990 research outputs found
Fatherhood and sperm DNA damage in testicular cancer patients
Testicular cancer (TC) is one of the most treatable of all malignancies and the
management of the quality of life of these patients is increasingly important, especially
with regard to their sexuality and fertility. Survivors must overcome anxiety and fears
about reduced fertility and possible pregnancy-related risks as well as health effects in
offspring. There is thus a growing awareness of the need for reproductive counseling
of cancer survivors. Studies found a high level of sperm DNA damage in TC patients
in comparison with healthy, fertile controls, but no significant difference between these
patients and infertile patients. Sperm DNA alterations due to cancer treatment persist
from 2 to 5 years after the end of the treatment and may be influenced by both the
type of therapy and the stage of the disease. Population studies reported a slightly
reduced overall fertility of TC survivors and a more frequent use of ART than the general
population, with a success rate of around 50%. Paternity after a diagnosis of cancer is
an important issue and reproductive potential is becoming a major quality of life factor.
Sperm chromatin instability associated with genome instability is the most important
reproductive side effect related to the malignancy or its treatment. Studies investigating
the magnitude of this damage could have a considerable translational importance in the
management of cancer patients, as they could identify the time needed for the germ
cell line to repair nuclear damage and thus produce gametes with a reduced risk for the
offspring
The order of the Roberge-Weiss endpoint (finite size transition) in QCD
We consider the endpoint of the Roberge-Weiss (RW) first order transition
line present for imaginary baryon chemical potentials. We remark that it
coincides with the finite size transition relevant in the context of large
QCD and study its order in the theory with two degenerate flavors. The RW
endpoint is first order in the limit of large and small quark masses, while it
weakens for intermediate masses where it is likely in the Ising 3d universality
class. Phenomenological implications and further speculations about the QCD
phase diagram are discussed.Comment: 5 pages, 8 figures. Version accepted for publication in Physical
Review D (R
Untenable nonstationarity: An assessment of the fitness for purpose of trend tests in hydrology
The detection and attribution of long-term patterns in hydrological time series have been important research topics for decades. A significant portion of the literature regards such patterns as âdeterministic componentsâ or âtrendsâ even though the complexity of hydrological systems does not allow easy deterministic explanations and attributions. Consequently, trend estimation techniques have been developed to make and justify statements about tendencies in the historical data, which are often used to predict future events. Testing trend hypothesis on observed time series is widespread in the hydro-meteorological literature mainly due to the interest in detecting consequences of human activities on the hydrological cycle. This analysis usually relies on the application of some null hypothesis significance tests (NHSTs) for slowly-varying and/or abrupt changes, such as Mann-Kendall, Pettitt, or similar, to summary statistics of hydrological time series (e.g., annual averages, maxima, minima, etc.). However, the reliability of this application has seldom been explored in detail. This paper discusses misuse, misinterpretation, and logical flaws of NHST for trends in the analysis of hydrological data from three different points of view: historic-logical, semantic-epistemological, and practical. Based on a review of NHST rationale, and basic statistical definitions of stationarity, nonstationarity, and ergodicity, we show that even if the empirical estimation of trends in hydrological time series is always feasible from a numerical point of view, it is uninformative and does not allow the inference of nonstationarity without assuming a priori additional information on the underlying stochastic process, according to deductive reasoning. This prevents the use of trend NHST outcomes to support nonstationary frequency analysis and modeling. We also show that the correlation structures characterizing hydrological time series might easily be underestimated, further compromising the attempt to draw conclusions about trends spanning the period of records. Moreover, even though adjusting procedures accounting for correlation have been developed, some of them are insufficient or are applied only to some tests, while some others are theoretically flawed but still widely applied. In particular, using 250 unimpacted stream flow time series across the conterminous United States (CONUS), we show that the test results can dramatically change if the sequences of annual values are reproduced starting from daily stream flow records, whose larger sizes enable a more reliable assessment of the correlation structures
Photon localization versus population trapping in a coupled-cavity array
We consider a coupled-cavity array (CCA), where one cavity interacts with a
two-level atom under the rotating-wave approximation. We investigate the
excitation transport dynamics across the array, which arises in the atom's
emission process into the CCA vacuum. Due to the known formation of atom-photon
bound states, partial field localization and atomic population trapping in
general take place. We study the functional dependance on the coupling strength
of these two phenomena and show that the threshold values beyond which they
become significant are different. As the coupling strength grows from zero,
field localization is exhibited first.Comment: 9 pages, 5 figures. Replaced one plot in Fig.
Remarks on the genus Severinia Finot 1902 and a description of two new genera of Oxyothespinae (Insecta Mantodea)
A resolution of the confusion surrounding the genus Severinia Finot 1902 is proposed. It is suggested that the males, presently attributed to Severinia lemoroi (Finot 1902), be transferred to the new genus, Paraseverinia, and that the genus Amblythespis Chopard 1943 be considered a synonym of Severinia. In addition, a description is provided of a new genus Somalithespis (Oxyothespini), characterised by the presence of a pre-apical lobe on the mid femurs, a character found for the first time among the tribe of Oxyothespini
A review of the genus Popa StÄl 1856 (Insecta Mantodea)
It is suggested that Mantis undata Fabricius 1793 does not belong to the genus Popa Stal 1856 as believed until now, but to the Indian genus Ambivia Stal 1877 (n. comb.). The systematic position of the species of Popa is re-examined and a single species, Popa spurca Stal 1856 (= P. undata auct. nec Fabricius) is recognised. The species is differentiated into two subspecies, one being Popa spurca spurca Stal 1856 (= P. stuhlmanni Rehn 1914, P. batesi Sauss. & Zehnt. 1895) (n. syn.) widespread throughout all Africa south of the Sahara, except in the east which is populated by the other subspecies, P. spurca crassa (Giglio-Tos 1917)
QCD at High Temperature : Results from Lattice Simulations with an Imaginary mu
We summarize our results on the phase diagram of QCD with emphasis on the
high temperature regime. For the results are compatible with a
free field behavior, while for this is not the case, clearly
exposing the strongly interacting nature of QCD in this regionComment: 7 pages, 2 figures; To appear in the proceedings of QCD@Work
2005,International Workshop on Quantum Chromodynamics, Conversano, Bari,
Italy, 16-20 Jun 200
Terapia della eiaculazione precoce
Lâeiaculazione precoce (EP) Ăš il piĂč frequente disturbo sessuale riferito nel maschio, ed Ăš a tutti gli effetti un sintomo auto-identificato, auto-riportato e auto-valutato da chi ne soffre. Attualmente la International Society for Sexual Medicine ha definito lâEP come unâeiaculazione che avviene sempre o quasi sempre entro 1 minuto (EP life-long) o 3 minuti (EP acquisita) dalla penetrazione, con incapacitĂ di ritardare lâeiaculazione e conseguenze negative sul piano personale come frustrazione, sofferenza e/o condotte di rifiuto dellâatto sessuale [1]. Dal punto di vista tassonomico, possiamo riconoscere forme assolute e relazionali, organiche e psicogene (o meglio non-organiche), acquisite o life-long.
Il corretto approccio allâEP consiste nel non considerarla esclusivamente una patologia a sĂ© stante, ma un possibile sintomo di una condizione latent
Heroin-piracetam mixture: suggested mechanisms of action and risks of misinterpretation for drug users
Piracetam is a positive allosteric modulator of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor that has been frequently used in the treatment of cognitive disorders. Press and internet reports indicate that the use of piracetam, as a heroin adulterant, has spread rapidly in some countries, especially in Asia and Europe. Its use, as adulterant, is believed to produce more profound desirable effects, while decreasing hangover. Recent surveys demonstrated that piracetam protects neurons from heroin-induced apoptosis. The protective role of this adulterating substance may be related to restoration of beta-endorphin levels and to its neuroprotective effects. The aim of this paper is to review the relevant literature and suggest the main hypothetical mechanisms that justify its use as a heroin adulterant, try to understand if its use could help people who want to come off heroin by reducing withdrawal symptoms and, finally, give useful information that permit us to understand why drug trafficking organisations started to use piracetam as heroin adulterant
Androgenetic alopecia: a review
Purpose
Androgenetic alopecia, commonly known as male
pattern baldness, is the most common type of progressive
hair loss disorder in men. The aim of this paper is to review
recent advances in understanding the pathophysiology and
molecular mechanism of androgenetic alopecia.
Methods
Using the PubMed database, we conducted a
systematic review of the literature, selecting studies pub-
lished from 1916 to 2016.
Results
The occurrence and development of androgenetic
alopecia depends on the interaction of endocrine factors and
genetic predisposition. Androgenetic alopecia is character-
ized by progressive hair follicular miniaturization, caused
by the actions of androgens on the epithelial cells of
genetically susceptible hair follicles in androgen-dependent
areas. Although the exact pathogenesis of androgenetic
alopecia remains to be clari
fi
ed, research has shown that it is
a polygenetic condition. Numerous studies have unequi-
vocally identi
fi
ed two major genetic risk loci for androge-
netic alopecia, on the X-chromosome AR
â
EDA2R locus and
the chromosome 20p11 locus.
Conclusions
Candidate gene and genome-wide association
studies have reported that single-nucleotide polymorphisms
at different genomic loci are associated with androgenetic
alopecia development. A number of genes determine the
predisposition for androgenetic alopecia in a polygenic fashion. However, further studies are needed before the
specific genetic factors of this polygenic condition can be
fully explaine
- âŠ