2,867 research outputs found
Portable high-end instrument for in-vivo infrared spectroscopy using spread spectrum modulation
Near infrared spectroscopy (NIRS) can be employed to monitor noninvasively and continuously local changes in hemodynamics and oxygenation of human tissues. In particular, the technique can be particularly useful for muscular functional monitoring during unattended physical activity. A portable NIRS research-grade acquisition system, dedicated to low-noise measurements during muscular exercise, is presented. A spread-spectrum multiplexing scheme significantly enhances system performance. The resulting instrument is compact, lightweight and efficient. Preliminary tests on oxygen consumption during exercise and venous occlusion show excellent detectivity and time response
Simple extractors via constructions of cryptographic pseudo-random generators
Trevisan has shown that constructions of pseudo-random generators from hard
functions (the Nisan-Wigderson approach) also produce extractors. We show that
constructions of pseudo-random generators from one-way permutations (the
Blum-Micali-Yao approach) can be used for building extractors as well. Using
this new technique we build extractors that do not use designs and
polynomial-based error-correcting codes and that are very simple and efficient.
For example, one extractor produces each output bit separately in
time. These extractors work for weak sources with min entropy , for
arbitrary constant , have seed length , and their
output length is .Comment: 21 pages, an extended abstract will appear in Proc. ICALP 2005; small
corrections, some comments and references adde
Are cognitive disorders more common in geriatric diabetic patients? What factors contribute to cognitive decline?
Cognitive screening is recommended for all geriatric DM patients. Suggested validated screening tests are the Short Portable Mental Status Questionnaire and the clock drawing test. Screening should be repeated on a twice-yearly basis in those who are borderline and annually in those who are negative. In the case of positive screening, a specialist clinical diagnostic assessment is recommended.
In patients with mild cognitive impairment and dementia, evaluating and treating possible modifiable risk factors is recommended, such as sensory and physical functional disorders, obstructive sleep apnea syndrome, etc.
Simplification of antidiabetic drug treatment is also recommended in these patients
On the Approximability of Digraph Ordering
Given an n-vertex digraph D = (V, A) the Max-k-Ordering problem is to compute
a labeling maximizing the number of forward edges, i.e.
edges (u,v) such that (u) < (v). For different values of k, this
reduces to Maximum Acyclic Subgraph (k=n), and Max-Dicut (k=2). This work
studies the approximability of Max-k-Ordering and its generalizations,
motivated by their applications to job scheduling with soft precedence
constraints. We give an LP rounding based 2-approximation algorithm for
Max-k-Ordering for any k={2,..., n}, improving on the known
2k/(k-1)-approximation obtained via random assignment. The tightness of this
rounding is shown by proving that for any k={2,..., n} and constant
, Max-k-Ordering has an LP integrality gap of 2 -
for rounds of the
Sherali-Adams hierarchy.
A further generalization of Max-k-Ordering is the restricted maximum acyclic
subgraph problem or RMAS, where each vertex v has a finite set of allowable
labels . We prove an LP rounding based
approximation for it, improving on the
approximation recently given by Grandoni et al.
(Information Processing Letters, Vol. 115(2), Pages 182-185, 2015). In fact,
our approximation algorithm also works for a general version where the
objective counts the edges which go forward by at least a positive offset
specific to each edge.
The minimization formulation of digraph ordering is DAG edge deletion or
DED(k), which requires deleting the minimum number of edges from an n-vertex
directed acyclic graph (DAG) to remove all paths of length k. We show that
both, the LP relaxation and a local ratio approach for DED(k) yield
k-approximation for any .Comment: 21 pages, Conference version to appear in ESA 201
Pasta-making properties of the new durum wheat variety biensur suitable for the northern mediterranean environment
Industrial pasta is commonly made from mixtures of semolina from different durum wheat varieties, and there is a very low market presence of mono-varietal pasta from local, short supply chains. In this work, dough rheological properties and pasta quality traits of the new durum wheat cv. Biensur, which has a high HMW/LMW-GS ratio, were evaluated with a view to developing short-chain, mono-varietal pasta production in NE Italy. Chemical and sensory analyses on short-cut pasta, viz. tubetti, made with semolina from cv. Biensur at two drying temperatures revealed that it has good technological characteristics and stability, excellent cooking and sensory properties, and is comparable to the high-quality commercial reference cv. Aureo. We conclude that Biensur provides farmers and traders with new market opportunities and offers improvements to the environmental and economic sustainability of the durum wheat chain
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