532 research outputs found
Association between family history and mismatch repair in colorectal cancer
BACKGROUND AND AIMS: Germline mutations in mismatch repair (MMR) genes cause a greatly increased
risk of cancer of the gastrointestinal and female reproductive tracts (hereditary non-polyposis colorectal
cancer (HNPCC)). Loss of MMR expression is common in colorectal cancer (CRC) overall. Such loss is
assumed to be acquired predominantly, although a population of CRC cases will include individuals with
unrecognised MMR mutations. This study examines the association between MMR gene expression and
family history of cancer among the CRC population.
METHODS: Individuals with CRC were identified from two well characterised populations: (1) consecutive
hospital patients (n = 644) and (2) a population based cases series (n = 249). CRC was examined for
expression of hMLH1 and hMSH2 using immunohistochemistry, and expression was related to family history using logistic regression.
RESULTS: hMLH1 and hMSH2 expression was assessed in 732 CRCs with 8% showing loss of expression.
No association was seen overall for hMLH1 or hMSH2 expression and family history of CRC. Loss of
hMSH2 was predicted by family history of extracolonic cancer (odds ratio (OR) 5.78 (95% confidence
interval (CI) 0.95–35.18)) and family history suggestive of HNPCC (OR 27.84 (95% CI 4.37–177.56)).
Loss of hMLH1 was not predicted by family history of extracolonic cancer or a family history suggestive of
HNPCC but was for a family history of at least two affected relatives (OR 4.88 (95% CI 1.25–19.03)).
CONCLUSIONS: Individuals with hMSH2 deficient CRC in the general population exhibit a family history and
other characteristics suggestive of HNPCC, and may carry germline MMR mutations. Loss of hMLH1 is only
associated with a strong family history of extracolonic cancer at older ages, suggesting a novel mechanism
of susceptibility
Sulfur management strategies to improve partial sulfur balance with irrigated peanut production on deep sands
Sands have favourable physical properties for harvesting peanut, but improving S and water use efficiency on these soils remains a challenge. We studied partial S balance in irrigated peanut crops on sands of Central Vietnam to identify key factors of S fertiliser management affecting S inputs and outputs. Field trials were conducted in the spring seasons of 2015 and 2016 to determine the effects of S application rates (0, 15, 30, 45 kg ha−1) on peanut yield and partial S balance. Sulfur balances were negative (-28.3 to 5.6 kg S ha−1) at rates < 30 kg S ha−1, while at higher rates of S fertiliser application that produced maximum pod yield (30 - 45 kg S ha−1), three of four sites showed neutral to slightly positive S balance (1.5 - 5.6 kg S ha−1). The negative partial S balance decreased with increasing S rates but was mostly attributable to the large S removal in peanut shoots (9.7 - 22.3 kg S ha−1) which are used on farms for animal feed. The negative partial S balance results in depletion of soil S reserves and hence efficient recycling of S on farms is critical for sustainable crop production on sands of VN
Integer Vector Addition Systems with States
This paper studies reachability, coverability and inclusion problems for
Integer Vector Addition Systems with States (ZVASS) and extensions and
restrictions thereof. A ZVASS comprises a finite-state controller with a finite
number of counters ranging over the integers. Although it is folklore that
reachability in ZVASS is NP-complete, it turns out that despite their
naturalness, from a complexity point of view this class has received little
attention in the literature. We fill this gap by providing an in-depth analysis
of the computational complexity of the aforementioned decision problems. Most
interestingly, it turns out that while the addition of reset operations to
ordinary VASS leads to undecidability and Ackermann-hardness of reachability
and coverability, respectively, they can be added to ZVASS while retaining
NP-completness of both coverability and reachability.Comment: 17 pages, 2 figure
Chiral Magnetic Effect in Hydrodynamic Approximation
We review derivations of the chiral magnetic effect (ChME) in hydrodynamic
approximation. The reader is assumed to be familiar with the basics of the
effect. The main challenge now is to account for the strong interactions
between the constituents of the fluid. The main result is that the ChME is not
renormalized: in the hydrodynamic approximation it remains the same as for
non-interacting chiral fermions moving in an external magnetic field. The key
ingredients in the proof are general laws of thermodynamics and the
Adler-Bardeen theorem for the chiral anomaly in external electromagnetic
fields. The chiral magnetic effect in hydrodynamics represents a macroscopic
manifestation of a quantum phenomenon (chiral anomaly). Moreover, one can argue
that the current induced by the magnetic field is dissipation free and talk
about a kind of "chiral superconductivity". More precise description is a
ballistic transport along magnetic field taking place in equilibrium and in
absence of a driving force. The basic limitation is exact chiral limit while
the temperature--excitingly enough- does not seemingly matter. What is still
lacking, is a detailed quantum microscopic picture for the ChME in
hydrodynamics. Probably, the chiral currents propagate through
lower-dimensional defects, like vortices in superfluid. In case of superfluid,
the prediction for the chiral magnetic effect remains unmodified although the
emerging dynamical picture differs from the standard one.Comment: 35 pages, prepared for a volume of the Springer Lecture Notes in
Physics "Strongly interacting matter in magnetic fields" edited by D.
Kharzeev, K. Landsteiner, A. Schmitt, H.-U. Ye
Testing small molecule analogues of acanthocheilonema viteae immunomodulator ES-62 against clinically relevant allergens
ES-62 is a glycoprotein secreted by the filarial nematode Acanthocheilonema viteae that protects against ovalbumin (OVA)-induced airway hyper-responsiveness in mice by virtue of covalently attached anti-inflammatory phosphorylcholine (PC) residues. We have recently generated a library of Small Molecule Analogues (SMAs) of ES-62 based around its active PC moiety as a starting point in novel drug development for asthma, and isolated two compounds - termed 11a and 12b – that mirror ES-62’s protective effects. In the present study we have moved away from OVA, a model allergen, to test the two SMAs against two clinically relevant allergens – house dust mite (HDM) and cockroach allergen (CR) extract. We show that whereas both SMAs offer some protection against development of lung allergic responses to CR, in particular reducing eosinophil infiltration, only SMA 12b is effective in protecting against eosinophil-dependent HDM-induced allergy. These data therefore suggest that helminth molecule-induced protection against model antigens may not necessarily translate to clinically relevant antigens. Nevertheless, in the present study we have managed to demonstrate that it is possible to produce synthetic drug-like molecules based on a parasitic worm product that show therapeutic potential with respect to asthma resulting from known triggers in humans
Nonclassical correlations of photon number and field components in the vacuum state
It is shown that the quantum jumps in the photon number n from zero to one or
more photons induced by backaction evasion quantum nondemolition measurements
of a quadrature component x of the vacuum light field state are strongly
correlated with the quadrature component measurement results. This correlation
corresponds to the operator expectation value which is equal to one
fourth for the vacuum even though the photon number eigenvalue is zero. Quantum
nondemolition measurements of a quadrature component can thus provide
experimental evidence of the nonclassical operator ordering dependence of the
correlations between photon number and field components in the vacuum state.Comment: 13 pages, 3 figures, corrections of omissions in equations (6) and
(25). To be published in Phys. Rev.
Biotechnology enhances utilization of Australian woody species for pulp, fuel and land rehabilitation
Selection and micropropagation of superior genotypes of species of Australian genera such as Eucalyptus, Acacia, Melaleuca and Casuarina offers a way of capitalizing on Australia's genetic resources without necessarily breaking the tradition of unrestricted export of seed for international forestry. A collaborative program of research and development between Alcoa (Australia), CSIRO Division of Forestry and Forest Products, The University of Western Australia, Murdoch University, North Broken Hill Ltd (APPM Forest Products) and Plantex (Australia) has examined the potential for the use of selected clones of species tolerant to saline waterlogging, and elite selections of E. Globulus and E. nitens for paper pulp production
Nonclassical correlations of phase noise and photon number in quantum nondemolition measurements
The continuous transition from a low resolution quantum nondemolition
measurement of light field intensity to a precise measurement of photon number
is described using a generalized measurement postulate. In the intermediate
regime, quantization appears as a weak modulation of measurement probability.
In this regime, the measurement result is strongly correlated with the amount
of phase decoherence introduced by the measurement interaction. In particular,
the accidental observation of half integer photon numbers preserves phase
coherence in the light field, while the accidental observation of quantized
values increases decoherence. The quantum mechanical nature of this correlation
is discussed and the implications for the general interpretation of
quantization are considered.Comment: 16 pages, 5 figures, final version to be published in Phys. Rev. A,
Clarifications of the nature of the measurement result and the noise added in
section I
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Comparative design study of a diesel exhaust gas heat exchanger for truck applications with conventional and state of the art heat transfer enhancements
The exhaust gas of heavy duty diesel engines can provide an important heat source that may be used in a number of ways to provide additional power and improve overall engine efficiency. The sizing of a heat exchanger that can manage the heat load and still be of reasonable size and weight without excessive pressure drop is of significant importance especially for truck applications. This is the subject of the present work. To approach the problem, a total of five different configurations are investigated and a comparison of conventional and state of the art heat transfer enhancement technologies is included. Two groups of configurations are examined: (a) a classical shell and tube heat exchanger using staggered cross-flow tube bundles with smooth circular tubes, finned tubes and tubes with dimpled surfaces and (b) a cross-flow plate heat exchanger, initially with finned surfaces on the exhaust gas side and then with 10 ppi and 40 ppi metal foam material substituting for the fins. Calculations were performed, using established heat exchanger design methodologies and recently published data from the literature to size the aforementioned configurations. The solutions provided reduce the overall heat exchanger size, with the plate and fin type consisting of plain fins presenting the minimum pressure drop (up to 98% reduction compared to the other configurations), and the 40 ppi metal foam being the most compact in terms of size and weight. Durability of the solutions is another issue which will be examined in a future investigation. However, coupling of the exhaust heat exchanger after a particulate trap appears to be the most promising solution to avoid clogging from soot accumulation
A measurable entanglement criterion for two qubits
We propose a directly measurable criterion for the entanglement of two
qubits. We compare the criterion with other criteria, and we find that for pure
states, and some mixed states, it coincides with the state's concurrency. The
measure can be obtained with a Bell state analyser and the ability to make
general local unitary transformations. However, the procedure fails to measure
the entanglement of a general mixed two-qubit state.Comment: 5 page
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