pinecone/core-2020-05-10-deduplication huggingface dataset:
On the Chvátal–Gomory closure of a compact convex set

In this paper, we show that the Chvátal–Gomory closure of any compact convex set is a rational polytope. This resolves an open question of Schrijver (Ann Discret Math 9:291–296, 1980) for irrational polytopes, and generalizes the same result for the case of rational polytopes (Schrijver in Ann Discret Math 9:291–296, 1980), rational ellipsoids (Dey and Vielma in IPCO XIV, Lecture Notes in Computer Science, vol 6080. Springer, Berlin, pp 327–340, 2010) and strictly convex bodies (Dadush et al. in Math Oper Res 36:227–239, 2011). An extended abstract of this paper appeared in [6]. After the completion of this work, it has been brought to our notice that the polyhedrality of the Chvátal–Gomory closure for irrational polytopes has recently been shown independently by Dunkel and Schulz [9]. The proof presented in this paper has been obtained independently.United States. National Science Foundation. (Grant CMMI-1030662)United States. National Science Foundation. (Grant CMMI-1030422
Small and strong formulations for unions of convex sets from the Cayley embedding

There is often a significant trade-off between formulation strength and size in mixed integer programming (MIP). When modelling convex disjunctive constraints (e.g. unions of convex sets) this trade-off can be resolved by adding auxiliary continuous variables. However, adding these variables can result in a deterioration of the computational effectiveness of the formulation. For this  reason, there has been considerable interest in constructing strong formulations that do not use continuous auxiliary variables. We introduce a technique to construct formulations without these  detrimental continuous auxiliary variables. To develop this technique we introduce a natural nonpolyhedral generalization of the Cayley embedding of a family of polytopes and show it inherits many geometric properties of the original embedding. We then show how the associated formulation technique can be used to construct small and strong formulation for a wide range of disjunctive constraints. In particular, we show it can recover and generalize all known strong formulations without continuous auxiliary variables.National Science Foundation (U.S.) (grant CMMI-1351619
On Conway's potential function for colored links

The Conway potential function (CPF) for colored links is a convenient version
of the multi-variable Alexander-Conway polynomial. We give a skein
characterization of CPF, much simpler than the one by Murakami. In particular,
Conway's `smoothing of crossings' is not in the axioms. The proof uses a
reduction scheme in a twisted group-algebra $\mathbb P_nB_n$, where $B_n$ is a
braid group and $\mathbb P_n$ is a domain of multi-variable rational fractions.
The proof does not use computer algebra tools. An interesting by-product is a
characterization of the Alexander-Conway polynomial of knots
Fuzzy intelligence approach for modeling the migration of contaminants ina reservoir affected by AMD  pollution

The Sancho Reservoir, located in the Huelva province (SW Spain), is supplied by the Meca River, which receives water contaminated by mining activities in Tharsis. This study focused on determining the relationship that temperature, pH, and electrical conductivity (EC) had with rainfall. The temperature, pH, and EC were simultaneously measured every 30 min by two probes suspended in the Sancho Reservoir. It was anticipated that the use of fuzzy logic and data mining would lead to a model that would show how the contaminant load evolved over space and time. Similar results were obtained for the two locations, except that the parameters had more outliers near the dam due to the greater distance from the contamination source. As expected, higher pH corresponded with lower EC, since, in the absence of chloride, sulphate was the principal anion. The dependency relationship of the variables as well as the cause–effect relationship with the rate of rainfall was more evident in the up-gradient sampling location than near the dam due to the different residence time and the transit time between the two points
Misguided ventures: a quasi-public European Union credit rating agency (in Forum: Credit rating agencies: part of the solution or part of the problem?)

As speculative attacks against Member States persist, the European Union (EU) is desperately attempting to allay fears concerning the disintegration of Economic and Monetary Union (EMU). Much of the fi repower for this onslaught is provided by those very financial intermediaries charged with assessing and communicating the health of euro area economies, namely credit rating agencies (CRAs). Thus, in 2008, the European Commission proposed a series of oversight initiatives which would centralise CRA supervision at the EU level. Endorsed by the High Level Group on Financial Supervision1 chaired by Jacques de Larosière, Regulation (EC) No 1060/2009 (CRA Regulation v1) came into effect on 7 December 2010. Shortly thereafter, the corresponding amendment (EU) No 513/2011 (CRA Regulation v2) was deemed necessary in order to compensate for outstanding issues
Path methods for strong shift equivalence of positive matrices

In the early 1990's, Kim and Roush developed path methods for establishing
strong shift equivalence (SSE) of positive matrices over a dense subring U of
the real numbers R. This paper gives a detailed, unified and generalized
presentation of these path methods. New arguments which address arbitrary dense
subrings U of R are used to show that for any dense subring U of R, positive
matrices over U which have just one nonzero eigenvalue and which are strong
shift equivalent over U must be strong shift equivalent over U_+. In addition,
we show positive real matrices on a path of shift equivalent positive real
matrices are SSE over R_+; positive rational matrices which are SSE over R_+
must be SSE over Q_+; and for any dense subring U of R, within the set of
positive matrices over U which are conjugate over U to a given matrix, there
are only finitely many SSE-U_+ classes.Comment: This version adds a 3-part program for studying SEE over the reals.
  One part is handled by the arxiv post "Strong shift equivalence and algebraic
  K-theory". This version is the author version of the paper published in the
  Kim memorial volume. From that, my short lifestory of Kim (and more) is on my
  web page http://www.math.umd.edu/~mboyle/papers/index.htm
Effect of dietary protein level and source on digestive enzyme proteolytic activity in juvenile Senegalese sole, Solea senegalensis Kaup 1850

The effect of dietary protein level and protein source on growth and proteolytic activity of juvenile Solea senegalensis was studied. In Experiment 1 fish were fed on four experimental diets containing increased levels of protein (36, 46, 56 and 67 %). In Experiment 2 Senegalese sole were fed on five diets with partial substitution of fish meal by soybean meal, soybean protein concentrate, soybean protein isolate, wheat gluten meal or pea protein concentrate. Results obtained evidenced that growth and proteolytic activity in distal intestine of fish were affected by the quantitative changes of dietary protein. The type of protein source used in the elaboration of experimental diets affected both the amount and the composition of alkaline proteases secreted into the intestinal lumen but without decreasing growth of animals. Juvenile Senegalese sole showed capability to modulate their digestive protease secretion when the concentration and/or source of dietary protein were modified. Quantity and quality of dietary protein affected intestinal protein hydrolysis in Senegalese sole. This study establishes that 30% fish meal protein can be replaced by soybean derivatives without affect intestinal proteases. The replacement with wheat gluten meal or pea protein concentrate should be taken with caution, but further research is needed to establish if growth performance and digestive enzyme physiology of Senegalese sole could be affected by plant protein-supplemented diets in a long-term trial
A theoretically-explained new-variant of Modified-Newtonian-Dynamics
  (MOND)

It is surprising that we hardly know only 5% of the universe. Rest of the
universe is made up of 70% of dark-energy and 25% of dark-matter. Dark-energy
is responsible for acceleration of the expanding universe; whereas dark-matter
is said to be necessary as extra-mass of bizarre-properties to explain the
anomalous rotational-velocity of galaxy. Though the existence of dark-energy
has gradually been accepted in scientific community, but the candidates for
dark-matter have not been found as yet and are too crazy to be accepted. Thus,
it is obvious to look for an alternative theory in place of dark-matter.
Israel-scientist M. Milgrom has suggested a 'Modified Newtonian Dynamics
(MOND)' which appears to be highly successful for explaining the anomalous
rotational-velocity. But unfortunately MOND lacks theoretical support. The
MOND, in-fact, is (empirical) modification of Newtonian-Dynamics through
modification in the kinematical acceleration term 'a' (which is normally taken
as $a=\frac{v^{2}}{r}$) as effective kinematic acceleration $a_{effective} = a
\mu (\frac{a}{a_{0}})$, wherein the $\mu$-function is 1 for usual-values of
accelerations but equals to $\frac{a}{a_{0}} (\ll 1)$ if the acceleration 'a'
is extremely-low lower than a critical value $a_0 (10^{-10} m/s^{2})$. In the
present paper, a novel variant of MOND is proposed with theoretical backing;
wherein with the consideration of universe's acceleration $a_{d}$ due to
dark-energy, a new type of $\mu$-function on theoretical-basis emerges out
leading to $a_{effective} = a(1 - K \frac{a_{0}}{a})$. The proposed
theoretical-MOND model too is able to fairly explain qualitatively the
more-or-less 'flat' velocity-curve of galaxy-rotation, and is also able to
predict a dip (minimum) on the curve.Comment: 13 pages, 4 figure
Double gauge invariance and covariantly-constant vector fields in Weyl
  geometry

The wave equation and equations of covariantly-constant vector fields (CCVF)
in spaces with Weyl nonmetricity turn out to possess, in addition to the
canonical conformal-gauge, a gauge invariance of another type. On a Minkowski
metric background, the CCVF system alone allows us to pin down the Weyl
4-metricity vector, identified herein with the electromagnetic potential. The
fundamental solution is given by the ordinary Lienard-Wiechert field, in
particular, by the Coulomb distribution for a charge at rest. Unlike the
latter, however, the magnitude of charge is necessarily unity, "elementary",
and charges of opposite signs correspond to retarded and advanced potentials
respectively, thus establishing a direct connection between the
particle/antiparticle asymmetry and the "arrow of time".Comment: 8 pages. Eq.(35) and some comments added. Misprints removed. Adapted
  for GERG-forma
Electrochemical polymerisation of phenol in aqueous solution\ud
on a Ta/PbO2 anode

This paper deals with the treatment of aqueous phenol solutions using an electrochemical technique. Phenol can be partly eliminated from aqueous solution by electrochemically initiated polymerisation. Galvanostatic electrolyses of phenol solutions at concentration up to 0.1 mol dm−3 were carried out on a Ta/PbO2 anode. The polymers formed are insoluble in acidic medium but soluble in alkaline. These polymers were filtered and then dissolved in aqueous solution of sodium hydroxide (1 mol dm−3). The polymers formed were quantified by total organic carbon (TOC) measurement. It was found that the conversion of phenol into polymers increases as a function of initial concentration, anodic current density, temperature, and solution pH. The percentage of phenol polymerised can reach 15%
Treatment of dairy wastes with a microbial anode formed from garden compost

Garden compost has already been identified as a source of efficient electro-active (EA) biofilms. The work described here consisted of lixiviating the compost and then using the leachate as a microbial source. This procedure gave promising results for the treatment of yogurt waste (YW) in a microbial fuel cell (MFC). Experiments performed in MFC set-ups were compared with electrochemical cells under polarization at +0.1 V versus SCE. Different parameters were tested to optimize the microbial anode. Preliminary acclimation of the compost microbial flora to YW was revealed to be unnecessary. Forming biofilms firstly in pure leachate before exposing them to YW showed that high concentrations of this type of substrate were detrimental to current generation. Pre-treatment of the electrode by pre-adsorbing YW led to a 10-fold increase in the current density. The highest current densities were obtained at 40 and 60 °C, revealing the diversity of electro-active microorganisms coming from soils. Values up to 1,450 mA m−2 were reached at 40 °C
Voltammetric determination of the critical micellar concentration of surfactants by using a boron doped diamond anode

The electrochemistry of three surfactants has been studied by voltammetry at boron doped diamond (BDD) electrode in sodium sulphate solutions. The electrochemical behaviour of these surfactants is characterized by an oxidation signal (peak or wave) situated before the electrolyte oxidation. The anodic current is found to follow a linear relation with the concentration of the surfactants; the slope decreases abruptly above the critical micellar concentration (CMC) of the surfactants. The CMC values obtained for an anionic (sodium dodecylbenzenesulfonate, SDBS), a cationic (polyoxyethylene-23-dodecyl ether, BRIJ 35) and a neutral (1-(hexadecyl)trimethylammonium bromide, CTAB) surfactant are found in good agreement with those measured by the classical technique of surface tension. This voltammetric method has the advantage not to require the use of a redox active electrochemical probe
Electropolymerization of phenol on a vitreous carbon electrode in acidic aqueous solution at different temperatures

Electrochemical oxidation of phenol in acidic aqueous solution was studied on a vitreous carbon electrode at different temperatures in the range of 25–85 °C by cyclic voltammetry and chronoamperometry. The kinetic aspect of the phenol oxidation was investigated as a function of its concentration and temperature. The electrode deactivation by formation of an adherent, compact, and insulating polymeric film was examined by monitoring the decrease in the peak current of phenol oxidation during the course of successive potential scans. Repeated potential scans in the region of water stability did not reactivate the electrode whatever the temperature used. Chronoamperometric curves recorded at different potentials in the region of water decomposition shown that the electrochemical activity of the electrode was partially restored even when performed at low temperature (25 °C). \u
Economic impact of remote monitoring on ordinary follow-up of implantable cardioverter defibrillators as compared with conventional in-hospital visits: a single-center prospective and randomized study

Few data are available on actual follow-up\ud
costs of remote monitoring (RM) of implantable defibrillators\ud
(ICD). Our study aimed at assessing current direct costs\ud
of 1-year ICD follow-up based on RM compared with\ud
conventional quarterly in-hospital follow-ups.\ud
Methods and results Patients (N=233) with indications for\ud
ICD were consecutively recruited and randomized at implant\ud
to be followed up for 1 year with standard quarterly inhospital\ud
visits or by RM with one in-hospital visit at 12\ud
months, unless additional in-hospital visits were required\ud
due to specific patient conditions or RM alarms. Costs were\ud
calculated distinguishing between provider and patient\ud
costs, excluding RM device and service cost. The frequency\ud
of scheduled in-hospital visits was lower in the RM group\ud
than in the control arm. Follow-up required 47 min per\ud
patient/year in the RM arm versus 86 min in the control\ud
arm (p=0.03) for involved physicians, generating cost estimates\ud
for the provider of USD 45 and USD 83 per patient/-\ud
year, respectively. Costs for nurses were comparable.\ud
Overall, the costs associated with RM and standard\ud
follow-up were USD 103±27 and 154±21 per patient/year,\ud
respectively (p=0.01). RM was cost-saving for the patients:\ud
USD 97±121 per patient/year in the RM group versus 287±\ud
160 per patient/year (p=0.0001).\ud
Conclusion The time spent by the hospital staff was significantly\ud
reduced in the RM group. If the costs for the device\ud
and service are not charged to patients or the provider,\ud
patients could save about USD 190 per patient/year while\ud
the hospital could save USD 51 per patient/year
Thermal and mechanical analysis of injection moulded poly(lactic acid) filled with poly(ethylene glycol) and talc

In our research, the effect of talc particle size was analysed on the thermal and mechanical properties of renewable resource based, biodegradable polymer Poly(Lactic Acid) (PLA). Various talc particles with an average particle size of 24 μm, 1.9 μm, and 0.7 μm were blend mixed with PLA in 10 and 20 mass% containing no or an additional 10 mass% of Poly(Ethylene Glycol) (PEG) to increase molecular chain mobility. It was demonstrated that with decreasing talc particle size, its nucleation ability increased as well as all of the investigated mechanical properties of the compounds, however, in case of compounds containing PEG, this tendency was the opposite according to Charpy impact strength results. The talc with the best nucleating ability was selected and a full factorial design of experiment was made to optimise the talc and PEG content and to investigate their cross-effect in the 1-3-5-10-15 mass% additive content range. Finally, the effect of mould temperature and cooling time was analysed on the crystallinity and heat deflection temperature of the final injection moulded parts
The Grothendieck Group of a Quantum Projective Space Bundle

We compute the Grothendieck group K_0 of non-commutative analogues of quantum
projective space bundles. Our results specialize to give the Grothendieck
groups of non-commutative analogues of projective spaces, and specialize to
recover the Grothendieck group of a usual projective space bundle over a
regular noetherian separated scheme. As an application we develop an
intersection theory for the quantum ruled surfaces defined by Van den Bergh.Comment: This paper is being replaced so I can correct the metadata, the
  title! I (Paul) spelled Grothendieck's name incorrectly. The paper is being
  reposted with the journal reference and doi added to the metadat
Strengthening the Healthy Start Workforce: A Mixed-Methods Study to Understand the Roles of Community Health Workers in Healthy Start and Inform the Development of a Standardized Training Program

Introduction Healthy Start (HS) is dedicated to preventing infant mortality, improving birth outcomes, and reducing disparities in maternal and infant health. In 2014, the HS program was reenvisioned and standardization of services and workforce development were prioritized. This study examined how HS community health workers (CHW), as critical members of the workforce, serve families and communities in order to inform the development of a CHW training program to advance program goals. Methods In 2015, an online organizational survey of all 100 HS programs was conducted. Ninety-three sites (93%) responded. Three discussion groups were subsequently conducted with HS CHWs (n = 21) and two discussion groups with HS CHW trainers/supervisors (n = 14). Results Most (91%) respondent HS programs employed CHWs. Survey respondents ranked health education (90%), assessing participant needs (85%), outreach/recruitment (85%), and connecting participants to services (85%) as the most central roles to the CHW’s job. Survey findings indicated large variation in CHW training, both in the amount and content provided. Discussion group findings provided further examples of the knowledge and skills required by HS CHWs. Conclusions The study results, combined with a scan of existing competencies, led to a tailored set of competencies that serve as the foundation for a HS CHW training program. This training program has the capacity to advance strategic goals for HS by strengthening HS CHWs’ capacity nationwide to respond to complex participant needs. Other maternal and child health programs may find these results of interest as they consider how CHWs could be used to strengthen service delivery. Keywords: Healthy start; Community health worker; Infant mortality; Maternal health; social determinants of healt
Soil moisture content determines the effect of the urease inhibitor NBPT on N2O emissions

Among the mitigation strategies to prevent nitrogen (N) losses from ureic fertilizers, urease inhibitors (UIs) have been demonstrated to promote high N use efficiency by reducing ammonia (NH3) volatilization. In the last few years, some field experiments have also shown its effectiveness in reducing nitrous oxide (N2O) losses from fertilized soils under conditions of low soil moisture. An incubation experiment was carried out with the aim of assessing the main biotic mechanisms behind N2O emissions once that the UIs N-(n-butyl) thiophosphoric triamid (NBPT) and phenil phosphorodiamidate (PPDA) were applied with Urea (U) under different soil moisture conditions (40, 60 and 80 % water-filled pore space, WFPS). In the same study we tried to analyze to what extent soil WFPS regulates the effect of these inhibitors on N2O emissions. The use of PPDA in our study allowed us to compare the effect of NBPT with that of another commercially available urease inhibitor, aiming to see if the results were inhibitor-specific or not. Based on the results from this experiment, a WFPS (i.e. 60 %) was chosen for a second study (i.e. mesocosm experiment) aiming to assess the efficiency of the UIs to indirectly affect N2O emissions through influencing the pool of soil mineral N. The N2O emissions at 40 % WFPS were almost negligible, being significantly lower from all fertilized treatments than that produced at 60 and 80 % WFPS. When compared to U alone, NBPT+U reduced the N2O emissions at 60 % WFPS but had no effect at 80 % WFPS. The application of PPDA significantly increased the emissions with respect to U at 80 % WFPS whereas no significant effect was found at 60 %. At 80 % WFPS, denitrification was the main source of N2O emissions for all treatments. In the mesocosm study, the application of NBPT+U was an effective strategy to reduce N2O emissions (75 % reduction compared to U alone), due to a lower soil ammonium (NH4 +) content induced by the inhibitor. These results suggest that adequate management of the UI NBPT could provide, under certain soil conditions, an opportunity for mitigation of N2O emissions from fertilized soils
Stability of a 2-dimensional Mathieu-type system with quasiperiodic
  coefficients

In the following we consider a 2-dimensional system of ODE's containing
quasiperiodic terms. The system is proposed as an extension of Mathieu-type
equations to higher dimensions, with emphasis on how resonance between the
internal frequencies leads to a loss of stability. The 2-d system has two
`natural' frequencies when the time dependent terms are switched off, and it is
internally driven by quasiperiodic terms in the same frequencies. Stability
charts in the parameter space are generated first using numerical simulations
and Floquet theory. While some instability regions are easy to anticipate,
there are some surprises: within instability zones small islands of stability
develop, and unusual `arcs' of instability arise also. The transition curves
are analyzed using the method of harmonic balance, and we find we can use this
method to easily predict the `resonance curves' from which bands of instability
emanate. In addition, the method of multiple scales is used to examine the
islands of stability near the 1:1 resonance