Metamorphic fluid flow around an igneous intrusion is governed by temperature, rheology, permeability and fluid pressure condition in the contact aureole. In the middle crust, where lithostatic fluid pressure and ductile deformation dominate, the impulse from incremental magma chamber growth facilitates ductile aureole compaction and induces syn-intrusive metamorphic devolatilization. However, the mechanism of metamorphic fluid expulsion from ductile contact aureole is vaguely understood. In this study, we numerically modeled the two-phase solid-fluid flow process in the ductile aureole above the growing chamber to examine the potential for fluid expulsion, the pattern of fluid flow and fluid pressure condition. The numerical model is constructed based on the geological structure of the Papoose Flat pluton in California, applying three different modes of pluton growth: continuous growth, episodic growth with an interval of 100 years and episodic growth with an interval of 1000 years. The results indicate that the metamorphic fluids propagate in the form of porosity wave in the ductile aureole with solid matrix compaction. Continuous pluton growth, with a slow pressurization of aureole, leads to a positive fluid pressure anomaly in most of the aureole, whereas the episodic growth results in a negative fluid pressure anomaly at the base and positive fluid pressure anomaly at the top of the aureole. Hydrofracturing can occur in the inner aureole, and the outer aureole may retain some fluid with low-frequency, high-flux magma injections. The solid-fluid flow models indicate that porosity wave is an important mechanism for metamorphic fluid expulsion from the pluton and wall rock system.

Aims: The incidence of cardiovascular events (CVEs) in patients with rheumatoid arthritis (RA) is higher than that in people without RA. This may be because inflammation promotes the progression of atherosclerosis. Anti-inflammatory drugs might reduce the occurrence of CVEs in patients with RA. Methotrexate (MTX) is a conventional synthetic anti-rheumatic drug that is widely used in the treatment of RA. We performed a meta-analysis to determine whether MTX can prevent CVEs in RA patients. Then, we discussed the possibility of using MTX to prevent recurred CVEs in patients with coronary heart disease (CHD). Methods: We searched PubMed, Embase, Web of Science, and the Cochrane Library using the key words "methotrexate," "cardiovascular," "acute coronary syndrome," "coronary heart disease," "myocardial infarction," "angina pectoris," and "rheumatoid arthritis." The efficacy outcome was defined as a composite of CVEs, including stable angina, acute coronary syndrome, stroke, heart failure, and cardiac death. Results: A total of 10 studies and 195,416 RA patients were included in our meta-analysis, and the effect size of relative risk (RR) was pooled using a fixed effect model. The results showed that MTX prevented CVEs in RA patients (RR: 0.798, 95% CI 0.726-0.876, P = .001, I-2 = 27. 9%). Conclusion: MTX can prevent CVEs in RA patients, but there is not sufficient evidence for using MTX to treat patients with CHD.

Abstract Aims: The incidence of cardiovascular events (CVEs) in patients with rheumatoid arthritis (RA) is higher than that in people without RA. This may be because inflammation promotes the progression of atherosclerosis. Anti-inflammatory drugs might reduce the occurrence of CVEs in patients with RA. Methotrexate (MTX) is a conventional synthetic anti-rheumatic drug that is widely used in the treatment of RA. We performed a meta-analysis to determine whether MTX can prevent CVEs in RA patients. Then, we discussed the possibility of using MTX to prevent recurred CVEs in patients with coronary heart disease (CHD). Methods: We searched PubMed, Embase, Web of Science, and the Cochrane Library using the key words “methotrexate,” “cardiovascular,” “acute coronary syndrome,” “coronary heart disease,” “myocardial infarction,” “angina pectoris,” and “rheumatoid arthritis.” The efficacy outcome was defined as a composite of CVEs, including stable angina, acute coronary syndrome, stroke, heart failure, and cardiac death. Results: A total of 10 studies and 195,416 RA patients were included in our meta-analysis, and the effect size of relative risk (RR) was pooled using a fixed effect model. The results showed that MTX prevented CVEs in RA patients (RR: 0.798, 95% CI 0.726–0.876, P = .001, I2 = 27. 9%). Conclusion: MTX can prevent CVEs in RA patients, but there is not sufficient evidence for using MTX to treat patients with CHD.

In the continental crust, the probability of dike propagation out of magma chambers is governed by thermal, rheological, and pressure conditions of magma chamber‐wall rock systems. Incremental injection of melt into an average‐size, laccolith‐shaped, midcrustal magma chamber produces a volume of mobile magma at the bottom of the chamber that has the potential to escape as dikes through the upper, immobile portion of the chamber and the roof. Here we numerically model the conditions needed for dike propagation out of a magma chamber during continuous and episodic injections of melt into the chamber. The roles of magma buoyancy and overpressure from melt injections in generating dikes are explored within 1.78 × 104 to 1.78 × 108 Pa·s range of magma viscosities (μmag), 10 to 40 GPa range of elastic moduli (E) of the immobile top portion of the magma chamber, and 10 and 20 kyr durations of chamber growth. During episodic, high‐flux melt injections (tens of km3/yr), magma overpressure can reach >100 MPa and initiate dike propagation even when μmag and E are near the high ends of the examined ranges. The probability of generating dikes diminishes when the injection flux is lower. Continuous low‐flux injections favor magma accumulation because injection overpressure never exceeds 20 MPa. During either continuous or episodic growth of magma chamber, there is never a sufficient amount of mobile magma in the chamber for dikes to be induced by magma buoyancy alone.

In a primitive relay channel, a new one-shot relaying scheme termed color-and-forward is proposed that guarantees a probability of error equal to zero. This relaying scheme constructs a relaying compression graph of relay outputs based on the joint conditional distribution of the relay and destination outputs, and forwards a minimum coloring of this graph. The $n$ -letter extension of the proposed color-and-forward scheme is shown to be optimal in the sense that it results in the smallest needed out-of-band relay to destination link rate for the overall message rate to equal the single-input multiple-output outer bound for any fixed number of channel uses. This is used to obtain an upper bound on the asymptotic minimal relay to destination link rate needed to achieve the single-input multiple-output outer bound.

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Magma is a molten rock that rises in the Earth's crust because it is hotter and less dense than the surrounding rocks. If the magma finds a way to the surface, a volcanic eruption occurs. When the magma cannot find a path upwards, it pools into a magma chamber. This process also deforms the cold country rocks (contact aureole) around it by pushing them and warming them up. Metamorphic reactions, especially fluid generation reactions, occur in the country rocks during the process. Magma chambers cool down at depth to form different types of igneous rocks (plutons), such as granite. Today, we still have many questions about what goes on during magma emplacement. For example, how do magma chambers grow? Are they emplaced effectively instantaneously by injection of large volumes of magma, or incrementally with magma injections accumulating over thousands to millions of years? Unlike studies of lava flows on the surface, we have had to rely on methods to "see" deep into the Earth. Numerical computer modeling is one of the methods. The Papoose Flat pluton in the White-Inyo Range, California, is one of the best examples of forcefully emplaced plutons within the crust, having country rocks surrounding it that deformed plastically without fracture (ductile deformation). I used the computer language Fortran to build pluton growth models and explore evolution of the pluton and its aureole. Instantaneous intrusion models and incremental intrusion models (continuous and episodic) were constructed. I explored how the frequency of magma input to the bottom of the pluton affects ductile width of the contact aureole, crystal distribution within the pluton, eruptibility of the magma chamber, and expulsion of the metamorphic fluid from the ductile aureole. The modeling results show that the ductile region above the Papoose Flat pluton is related to thermal weakening. The ductile region in the incremental emplacement models is ~110 m thick, matching the observed thickness. It is 10 times thinner than in the instantaneous growth model. The pluton remains hot and only partially crystalline at the bottom throughout incremental growth. When a pluton grows by lowfrequency but high-flux injections, the chamber overpressure can be as high as 105 MPa. Dike propagation will occur under this condition. Conversely, the growth of magma chambers is favored by high-frequency injections of small melt batches. Metamorphic fluid is likely to be expelled from ductile aureoles by waves of self-propagating, fluid-filled porosity. However, when the growth rate of a pluton is high, fluids can be squeezed out because of compaction imposed by the growing pluton from below.

We consider an L-user multiple access channel where transmitter m has access to the linear equation u m = ⊕ l=1 L f ml w l of independent messages w l ∈ F p k l with f ml ∈ F p , and the destination wishes to recover all L messages. This problem may be motivated as the last hop in a network where relay nodes employ the compute-and-forward strategy and decode linear equations of messages; we seek to do the reverse and extract messages from sums over a multiple access channel. In particular, we exploit the particular form of dependencies between the equations at the different relays to improve the reliable communication rates beyond those achievable by simply forwarding all equations to the destination independently. The presented achievable rate region for the discrete memoryless channel model is shown to be capacity for the additive white Gaussian noise channel.

Recently a new “Colour-and-Forward” relaying strategy was proposed for the zero-error primitive relay channel, a relay channel in which the relay to destination link is out of band and of fixed, error-free capacity. This “Colour-and-Forward” scheme forwards the colour (from a minimum colouring) of the node corresponding to its received signal. This colouring is of a carefully designed graph based on the joint distribution of the relay and destination outputs given the transmit signal. This scheme was used to provide a non-trivial upper bound on the minimum required conference link capacity to allow the overall network to achieve the single-input multi-output (SIMO) upper bound. In this paper, we strengthen the result and show that this upper bound is tight if one wants to achieve the SIMO bound in the overall network for any fixed number of channel uses.

Zero-error communication over a primitive relay channel is for the first time proposed and studied. This model is used to highlight how one may exploit the channel structure to design a relaying strategy that explicitly provides “what destination needs”. We propose the Colour-and-Forward relaying scheme which constructs a graph GR of relay outputs based on the joint conditional distribution of the relay and destination outputs given the channel input. The colours of this graph GR are sent over the out-of-band link in the primitive relay channel and are shown to be information lossless in the zero-error sense; they result in the same confusability graph as if the destination had the relay's received signal. This allows us to obtain an achievable zero-error communication rate for the primitive relay channel, which may be shown to be capacity for a class of channels.

We consider a three user multiple access channel where transmitter m has access to the linear equation um = Σ3l = 1 fml wl of independent messages w1 ϵ Fpk1, w2 ϵ Fpk2, w3 ϵ Fpk3 (and fml ϵ Fp), and the destination wishes to recover all three messages. This problem is motivated as the last hop in a network where relay nodes employ the Compute-and-Forward strategy and decode linear equations of messages; we seek to do the reverse and extract messages from sums over a multiple access channel. An achievable rate region for the two user problem was previously derived; here we extend and strengthen this work to show capacity for the two and three user Gaussian channel models subject to invertability conditions on the matrix of coefficients describing the given linear equations of messages. The optimal transmission scheme is not to independently send the three equations um over the MAC but rather to exploit their special correlation structure.

It is generally thought that garnet in metapelites is produced by continuous reactions involving chlorite or chloritoid. Recent publications have suggested that the equilibrium temperatures of garnet‐in reactions may be significantly overstepped in regionally metamorphosed terranes. The growth of small spessartine–almandine garnet crystals on Mn‐siderite at the garnet isograd in graphitic metapelites in the Proterozoic Black Hills orogen, South Dakota, demonstrates that Mn‐siderite was the principal reactant that produced the initial garnet in the schists. Moreover, the positions of garnet compositions in isobaric, T–(C/H) pseudosections for the schists show that the temperature of the garnet‐in reaction from Mn‐siderite was overstepped minimally at the most. In the Black Hills, garnet was initially produced during regional metamorphism beginning at c. 1755 Ma due to the collision of Wyoming and Superior cratons, and was subsequently partially or fully re‐equilibrated at more elevated temperatures and pressures during intrusion of the Harney Peak Granite (HPG) at c. 1715 Ma. Garnet occurs in graphitic schists in garnet, staurolite and sillimanite zones, the latter being a product of contact metamorphism by HPG. During metamorphism, coexisting fluid contained both CO2 and CH4. In the garnet zone, garnet crystals contain petrographically distinct cores with inclusions of quartz, graphite and other minerals. Centres of the cores have distinctly elevated Y concentrations that mark the positions of garnet nucleation. The elevated Y is thought to have come from the Mn‐siderite onto which Y was probably absorbed during precipitation in an ocean. In the upper garnet and staurolite zones, the cores were overgrown by inclusion‐poor mantles. Mantles are highly zoned and have more elevated Fe and Mg and lower Mn and Ca than cores. The growth of mantles is attributed to late‐orogenic heating by leucogranite magmas and attendant influx of H2O that caused consumption of graphite in rock matrices. A portion of the Proterozoic terrane that includes the HPG is surrounded by four large faults. In this ‘HPG block’, garnet is inclusion‐poor and its composition does not preserve its early growth history. This garnet appears to have re‐equilibrated by internal diffusion of its major components and/or recrystallization of an earlier inclusion‐rich garnet. It has equilibrated within the kyanite stability range, and together with remnant kyanite in the high‐strain aureole of the HPG, indicates that the HPG block had a ≥6 kbar history. The HPG block has undergone decompression during emplacement of the HPG. The decompression is evident in occurrences of retrograde andalusite and cordierite in the thermal aureole of the HPG. The data support a polybaric metamorphic history of the Black Hills orogen with different segments of the orogen having their own clockwise P–T–t paths.