110 research outputs found
Generalized Strong Curvature Singularities and Cosmic Censorship
A new definition of a strong curvature singularity is proposed. This
definition is motivated by the definitions given by Tipler and Krolak, but is
significantly different and more general. All causal geodesics terminating at
these new singularities, which we call generalized strong curvature
singularities, are classified into three possible types; the classification is
based on certain relations between the curvature strength of the singularities
and the causal structure in their neighborhood. A cosmic censorship theorem is
formulated and proved which shows that only one class of generalized strong
curvature singularities, corresponding to a single type of geodesics according
to our classification, can be naked. Implications of this result for the cosmic
censorship hypothesis are indicated.Comment: LaTeX, 11 pages, no figures, to appear in Mod. Phys. Lett.
Is Neuropathic Pain a Good Marker of Peripheral Neuropathy in Hospice Patients with Advanced Cancer? The Single Center Pilot Study
Neuropathic pain (NP) affects approximately 30% of patients with advanced cancer. The prevalence of neuropathic pain related to peripheral neuropathy (NP-RPN) in these patients is not known. The aim of the study was to evaluate NP-RPN prevalence in hospice patients and to find out whether the absence of this pain is sufficient to rule out peripheral neuropathy. The study included a total of 76 patients with advanced cancer who were cared for at inpatient hospices. All patients were asked about shooting or burning pain (of the feet and hands), were examined systematically for sensory deficits and had a nerve conduction study performed. NP-RPN was found in 29% of the patients. Electrophysiologically-diagnosed peripheral neuropathy was found in 79% of patients, and the diagnostic electrophysiological criteria for neuropathy were met by one half of the patients without NP-RPN. The severity of NP-RPN was correlated with the clinically assessed severity of sensory neuropathy and the Karnofsky score, but was not correlated with the intensity of the clinical signs of motor neuropathy. The presence of NP-RPN did not reflect greater prevalence of motor and sensory abnormalities in neurological and electrophysiological examinations. The absence of NP-RPN did not rule out polyneuropathy in hospice patients
Versatile Functions of Heat Shock Factors: It is Not All About Stress
Organisms are constantly exposed to acute and chronic stress conditions, which challenge the maintenance of protein homeostasis. Heat ShockProteins (HSPs) function as molecular chaperones to stabilize protein structures, facilitate refolding of misfolded proteins, and prevent uncontrolled protein aggregation. Therefore, HSPs serve as the first and last line ofdefense in the events of proteotoxic stresses. The stress-inducible expression of HSPs, which is a hallmark of the heat shock response, is understrict control of evolutionary conserved transcription factors, known as Heat Shock Factors (HSFs). Invertebrates have only a single HSF, whereas the HSF family in vertebrates consists of multiple members. Direct interactions of HSFs with various proteins, including HSPs, chromatin-associated proteins, and other HSF family members as well as their complex post-translational modifications, allow these transcription factors to function not only in stress responses but also in many other biological processes. For example, mammalian HSF1, HSF2 and HSF4 are fundamental for normal organismal development and healthy aging. Moreover, recent discoveries have highlighted the importance of HSFs in tumorigenesis, neurodegeneration, and metabolic disorders, which positions them as promising therapeutic targets in multiple human diseases. In this review, we focus on recent advances in the HSF biology and discuss the functional impact of HSFs on stress responses, development, aging, and age-related pathologies.</div
Cytogenetyczne i molekularne uwarunkowania agresywnej postaci przewlekłej białaczki limfocytowej
Chronic lymphocytic leukemia (CLL) mainly affects people older than 60 years. Accumulation of morphologically mature but dysfunctional B-lymphocytes in the bone marrow, lymph nodes and peripheral blood is a characteristic feature of this disease. Chromosomal aberrations are observed in lymphocytes of most CLL patients. Typical alterations include deletions of 13q14 and 11q, trisomy 12, and deletions of 17p. Altered expression of the genes located within involved regions, i.e. microRNA15/16 (13q14.3), ATM (11q22-q23) or TP53 (17p13) may be associated with the development and progression of the disease. Cryptic mutations may also contribute to leukemogenesis. Among others, they affect TP53, NOTCH1, SF3B1 and BIRC genes.CLL is a disease with heterogeneous course. There are two clinical forms – indolent and aggressive. The former is characterized by long time to first treatment and demise usually occurs because of coexisting diseases or is associated with leukemia-dependent immunodeficiency. Rapid clinical course and short overall survival, sometimes in spite of appropriate treatment implementation, is typical for aggressive form of CLL. For patients with this form, the moment of treatment initiation and the choice of first-line therapy are especially important, and depend inter alia on prognostic and predictive factors.Established poor prognostic factors in CLL include chromosomal aberrations, i.e., deletion of 17p or 11q, high ZAP-70 kinase expression, mutations/deletions of TP53, and lack of mutation of immunoglobulin heavy chain variable region genes (IgVH).In this paper we tried to point out the importance of some of the prognostic and predictive factors used routinely in the diagnostic management of CLL. Prognostic and predictive potential of microRNA expression level and recently described cryptic changes in the TP53, NOTCH1, SF3B1 and BIRC3 have also been presented
MicroRNA molecules as a significant constituent in gene regulation mechanisms related to cancer
W niniejszej pracy przedstawiono zależności pomiędzy zmianami w ekspresji poszczególnych mikroRNA a powstawaniem i rozwojem wybranych nowotworów. Dokonano przeglądu doniesień na temat użyteczności badań nad ekspresją mikroRNA, które w przyszłości mogą być wartościowymi i pożądanymi przez diagnostów i lekarzy wskaźnikami prognostycznymi i predykcyjnymi. Mogą się one stać podwaliną do opracowania nowych metod leczniczych z wykorzystaniem antysensownych miRNA (antagomiry) czy leków mających na celu kompensację ilości cząsteczek w przypadku delecji lub uszkodzeń genów dla konkretnych mikroRNA. Dałoby to potencjalną możliwość regulacji ekspresji genów o znaczeniu strategicznym w procesach związanych z powstawaniem i rozwojem nowotworów.This paper presents the relationship between changes in the expression of specific microRNAs and the formation and development of selected cancers. An overview of reports is provided on the usefulness of research on microRNA expression, which in the future may become valuable and desirable prognostic and prediction factors for diagnosticians and clinicians. miRNA will presumably become the cornerstone for the development of new therapeutic approaches using antisense miRNAs (antagomirs) or drugs aimed at miRNA offsetting in the case of deletion or damage to their genes. It would offer the potential possibility of the regulation of gene expression which is of great significance for the origin and development of cancers
On Unbounded Composition Operators in -Spaces
Fundamental properties of unbounded composition operators in -spaces are
studied. Characterizations of normal and quasinormal composition operators are
provided. Formally normal composition operators are shown to be normal.
Composition operators generating Stieltjes moment sequences are completely
characterized. The unbounded counterparts of the celebrated Lambert's
characterizations of subnormality of bounded composition operators are shown to
be false. Various illustrative examples are supplied
Applications of distance between probability distributions to gravitational wave data analysis
We present a definition of the distance between probability distributions.
Our definition is based on the norm on space of probability measures. We
compare our distance with the well-known Kullback-Leibler divergence and with
the proper distance defined using the Fisher matrix as a metric on the
parameter space. We consider using our notion of distance in several problems
in gravitational wave data analysis: to place templates in the parameter space
in searches for gravitational-wave signals, to assess quality of search
templates, and to study the signal resolution.Comment: 18 pages, 5 figure
All-sky search of NAUTILUS data
A search for periodic gravitational-wave signals from isolated neutron stars
in the NAUTILUS detector data is presented. We have analyzed half a year of
data over the frequency band Hz/s and over the entire sky. We have divided the
data into 2 day stretches and we have analyzed each stretch coherently using
matched filtering. We have imposed a low threshold for the optimal detection
statistic to obtain a set of candidates that are further examined for
coincidences among various data stretches. For some candidates we have also
investigated the change of the signal-to-noise ratio when we increase the
observation time from two to four days. Our analysis has not revealed any
gravitational-wave signals. Therefore we have imposed upper limits on the
dimensionless gravitational-wave amplitude over the parameter space that we
have searched. Depending on frequency, our upper limit ranges from to . We have attempted a statistical
verification of the hypotheses leading to our conclusions. We estimate that our
upper limit is accurate to within 18%.Comment: LaTeX, 12 page
The phenology of winter rye in Poland: an analysis of long-term experimental data
The study of the phenology of crops, although quite popular, has limitations, mainly because of frequent changes to crop varieties and management practices. Here, we present data on the phenology and yield of winter rye in western Poland collected between 1957 and 2012 from a long-term field experiment. Data were examined for trends through time and compared to climatological factors using regression analysis. Both annual air temperature and precipitation increased during the study period, equivalent to 2 °C and 186 mm, respectively, over the 52-year period for which met data were available. We detected significant delays in sowing date and recently in emergence, but significant advances were apparent in full flowering date equivalent to 4 days/decade. Yield and plant density experienced a step like change in 1986; yield increasing by ca. 70 % and plant density increasing by ca. 50 %, almost coinciding with a similar change in annual mean temperature, but most likely caused by a changed seed rate and use of herbicides. Future climate change is expected to have a greater impact on this crop, but farmers may be able to adapt to these changes by modifying water regimes, using new machinery and sowing new rye varieties
Virgo calibration and reconstruction of the gravitational wave strain during VSR1
Virgo is a kilometer-length interferometer for gravitational waves detection
located near Pisa. Its first science run, VSR1, occured from May to October
2007. The aims of the calibration are to measure the detector sensitivity and
to reconstruct the time series of the gravitational wave strain h(t). The
absolute length calibration is based on an original non-linear reconstruction
of the differential arm length variations in free swinging Michelson
configurations. It uses the laser wavelength as length standard. This method is
used to calibrate the frequency dependent response of the Virgo mirror
actuators and derive the detector in-loop response and sensitivity within ~5%.
The principle of the strain reconstruction is highlighted and the h(t)
systematic errors are estimated. A photon calibrator is used to check the sign
of h(t). The reconstructed h(t) during VSR1 is valid from 10 Hz up to 10 kHz
with systematic errors estimated to 6% in amplitude. The phase error is
estimated to be 70 mrad below 1.9 kHz and 6 micro-seconds above.Comment: 8 pages, 8 figures, proceedings of Amaldi 8 conference, to be
published in Journal of Physics Conference Series (JPCS). Second release:
correct typo
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