bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic Facies Identification and Classification Using Simple Statistics
Authors: John Abraham K. , Lake Larry W. , Torres-Verdin Carlos , Srinivasan Sanjay
Published: January 2009

The identification and mapping of rock facies is important to reliable reservoir characterization. Traditionally, facies identification and mapping are based on inspection of core data and/or well-log signatures, a procedure that has subjective aspects because it is relies on samples from only a very small portion of the reservoir. Such identification is also difficult to perform at the onset of the exploration stage because of lack of sufficient well data. This paper demonstrates a simple practical approach to identify and classify facies from seismic-amplitude data using basic statistical concepts.

Within a geologic facies, measured properties [in this case acoustic impedance (AI)] are assumed to differ mainly as a result of random additive events and are modeled by a normal distribution, as justified by the central-limit theorem. The facies are identified by estimating the combination of facies volume fractions and distribution parameters (means and standard deviations of the facies probability-density function) that best fit the population distribution of AI. A simple form of Bayes theorem is then used to compute the probability of occurrence of each of the facies at the measured locations. This generates a volume of facies probabilities corresponding to the seismic volume. Such a volume can be used to perform facies-specific petrophysical analysis or be a starting point to generate multiple realizations of petrophysical properties. The approach is simple and transparent to use, with no significant computational requirements even on large data sets.

We describe an application of the procedure to a synthetic reference data set and a Gulf of Mexico AI data set. Mapped probabilities of the individual facies show the spatial continuity and geologic character of the underlying depositional environment. Property values within the mapped regions are substantially less variable than the original data across the entire region. The within-facies semivariograms exhibit much less spatial correlation than across all facies. Since the facies are mapped across an exhaustive data volume, this approach considerably reduces the need for the geostatistical construction of property distributions within them as long as a high correlation exists between the seismic attribute and petrophysical properties.
Nondestructive Measurement of Grapevine Leaf Area by Ground Normalized Difference Vegetation Index
Authors: Drissi Rachid , Goutouly Jean‐Pascal , Forget Dominique , Gaudillere Jean‐Pierre
Published: January 2009

Vine leaf area index has a great impact on berry quality. This study was conducted to determine whether vine leaf area index could be estimated, and mapped through normalized difference vegetation index (NDVI) ground‐based measurements. The NDVI measurements were performed using a Greenseeker (N‐Tech Industires, Ukiah, CA and Oklahoma State Univ., Stillwater), pointed sideways at the vertical shoot positioned vines [Vitis vinifera (L.)] at Bordeaux, France. Canopy gap fraction and vertical leaf area index (VLAI) measurements were also performed. Plot NDVI maps were obtained by linking the GreenSeeker to a GPS during measurements. The NDVI delivered by the sensor was sensitive to the variations of vertical leaf area index and gap fraction of the canopy, that is, vine vigor. The GreenSeeker was successfully used to carry out a follow‐up of the foliar growth of the vine, but with many precautions. The maps obtained showed relative variations of vigor at an intraplot level, enabling access to relevant information for better vineyard management.
Goosegrass and Bermudagrass Competition under Compaction
Authors: Arrieta Claudia , Busey Philip , Daroub Samira H.
Published: January 2009

Goosegrass (Eleusine indica L.) is a serious weed in trafficked areas of bermudagrass (Cynodon spp.) golf and sports turf. The objective of this study was to evaluate soil compaction and canopy cover as determinants of goosegrass competition in bermudagrass turf in sand soil. Goosegrass cover, plant density, and soil penetration resistance (SPR) were measured in traffic and no‐traffic plots in bermudagrass golf course tees and sports field foul areas. Goosegrass plant density and cover were larger in traffic plots compared with no‐traffic plots. Soil penetration resistance increased only at 5.0 cm depth due to traffic, while other soil properties including bulk density measured in golf course tees showed no effect from traffic. Two experiments measured the effect of controlled soil compaction on root and shoot dry weight of goosegrass and bermudagrass in containers. The first experiment evaluated effects of three soil compaction levels (1.14, 1.24, 1.33 g cm−3 bulk density) on goosegrass and bermudagrass grown separately. The second experiment evaluated effects on the two species grown together in competition, from two soil compaction levels (1.07 and 1.26 g cm−3 bulk density), two N application rates (48 and 96 kg ha−1 mo−1), and two mowing heights (1.3 and 2.5 cm). The second experiment also evaluated goosegrass seedling emergence and tiller numbers. When species were grown separately, bermudagrass root and shoot dry weight showed no effect from soil compaction, but goosegrass root weight was reduced. When species were grown together, bermudagrass root weight was reduced by compaction, but goosegrass was not affected. Goosegrass seedling emergence was reduced 58% by high mowing height, which paralleled an increase in bermudagrass canopy cover based on shoot dry weight. Canopy cover, not compaction, more readily explained the competition and infestation of goosegrass in trafficked areas in sand soil.
Differential Responses of Cotton Cultivars when Applying Mepiquat Pentaborate
Authors: O'Berry Nathan B. , Faircloth Joel C. , Jones Michael A. , Herbert David A. , Abaye Azenegashe O. , McKemie Thomas E. , Brownie Cavell
Published: January 2009

Plant growth regulators are routinely used in cotton (Gossypium hirsutum L.) production to reduce plant height and hasten maturity. The objective of this research was to determine the response of several cotton cultivars to mepiquat pentaborate (MPB) application in environments accumulating different levels of heat units. Four MPB application regimes were imposed on three cultivars in Virginia and South Carolina in 2005 and 2006. Total MPB season rates of 0.0, 54.9, 85.3, or 121.9 g ai ha−1 applied at the five‐leaf stage, pin‐head square, match‐head square, and early bloom were used. The cultivars were: Deltapine (DP) 444 BG/RR, an “early‐maturing” cultivar; Fibermax (FM) 960 BR, a “medium‐maturing” cultivar; and DP 555 BG/RR, a “late‐maturing” cultivar. In South Carolina in 2006, FM 960 BR July plant height was reduced by 25% with MPB application compared to only 12 and 13% for DP 444 BG/RR and DP 555 BG/RR, respectively, although actual plant height reductions were not different among cultivars. Mepiquat pentaborate applications decreased plant height at harvest by 8 to 34%, height‐to‐node ratio by 10 to 32%, enhanced maturity as measured by nodes above white flower for all cultivars, and decreased lint yield by 3.7 to 8.5% compared to untreated cotton. Higher seasonal totals and earlier initiation of MPB application resulted in the greatest decrease in lint yield.
Animal and Pasture Productivity of ‘Coastal’ and ‘Tifton 44’ Bermudagrass at Three Nitrogen Rates and Associated Soil Nitrogen Status
Authors: Burns J. C. , Wagger M. G. , Fisher D. S.
Published: January 2009

‘Coastal’ and ‘Tifton 44’ (T44) bermudagrass [Cynodon dactylon (L.) Pers.] are well adapted across the lower southern United States, but the grazing response of (T44) to N application in the Piedmont of the upper South warrants further evaluation. This 3‐yr experiment compared animal and pasture productivity of Coastal and T44 with three annual N rates of 101, 202, and 303 kg of N ha−1 on a Cecil clay loam (fine, kaolinitic thermic Typic Kanhapludult) soil typical of the Piedmont. Herbage mass differed for Coastal and T44 (3.5 and 3.0 Mg ha−1 respectively, P < 0.01), but not among N rates. The canopy of T44 was leafier (20.6 vs. 14.5% of dry matter) than Coastal and greater for in vitro true organic matter disappearance (IVTOD) (522 vs. 498 g kg−1) and CP (107 vs. 84 g kg−1) and lesser in NDF (596 vs. 605 g kg−1). The diet selected from T44 was greater in IVTOD (764 vs. 743 g kg−1) and lesser in NDF (596 vs. 605 g kg−1) giving greater steer average daily gain (0.63 kg vs. 0.57 kg; P < 0.01) which increased (P = 0.05) with N rate. Weight gain ha−1 (884 kg) and effective feed units (EFU) (4735 kg ha−1) were similar, and N rate linearly increased gain from 723 to 1073 kg ha−1 and EFU from 3978 to 5523 kg ha−1. Soil inorganic N was similar between cultivars but differed among soil depths. Tifton 44 pasture was greater in nutritive value, hence steer performance, and as productive as Coastal in the Piedmont.
Canopy Gas Exchange Measurements of Cotton in an Open System
Authors: Baker Jeffrey T. , Van Pelt Scott , Gitz Dennis C. , Payton Paxton , Lascano Robert Joseph , McMichael Bobbie
Published: January 2009

A portable, open transparent chamber system for measuring canopy gas exchanges was developed and tested. Differentials between incoming and outgoing atmospheric H2O and CO2 concentrations were used to calculate canopy transpiration (E) and net assimilation (A) at 10‐s intervals using solenoid valve actuated sample lines connected to an infrared gas analyzer. A programmable data logger controlled fan speed and air flow rate to control daytime chamber air temperature to within 0.5°C of ambient air temperature. To validate the mass balance equations used to calculate E, the chamber was positioned over sealed soil potted cotton (Gossypium hirsutum L.) plants which were placed on a weighing scale. A second scale was used to measure E of cotton plants outside the chamber to quantify potential chamber effects. A wide range of crop canopy leaf areas and soil water contents were created with greenhouse‐grown plants for these comparisons. Data analysis indicated agreement between chamber E measurements and the internal weighing scale (R2 = 0.93), as well as comparison between the internal and external scales (R2 = 0.88) across wide ranges of soil water contents and canopy leaf area. Transpiration ranged from near zero at night to 900 g (H2O) h−1 during the day. Bias estimates of E for chamber vs. internal scale and the internal vs. external scale were −6.0 and 4.6 g (H2O) h−1. With minor chamber effect, the chamber accurately estimates E for many field applications such as comparison of canopy gas exchanges and water use efficiencies among irrigation treatments.
Effect of Seeding Rate and Planting Arrangement on Rye Cover Crop and Weed Growth
Authors: Boyd Nathan S. , Brennan Eric B. , Smith Richard F. , Yokota Ron
Published: January 2009

Weed growth in winter cover crops in warm climates may contribute to weed management costs in subsequent crops. A 2‐yr experiment was conducted on an organic vegetable farm in Salinas, California, to determine the impact of seeding rate and planting arrangement on rye (Secale cereale L. ‘Merced’) cover crop growth and weed suppression. Each year, rye was planted in October at three rates (90, 180, and 270 kg ha−1) and two planting arrangements (one‐way versus grid pattern). Averaged across years, rye population densities were 322, 572, and 857 plants m−2 at the 90, 180, and 270 kg ha−1 seeding rates, respectively. Early season rye ground cover increased with seeding rate and was higher in the grid than one‐way arrangement in Year 1; however, rye ground cover was not affected by rate and was higher in the one‐way arrangement in Year 2. Aboveground dry matter (DM) of rye increased with seeding rate at the first two harvests but not at the final one. Planting arrangement did not affect rye aboveground DM in Year 1, but rye DM was higher in the grid pattern at the first and final harvests in Year 2. Weed emergence was not affected by seeding rate or planting arrangement. Weed biomass decreased with increased seeding rate and was also lower in the grid than in the one‐way arrangement in Year 2. A grid planting pattern provided no consistent benefit but planting rye at higher seeding rates maximizes early season rye DM production and minimizes weed growth.
Linking Wisconsin Dairy and Grain Farms via Manure Transfer for Corn Production
Authors: Sanford Gregg R. , Cook Amy R. , Posner Josh L. , Hedtcke Janet L. , Hall John A. , Baldock Jon O.
Published: January 2009

One relatively under‐used manure management strategy employed by dairy farmers is to transport and apply manure onto the fields of nearby grain farmers. While this system offers advantages to both parties, little of the existing research on manure management has been conducted on grain farms. As part of an effort to link grain and livestock farms in southern Wisconsin, 20 on‐farm trials were conducted to study the agronomic and environmental effects of including manure in cash‐grain rotations. Manure was applied at a rate of approximately 107 m3 ha−1 as slurry (11,000 gal acre−1) or 54 Mg ha−1 (24 ton acre−1) as a solid. Across‐site analysis indicated that the manured treatment increased corn (Zea mays L.) yields significantly (alpha = 0.05), by 0.5 Mg ha−1 (11.5 vs. 11.0 Mg ha−1), with 67 kg ha−1 less purchased fertilizer N during the 3 yr of this study. However, there were environmental concerns: (i) Early fall manure spreading significantly increased fall nitrate (NO3) levels in the manured plots (175 vs. 87 kg NO3–N ha−1); (ii) Following corn harvest, fall NO3 levels were fairly low and equivalent between treatments with the exception of three sites where manuring resulted in significantly higher NO3–N; and (iii) Soil tests following corn harvest indicated a significant increase in soil test phosphorus (STP) on the manured plots. These results indicate that dairy manure can reduce fertilizer inputs although there is a risk of NO3–N leaching and P accumulation. Informal interviews were conducted with farmer‐participants following this study to asses current manure use.
Methods for Creating Stomatal Impressions Directly onto Archivable Slides
Authors: Gitz Dennis C. , Baker Jeffrey T.
Published: January 2009

Stomatal density has been shown to be a primary determinant of crop yield, water use efficiency, and limitation to CO2 assimilation rate. Widely used methods of assessing stomatal density sample relatively small regions of the leaf, are labor intensive, or do not yield stable archivable samples for revisiting samples. We describe several methods of producing such epidermal impressions that yield samples large enough to generate stomatal density maps across entire leaf surfaces.
Occurrence and Proposed Cause of Hollow Husk in Maize
Authors: Below Fred E. , Duncan Kateri A. , Uribelarrea Martin , Ruyle Thomas B.
Published: January 2009

In 2007, a maize (Zea mays L.) ear abnormality that we term here as “hollow husk” occurred in research trials designed to alter the level or the sensing of plant ethylene. The unique experimental conditions of 2007 enabled us to document the occurrence of hollow husk and propose a physiological mechanism for its cause. Ears exhibiting hollow husk have normal appearing husks that feel hollow due to an abrupt cessation in ear development and a concomitant lack of silk emergence. Hollow husk occurred when the foliage of actively growing plants was sprayed before the VT growth stage with a chemical treatment that should either lower the level of plant ethylene (a strobilurin fungicide), or one that should decrease the plant's sensitivity to ethylene (1‐MCP). An attempt to increase ethylene status (via ethephon) led to virtually no hollow husk symptoms. The percentage of plants exhibiting hollow husk symptoms depended on the hybrid, the stage of plant growth when sprayed, and the combination of management conditions that promoted plant growth. Plants sprayed at V15 generally exhibited greater symptoms than those sprayed at V11, and hollow husk successively increased with increases in N supply and decreased with increases in plant population. Based on our data, we speculate that hollow husk is a physiological ear abnormality related to a perturbation in the level or the sensitivity of the plant to ethylene.
Rotational and Cover Crop Determinants of Soil Structural Stability and Carbon in a Potato System
Authors: Po Edgar A. , Snapp Sieglinde S. , Kravchenko Alexandra
Published: January 2009

Understanding processes that ameliorate structural degradation in sandy soils is particularly important in intensively managed potato (Solanum tuberosumL.) systems. Seven 2‐yr potato rotation systems were evaluated over 3 yr in an irrigated field trial comparing winter management systems bare (B) and cover crops: rye (Secale cerealeL.; R), rye‐hairy vetch (Vicia villosaRoth; RV) mixture and red clover (Trifolium pratenseL.; C). Crops rotated with potatoes (P) were snap bean (Phaseolus vulgaris(L.); SB), wheat (Triticum aestivumL.; W) and sweet corn (Zea maysL.; SC). The systems consisted of: S1 PBSBB; S2 PRSBR; S3 PRSCB; S4 PWWR; S5 PWWCC; S6 PRVSBRV; and S7 PRVSCRV, both entry points evaluated each year. Carbon inputs above‐ and belowground were measured and systems grouped as low (S1 and S4), medium (S2 and S6), and high (S5, S3 and S7): 1.2, 2.0, and 2.8 Mg C ha−1, respectively. Response variables included water stable aggregate (WSA) size fractions, macroaggregates (≥0.25 mm) and microaggregates (<0.25 mm), mean weight diameter (MWD), soil C, nitrogen mineralization potential (NMP), and potato tuber yield. Systems with SC contributed twofold higher biomass than rotations with W or SB, and the presence of RC contributed higher amounts of carbon (1.2 Mg ha−1) compared to R (0.7 Mg ha−1). Only the entry year influenced macroaggregates in 2001; both entry year and cropping system influenced aggregate size classes in 2004. Over 3 yr the macro‐WSAs declined by 13%, except for high carbon input systems. Residue C input was a moderate predictor of total soil C (31% of variability explained), whereas macro‐ and micro‐WSAs were predictors of soil C, accounting for 58 and 72% of observed variability, respectively. Low levels of aggregation were observed in this sandy soil and the modest amounts of C inputs from winter cover crops posed a challenge to detecting treatment effects, which was in part overcome by georeferencing, to improve precision of sampling over time.
Uptake of Point Source Depleted 15N Fertilizer by Neighboring Corn Plants
Authors: Hodgen P. J. , Ferguson R. B. , Shanahan J. F. , Schepers J. S.
Published: January 2009

Ground‐based active (self‐illuminating) sensors make it possible to collect canopy data that are useful for making on‐the‐go N fertilizer application decisions. These technologies raise questions about plant‐to‐plant competition for targeted fertilizer N applications. This study evaluated the extent to which fertilizer N applied to an individual corn (Zea mays L.) plant might be intercepted by adjacent plants in the row. Depleted 15N ammonium‐nitrate was injected under the center maize plant while the four neighboring plants on each side in the row received the same rate as natural abundance ammonium‐nitrate fertilizer. Aboveground biomass was collected 10 (at V12) and 7 (at R1) d after each fertilizer application. Plants were separated into three components at each sampling date. The uptake pattern of depleted 15N indicated an individual maize plant acquires most of its in‐season N from an area within a ∼40‐cm radius. Adjacent plants ∼18‐cm away from the tagged‐N source contained 32 to 40% of the total depleted 15N that was taken up by all nine plants in the sequence. Maize plants ∼36 cm from the point source only acquired 5 to 13% of the depleted 15N source that was taken up by all nine plants. It is presently impractical to position in‐season by‐plant N applications beneath plants as done in this study. Surface applications of liquid N near target plants is presently possible, but the relative effectiveness would likely be less than for injection of the fertilizer beneath each plant.
Growth, Yield, and Yield Component Changes among Old and New Soybean Cultivars
Authors: De Bruin Jason L. , Pedersen Palle
Published: January 2009

Soybean [Glycine max (L.) Merr.] yield has increased at a rate of 25 to 30 kg ha−1 yr−1 due in part to improved genetic gain, and has been further advanced by the addition of resistance to soybean cyst nematode (Heterodera glycines Ichinohe; SCN) in new cultivars. The objective was to determine specific growth changes that explain the yield improvement from old to new cultivars and the further yield improvement gained from the addition of SCN resistance. Studies were conducted at three Iowa locations during 2005 and 2006. Two old and two new SCN‐susceptible, and two new SCN‐resistant cultivars were evaluated for total dry matter (TDM) accumulation and leaf area index (LAI) through the season along with yield and yield components at harvest. New cultivars produced yields superior to older cultivars due to increased crop growth rate (CGR) culminating in greater TDM 105 days after emergence (DAE). Yield was strongly associated with the number of seeds produced m−2 and this yield component accounted for almost all of the yield differences among cultivars. Seeds m−2 was positively related to CGR between 42 and 105 (growth stage R1–R5.5) DAE and to LAI 105 DAE. New SCN‐resistant cultivars produced yields 17 to 19% greater than new susceptible cultivars across three locations. Increased TDM and CGR explained the yield response at the low‐yield location, but not at the high‐yield locations. Apparent harvest index (HI) was similar among all cultivars at each location. Selection for increased yield has indirectly selected for increased TDM and CGR with a similar amount partitioned to seed dry weight. Future yield gains will be made by (i) increasing the amount and the rate of dry matter (DM) and (ii) through the increased production and duration of leaf area.
Exhaustible sets in higher-type computation
Authors: Escardo Martin
Published: January 2009

We say that a set is exhaustible if it admits algorithmic universal
quantification for continuous predicates in finite time, and searchable if
there is an algorithm that, given any continuous predicate, either selects an
element for which the predicate holds or else tells there is no example. The
Cantor space of infinite sequences of binary digits is known to be searchable.
Searchable sets are exhaustible, and we show that the converse also holds for
sets of hereditarily total elements in the hierarchy of continuous functionals;
moreover, a selection functional can be constructed uniformly from a
quantification functional. We prove that searchable sets are closed under
intersections with decidable sets, and under the formation of computable images
and of finite and countably infinite products. This is related to the fact,
established here, that exhaustible sets are topologically compact. We obtain a
complete description of exhaustible total sets by developing a computational
version of a topological Arzela--Ascoli type characterization of compact
subsets of function spaces. We also show that, in the non-empty case, they are
precisely the computable images of the Cantor space. The emphasis of this paper
is on the theory of exhaustible and searchable sets, but we also briefly sketch
applications.
Separability in the Ambient Logic
Authors: Hirschkoff Daniel , Lozes Etienne , Sangiorgi Davide
Published: January 2009

The \it{Ambient Logic} (AL) has been proposed for expressing properties of
process mobility in the calculus of Mobile Ambients (MA), and as a basis for
query languages on semistructured data. We study some basic questions
concerning the discriminating power of AL, focusing on the equivalence on
processes induced by the logic $(=_L>)$. As underlying calculi besides MA we
consider a subcalculus in which an image-finiteness condition holds and that we
prove to be Turing complete. Synchronous variants of these calculi are studied
as well. In these calculi, we provide two operational characterisations of
$_=L$: a coinductive one (as a form of bisimilarity) and an inductive one
(based on structual properties of processes). After showing $_=L$ to be stricly
finer than barbed congruence, we establish axiomatisations of $_=L$ on the
subcalculus of MA (both the asynchronous and the synchronous version), enabling
us to relate $_=L$ to structural congruence. We also present some
(un)decidability results that are related to the above separation properties
for AL: the undecidability of $_=L$ on MA and its decidability on the
subcalculus.
First-Order and Temporal Logics for Nested Words
Authors: Alur Rajeev , Arenas Marcelo , Barcelo Pablo , Etessami Kousha , Immerman Neil , Libkin Leonid
Published: January 2009

Nested words are a structured model of execution paths in procedural
programs, reflecting their call and return nesting structure. Finite nested
words also capture the structure of parse trees and other tree-structured data,
such as XML. We provide new temporal logics for finite and infinite nested
words, which are natural extensions of LTL, and prove that these logics are
first-order expressively-complete. One of them is based on adding a "within"
modality, evaluating a formula on a subword, to a logic CaRet previously
studied in the context of verifying properties of recursive state machines
(RSMs). The other logic, NWTL, is based on the notion of a summary path that
uses both the linear and nesting structures. For NWTL we show that
satisfiability is EXPTIME-complete, and that model-checking can be done in time
polynomial in the size of the RSM model and exponential in the size of the NWTL
formula (and is also EXPTIME-complete). Finally, we prove that first-order
logic over nested words has the three-variable property, and we present a
temporal logic for nested words which is complete for the two-variable fragment
of first-order.
Symbolic Backwards-Reachability Analysis for Higher-Order Pushdown Systems
Authors: Hague Matthew , Ong C. -H. Luke
Published: January 2009

Higher-order pushdown systems (PDSs) generalise pushdown systems through the
use of higher-order stacks, that is, a nested "stack of stacks" structure.
These systems may be used to model higher-order programs and are closely
related to the Caucal hierarchy of infinite graphs and safe higher-order
recursion schemes.
We consider the backwards-reachability problem over higher-order Alternating
PDSs (APDSs), a generalisation of higher-order PDSs. This builds on and extends
previous work on pushdown systems and context-free higher-order processes in a
non-trivial manner. In particular, we show that the set of configurations from
which a regular set of higher-order APDS configurations is reachable is regular
and computable in n-EXPTIME. In fact, the problem is n-EXPTIME-complete.
We show that this work has several applications in the verification of
higher-order PDSs, such as linear-time model-checking, alternation-free
mu-calculus model-checking and the computation of winning regions of
reachability games.
The Wadge Hierarchy of Deterministic Tree Languages
Authors: Murlak Filip
Published: January 2009

We provide a complete description of the Wadge hierarchy for
deterministically recognisable sets of infinite trees. In particular we give an
elementary procedure to decide if one deterministic tree language is
continuously reducible to another. This extends Wagner's results on the
hierarchy of omega-regular languages of words to the case of trees.
Logical Reasoning for Higher-Order Functions with Local State
Authors: Yoshida Nobuko , Honda Kohei , Berger Martin
Published: January 2009

We introduce an extension of Hoare logic for call-by-value higher-order
functions with ML-like local reference generation. Local references may be
generated dynamically and exported outside their scope, may store higher-order
functions and may be used to construct complex mutable data structures. This
primitive is captured logically using a predicate asserting reachability of a
reference name from a possibly higher-order datum and quantifiers over hidden
references. We explore the logic's descriptive and reasoning power with
non-trivial programming examples combining higher-order procedures and
dynamically generated local state. Axioms for reachability and local invariant
play a central role for reasoning about the examples.
Flow Faster: Efficient Decision Algorithms for Probabilistic Simulations
Authors: Zhang Lijun , Hermanns Holger , Eisenbrand Friedrich , Jansen David N.
Published: January 2009

Strong and weak simulation relations have been proposed for Markov chains,
while strong simulation and strong probabilistic simulation relations have been
proposed for probabilistic automata. However, decision algorithms for strong
and weak simulation over Markov chains, and for strong simulation over
probabilistic automata are not efficient, which makes it as yet unclear whether
they can be used as effectively as their non-probabilistic counterparts. This
paper presents drastically improved algorithms to decide whether some
(discrete- or continuous-time) Markov chain strongly or weakly simulates
another, or whether a probabilistic automaton strongly simulates another. The
key innovation is the use of parametric maximum flow techniques to amortize
computations. We also present a novel algorithm for deciding strong
probabilistic simulation preorders on probabilistic automata, which has
polynomial complexity via a reduction to an LP problem. When extending the
algorithms for probabilistic automata to their continuous-time counterpart, we
retain the same complexity for both strong and strong probabilistic
simulations.
Compactly accessible categories and quantum key distribution
Authors: Heunen Chris
Published: January 2009

Compact categories have lately seen renewed interest via applications to
quantum physics. Being essentially finite-dimensional, they cannot accomodate
(co)limit-based constructions. For example, they cannot capture protocols such
as quantum key distribution, that rely on the law of large numbers. To overcome
this limitation, we introduce the notion of a compactly accessible category,
relying on the extra structure of a factorisation system. This notion allows
for infinite dimension while retaining key properties of compact categories:
the main technical result is that the choice-of-duals functor on the compact
part extends canonically to the whole compactly accessible category. As an
example, we model a quantum key distribution protocol and prove its correctness
categorically.
Effects of Self-Management Support on Structure, Process, and Outcomes Among Vulnerable Patients With Diabetes
Authors: Schillinger Dean , Handley Margaret , Wang Frances , Hammer Hali
Published: January 2009

OBJECTIVE

Despite the importance of self-management support (SMS), few studies have compared SMS interventions, involved diverse populations, or entailed implementation in safety net settings. We examined the effects of two SMS strategies across outcomes corresponding to the Chronic Care Model.

RESEARCH DESIGN AND METHODS

A total of 339 outpatients with poorly controlled diabetes from county-run clinics were enrolled in a three-arm trial. Participants, more than half of whom spoke limited English, were uninsured, and/or had less than a high school education, were randomly assigned to usual care, interactive weekly automated telephone self-management support with nurse follow-up (ATSM), or monthly group medical visits with physician and health educator facilitation (GMV). We measured 1-year changes in structure (Patient Assessment of Chronic Illness Care [PACIC]), communication processes (Interpersonal Processes of Care [IPC]), and outcomes (behavioral, functional, and metabolic).

RESULTS

Compared with the usual care group, the ATSM and GMV groups showed improvements in PACIC, with effect sizes of 0.48 and 0.50, respectively (P < 0.01). Only the ATSM group showed improvements in IPC (effect sizes 0.40 vs. usual care and 0.25 vs. GMV, P < 0.05). Both SMS arms showed improvements in self-management behavior versus the usual care arm (P < 0.05), with gains being greater for the ATSM group than for the GMV group (effect size 0.27, P = 0.02). The ATSM group had fewer bed days per month than the usual care group (−1.7 days, P = 0.05) and the GMV group (−2.3 days, P < 0.01) and less interference with daily activities than the usual care group (odds ratio 0.37, P = 0.02). We observed no differences in A1C change.

CONCLUSIONS

Patient-centered SMS improves certain aspects of diabetes care and positively influences self-management behavior. ATSM seems to be a more effective communication vehicle than GMV in improving behavior and quality of life.
Changes in Albumin Excretion in the Diabetes Prevention Program
Authors:   Diabetes Prevention Program Research Group
Published: January 2009

OBJECTIVE

Increased urinary albumin excretion rates have been linked to nephropathy and macrovascular disease. We here describe the baseline prevalence and effect of Diabetes Prevention Program (DPP) interventions on the development and reversal of elevated albumin excretion.

RESEARCH DESIGN AND METHODS

Urine albumin-to-creatinine ratios (ACRs) were calculated from untimed urine collections. Analyses compared participants by treatment group, diabetes and hypertension status, and use of ACE inhibitors or angiotensin II receptor blockers (ARBs).

RESULTS

Elevated ACR levels (≥30 mg/g creatinine) were present at baseline in 198 (6.2%) of 3,188 participants: placebo 5.3%, metformin 6.5%, and intensive lifestyle (ILS) 6.8%. Of the 2,802 with ACR measurements at baseline and at the end of the study, the percentage with elevated levels declined (incident and regression) from 6.2 to 6.1%, with no significant differences between the groups even with adjustment for ACE inhibitor and ARB use. The odds of developing an elevated ACR were 59% higher for a participant who developed diabetes compared with one who did not.

CONCLUSIONS

At entry into the DPP, an elevated ACR was present in 6.2%. Despite the marked decrease in progression to diabetes and the improvement in insulin resistance and other cardiovascular risk markers in the ILS and metformin groups, there was no improvement in ACR, on average, in those two groups. However, the frequency of an elevated ACR was higher in participants who developed diabetes. An increased ACR may have multiple causes, thus obscuring the improvements that might have been expected with the reduction in insulin resistance seen in the DPP.
Growth Factors and Adipocytokines in Prepubertal Children Born Small for Gestational Age
Authors: Challa Anna S. , Evagelidou Eleni N. , Cholevas Vasilios I. , Kiortsis Dimitrios N. , Giapros Vasileios I. , Drougia Aikaterini A. , Andronikou Styliani K.
Published: January 2009

OBJECTIVE

The aim of this study was to test whether being born small for gestational age (SGA) has an impact on adiponectin and leptin levels and the IGF system in relation to insulin sensitivity, taking into consideration the severity of growth restriction.

RESEARCH DESIGN AND METHODS

Serum levels of adiponectin, leptin, fasting glucose, fasting insulin (IF), the homeostasis model assessment insulin resistance index (HOMA-IR), IGF-1, free IGF-1, IGF-binding protein (IGFBP)-1 and -3, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides were evaluated in 57 children at age 4–10 years. Of these, 32 had been born appropriate size for gestational age (AGA) and 25 SGA (14 in the <3rd percentile and 11 in the 3rd–10th percentile).

RESULTS

The SGA 3rd–10th percentile children were already insulin resistant at prepubertal age (IF 39.6 ± 16.8 vs. 27 ± 12 pmol/l, P < 0.01, and HOMA-IR 1.4 ± 0.6 vs. 0.95 ± 0.42 in SGA vs. AGA children, P < 0.05). Their IGF-1 and IGFBP-3 concentrations were significantly lower than those in AGA children (160.4 ± 66.2 vs. 207 ± 66.8 μg/l, P < 0.05 and 2.3 ± 0.4 vs. 3.51 ± 1.21 mg/l in SGA vs. AGA children, P < 0.01). The SGA <3rd percentile children had higher adiponectin (15.6 ± 5.7 mg/l, P < 0.05) and IGFBP-1 levels (113.5 ± 33.9 μg/l, P < 0.05) than AGA children (11.3 ± 6.6 mg/l and 90.8 ± 24.2 μg/l, respectively) and lower IGF-1 and IGFBP-3 concentrations (162.6 ± 68.4 μg/l, P < 0.05 and 2.4 ± 0.7 mg/l, P < 0.01). They also had significantly lower waist circumference (P < 0.05). Leptin levels did not differ among groups, but an inverse correlation with IGFBP-1 (r = −0.55, P < 0.01) was found in the pooled SGA group.

CONCLUSIONS

Intrauterine growth restriction appears to affect the IGF axis at prepubertal age, and its severity plays a role in insulin sensitivity.
Influence of Adiponectin Gene Polymorphisms on Adiponectin Level and Insulin Resistance Index in Response to Dietary Intervention in Overweight-Obese Patients With Impaired Fasting Glucose or Newly Diagnosed Type 2 Diabetes
Authors: Chung Hye Kyung , Chae Jey Sook , Hyun Yae Jung , Paik Jean Kyung , Kim Ji Young , Jang Yangsoo , Kwon Hyuck Moon , Song Young Duk , Lee Hyun Chul , Lee Jong Ho
Published: January 2009

OBJECTIVE

The aim of this study was to determine the effect of common adiponectin gene polymorphisms on dietary intervention-mediated changes in adiponectin levels and homeostasis model assessment of insulin resistance (HOMA-IR) indexes.

RESEARCH DESIGN AND METHODS

A total of 363 subjects with impaired fasting glucose (IFG) or newly diagnosed type 2 diabetes followed a dietary intervention (replacement of cooked refined rice with whole grains and an increase in vegetable intake) and regular walking for 12 weeks without any medication. Adiponectin gene single nucleotide polymorphisms (SNPs) (45, 276, and −11377) were examined in these subjects.

RESULTS

After this dietary intervention, fasting glucose levels decreased in all three SNP 45T>G genotype groups. Subjects with the SNP 45TT genotype showed increased adiponectin levels and decreased HOMA-IR indexes. Haplotype analysis revealed that homozygous carriers of the TG haplotype (45TT and 276GG) and heterozygous carriers of the TG haplotype (TG/X) showed a reduction in the HOMA-IR index after adjustment for baseline levels. Significant differences were observed in changes in HOMA-IR indexes and adiponectin concentrations according to the 45-276 TG haplotype in overweight-obese, but not in normal-weight subjects: the greatest decrease in HOMA-IR indexes and the greatest increase in adiponectin levels were shown in overweight-obese subjects with the TG/TG haplotype.

CONCLUSIONS

ADIPOQ genetic variants can affect circulating adiponectin levels and insulin resistance indexes in subjects with IFG or newly diagnosed type 2 diabetes in response to dietary intervention.
Antidiabetic Action of Bezafibrate in a Large Observational Database
Authors: Flory James H. , Ellenberg Susan , Szapary Philippe O. , Strom Brian L. , Hennessy Sean
Published: January 2009

OBJECTIVE

The purpose of this study was to test the hypothesis that bezafibrate, an approved fibrate, can prevent or delay type 2 diabetes.

RESEARCH DESIGN AND METHODS

This was a retrospective cohort study using data from routine medical practice in the U.K., as captured by the General Practice Research Database (GPRD). Individuals chronically exposed to bezafibrate were compared with individuals chronically exposed to other fibrates. Hazard ratios (HRs) for incident type 2 diabetes were calculated using a Cox proportional hazards model. A post hoc analysis was used to examine the effect of bezafibrate on progression to use of oral antidiabetic medications or insulin in individuals with diabetes at baseline.

RESULTS

Bezafibrate users had a lower hazard for incident diabetes than users of other fibrates (HR 0.66 [95% CI 0.53–0.81]). This effect became stronger with increasing duration of therapy. Post hoc analysis of the effect of bezafibrate on progression of preexisting diabetes also showed a lower hazard for progression to use of antidiabetic medication (0.54 [0.38–0.76]) or progression to use of insulin (0.78 [0.55–1.10]).

CONCLUSIONS

Bezafibrate appears to have clinically important antidiabetic properties. Randomized controlled trials should be considered to assess the utility of bezafibrate in treating patients with diabetes or in preventing diabetes in high-risk patients.
Misconceptions About Diabetes and Its Management Among Low-Income Minorities With Diabetes
Authors: Mann Devin M. , Ponieman Diego , Leventhal Howard , Halm Ethan A.
Published: January 2009

OBJECTIVE

To determine diabetic patients' knowledge and beliefs about the disease and medications that could hinder optimal disease management.

RESEARCH DESIGN AND METHODS

A cross-sectional survey of 151 type 2 diabetic patients characterizing diabetes knowledge and beliefs about the disease and medications was conducted.

RESULTS

Mean diabetes duration was 13 years. Over half of the patients (56%) believed that normal glucose is ≤200 mg/dl, 54% reported being able to feel when blood glucose levels are high, 36% thought that they will not always have diabetes, 29% thought that their doctor will cure them of diabetes, one in four (23%) said there is no need to take diabetes medications when glucose levels are normal, and 12% believed they have diabetes only when glucose levels are high.

CONCLUSIONS

Diabetes knowledge and beliefs inconsistent with a chronic disease model of diabetes were prevalent in this sample. Suboptimal knowledge and beliefs are potentially modifiable and are logical targets for educational interventions to improve diabetes self-management.
Alanine Aminotransferase, γ-Glutamyltransferase, and Incident Diabetes
Authors: Fraser Abigail , Harris Ross , Sattar Naveed , Ebrahim Shah , Davey Smith George , Lawlor Debbie A.
Published: January 2009

OBJECTIVE

To estimate and compare associations of alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT) with incident diabetes.

RESEARCH DESIGN AND METHODS

ALT and GGT were studied as determinants of diabetes in the British Women's Heart and Health Study, a cohort of 4,286 women 60–79 years old (median follow-up 7.3 years). A systematic review and a meta-analysis of 21 prospective, population-based studies of ultrasonography, which diagnosed nonalcoholic fatty liver disease (NAFLD), ALT, and GGT as determinants of diabetes, were conducted, and associations of ALT and GGT with diabetes were compared.

RESULTS

Ultrasonography-diagnosed NAFLD was associated with more than a doubling in the risk of incident diabetes (three studies). ALT and GGT both predicted diabetes. The fully adjusted hazard ratio (HR) for diabetes per increase in one unit of logged ALT was 1.83 (95% CI 1.57–2.14, I2 = 8%) and for GGT was 1.92 (1.66–2.21, I2 = 55%). To directly compare ALT and GGT as determinants of diabetes, the fully adjusted risk of diabetes in the top versus bottom fourth of the ALT and GGT distributions was estimated using data from studies that included results for both markers. For ALT, the HR was 2.02 (1.59–2.58, I2 = 27%), and for GGT the HR was 2.94 (1.98–3.88, I2 = 20%), suggesting that GGT may be a better predictor (P = 0.05).

CONCLUSIONS

Findings are consistent with the role of liver fat in diabetes pathogenesis. GGT may be a better diabetes predictor than ALT, but additional studies with directly determined liver fat content, ALT, and GGT are needed to confirm this finding.
Subclinical Inflammation and Diabetic Polyneuropathy
Authors: Herder Christian , Lankisch Mark , Ziegler Dan , Rathmann Wolfgang , Koenig Wolfgang , Illig Thomas , Döring Angela , Thorand Barbara , Holle Rolf , Giani Guido , Martin Stephan , Meisinger Christa
Published: January 2009

OBJECTIVE

Subclinical inflammation represents a risk factor of type 2 diabetes and several diabetes complications, but data on diabetic neuropathies are scarce. Therefore, we investigated whether circulating concentrations of acute-phase proteins, cytokines, and chemokines differ among diabetic patients with or without diabetic polyneuropathy.

RESEARCH DESIGN AND METHODS

We measured 10 markers of subclinical inflammation in 227 type 2 diabetic patients with diabetic polyneuropathy who participated in the population-based MONICA/KORA Survey F3 (2004–2005; Augsburg, Germany). Diabetic polyneuropathy was diagnosed using the Michigan Neuropathy Screening Instrument (MNSI).

RESULTS

After adjustment for multiple confounders, high levels of C-reactive protein and interleukin (IL)-6 were most consistently associated with diabetic polyneuropathy, high MNSI score, and specific neuropathic deficits, whereas some inverse associations were seen for IL-18.

CONCLUSIONS

This study shows that subclinical inflammation is associated with diabetic polyneuropathy and neuropathic impairments. This association appears rather specific because only certain immune mediators and impairments are involved.
Impaired Mitochondrial Function and Insulin Resistance of Skeletal Muscle in Mitochondrial Diabetes
Authors: Szendroedi Julia , Schmid Albrecht Ingo , Meyerspeer Martin , Cervin Camilla , Kacerovsky Michaela , Smekal Gerhard , Gräser-Lang Sabine , Groop Leif , Roden Michael
Published: January 2009

OBJECTIVE

Impaired muscular mitochondrial function is related to common insulin resistance in type 2 diabetes. Mitochondrial diseases frequently lead to diabetes, which is mostly attributed to defective β-cell mitochondria and secretion.

RESEARCH DESIGN AND METHODS

We assessed muscular mitochondrial function and lipid deposition in liver (hepatocellular lipids [HCLs]) and muscle (intramyocellular lipids [IMCLs]) using 31P/1H magnetic resonance spectroscopy and insulin sensitivity and endogenous glucose production (EGP) using hyperinsulinemic-euglycemic clamps combined with isotopic tracer dilution in one female patient suffering from MELAS (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) syndrome and in six control subjects.

RESULTS

The MELAS patient showed impaired insulin sensitivity (4.3 vs. 8.6 ± 0.5 mg · kg−1 · min−1) and suppression of EGP (69 vs. 94 ± 1%), and her baseline and insulin-stimulated ATP synthesis were reduced (7.3 and 8.9 vs. 10.6 ± 1.0 and 12.8 ± 1.3 μmol · l−1 · min−1) compared with those of the control subjects. HCLs and IMCLs were comparable between the MELAS patient and control subjects.

CONCLUSIONS

Impairment of muscle mitochondrial fitness promotes insulin resistance and could thereby contribute to the development of diabetes in some patients with the MELAS syndrome.