Homogenization of carbonate-bearing microinclusions in diamond at <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> parameters of the upper mantle

The staged high-pressure annealing of natural cubic diamonds with numerous melt microinclusions from the Internatsional’naya kimberlite pipe was studied experimentally. The results mainly show that the carbonate phases, the daughter phases in partially crystallized microinclusions in diamonds, may undergo phase transformations under the mantle P–T conditions. Most likely, partial melting and further dissolution of dolomite in the carbonate–silicate melt (homogenization of inclusions) occur in inclusions. The experimental data on the staged high-pressure annealing of diamonds with melt microinclusions allow us to estimate the temperature of their homogenization as 1400–1500°C. Thus, cubic diamonds from the Internatsional’naya pipe could have been formed under quite high temperatures corresponding to the lithosphere/asthenosphere boundary. However, it should be noted that the effect of selective capture of inclusions with partial loss of volatiles in relation to the composition of the crystallization medium is not excluded during the growth. This may increase the temperature of their homogenization significantly between 1400 and 1500°C.     

Gently sloping shear zones in the Belomorian Mobile Belt: Geology,structure, and <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> parameters

The Belomorian Mobile Belt (BMB) in northern Karelia mostly consists of gently sloping shear zones, whose gneisses and migmatized amphibolites and blastomylonites are typically thinly banded, with their banding consistently dipping north- and northeastward. These gently sloping shear zones were not affected by folding after they were produced and are not cut by Paleoproterozoic metabasite dikes. Intrusive metabasites in the gently sloping shear zones make up relatively small (usually <5 m) equant or elongate bodies and occur as fragments of larger bodies. These fragments are often concentrated in stripes. Metabasites in the gently sloping shear zone are sometimes also found as lenses and tabular bodies of relatively small thickness, which are conformable with the foliation of the host rocks. The gently sloping shear zones cut across older domains of more complicated structure, which suggests that these zones are gently sloping ductile shear zones. Along these zones, the nappes were thrust south- and southwestward, and this process was the last in the origin of major structural features of BMB when the Paleoproterozoic Lapland–Kola orogen was formed. Practically identical age values were obtained for the gently sloping shear zone in the two widely separated Engonozero and Chupa segments of BMB: 1879 ± 21 Ma (⁴⁰Ar/³⁹Ar amphibole age of amphibolite whose protolith was mafic rock) and 1857 ± 13 Ma (Sm–Nd mineral isochron age of garnet amphibolites after gabbronorite). The P–T metamorphic parameters in these gently sloping shear zones are remarkably different from the metamorphic parameters outside these zones: the pressure is 3–4 kbar lower and the temperature is 60–100°C lower. Thrusting-related decompression triggered the transition from the older high-pressure episode of Paleoproterozoic metamorphism to a younger syn-thrusting higher temperature metamorphic episode. The peak metamorphic parameters corresponding to the boundary between the amphibolite and granulite facies were reached only in the central portions of the shear zones: T= 680–760°C, P = 8.0–11.9 kbar. In areas of the most intense migmatization, temperature estimates in the central portions of the shear are as high as 810–830°C. The marginal portions of the shear zones were formed at lower temperatures of 610–630°C. The temperature heterogeneous and rock heating in the gently sloping shear zones may have resulted from flows of high-temperature metamorphic fluid that were focused to the central portions of the zones.     

Analysis of MOST light curves of the active stars <Emphasis Type="Italic">ɛ</Emphasis> Eri AND <Emphasis Type="Italic">κ</Emphasis> Cet

We have analyzed light curves from the MOST satellite for the two active dwarfs ? Eri and κ Cet. Our maps of the stellar surface-temperature inhomogeneities were obtained with no a priori assumptions about the shape, configuration, and number of spots. We find variations of the surface-temperature inhomogeneities with time, also on time scales about equal to their rotation periods. We consider a model of a spotted star with two types of surface inhomogeneities—spots and related plage fields—and demonstrate that the best agreement between the theoretical and observed light curves is achieved for small ratios of the plage-field area to the area of cool spots. This conclusion indicates that long-term brightness variations of stars younger than the Sun are mainly due to variable spots on their surfaces, while the contribution from plage fields becomes more significant for older stars.     

Deciphering the geologic memory of a Permian conglomerate of the Southern Alps by pebble <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> estimates

The volcano–clastic sequence of Trompia Valley, which caps the Tre Valli Bresciane Variscan basement (TVB), comprises the Dosso dei Galli Conglomerate (DGC), the oldest deposit containing up to metre-sized metamorphic pebbles. This Lower Permian formation of the Trompia Basin was fed by the erosion products of the Variscan chain. We used microstructural and mineral chemical data on metamorphic pebbles of the DGC to infer a quantitative tectono-thermal evolution of the eroded pre-Permian basement and to compare them with those of TVB and the surrounding Southalpine basement units (tectono-metamorphic units = TMUs). Metapelitic and metaintrusive pebbles record a polyphase metamorphism with two metamorphic re-equilibrations: the first under epidote amphibolite facies (M1, ) and the second under greenschist facies (M2) conditions. Rock types and metamorphic data largely match those of TVB basement unit. The structural and metamorphic records in the pebbles are pre-Permian, and the conglomerate matrix is non-metamorphic. The DGC deposition age (283 ± 1–280.5 ± 2 Ma) constrains the minimal exhumation age of its basement source. The lack of staurolite bearing assemblages in metamorphic pebbles suggests that the DGC basement source was already exhumed to shallow structural levels (greenschist facies conditions) before the thermal equilibration consequent upon continental crust thickening induced by the Variscan collision.     

Metamorphic <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> paths of the Zanhuang amphibolites and metapelites: constraints on the tectonic evolution of the Paleoproterozoic Trans-North China Orogen

Garnet-bearing metapelites and amphibolites are exposed in the south and middle parts of the Zanhuang complex, which is located in the central segment of the nearly NS-striking Trans-North China Orogen. These rocks preserve three metamorphic mineral assemblages forming at the prograde, peak and post-peak decompression stages. The prograde metamorphic stage (M₁) is represented by mineral inclusions within garnet porphyroblasts, the peak metamorphic stage (M₂) is represented by garnet rims and matrix minerals, whereas the retrograde stage (M₃) is represented by amphibole + plagioclase symplectite rimming garnet porphyroblasts in the amphibolites and biotite + plagioclase symplectite rimming garnet porphyroblasts in the metapelites. All garnet porphyroblasts in the metapelites preserve prograde chemical zoning except for the ubiquitous, quite narrow zones from the underwent post-peak decompression. It has been determined through thermobarometric computation that the metamorphic conditions are 650–710°C at 8.2−9.2 kbar for the M₁ (inclusion) assemblages, >810°C at >12.5 kbar for the metamorphic peak M₂ (matrix) assemblages, and 660–680°C at 4.4–4.5 kbar for the retrograde M₃ (symplectite) assemblages. These rocks are thus determined to have undergone metamorphism with clockwise P–T paths involving nearly isothermal decompression (ITD) segments, which is inferred to be related to the amalgamation of the Eastern and Western Blocks to form the coherent basement of the North China Craton along the Trans-North China Orogen in the late Paleoproterozoic (1.88–1.85 Ga).     

First Data on the Age and <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> Formation Conditions of Zones of Low-Angle Dip Schistosity of the Belomorian Mobile Belt

The low-angle dip schistosity zones of the Belomorian mobile belt of northern Karelia are zones of plastic flow of thrust origin. They were formed from 1.85 to 1.90 Ga: 1879 ± 21 Ma according to ⁴⁰Ar/³⁹Ar for amphibole from amphibolites and 1857 ± 13 Ma according to the Sm–Nd isochron in amphibolites. The P–T parameters of rock metamorphism in low-angle dip schistosity zones correspond to the boundary of amphibolite and granulite facies of metamorphism: T = 640–765°C, rarely rising to 826°C; P = 8.0–11.7 kbar. The hypothesis of the two-stage Paleoproterozoic metamorphism of rocks of the Belomorian mobile belt was introduced.     

Does bicarbonate affect the nitrate utilization and photosynthesis of <Emphasis Type="Italic">Orychophragmus violaceus</Emphasis>?

The effect of bicarbonate (HCO₃^?) on the growth and development of plants varies by species. To better understand inorganic carbon and nitrogen assimilation changes of karst-adaptable plants under different HCO₃^? treatments, we conducted experiments on seedlings and in vitro plantlets of Orychophragmus violaceus (Ov). We found that the vital photosynthesis potential (as measured by net photosynthetic rate, actual photochemical efficiency of photosystem-II, photochemical quenching coefficient, and the instantaneous carbon isotope ratio of 3-phosphoglycerate) was consistent under different HCO₃^? treatments of Ov. Bicarbonate’s lack of effect on carbon assimilation of Ov may be related to carbonic anhydrase in Ov converting HCO₃^? to H₂O and CO₂. In this way, Ov could prevent HCO₃^? ion toxicity and high pH from harming its growth and development under HCO₃^? stress. This study also found that high HCO₃^? concentrations could promote nitrogen assimilation and utilization of Ov through changes in related indexes (foliar nitrogen isotope fractionation ratio, stable nitrogen isotope assimilation ratio, foliar stable nitrogen isotope fractionation, nitrate nitrogen utilization efficiency, and nitrate utilization share) under different HCO₃^? treatments. Bicarbonate has different effects on photosynthesis and on inorganic nitrogen assimilation of Ov, which may be connected to photosynthesis providing electrons for nitrate/nitrite reduction through the photosynthetic chain.     

Bearing capacity of strip footings on <Emphasis Type="Italic">c</Emphasis>–<Emphasis Type="Italic">φ</Emphasis> soils with square voids

The presence of underground voids has an adverse influence on the performance of shallow foundations. In this study, the bearing capacity and failure mechanism of footings placed on cohesive-frictional soils with voids are evaluated using discontinuity layout optimization. By introducing a reduction coefficient, a set of design charts that can be directly applied to the classical bearing capacity formulation is presented. The results indicate that the undrained bearing capacity with voids is sensitive to soil weight and cohesion, as both the bearing capacity and stability issues exist in the problem. The failure mechanism is directly related to a variety of soil properties, the locations of single voids, and the horizontal distance between two voids. The presence of voids has a more dominant effect on c–φ soils compared to that on undrained soil. An interpretation of the critical and adverse locations for single-void and dual-void cases with various soil strengths is presented.     

<Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">V</Emphasis>–<Emphasis Type="Italic">T</Emphasis> equation of state of CaAl<Subscript>4</Subscript>Si<Subscript>2</Subscript>O<Subscript>11</Subscript> CAS phase

The thermoelastic parameters of the CAS phase (CaAl₄Si₂O₁₁) were examined by in situ high-pressure (up to 23.7 GPa) and high-temperature (up to 2,100 K) synchrotron X-ray diffraction, using a Kawai-type multi-anvil press. P–V data at room temperature fitted to a third-order Birch–Murnaghan equation of state (BM EOS) yielded: V _0,300 = 324.2 ± 0.2 Å³ and K _0,300 = 164 ± 6 GPa for K′ _0,300 = 6.2 ± 0.8. With K′ _0,300 fixed to 4.0, we obtained: V _0,300 = 324.0 ± 0.1 Å³ and K _0,300 = 180 ± 1 GPa. Fitting our P–V–T data with a modified high-temperature BM EOS, we obtained: V _0,300 = 324.2 ± 0.1 Å³, K _0,300 = 171 ± 5 GPa, K′ _0,300 = 5.1 ± 0.6 (?K _0,T /?T) _P  = ?0.023 ± 0.006 GPa K^?1, and α_0,T  = 3.09 ± 0.25 × 10^?5 K^?1. Using the equation of state parameters of the CAS phase determined in the present study, we calculated a density profile of a hypothetical continental crust that would contain ~10 vol% of CaAl₄Si₂O₁₁. Because of the higher density compared with the coexisting minerals, the CAS phase is expected to be a plunging agent for continental crust subducted in the transition zone. On the other hand, because of the lower density compared with lower mantle minerals, the CAS phase is expected to remain buoyant in the lowermost part of the transition zone.     

Faunistic Substantiation of Stratigraphic Occurrence of the <Emphasis Type="Italic">Pleuromeia</Emphasis> (<Emphasis Type="Italic">Isoëtopsida</Emphasis>) Plant in the Triassic of Gorny Mangyshlak,Republic of Kazakhstan

Joint burial places of mollusks and Pleuromeia plants allow specification of a period of stratigraphic occurrence of this genus in the west of the Republic of Kazakhstan within the Gorny Mangyshlak. Two places of occurrences of pleuromeias were found in marine Triassic rocks: one in the Karadzhatyk Formation of the northern slope of the Karatauchik Range close to the Dolnapa well, where the fossils of Pleuromeia sternbergii (Münster) Corda plants are associated with ammonoid shells, and the other one in the Karaduan Formation of the southern slope of Mt. Karashek, where this plant was found along with bivalves and gastropods. The mollusk fauna from both occurrences indicates that the Mangyshlak pleuromeias occurred from the late Olenekian Substage to Anisian Stage.     

The evolving narrative of the Darfur conflict as represented in <Emphasis Type="Italic">The New York Times</Emphasis> and <Emphasis Type="Italic">The Washington Post</Emphasis>, 2003–2009

News media influence local to global interactions between people, societies, and governments by producing place images. Representations of Africa in Western news media are heavily imbued with colonialist notions of cultural geography. In particular, Western news media have represented conflicts in Africa as ‘tribal’, a trope that erases geographic and historical context, and discourages actions that could prevent or reduce violent conflict. To determine if ‘tribalism’ remains important in coverage of African conflict, we use framing analysis to evaluate news on Sudan’s Darfur region in The New York Times and The Washington Post during 2003–2009. We find that these newspapers predictably relied on stereotypes related to tribalism to simplify Darfur’s geography and make the conflict meaningful to intended readers. Tribal portrayal of African war is inherently political, and, problematically, neither newspaper recognized that their use of the tribal narrative was parallel to the views of both the Sudanese government and external observers that challenged the actions of the Sudanese government. However, we also found that stereotypical representations became less prominent over time, apparently because reporters found that the initial, simplistic framing of the conflict did not match their encounters with geographic reality. We emphasize the decline in stereotypical tropes, because this suggests behind-the-scenes negotiation about representations in these news organizations. Recognizing voices that challenge stereotypical portrayals is necessary to developing place images that are geographically more accurate.     

The transformation features of impurity defects in natural diamonds of various habits under high <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> conditions

The results of the investigations of the transformation of impurity defects in natural diamonds of various habits at the stage of high-temperature annealing at P = 6 GPa and T = 2200°C are presented. The studies conducted allowed us to ascertain that the transformations of Aand B-defects in diamonds of octahedral and cubic habits follow general regularities. This fact shows that most of the diamonds of cubic habit with low degree of aggregation of nitrogen centers were not really annealed over a long-term interval. Unlike octahedral diamonds, those of cubic habit are characterized by a pronounced increase in the peak of H-containing defects (3107 cm^–1) after annealing.     

Sapphirine-Bearing Ultrahigh-Temperature Granulites of the Anabar Shield: Chemical Composition,U–Pb Zircon Ages,and <Emphasis Type="Italic">P</Emphasis>–<Emphasis Type="Italic">T</Emphasis> Conditions of Metamorphism

The results of thermobarometry yielded the P–T parameters of formation and evolution of sapphirine- bearing granulites in the Anabar shield with peak values of UHT metamorphism in the range of T = 920–1000°C at P = 9–11 kbar. Isotope–geochronological data indicate a polymetamorphic evolution of these rocks. Detrital zircon cores in the center of crystals yielded ages of 3.36, 2.75, 2.6, and 2.5 Ga. Later, superimposed metamorphic transformations of the detrital zircon formed rims dated to 2.4, 2.3, 2.2, and 1.83 Ga. A potential provenance source of the detrital zircons could be hypersthene plagiogneisses and metabasics of the Daldyn Group with a premetamorphic age no less than 3.32 Ga and products of their metamorphism of about 2.7 Ga old.     

The effects of water stress on yield performance of drip-irrigated pepper (<Emphasis Type="Italic">Capsicum annum</Emphasis> L. cv<Emphasis Type="Italic">. Capya</Emphasis> var. <Emphasis Type="Italic">Yalova yağlık</Emphasis> 28) in the Central Anatolian region of Turkey

The aim of this study is to investigate the effects of conventional deficit irrigation strategy on yield components and water use efficiency in the red pepper. The field study was performed in Çumra, a town in the province of Konya in the years of 2012 and 2013. The irrigation treatments were applied as follows: (i) full irrigation regime (100% of water requirement for plant, I₁₀₀) and (ii) two conventional deficit irrigations regime at the rate of 80% (I₈₀) and 60% (I₆₀) of I₁₀₀ at 5-day intervals. The irrigation water was used based on soil water content measurement through the gravimetric method where evaporation was measured by a class A pan cup simultaneously. The maximum marketable yields were obtained in the treatment of I₁₀₀ with 22.0 and 24.0 t ha^?1 for the years of 2012 and 2013, respectively. The seasonal crop water requirement was calculated as 454, 591, and 726 mm for 2012 and as 498, 652, and 806 mm for 2013, respectively. The values of crop yield response factors (ky) at I₈₀ and I₆₀ were found as 1.03 and 1.37 in 2012 and 0.66 and 1.54 in 2013, respectively. The highest levels of water use efficiency (WUE) and irrigation water use efficiency (IWUE) were determined for the treatment of 20% deficit during the period of study. The complete irrigation levels (FC) were calculated through 0.87 times the pan A evaporation. The results reveal that full irrigation strategy is the best choice to obtain maximum yield or net return while 20% deficit irrigation is a viable solution for water poor environments.     

Experimental study of eclogitization and melting of basic rocks at <Emphasis Type="Italic">Р</Emphasis> = 4 GPa and <Emphasis Type="Italic">Т</Emphasis> = 1200–1400°С

Experimental study of gabbro–norite eclogitization and melting at P = 4 GPa has made it possible to reveal the effective influence of fluid and temperature on the phase relationships. The melt composition varies from andesite–dacite in “dry conditions” to phonolite and carbonate in the presence of a fluid. The Grt-containing melting curve is replaced by the Cpx-containing liquidus as the temperature changes or a fluid is added. Hence, the possible presence of “garnetitite” and “clinopyroxenite” in the upper mantle was proved experimentally. The ultimate pressure of the spinel facies at the depth of the eclogite upper mantle is controlled by the stability of Cht ≤ 4 GPa. The revealed similarity of the spectra of REE-adakite, tonalite–trondhjemite–granodiorite (TTG), and melts formed under the partial melting of eclogitized gabbro–norite does not contradict the existing ideas of the eclogite source of the TTG rocks. Wide variations in the interphase microelement distribution factors D (Grt, Cpx)/L are indicative of effective fractionation of the microelements in the course of eclogite melting and differentiation.     

Assessing the impact of EI Niño southern oscillation index and land surface temperature fluctuations on dengue fever outbreaks using ARIMAX(<Emphasis Type="Italic">p</Emphasis>)-PARX(<Emphasis Type="Italic">p</Emphasis>)-NBARX(<Emphasis Type="Italic">p</Emphasis>) models

The dengue infectious disease remnants a human health problem in tropical and subtropical countries. In an Auto Regressive model to assess the role of climatic parameter El Niño Southern Oscillation and land surface mean monthly temperture on dengue outbreaks of the Karachi region over the monthly time interval January 2001 to December 2016, subsequent to stabilization of variance, we are able to apply and predict an Auto Regressive Integrated Moving Average Exogenous-Transfer Function model by using the order selection criteria namely Final Prediction Error and Akaike’s information. The results confirmed that ARIMAX (2,1,2) has fitted model, although an Auto Regressive model predicts a smaller decline in dengue data series than the auto Poisson Regression model. Additionally, we developed an alternative model for the Poisson Autoregressive Exogenous model in order (p) and Negative Binomial Auto Regressive Exogenous model, deliver the best fit as compared to the Poisson Auto Regressive Exogenous model whereas indicated by the deviances. The Pearson test showed a strong positive association between temperature and dengue, while ENSO inverse indication. High dengue outbreaks are detected in the months of September, October, and November. This comparative study exposed a significant relationship among monthly dengue and climatic variation by Auto Regressive Integrated Moving Average Exogenous (ARIMAX), Poisson and Negative-Binomial Autoregressive Exogenous (PARX-NBARX) models, while smallest values of AIC (3.89), Negative Binomial Auto Regressive Exogenous, are preferred more accurate model for the next 12 months forecasting. This study has provided useful information for the development of dengue predictions and future warning systems.     

What Is Going on with <Emphasis Type="Italic">Perkinsus marinus</Emphasis> in the Gulf of Mexico?

The National Oceanic and Atmospheric Administration (NOAA) Status and Trends Mussel Watch Program sampled the largest oysters in nearly every major US coastal lagoon and estuary in the Gulf of Mexico once during the winter from 1986 to 2010. This contribution examines trends in the principal oyster disease in the Gulf of Mexico, Dermo, caused by Perkinsus marinus, and some related population dynamic characteristics for its host, Crassostrea virginica. During the 1986–2000 period, P. marinus prevalence and infection intensity and oyster population dynamics followed the El Niño-Southern Oscillation (ENSO) cycle, responding to variations in salinity caused by variations in rainfall and freshwater inflow. The ENSO signal in the oyster population effectively ceased circa 2002. Beginning around this time, wintertime P. marinus prevalence and weighted prevalence began a decadal decline, as did the length of the largest oysters and the fraction of these largest animals that were female. The trends in Dermo disease, oyster length, and oyster sex ratio are all consistent with the following hypothesis: increasing temperature during the 2000s resulted in an increase in P. marinus infection intensity sufficient to increase the mortality rate in late summer and fall in the larger animals. This simultaneously reduced Dermo prevalence and infection intensity in the winter at the time of sampling and also resulted in the decline in the length of the largest animals targeted by Mussel Watch. Coincident with the decline in length is the expected decline in the fraction female, such that the percent female in the largest animals dropped to ≤50 % throughout much of the Gulf of Mexico. The decline in length leading to fewer large animals reproducing and the loss of females are predicted to have reduced oyster population reproductive capacity substantially during the 2000s. The early 60 % of the Mussel Watch time series took place during a period of negative Atlantic Multidecadal Oscillation (AMO) indices. The AMO moved into positive territory circa 2000. A positive AMO index is consistent with observed warmer water temperatures, and increased water temperature is consistent with an increase in Dermo-induced mortality.     

<Emphasis Type="Italic">BVRI</Emphasis>Hα CCD photometry of the spiral galaxy NGC 3184

We have carried out BVRIHα CCD surface photometry of the spiral galaxy with active star formation NGC 3184 using the 1-m telescope of the Special Astrophysical Observatory. B and Hα data from the ING Archive (La Palma Observatory) were also used. We consider the structure and radial brightness distribution of the galaxy. Stellar populations in different regions of the galaxy are analyzed using two-color diagrams. We have identified and studied star-forming regions in NGC 3184 and estimated their ages based on evolutionary modeling.