
Abstract: Background Germ-line mutations in DNA mismatch-repair genes (MSH2, MLH1, PMS1, PMS2, and MSH6 ) cause susceptibility to hereditary nonpolyposis colorectal cancer. We assessed the prevalence of MSH2...
TL;DR: This paper reviewed the geological observations and interpretations regarding the size and timing of the Late Weichselian Barents ice sheet, combined with numerical modelling of its formation in order to produce a reconstruction of ice sheet extent and behaviour.
TL;DR: It is suggested that the growth rates of not only phytoplankton, but also of heterotrophic bacteria, are P limited in this environment in summer, which has important implications for the dynamics of accumulation of dissolved organic carbon in the photic zone and thus for the carbon cycle of oceans.
Abstract: Surface-water microbial populations were investigated in the northwest Mediterranean for possible indicators of phosphate deficiency and limitation. Low phosphorus availability was suggested by short turnover time (min. observed 0.68 h), high-alkaline phosphatase activity (V,,,,, = 28 nM hydrolyzed h-l), subsaturation of phosphate uptake (2.6-9% of V,,,), and high-pulse uptake capacity of added orthophosphate. Based on high pulse uptake capacity and subsaturated uptake in both the >l-pm and in the 0.2-l-pm size fractions, P deficiency is suggested for both phytoplankton and heterotrophic bacteria. P limitation of heterotrophic bacteria was also supported by fast positive responses after phosphate addition in both thymidine incorporation in whole-water samples and increased bacterial cell numbers in predator-free water. No effects were found after addition of carbon or nitrogen sources alone. Combined with other published evidence, we suggest that the growth rates of not only phytoplankton, but also of heterotrophic bacteria, are P limited in this environment in summer. The finding has important implications for the dynamics of accumulation of dissolved organic carbon in the photic zone and thus for the carbon cycle of oceans. The generally oligotrophic state of the Mediterranean Sea has traditionally been explained as a consequence of its antiestuarine circulation; the net evaporation from the Mediterranean produces an inflow of low-nutrient surface water through the Gibraltar and an eastward surface current in the Mediterranean (Redfield et al. 1963). If one combines an assumption of nitrogen-limited growth in the inflowing Atlantic water with the usual assumption of a faster recycling of phosphorus than of nitrogen, one might expect a strong nitrogen limitation in the upper photic zone during Mediterranean summer stratification. Contrary to such an expectation, accumulated experimental data seem to indicate that parts of the Mediterranean are characterized by a nitrate : phosphate ratio below Redfield (Krom et al. 1991). This seems to be particularly prominent in the eastern parts of the Mediterranean (Krom et al. 1991) and in the Adriatic Sea (Vukadin and Stojanski 1976). In an investigation of orthophosphate uptake in surface water from Villefranche Bay on the French Mediterranean coast, Dolan et al. (1995) found relatively short turnover times (down to 1.6 h). Estimates of bioavailable orthophosphate concentrations in this area (Thingstad et al. 1995) are also very low (0.8 nM), indicating, but not proving, that P may be the limiting nutrient also in this part of the western Mediterranean. The underlying biogeochemical mechanisms behind such an apparent shift toward P deficiency seem still to be unknown,
TL;DR: The injection into cells of a key mitochondrial protein, cytochrome c, activates apoptosis, and it is shown that mitochondrial constituents leak out through these permeability transition channels, and activate the apoptotic machinery in the cytosol.
Abstract: Mitochondria, the cell's energy-producing organelles, are thought to play a central role in mediating apoptosis, or programmed cell death Mitochondrial morphology remains intact during the process, the apoptosis-blocking protein Bcl-2 is localized in the outer mitochondrial membrane1, several critical steps in the process require ATP2, and mitochondrial ‘megachannels’ or ‘permeability transitions’ open during apoptosis It has been suggested that mitochondrial constituents leak out through these permeability transition channels, and activate the apoptotic machinery in the cytosol3 Here we show that the injection into cells of a key mitochondrial protein, cytochrome c, activates apoptosis
TL;DR: The difference between the two agricultural soils was significantly higher when the total bacterial population was analyzed than when the cultivable population was, indicating that analysis of microbial diversity must ultimately embrace the entire microbial community DNA, rather than DNA from cultivable bacteria.
Abstract: In this study, two different agricultural soils were investigated: one organic soil and one sandy soil, from Stend (south of Bergen), Norway. The sandy soil was a field frequently tilled and subjected to crop rotations. The organic soil was permanent grazing land, infrequently tilled. Our objective was to compare the diversity of the cultivable bacteria with the diversity of the total bacterial population in soil. About 200 bacteria, randomly isolated by standard procedures, were investigated. The diversity of the cultivable bacteria was described at phenotypic, phylogenetic, and genetic levels by applying phenotypical testing (Biolog) and molecular methods, such as amplified rDNA restriction analysis (ARDRA); hybridization to oligonucleotide probes; and REP-PCR. The total bacterial diversity was determined by reassociation analysis of DNA isolated from the bacterial fraction of environmental samples, combined with ARDRA and DGGE analysis. The relationship between the diversity of cultivated bacteria and the total bacteria was elucidated. Organic soil exhibited a higher diversity for all analyses performed than the sandy soil. Analysis of cultivable bacteria resulted in different resolution levels and revealed a high biodiversity within the population of cultured isolates. The difference between the two agricultural soils was significantly higher when the total bacterial population was analyzed than when the cultivable population was. Thus, analysis of microbial diversity must ultimately embrace the entire microbial community DNA, rather than DNA from cultivable bacteria.
TL;DR: In this article, the fourfold rift basin infill classification scheme was proposed for predicting the distribution and geometry of synrift reservoir and source rock types, despite the inherent variability of the marine synrift infills.
Abstract: Marine rift basins represent a continuum ranging from mixed nonmarine/marine through shallow marine to deep marine, or from partly emergent through partly submergent to completely submergent basin types. These rift basin types have strongly variable synrift sedimentary architectures because of temporal changes in relative sea level, accommodation creation, and sediment supply throughout the rift cycle. Accommodation changes are controlled mainly by local basin-floor rotation, basinwide background subsidence, and, to a lesser degree, by eustatic changes. Sediment supply determines how much of the accommodation is filled and in what manner, and is controlled by the distance to the main hinterland areas, and the size and sediment- yield potential of any local fault-block source area. Marine siliciclastic synrift successions, whether dominantly shallow or deep marine in nature, are classified in terms of sediment supply as overfilled, balanced, underfilled, and starved. Sediment-overfilled and sediment-balanced infill types are characterized by a threefold sandstone-mudstone- sandstone synrift sediment-infill motif; the sediment-underfilled type is represented by a two-fold conglomerate-sandstone-mudstone motif; and the sediment-starved type commonly is represented by a one-fold mudstone motif. The sequential development, linked depositional systems, and stratigraphic signatures of the early synrift, the rift climax, and the late synrift to early postrift stages vary significantly between these rift basin infill types, as do the tectonic significance (timing of initiation and duration) of stratal surfaces, such as footwall unconformities, nondepositional hiatuses, and marine condensed sections. The construction of the fourfold rift basin infill classification scheme provides a first basis and a strong tool for predicting the distribution and geometry of synrift reservoir and source rock types, despite the inherent variability of the marine synrift infills.
TL;DR: The results indicate that accelerometry without need for stationary instrumentation is a reliable method that may be useful for studying standing balance and gait in the clinic.
TL;DR: A new alternative to the traditions of measuring balance in standing and movements of the legs in walking is suggested, which allows balance in gait to be assessed at self-selected speeds in relevant environmental conditions, which may facilitate gait analysis in the clinic and improve the validity of the results.
TL;DR: In this article, a study on petanin color variation (intensity, λmax, e) over the pH range 1-9 during 60 days of storage, was conducted on petunidin 3-[6-O-(4-O-E-p-coumaroyl]-O-α-l-rhamnopyranosyl)-β-d-glucopyraniumide]-5-O-,β-γ-d−glucophyranoside (petanin) and cyanidin (cy3gl
23 Mar 1998
TL;DR: In this paper, the DES S-boxes are used in a new structure that simultaneously allows a more rapid avalanche, a more efficient bitslice implementation, and an easy analysis that enables them to demonstrate its security against all known types of attack.
Abstract: We propose a new block cipher as a candidate for the Advanced Encryption Standard. Its design is highly conservative, yet still allows a very efficient implementation. It uses the well-understood DES S-boxes in a new structure that simultaneously allows a more rapid avalanche, a more efficient bitslice implementation, and an easy analysis that enables us to demonstrate its security against all known types of attack. With a 128-bit block size and a 256-bit key, it is almost as fast as DES on a wide range of platforms, yet conjectured to be at least as secure as three-key triple-DES.
TL;DR: In this paper, generalized Runge-Kutta methods for integration of differential equations evolving on a Lie group are presented. But these methods must satisfy two different criteria to achieve a given order.
Abstract: We construct generalized Runge-Kutta methods for integration of differential equations evolving on a Lie group. The methods are using intrinsic operations on the group, and we are hence guaranteed that the numerical solution will evolve on the correct manifold. Our methods must satisfy two different criteria to achieve a given order.
These tasks are completely independent, so once correction functions are found to the given order, we can turn any classical RK scheme into an RK method of the same order on any Lie group. The theory in this paper shows the tight connections between the algebraic structure of the order conditions of RK methods and the algebraic structure of the so called ‘universal enveloping algebra’ of Lie algebras. This may give important insight also into the classical RK theory.
University of Turin1, University of Milan2, Darmstadt University of Applied Sciences3, Stanford University4, University of Hamburg5, University of Vienna6, CERN7, Lorentz Institute8, RWTH Aachen University9, Moscow State University10, Weizmann Institute of Science11, University of Glasgow12, University of Florence13, Northeastern University14, Istituto Nazionale di Fisica Nucleare15, Paul Scherrer Institute16, Centre national de la recherche scientifique17, University of Cambridge18, University of Montpellier19, Rutherford Appleton Laboratory20, University of Paris21, Leipzig University22, University of Geneva23, Indian Institute of Science24, Aristotle University of Thessaloniki25, Karlsruhe Institute of Technology26, Helsinki Institute of Physics27, Heidelberg University28, Silesian University29, University of Warsaw30, Max Planck Society31, Ludwig Maximilian University of Munich32, Autonomous University of Barcelona33, Sapienza University of Rome34, University College London35, University of Barcelona36, University of Bergen37, University of Trieste38, Rutgers University39, University of Valencia40, University of Würzburg41, Lund University42, Durham University43
TL;DR: The physics potential of linear linear colliders has been discussed in this paper, where the authors describe the potential for the discovery of particles in supersymmetric extensions of the Standard Model, the spectrum of Higgs particles, the super-ymmetric partners of the electroweak gauge and Higgs bosons.
TL;DR: In this article, the authors used radiocarbon, luminescence and amino acid dating of interbedded interstadial and interglacial sediments to identify three major glacial advances during the Weichselian.
TL;DR: No difference was observed between the medical exercise therapy and conventional physiotherapy groups, but both were significantly better than self‐exercise group, and patient satisfaction was highest formedical exercise therapy.
Abstract: Study design A multicenter, randomized, single-blinded controlled trial with 1-year follow-up. Objectives To evaluate the efficiency of progressively graded medical exercise therapy, conventional physiotherapy, and self-exercise by walking in patients with chronic low back pain. Summary and background data Varieties of medical exercise therapy and conventional physiotherapy are considered to reduce symptoms, improve function, and decrease sickness absence, but this opinion is controversial. Methods Patients with chronic low back pain or radicular pain sick-listed for more than 8 weeks and less than 52 weeks (Sickness Certificate II) were included. The treatment lasted 3 months (36 treatments). Pain intensity, functional ability, patient satisfaction, return to work, number of days on sick leave, and costs were recorded. Results Of the 208 patients included in this study, 71 were randomly assigned to medical exercise therapy, 67 to conventional physiotherapy, and 70 to self-exercise. Thirty-three (15.8%) patients dropped out during the treatment period. No difference was observed between the medical exercise therapy and conventional physiotherapy groups, but both were significantly better than self-exercise group. Patient satisfaction was highest for medical exercise therapy. Return to work rates were equal for all 3 intervention groups at assessment 15 months after therapy was started, with 123 patients were back to work. In terms of costs for days on sick leave, the medical exercise therapy group saved 906,732 Norwegian Kroner (NOK) ($122,531.00), and the conventional physiotherapy group saved NOK 1,882,560 ($254,200.00), compared with the self-exercise group. Conclusions The efficiency of medical exercise therapy and conventional physiotherapy is shown. Leaving patients with chronic low back pain untampered poses a risk of worsening the disability, resulting in longer periods of sick leave.
TL;DR: The most notable change in δ18O in Greenland ice cores during the Holocene occurs at 8200 cal. yr BP as mentioned in this paper, and the synchronous timing of the cooling event in the Greenland ice-cores, marine record and tree-ring data from northwest Europe reflects a regional influence on the North Atlantic ocean-atmospheric system, suggesting a prominent role of the NorthAtlantic thermohaline circulation.
Abstract: The most notable change in δ18O in Greenland ice cores during the Holocene occurs at 8200 cal. yr BP. Here we present a new high-resolution marine record from the northern North Sea, along with tree-ring data from Germany, which contain evidence of a pronounced temperature drop (>2°C) contemporaneous with that of the Greenland ice-core records. The synchronous timing of the cooling event in the Greenland ice-cores, marine record and tree-ring data from northwest Europe reflects a regional influence on the North Atlantic ocean–atmospheric system, suggesting a prominent role of the North Atlantic thermohaline circulation. The operation of the North Atlantic ocean circulation is sensitive to variation in the freshwater budget, implying that any change in freshwater flux is capable of altering the North Atlantic circulation system. We hypothesise minor but long-term freshwater fluxes in the final stages of the deglaciation of the Laurentide ice-sheet as a forcing mechanism. © 1998 John Wiley & Sons, Ltd.
TL;DR: A logical and efficient treatment strategy for PD is based on correcting or bypassing the enzyme deficiency by treatment withl-DOPA, DA agonists, inhibitors of DA metabolism, or brain grafts with cells expressing TH.
Abstract: A consistent neurochemical abnormality in Parkinson's disease (PD) is degeneration of dopaminergic neurons in substantia nigra, leading to a reduction of striatal dopamine (DA) levels. As tyrosine hydroxylase (TH) catalyses the formation ofl-DOPA, the rate-limiting step in the biosynthesis of DA, the disease can be considered as a TH-deficiency syndrome of the striatum. Similarly, some patients with hereditaryl-DOPA-responsive dystonia, a neurological disorder with clinical similarities to PD, have mutations in the TH gene and decreased TH activity and/or stability. Thus, a logical and efficient treatment strategy for PD is based on correcting or bypassing the enzyme deficiency by treatment withl-DOPA, DA agonists, inhibitors of DA metabolism, or brain grafts with cells expressing TH. A direct pathogenetic role of TH has also been suggested, as the enzyme is a source of reactive oxygen species (ROS) in vitro and a target for radical-mediated oxidative injury. Recently, it has been demonstrated thatl-DOPA is effectively oxidized by mammalian TH in vitro, possibly contributing to the cytotoxic effects of DOPA. This enzyme may therefore be involved in the pathogenesis of PD at several different levels, in addition to being a promising candidate for developing new treatments of this disease.
TL;DR: It is concluded that exogenous BDNF induces a lasting potentiation of synaptic efficacy in the dentate gyrus of anesthetized adult rats.
Abstract: Messaoudi, Elhoucine, Kjetil Bardsen, Bolek Srebro, and Clive R. Bramham. Acute intrahippocampal infusion of BDNF induces lasting potentiation of synaptic transmission in the rat dentategyrus. J. N...
TL;DR: The association of diet, smoking/drinking and occupation with subsequent risk of fatal colorectal cancer was investigated in a cohort of white males aged 35 and older and support previous reports that a high intake of red meat and a sedentary life‐style may increase the risk of colon cancer.
Abstract: The association of diet, smoking/drinking and occupation with subsequent risk of fatal colorectal cancer was investigated in a cohort of 17,633 white males aged 35 and older, who completed a mail questionnaire in 1966. During the subsequent 20 years of follow-up, 120 colon cancer and 25 rectal cancer deaths were identified. Due to small numbers, no significant dose-response trends were observed in the study, but risk of colon cancer was elevated among heavy cigarette smokers (> or = 30/day; RR = 2.3, 95% CI 0.9-5.7), heavy beer drinkers (> or = 14 times/month; RR = 1.9, 95% CI 1.0-3.8) and white-collar workers (RR = 1.7, 95% CI 1.0-3.0) or crafts workers within service and trade industries (RR = 2.6, 95% CI 1.1-5.8). In addition, an increased risk was seen for those who consumed red meat more than twice a day (RR = 1.8, 95% CI 0.8-4.4). Risk patterns for cancers of the colon and rectum combined were similar to those reported for cancer of the colon, but the estimates were somewhat dampened. Our findings support previous reports that a high intake of red meat and a sedentary life-style may increase the risk of colon cancer.