Slight Upturn Research Articles

Thermodynamic and magnetotransport properties of EuAg2Ge2 single crystals

Here, we report the crystallographic, thermodynamic, and magnetotransport properties of flux grown EuAg2Ge2 single crystals using X-ray diffraction, anisotropic magnetic susceptibility, and magnetization, heat capacity, electrical resistivity, and magnetoresistance measurements. The room temperature powder X-ray diffraction pattern confirms that EuAg2Ge2 crystallizes in a body-centered tetragonal ThCr2Si2–type structure (space group I4/mmm) with lattice parameters, a = 4.401 Å and c = 10.845 Å. The magnetic susceptibility data reveal two subsequent antiferromagnetic transitions at TN1 ∼ 8.3 K, and TN2 ∼ 6.2 K. For H‖c at T = 5 K, the magnetization data show the spin-flop like metamagnetic transition around the critical field of 1.4 T. The existence of antiferromagnetic transitions is further confirmed by the heat capacity measurements, which display two anomalies around TN1 = 8.3 K and TN2 = 6.1 K. The electrical resistivity data show the metallic behavior of the compound, which is best described by the Bloch-Grüneisen model above 30 K. At low temperatures, the antiferromagnetic transition manifests through a slight upturn around 8 K, followed by a sharp drop in the resistivity data. The transverse magnetoresistance (MR) measured for H‖c below TN first increases, showing a broad maximum at critical field strength that shifts towards lower fields with increasing temperature. With further increasing fields beyond the maximum, MR decreases, and changes its value from positive to negative. The evolution of MR from positive to negative could be associated with the metamagnetic transition in EuAg2Ge2. In the paramagnetic region, MR remains negative across the entire field range.

Spectroscopic Determination of C, N, and O Abundances of Solar-analog Stars Based on the Lines of Hydride Molecules

Photospheric C, N, and O abundances of 118 solar-analog stars were determined by applying the synthetic-fitting analysis to their spectra in the blue or near-UV region comprising lines of CH, NH, and OH molecules, with an aim of clarifying the behaviors of these abundances in comparison with [Fe/H]. It turned out that, in the range of −0.6 ≲ [Fe/H] ≲ +0.3, [C/Fe] shows a marginally increasing tendency with decreasing [Fe/H] with a slight upturn around [Fe/H] ∼ 0, [N/Fe] tends to somewhat decrease toward lower [Fe/H], and [O/Fe] systematically increases (and thus [C/O] decreases) with a decrease in [Fe/H]. While these results are qualitatively consistent with previous determinations mostly based on atomic lines, the distribution centers of these [C/Fe], [N/Fe], and [O/Fe] at the near-solar metallicity are slightly negative by several hundredths of dex, which is interpreted as due to unusual solar abundances possibly related to the planetary formation of our solar system. However, clear anomalies are not observed in the [C, N, O/Fe] ratios of planet-host stars. Three out of four very Be-deficient stars were found to show anomalous [C/Fe] or [N/Fe] which may be due to mass transfer from the evolved companion, though its relation to the Be depletion mechanism is still unclear.

Transport properties around the metal-insulator transition for SrVO3 ultrathin films fabricated by electrochemical etching

By using electrochemical etching, we fabricated conductive ultrathin ${\mathrm{SrVO}}_{3}$ (SVO) films that exhibited metallic behavior down to 3 monolayers (ML). From an observed systematic change in transport properties with decreasing film thickness, it was found that the disorder in the films remained nearly unchanged during etching, and only the thickness was reduced. This is in contrast to the insulating behavior found for as-deposited SVO ultrathin films. For the etched films, the electron mobility at 200 K decreased with decreasing film thickness below 10 ML, originating from an increased scattering rate and electron effective mass near the metal-insulator transition. A slight upturn in the resistivity and a positive magnetoresistance at low temperatures were typically observed for the etched films down to 3 ML, which was explained by weak antilocalization of electrons in a weakly disordered metal.

Vortex-lattice melting and paramagnetic depairing in the nematic superconductor FeSe

The full H-T phase diagram in the nematic superconductor FeSe is mapped out using specific-heat and thermal-expansion measurements down to 0.7 K and up to 30 T for both field directions. A clear thermodynamic signal of an underlying vortex-melting transition is found in both datasets and could be followed down to low temperatures. The existence of significant Gaussian thermal superconducting fluctuations is demonstrated by a scaling analysis, which also yields the mean-field upper critical field Hc2(T). For both field orientations, Hc2(T) shows Pauli-limiting behavior. Whereas the temperature dependence of the vortex-melting line is well described by the model of Houghton et al., Phys. Rev. B 40, 6763 (1989) down to the lowest temperatures for H $\perp$ FeSe layers, the vortex-melting line exhibits an unusual behavior for fields parallel to the planes, where the Pauli limitation is much stronger. Here, the vortex-melting anomaly is only observed down to T*= 2-3 K, and then merges with the Hc2(T) line as predicted by Adachi and Ikeda, Phys. Rev. B 68 184510 (2003). Below T*, Hc2(T) also exhibits a slight upturn possibly related to the occurence of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state.

Synthesis, structure, and physical properties of bilayer molybdate Sr3Mo2O7 with flat-band

ABSTRACT Bilayer molybdate SrMoO has been successfully synthesized by a modified solid-state reaction method. Magnetization measurements show that the compound is a paramagnetic material with a weak spin-glass state below about 4.5 K. Fitting to the magnetic susceptibility under a high magnetic field based on the Currie–Weiss law yields a magnetic moment of about 1.61 per Mo atom. The temperature dependence of resistivity exhibits a metallic behaviour in wide temperature region from 20 K to 300 K, but a slight upturn of resistivity with the behaviour of is observed at temperatures below about 20 K. Negative magneto-resistance behaviour has also been observed in the temperature region with resistivity upturning. Both effects indicate that a Kondo-like scattering occurs in the material. Resistivity measurements under high pressures up to 33.7 GPa are carried out, no superconductivity above 2 K has been observed, which is in contradiction to the theoretical prediction. We argue that the absence of superconductivity maybe because the flat-band is still too far away from the Fermi energy.

Violence in Colombia and Mexico: trend and impact on life expectancy of homicide mortality between 1998 and 2015.

Colombia is considered one of the most violent countries in the world even though homicide mortality has decreased since 2002. Mexico's homicide rate has tripled since 2008, after a period of decreasing mortality; this fact has been compared with Colombia in the 1990s and defined as a 'Colombianization' of violence in Mexico. We analyzed and compared the trend and impact of homicide mortality in Colombia and Mexico between 1998 and 2015. Cross-sectional descriptive study. We calculated the standardized mortality rates and the years of life lost using data from the National Institute of Statistics and Geography in Mexico and the National Management Department of Statistics in Colombia. We used the joinpoint regression analysis to identify significant changes in the mortality trend. During the 1990s, Colombia reached the highest homicide mortality rates in the world, but these rates have since decreased significantly. In Mexico, homicide mortality had a decreasing trend from 1998 to 2007; however, since 2008, the rate grew significantly, and although mortality tended to decrease after reaching its peak in 2011, a slight upturn was observed in 2015. We found that the trend in mortality in both countries has had certain similarities, such as the increase in mortality after the implementation of antidrug policies and the subsequent decrease; however, the political processes, the level of mortality reached, its impact on life expectancy, and its distribution by gender are dissimilar. We consider speaking of a 'Colombianization' of violence in Mexico to be inaccurate.

Electrical Conductivity of a Single Electro-deposited CoZn Nanowire**Supported by the National Natural Science Foundation of China under Grant No 51571152, and the Key Research Project of Shaanxi University of Science and Technology under Grant Nos 2016GBJ-12 and 2016BJ-59.

CoZn nanowires are fabricated by the electrodeposition method at constant voltage mode with porous anodic aluminum oxide as templates. Scanning electron microscope and transmission electron microscope images show that the CoZn nanowires have a rather smooth surface. The nanowires have an average diameter of 50 nm, which coincides with the diameter of the used templates. The x-ray diffraction pattern reveals the polycrystalline structure of the CoZn nanowires. The electrical conductivity of a single CoZn nanowire is studied. The metallic behavior is observed at temperatures from 230 K to 30 K. Moreover, an abnormal behavior appears around 30 K. The resistance shows the slight upturn phenomenon below 30 K down to 2 K, which is due to the major conduction role of the oxidation layer on the surface of the CoZn nanowire.

Chinese agricultural cooperation in sub-Saharan Africa. Challenging preconceptions

Chinese agricultural cooperation in sub-Saharan Africa is surrounded by preconceptions: high amounts of aid, massive land grabs to feed China, an inert cooperation model, and centralised orchestration by the government. These ideas mean that certain long-standing operators in the field of cooperation with Africa mistrust or even disregard this key player. This mistrust must be overcome in the current context. Since the mid-1980s, funding for Africa's agricultural development has been steadily declining, despite a slight upturn since the 2008 food crisis. Moreover, the cooperation models of traditional donors are being reformed, and agriculture is becoming an international priority once more. Although information is still lacking or opaque, it is important to clarify the rationale and the instruments of Chinese cooperation, and to compare viewpoints.

Vortioxetine efficiency in controlling obsessive symptoms in patients with depression. A case report

IntroductionObsessive symptomatology can sometimes be worsened when a patient with this personality trait suffers through a period of increased stress.AimTo review articles in PubMed related to how vorticoxetine affects obsessive symptoms in patients with depression.MethodsWe review the case of a 45-year-old male with obsessive personality traits diagnosed of recurrent depression. He was going through a period of stress at work that had worsened his obsessive symptoms (primarily obsessive thoughts). In a previous depressive episode, he was treated with an antidepressant that triggered sexual dysfunction as a side effect. Trying to prevent another antidepressant-induce sexual dysfunction, we decided to use voricoxetine because of its low tendency to interact with the sexual function.ResultsWe started treatment with vorticoxetine reaching a dose of 10 mg/day. Three weeks later the patient reported a decrease in his levels of anxiety, a slight upturn of his mood and a relieve of his obsessive symptoms.ConclusionsVorticoxetine can be considered a good therapeutic option in the treatment of obsessive symptoms in a depressive episode with patients with a history of antidepressant-induce sexual dysfunction.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Investment in general practice rises slightly after years of cuts.

The amount of money invested into general practice in the United Kingdom has fallen by around 2% over the past decade but has slightly improved in the past few years, new figures have shown. A report published on 21 September by NHS Digital showed a slight upturn after years of falling investment.1 The government allocated £11.03bn (€12.84bn; $14.32) to general practice in the UK in 2015-16, which represented a 4.36% increase on the previous year (£10.57bn). Excluding drugs reimbursement, UK funding rose by 4.67% (£10.31bn in 2015-16 compared with £9.85bn in 2014-15). However, the BMA has called on …

Comparison of the spatiotemporal variability of rainfall from four different interpolation methods and impact on the result of GR2M hydrological modeling—case of Bani River in Mali, West Africa

The climatic evolution of the Bani river watershed, the main tributary to the upper Niger River, is approached through the spatiotemporal variability of rainfall grids over the 1950–2006 period. The analyses are conducted, and their results compared, using four different methods of spatial interpolation of rainfall fields: the spline, kriging, weighted inverse distance, and nearest neighbor methods. The largest changes are observed for all of these grids, but differences—and in some cases divergent results—appear in the details. The analysis shows a substantial decline in rainfall, particularly marked in the center of the basin, during the 1970–2000 period with respect to the 1950–1969 period, and a slight upturn in the northern part, mainly since the beginning of the 1990s. The rainfall deficit can be attributed to a combination of factors: an earlier and drier end of the rainy season, less precipitation in the middle of the rainy season, more dry days and lower amounts of precipitation on rainy days. Two drought indices—the Effective Drought Index and Standardized Precipitation Index—revealed that the maximum duration of drought events increased most in the central part of the basin. Lastly, to supplement this comparison of methods of spatial interpolation of rainfall fields, the sensitivity of a hydrological model (GR2M) to rainfall data was tested. Given the distribution and density of rain gauge stations available in the Bani watershed, the kriging method is found to yield the best hydrological modeling performance.

Zinc enhances bone metabolism in ovariectomized rats and exerts anabolic osteoblastic/adipocytic marrow effects ex vivo.

Investigations of bone mass and marrow adiposity are critical for defining the role of zinc (Zn) in bone metabolism. Rats used for study were grouped as follows: control (sham), ovariectomy (OVX), ovariectomy + estradiol (OVX-E), ovariectomy + Zn treatment (OVX-Zn). Bone mineral density (BMD) was quantified (microCT); serum osteocalcin, adiponectin, RANKL, and TRAP levels were assayed (ELISA); and biochemical determinations of serum alkaline phosphatase (ALP), calcium (Ca), and phosphorus (P) were done. Cells derived from bone mesenchymal stem cell (BMSC) isolates of respective test groups were compared, identifying primary osteoblasts by MTT assay and adipocytes by Oil Red O stain. Osteocalcin and adiponectin levels in culture supernatants were determined by ELISA. Zn supplementation resulted in a modest increase in BMD, but serum osteocalcin and ALP activity increased significantly (P < 0.01, both). Serum levels of RANKL and TRAP were lower in OVX-Zn (vs OVX) rats (P < 0.01), whereas serum concentrations of adiponectin, Ca, and P did not differ by group. Osteocalcin level was significantly upregulated ex vivo (P < 0.01) in the supernatant of cultured OVX-Zn (vs OVX) cells, accompanied by a slight upturn in osteoblastic differentiation. However, Oil Red O uptake and adiponectin level in supernatant were sharply diminished in cultured OVX-Zn (vs OVX) cells (P < 0.01). Overall, we concluded that Zn contributes to bone mass by marginally stimulating differentiation and proliferation of osteoblasts and by effectively inhibiting osteoclastic and adipocytic differentiation of BMSCs.

Role of Intrachain Rigidity in the Plasticization of Intrinsically Microporous Triptycene-Based Polyimide Membranes in Mixed-Gas CO2/CH4 Separations

Based on high-pressure pure- and mixed-gas (50:50) CO2/CH4 separation properties of two intrinsically microporous triptycene-based polyimides (TPDA–TMPD and TPDA–6FpDA), the intrachain rigidity central to “conventional PIM” design principles is not a singular solution to intrinsic plasticization resistance. Despite the significant intrachain rigidity in TPDA–TMPD, a 300% increase in PMIX(CH4), 50% decrease in α(CO2/CH4) from 24 to 12, and continuous increase in PMIX(CO2) occurred from 4 to 30 bar. On the other hand, the more flexible and densely packed TPDA–6FpDA exhibited a slight upturn in PMIX(CO2) at 20 bar similar to a dense cellulose acetate (CA) film, also reported here, despite a 4-fold higher CO2 sorption capacity. Microstructural investigations suggest that the interconnected O2- and H2-sieving ultramicroporosity of TPDA–TMPD is more sensitive to slight CO2-induced dilations and is the physical basis for a more extensive and accelerated plasticization. Interchain rigidity, potentially by interchain interactions, is emphasized and may be facilitated by intrachain mobility.

Synthesis of SnTe nanoplates with {100} and {111} surfaces.

SnTe is a topological crystalline insulator that possesses spin-polarized, Dirac-dispersive surface states protected by crystal symmetry. Multiple surface states exist on the {100}, {110}, and {111} surfaces of SnTe, with the band structure of surface states depending on the mirror symmetry of a particular surface. Thus, to access surface states selectively, it is critical to control the morphology of SnTe such that only desired crystallographic surfaces are present. Here, we grow SnTe nanostructures using vapor-liquid-solid and vapor-solid growth mechanisms. Previously, SnTe nanowires and nanocrystals have been grown [Saghir et al. Cryst. Growth Des. 2014, 14, 2009-2013; Safdar et al. Cryst. Growth Des. 2014, 14, 2502-2509; Safdar et al. Nano Lett. 2013, 13, 5344-5349; Li et al. Nano Lett. 2013, 13, 5443-5448]. In this report, we demonstrate the synthesis of SnTe nanoplates with lateral dimensions spanning tens of micrometers and thicknesses of a few hundred nanometers. The top and bottom surfaces are either (100) or (111), maximizing topological surface states on these surfaces. Magnetotransport on these SnTe nanoplates shows a high bulk carrier density, consistent with bulk SnTe crystals arising due to defects such as Sn vacancies. In addition, we observe a structural phase transition in these nanoplates from the high-temperature rock salt to a low-temperature rhombohedral structure. For nanoplates with a very high carrier density, we observe a slight upturn in resistance at low temperatures, indicating electron-electron interactions.

Perceived Intelligence Is Associated with Measured Intelligence in Men but Not Women

BackgroundThe ability to accurately assess the intelligence of other persons finds its place in everyday social interaction and should have important evolutionary consequences.Methodology/Principal FindingsWe used static facial photographs of 40 men and 40 women to test the relationship between measured IQ, perceived intelligence, and facial shape. Both men and women were able to accurately evaluate the intelligence of men by viewing facial photographs. In addition to general intelligence, figural and fluid intelligence showed a significant relationship with perceived intelligence, but again, only in men. No relationship between perceived intelligence and IQ was found for women. We used geometric morphometrics to determine which facial traits are associated with the perception of intelligence, as well as with intelligence as measured by IQ testing. Faces that are perceived as highly intelligent are rather prolonged with a broader distance between the eyes, a larger nose, a slight upturn to the corners of the mouth, and a sharper, pointing, less rounded chin. By contrast, the perception of lower intelligence is associated with broader, more rounded faces with eyes closer to each other, a shorter nose, declining corners of the mouth, and a rounded and massive chin. By contrast, we found no correlation between morphological traits and real intelligence measured with IQ test, either in men or women.ConclusionsThese results suggest that a perceiver can accurately gauge the real intelligence of men, but not women, by viewing their faces in photographs; however, this estimation is possibly not based on facial shape. Our study revealed no relation between intelligence and either attractiveness or face shape.

Chinese agricultural cooperation in sub-Saharan Africa. Challenging preconceptions

Chinese agricultural cooperation in sub-Saharan Africa is surrounded by preconceptions: high amounts of aid, massive land grabs to feed China, an inert cooperation model, and centralised orchestration by the government. These ideas mean that certain long-standing operators in the field of cooperation with Africa mistrust or even disregard this key player. This mistrust must be overcome in the current context. Since the mid-1980s, funding for Africa's agricultural development has been steadily declining, despite a slight upturn since the 2008 food crisis. Moreover, the cooperation models of traditional donors are being reformed, and agriculture is becoming an international priority once more. Although information is still lacking or opaque, it is important to clarify the rationale and the instruments of Chinese cooperation, and to compare viewpoints.

2012 Top Financial Performers in the Club Industry

This study uses survey research to examine the financial performance of the U.S. club industry for 2012. One hundred and ten clubs submitted financial data to this study. 24 financial ratios, together with median key financial data from the balance sheet and the statement of activities were calculated for the sample. Results provide a better understanding of the key financial characteristics of top- and low-performing clubs in 2012. Results further show that regardless of the slight upturn in the U.S. economy in 2012, the financial results for the club industry in 2012 were mixed.

Obesity Paradox in Amputation Risk Among Nonelderly Diabetic Men

The association between BMI and amputation risk is not currently well known. We used data for a cohort of diabetic patients treated in the US Department of Veterans Affairs Healthcare System in 2003. Men aged <65 years at the end of follow-up were examined for their amputation risk and amputation-free survival during the next 5 years (2004-2008). Compared to overweight individuals (BMI 25-29.9 kg/m(2)), the risks of amputation and treatment failure (amputation or death) were higher for patients with BMI <25 kg/m(2) and were lower for those with BMI ≥30 kg/m(2). Individuals with BMI ≥40 kg/m(2) were only half as likely to experience any (hazard ratios (HR) = 0.49; 95% confidence interval (CI), 0.30-0.80) and major amputations (HR = 0.53; 95% CI, 0.39-0.73) during follow-up as overweight individuals. While the amputation risk continued to decrease for higher BMI, amputation-free survival showed a slight upturn at BMI >40 kg/m(2). The association between obesity and amputation risk in our data shows a pattern consistent with "obesity paradox" observed in many health conditions. More research is needed to better understand pathophysiological mechanisms that may explain the paradoxical association between obesity and lower-extremity amputation (LEA) risk.

Synthesis and Electrical Characterization of Magnetic Bilayer Graphene Intercalate

We report synthesis and transport properties of the minimal graphite intercalation compound, a ferric chloride (FeCl(3))(n) island monolayer inside bilayer graphene. Chemical doping by the intercalant is simultaneously probed by micro-Raman spectroscopy and Hall measurements. Quantum oscillations of conductivity originate from microscopic domains of intercalated and unintercalated regions. A slight upturn in resistance related to magnetic transition is observed. Two-dimensional intercalation in bilayer graphene opens new possibilities to engineer two-dimensional properties of intercalates.

Nd-induced Mn spin-reorientation transition in NdMnAsO

A combination of synchrotron X-ray, neutron powder diffraction, magnetization, heat capacity and electrical resistivity measurements reveals that NdMnAsO is an antiferromagnetic semiconductor with large Neel temperature (TN = 359(2) K). At room temperature the magnetic propagation vector k = 0 and the Mn moments are directed along the crystallographic c-axis (mMn = 2.41(6) BM). Upon cooling a spin reorientation (SR) transition of the Mn moments into the ab-plane occurs (TSR = 23 K). This coincides with the long range ordering of the Nd moments, which are restricted to the basal plane. The magnetic propagation vector remains k = 0. At base temperature (1.6 K) the fitted moments are mab,Mn = 3.72(1) BM and mab,Nd = 1.94(1) BM. The electrical resistivity is characterized by a broad maximum at 250 K, below which it has a metallic temperature dependence but semiconducting magnitude (rho250K = 50 Ohm cm, residual resistivity ratio = 2), and a slight upturn at the SR transition.