Miracle-dz/UniFAR-FTUs huggingface dataset:
Multidimensional Learning, Optimal Contract, and On-the-job Search

We study a model of on-the-job search and optimal wage contracts under uncertainty about both worker ability and match quality. Firms and workers update beliefs through random output realizations, and the optimal contracts and search decisions respond differently to the belief about ability and match quality. We show that the optimal wage has a continuous path even when beliefs jump. The optimal contract exhibits wage cuts over tenure within a match if the worker is valuable only to outside firms. We numerically calculate the optimal wage policy as a function of each belief, identifying how the implications of learning can differ if uncertainty is about a worker or match. The multidimensional aspect of learning can explain empirical phenomena which are not easily understood in standard models: the adverse wage effects of previous job-to-job transitions and the higher likelihood of wage cuts for high-wage/ability workers in firms.
The physicochemical properties of surface water resources around fuel filling stations and auto-mobile repair workshops in Bamenda-City, North West Region of Cameroon

Surface and ground water resources in urban areas are at risk of contamination from many human activities such as oil spills due to improper location of fuel filling stations and auto mobile repair workshops in fast developing cities in third world countries like Cameroon. The study was aimed at determining the physicochemical properties of surface water resources around fuel filling stations and auto-mobile repair workshops in the Bamenda city, North West Region of Cameroon. Ten water samples were collected from surface water sources around two fuel filling stations and three automobile repair workshops. The pH, temperature and electrical conductivity were tested using a Bluelab pH meter, Mercury in glass thermometer, and a WTW LF 91 meter, respectively. The total hardness of water was measured using EDTA titrimetric method; alkalinity was determined using titrimetric method with 0.01 M concentration of HCl as titrant while the concentrations of calcium, magnesium and chlorine were measured using complexometric titration. Results showed that the pH values ranged from 5.62 to 6.24 for auto-mobile repair workshops and 6.15 to 6.70 for fuel filling stations which were below the World Health Organization (WHO) range (6.5 to 8.5) recommended for potable water. Other physicochemical parameters like electrical conductivity, water hardness, temperature and alkalinity were all within WHO recommended range. Ca + and Mg 2+ concentration was within limits while Cl was above WHO recommended limits. The study concludes that the amount of waste oil generated at fuel filling stations and auto mobile repair workshops is significant to cause negative effects on the environment in the Bamenda city, North West Region of Cameroon.
Unmasking the Lottery Ticket Hypothesis: Efficient Adaptive Pruning for Finding Winning Tickets

Modern deep learning involves training costly, highly overparameterized networks, thus motivating the search for sparser networks that require less compute and memory but can still be trained to the same accuracy as the full network ( i.e. matching ). Iterative magnitude pruning (IMP) is a state of the art algorithm that can find such highly sparse matching subnetworks , known as winning tickets , that can be retrained from initialization or an early training stage. IMP operates by iterative cycles of training, masking a fraction of smallest magnitude weights, rewinding unmasked weights back to an early training point, and repeating. Despite its simplicity, the underlying principles for when and how IMP finds winning tickets remain elusive. In particular, what useful information does an IMP mask found at the end of training convey to a rewound network near the beginning of training? We find that—at higher sparsities—pairs of pruned networks at successive pruning iterations are connected by a linear path with zero error barrier if and only if they are matching. This indicates that masks found at the end of training encodes information about the identity of an axial subspace that intersects a desired linearly connected mode of a matching sublevel set. We leverage this observation to design a simple adaptive pruning heuristic for speeding up the discovery of winning tickets and achieve a 30% reduction in computation time on CIFAR-100. These results make progress toward demystifying the existence of winning tickets with an eye towards enabling the development of more efficient pruning algorithms.
Immunomodulatory meaning of diet and COVID-19 Immunomodulacyjne znaczenie diety i COVID-19

Introduction and Objective . The latest scientific reports showed that there is a relationship between the state of the gastrointestinal tract and the immune system, and the incidence of COVID-19. Diet can exert an immunomodulatory effect and regulate the immune response of an organism. The aim of the review is to show the effects of immunomodulators contained/supplemented in a diet on the infection SARS-CoV-2 and the course of COVID-19. Review Methods. The literature review was conducted using PubMed, Google Scholar and the Medline database. Results. Regular vitamin D supplementation significantly reduces the risk of respiratory infection with SARS-CoV-2; vitamin C may inhibit the expression of the ACE2 receptor in human small alveolar epithelial cells and limit the penetration of SARS-CoV-2; reduced iron levels predispose people to severe COVID-19 symptoms; selenium deficiency may be responsible for a decreased level of antibodies and NK cell cytotoxicity. Aloë vera isolated polysaccharides strengthens the immune system; the quercetin and ellagic acid in combination with virus proteins show potential antiviral activity against SARS-CoV-2. Subsequently, adaptogens, ginger, echinacea and curcumin - showed anti-inflammatory effects. Also, the optimal composition of the gut microbiota improved/maintained the integrity of the lymphoid tissue found in the gastrointestinal tract (GALT) and the functioning of the gut-pulmonary axis. Summary . Natural immunomodulators may be a relatively safe therapeutic option in patients during the course of COVID-19, but there are still no official recommendations for their practical use in therapy. It should be emphasized that there is a need for further scientific research into the mechanisms of action and efficacy of phytotherapy in the context of the effectiveness of plant-based immunostimulants in alleviating the course of COVID-19 disease.
MIT Open Access Articles The submodular joint replenishment problem

The joint replenishment problem is a fundamental model in supply chain management theory that has applications in inventory management, logistics, and maintenance scheduling. In this problem, there are multiple item types, each having a given time-dependent sequence of demands that need to be satisﬁed. In order to satisfy demand, orders of the item types must be placed in advance of the due dates for each demand. Every time an order of item types is placed, there is an associated joint setup cost depending on the subset of item types ordered. This ordering cost can be due to machine, transportation, or labor costs, for example. In addition, there is a cost to holding inventory for demand that has yet to be served. The overall goal is to minimize the total ordering costs plus inventory holding costs. In this paper, the cost of an order, also known as a joint setup cost, is a monotonically increasing, submodular function over the item types. For this general problem, we show that a greedy approach provides an approximation guarantee that is logarithmic in the number of demands. Then we consider three special cases of submodular functions which we call the laminar, tree, and cardinality cases, each of which can model real world scenarios that previously have not been captured. For each of these cases, we provide a constant factor approximation algorithm. Speciﬁcally, we show that the laminar case can be solved optimally in polynomial time via a dynamic programming approach. For the tree and cardinality cases, we provide two diﬀerent linear programming based approximation algorithms that provide guarantees of three and ﬁve, respectively.
Damped Lyalpha Absorption Associated with an Early-Type Galaxy at Redshift z=0.16377.

We report new HST and ground-based observations of a damped Lyman-alpha absorption system toward the QSO 0850+4400. The redshift of the absorption system is z = 0.163770 and the neutral hydrogen column density of the absorption system is log N = 19.81 cm**-2. The absorption system is by far the lowest redshift confirmed damped Lyman-alpha absorption system yet identified, which provides an unprecedented opportunity to examine the nature, impact geometry, and kinematics of the absorbing galaxy in great detail. The observations indicate that the absorption system is remarkable in three respects: First, the absorption system is characterized by weak metal absorption lines and a low metal abundance, possibly less than 4% of the solar metal abundance. This cannot be explained as a consequence of dust, because the neutral hydrogen column density of the absorption system is far too low for obscuration by dust to introduce any significant selection effects. Second, the absorption system is associated with a moderate-luminosity early-type S0 galaxy, although the absorption may actually arise in one of several very faint galaxies detected very close to the QSO line of sight. Third, the absorbing material moves counter to the rotating galaxy disk, which rules out the possibility that the absorption arises in a thin or thick co-rotating gaseous disk. These results run contrary to the expectation that low-redshift damped Lyman-alpha absorption systems generally arise in the gas- and metal-rich inner parts of late-type spiral galaxies. We suggest instead that mounting evidence indicates that low-redshift galaxies of a variety of morphological types may contain significant quantities of low metal abundance gas at large galactocentric distances.
Graph Theory 1736-1936

1. Oaths 2. Circuits 3. Trees 4. Chemical graphs 5. Euler's polyhedral formula 6. The four-colour problem - early history 7. Colouring maps on surfaces 8. Ideas from algebra and topology 9. The four-colour problem - to 1936 10. The factorization of graphs Appendix 1: Graph theory since 1936 Appendix 2: Bibliographical notes Appendix 3: Bibliography: 1736-1936
Co-simulation of Smart Grids and Homes including Ultra-fast HVAC Models with CTA-2045 Control and Consideration of Thermal Comfort

A novel co-simulation framework was developed and demonstrated through virtual power plant (VPP) simulations that include hundreds of unique building models randomly populated into a modified IEEE 123-bus feeder system. The framework employs ultra-fast models for heating, ventilation, and air-conditioning (HVAC) systems as well as building thermal envelopes that are satisfactorily accurate for both electric power and indoor temperature. The approach circumvents generic control time limits typically in conventional implementations by enabling occupant thermal comfort monitoring. The HVAC and building models contain parameters by which they are characterized as generalized energy storage (GES) systems based on Energy Star definitions. This enables their compatibility with the Consumer Technology Association (CTA) 2045 standard control commands and event types. Example CTA-2045 “shed” events are illustrated to exemplify this feature and to analyze power distribution system effects in terms of power flow and voltages.
INVARIANT FUNCTIONALS

l Introduction. Let E be a normed linear space and G a solvable group of bounded linear operators on E. If there exists a non-trivial bounded linear functional invariant under G then there exists xoe E such that inf ||T(^0)j|>0? TeGl9 the convex envelope of G. Assume that such an x0 exists. If G is bounded then there exists an invariant functional [7]. If G is unbounded, however, such a functional may or may not exist. For simplicity we discuss here the abelian case. In a previous work [7] it was shown that the invariant functional exists if there is a constant 1Γ>O such that to each UeGL there corresponds VeG1 where ||F||<IliΓ and ||FZ7||^ϋΓ. A consequence of this condition is that for each xe E
Feedback Control and Characterization of a Microcantilever Using Optical Radiation Pressure

The authors describe a simple method for feedback regulation of the response of a microcantilever using the radiation pressure of a laser. A modified fiber-optic interferometer uses one laser to read out the position of the cantilever and another laser of a different wavelength to apply a force that is a phase-shifted function of that position. The method does not require a high-finesse cavity, and the feedback force is due solely to the momentum of the photons in the second laser. The feedback phase can be adjusted to increase or decrease the microcantilever’s effective quality factor Qeff and effective temperature Teff. The authors demonstrate a reduction of both Qeff and Teff of a silicon nitride microcantilever by more than a factor of 15 using a root-mean-square optical power variation of ∼2μW. Additionally, the authors suggest a method for determination of the spring constant of a cantilever using the known force exerted on it by radiation pressure.
Dynamic Contracting with Flexible Monitoring (cid:3)

We study a dynamic contracting problem in which the principal can allocate his limited capacity between seeking evidence that con-(cid:133)rms or that contradicts the agent(cid:146)s e⁄ort, as the basis for reward or punishment. Such (cid:135)exibility calls for jointly designed monitoring and compensation schemes practically relevant but novel in the literature. When the agent(cid:146)s continuation value is low, the principal seeks only con-(cid:133)rmatory evidence, but when the agent(cid:146)s continuation value exceeds a threshold, the principal switches to seeking mainly contradictory evidence. Moreover, the agent(cid:146)s e⁄ort can be perpetuated if and only if both synergy and (cid:135)exibility in monitoring are su¢ ciently large.
Vorticity in holographic fluids

In view of the recent interest in reproducing holographically various properties of conformal fluids, we review the issue of vorticity in the context of AdS/CFT. Three-dimensional fluids with vorticity require four-dimensional bulk geometries with either angular momentum or nut charge, whose boundary geometries fall into the Papapetrou--Randers class. The boundary fluids emerge in stationary non-dissipative kinematic configurations, which can be cyclonic or vortex flows, evolving in compact or non-compact supports. A rich network of Einstein's solutions arises, naturally connected with three-dimensional Bianchi spaces. We use Fefferman--Graham expansion to handle holographic data from the bulk and discuss the alternative for reversing the process and reconstruct the exact bulk geometries.
Cosmic-Lab: Optical companions to binary Millisecond Pulsars

Millisecond Pulsars (MSPs) are fast rotating, highly magnetized neutron stars. According to the"canonical recycling scenario", MSPs form in binary systems containing a neutron star which is spun up through mass accretion from the evolving companion. Therefore, the final stage consists of a binary made of a MSP and the core of the deeply peeled companion. In the last years, however an increasing number of systems deviating from these expectations has been discovered, thus strongly indicating that our understanding of MSPs is far to be complete. The identification of the optical companions to binary MSPs is crucial to constrain the formation and evolution of these objects. In dense environments such as Globular Clusters (GCs), it also allows us to get insights on the cluster internal dynamics. By using deep photometric data, acquired both from space and ground-based telescopes, we identified 5 new companions to MSPs. Three of them being located in GCs and two in the Galactic Field. The three new identifications in GCs increased by 50% the number of such objects known before this Thesis. They all are non-degenerate stars, at odds with the expectations of the"canonical recycling scenario". These results therefore suggest either that transitory phases should also be taken into account, or that dynamical processes, as exchange interactions, play a crucial role in the evolution of MSPs. We also performed a spectroscopic follow-up of the companion to PSR J1740-5340A in the GC NGC 6397, confirming that it is a deeply peeled star descending from a ~0.8$M_{\odot}$ progenitor. This nicely confirms the theoretical expectations about the formation and evolution of MSPs.
Geology and vegetation control landsliding on forest-managed slopes in scarplands

Abstract. Landslides are important agents of sediment transport, cause hazards and are key agents for the evolution of scarplands. Scarplands are characterized by high-strength layers overlying low-inclined landslide-susceptible layers that precondition and prepare landsliding on geological timescales. These landslides can be reactivated, and their role in past hillslope evolution affected geomorphometry and material properties that set the framework for present-day shallow landslide activity. To manage present-day landslide hazards in scarplands, a combined assessment of deep-seated and shallow landsliding is required to quantify the interaction between geological conditions and vegetation that controls landslide activity. For this purpose, we investigated three hillslopes affected by landsliding in the Franconian scarplands. We used geomorphic mapping to identify landforms indicating landslide activity, electrical resistivity to identify shear plane location and a mechanical stability model to assess the stability of deep-seated landslides. Furthermore, we mapped tree distribution and quantified root area ratio and root tensile strength to assess the influence of vegetation on shallow landsliding. Our results show that deep-seated landslides incorporate rotational and translational movement and suggest that sliding occurs along a geologic boundary between permeable Rhätolias sandstone and impermeable Feuerletten clays. Despite low hillslope angles, landslides could be reactivated when high pore pressures develop along low-permeability layers. In contrast, shallow landsliding is controlled by vegetation. Our results show that rooted area is more important than species-dependent root tensile strength and basal root cohesion is limited to the upper 0.5 m of the surface due to geologically controlled unfavourable soil conditions. Due to low slope inclination, root cohesion can stabilize landslide toes or slopes undercut by forest roads, independent of potential soil cohesion, when tree density is sufficient dense to provide lateral root cohesion. In summary, geology preconditions and prepares deep-seated landslides in scarplands, which sets the framework of vegetation-controlled shallow landslide activity.
protec-Excretion pathways and ruminal disappearance of glyphosate and its degradation product aminomethylphosphonic

From 6 balance experiments with total collection of feces and urine, samples were obtained to investigate the excretion pathways of glyphosate (GLY) in lactating dairy cows. Each experiment lasted for 26 d. The first 21 d served for adaptation to the diet, and during the remaining 5 d collection of total feces and urine was conducted. Dry matter intake and milk yield were recorded daily and milk and feed samples were taken during the sampling periods. In 2 of the 6 experiments, at the sampling period for feces and urine, duodenal contents were collected for 5 d. Cows were equipped with cannulas at the dorsal sac of the rumen and the proximal duodenum. Duodenal contents were collected every 2 h over 5 consecutive days. The daily duodenal dry matter flow was measured by using chromium oxide as a volume marker. All samples (feed, feces, urine, milk and duodenal contents were analyzed for GLY and aminomethylphosphonic acid (AMPA). Overall, across the 6 experiments (n = 32) the range of GLY intake was 0.08 to 6.67 mg/d. The main proportion (61 ± 11%; ±SD) of consumed GLY was excreted with feces; whereas excretion by urine was 8 ± 3% of GLY intake. Elimination via milk was negligible. The GLY concentrations above the limit of quantification were not detected in any of the milk samples. A potential ruminal degradation of GLY to AMPA was derived from daily duodenal GLY flow. The apparent ruminal disappearance of GLY intake was 36 and 6%. In conclusion, the results of the present study indicate that the gastrointestinal absorption of GLY is of minor importance and fecal excretion represents the major excretion pathway. account.
N-Band Imaging of Seyfert Nuclei and the Mid-Infrared-X-Ray Correlation

We present new mid-infrared (N-band) images of a sample of eight nearby Seyfert galaxies. In all of our targets, we detect a central unresolved source, which in some cases has been identified for the first time. In particular, we have detected the mid-infrared emission from the active nucleus of NGC 4945, which previously remained undetected at any wavelength but hard X-rays. We also detect circumnuclear extended emission in the Circinus galaxy along its major axis and find marginal evidence for extended circumnuclear emission in NGC 3281. The high spatial resolution (1.″7) of our data allows us to separate the flux of the nuclear point sources from the extended circumnuclear starburst (if present). We complement our sample with literature data for a number of nonactive starburst galaxies and relate the nuclear N-band flux to published hard (2-10 keV) X-ray fluxes. We find tight and well-separated correlations between the nuclear N-band flux and X-ray flux for both Seyfert and starburst nuclei that span over 3 orders of magnitude in luminosity. We demonstrate that these correlations can be used as a powerful classification tool for galactic nuclei. For example, we find strong evidence against NGC 1808 currently harboring an active Seyfert nucleus based on its position in the mid-infrared-X-ray diagram. On the other hand, we confirm that NGC 4945 is in fact a Seyfert 2 galaxy.
K − / K + ratios in relativistic heavy-ion collisions

We study K{sup {minus}}/K{sup +} ratios as a function of centrality (participant nucleon number), transverse mass (m{sub t}), and rapidity, in heavy-ion collisions at beam energies between 1 and 2 AthinspGeV. We use the relativistic transport model that includes explicitly the strangeness degrees of freedom and consider two scenarios for kaon properties in dense matter, one with and one without medium modifications of their properties. In both scenarios, the K{sup {minus}}/K{sup +} ratio does not change very much with the centrality, while the K/{pi} and {bar K}/{pi} ratios increase with increasing centrality. Significant differences are predicted, both in magnitudes and shapes, for the m{sub t} spectra and rapidity distributions of K{sup {minus}}/K{sup +} ratio. Experimental measurement of these ratios, currently under investigation by the FOPI, KaoS, E866, and E895 Collaborations, will be useful in revealing the kaon in-medium properties. {copyright} {ital 1998} {ital The American Physical Society}