Instantonic approach to triple well potential

By using a usual instanton method we obtain the energy splitting due to quantum tunneling through the triple well barrier. It is shown that the term related to the midpoint of the energy splitting in propagator is quite different from that of double well case, in that it is proportional to the algebraic average of the frequencies of the left and central wells.Comment: Revtex, 11 pages, Included one eps figur

Households’ aspirations for rural development through agriculture

In sub-Saharan Africa, rural households are the focus of many development efforts and the transformation of smallholder agriculture is one entry point for this process. Understanding farming households’ technology choices remains one of the most critical aspects of agricultural research in rural areas. However, many technologies that are known to be effective and potentially highly beneficial have remained widely unused. One reason is that predicting farmers’ decisions concerning agricultural technologies using conventional economic theories is flawed. In this article, we suggest that human aspirations have a much greater influence on technology choices than hitherto believed. We further argue that a better understanding of aspirations will improve the targeting of technology development by researchers. We propose distributed ethnography to empirically test the influence of human aspirations on technology choice. From such insight, we anticipate better research priority setting as well as more effective rural development strategies in general

Exclusive Measurement of the Nonmesonic Weak Decay of ^{5}_{\Lambda}He Hypernucleus

We performed a coincidence measurement of two nucleons emitted from the nonmesonic weak decay (NMWD) of ^{5}_{\Lambda}He formed via the ^{6}Li(\pi^+,K^+) reaction. The energies of two nucleons and the pair number distributions in the opening angle between them were measured. In both np and nn pairs, we observed a clean back-to-back correlation coming from the two-body decay of \Lambda p --> n p and \Lambda n --> n n, respectively. The ratio of the nucleon pair numbers was N_{nn}/N_{np}=0.45 \pm 0.11(stat)\pm 0.03(syst) in the kinematic region of cos(theta_{NN}) < -0.8. Since each decay mode was exclusively detected, the measured ratio should be close to the ratio of \Gamma(\Lambda p --> np)/\Gamma(\Lambda n --> nn). The ratio is consistent with recent theoretical calculations based on the heavy meson/direct quark exchange picture.Comment: Submitted to Phys. Rev. lett., 4 pages, 3 figure

Soil texture is a stronger driver of the maize rhizosphere microbiome and extracellular enzyme activities than soil depth or the presence of root hairs

Aims Different drivers are known to shape rhizosphere microbiome assembly. How soil texture (Texture) and presence or lack of root hairs (Root Hair) of plants affect the rhizosphere microbiome assembly and soil potential extracellular enzyme activities (EEA) at defined rooting depth (Depth) is still a knowledge gap. We investigated effects of these drivers on microbial assembly in rhizosphere and on potential EEA in root-affected soil of maize. Methods Samples were taken from three depths of root hair defective mutant rth3 and wild-type WT maize planted on loam and sand in soil columns after 22 days. Rhizosphere bacterial, archaeal, fungal and cercozoan communities were analysed by sequencing of 16S rRNA gene, ITS and 18S rRNA gene fragments. Soil potential EEA of ss-glucosidase, acid phosphatase and chitinase were estimated using fluorogenic substrates. Results The bacterial, archaeal and cercozoan alpha- and beta-diversities were significantly and strongly altered by Texture, followed by Depth and Root Hair. Texture and Depth had a small impact on fungal assembly, and only fungal beta-diversity was significantly affected. Significant impacts by Depth and Root Hair on beta-diversity and relative abundances at taxonomic levels of bacteria, archaea, fungi and cercozoa were dependent on Texture. Likewise, the patterns of potential EEA followed the trends of microbial communities, and the potential EEA correlated with the relative abundances of several taxa. Conclusions Texture was the strongest driver of rhizosphere microbiome and of soil potential EEA, followed by Depth and Root Hair, similarly to findings in maize root architecture and plant gene expression studies

Prenatal allostatic load and preterm birth: A systematic review

Objective: Allostatic load refers to cumulative neuroendocrine burden and has been postulated to mediate and moderate physiological and psychological stress-related responses. This may have important implications for the risk of preterm birth. This systematic review examines the evidence on the association between prenatal allostatic load and preterm birth. Data sources: A comprehensive search of seven electronic databases was conducted from inception to August 23, 2022 to identify all English-language observational and mixed methods studies examining allostatic load and preterm birth with no year or geographic restrictions. Study eligibility criteria: Studies were included if they measured allostatic load, evaluated as the cumulative effect of any combination of more than one allostatic load biomarker, during pregnancy. Studies must have observed preterm birth, defined as \u3c 37 weeks\u27 gestational age, as a primary or secondary outcome of interest. Study appraisal and synthesis methods: The Quality In Prognosis Studies tool was used to evaluate risk of bias within included studies. A narrative synthesis was conducted to explore potential associations between allostatic load and preterm birth, and sources of heterogeneity. Results: Three prospective cohort studies were identified and revealed mixed evidence for an association between allostatic load and preterm birth. One study reported a statistically significant association while the other two studies reported little to no evidence for an association. Heterogeneity in when and how allostatic load was measured, limitations in study design and cohort socio-demographics may have contributed to the mixed evidence. Conclusions: This review provides insight into key individual-, community-, and study-level characteristics that may influence the association between allostatic load and preterm birth. Knowledge gaps are identified as foci for future research, including heterogeneity in allostatic load biomarkers and allostatic load index algorithms as well as pregnancy-specific considerations for allostatic load measurement. Further investigation of the allostatic load framework in the context of perinatal mental health is needed to advance understandings of maternal, infant, and child health

ΛN\Lambda N correlations from the stopped K−K^- reaction on 4{}^4He

We have investigated correlations of coincident $\Lambda N$ pairs from the stopped $K^-$ reaction on ${}^4$He, and clearly observed $\Lambda p$ and $\Lambda n$ branches of the two-nucleon absorption process in the $\Lambda N$ invariant mass spectra. In addition, non-mesonic reaction channels, which indicate possible exotic signals for the formation of strange multibaryon states, have been identified.Comment: 5 pages, 3 figures, submitted to Physical Review Letter

Strain engineering and one-dimensional organization of metal-insulator domains in single-crystal VO2 beams

Spatial phase inhomogeneity at the nano- to microscale is widely observed in strongly-correlated electron materials. The underlying mechanism and possibility of artificially controlling the phase inhomogeneity are still open questions of critical importance for both the phase transition physics and device applications. Lattice strain has been shown to cause the coexistence of metallic and insulating phases in the Mott insulator VO2. By continuously tuning strain over a wide range in single-crystal VO2 micro- and nanobeams, here we demonstrate the nucleation and manipulation of one-dimensionally ordered metal-insulator domain arrays along the beams. Mott transition is achieved in these beams at room temperature by active control of strain. The ability to engineer phase inhomogeneity with strain lends insight into correlated electron materials in general, and opens opportunities for designing and controlling the phase inhomogeneity of correlated electron materials for micro- and nanoscale device applications.Comment: 14 pages, 4 figures, with supplementary informatio