Contract farming (CF) has long been practiced but is becoming increasingly common in both developed and developing countries with the heightened interest of consumers in food safety and quality. Under CF, farmers and buyers make advance agreements on volume, quality, time of delivery, use of inputs, and price or pricing formula. This article critically reviews the literature on CF to assess how it contributes to improving production efficiency and income of farmers in general and of small-scale farmers in particular. Although our review focuses on literature in developing countries because of its predominance, we refer to literature in developed countries (primarily the United States) to gain a deeper understanding of the impacts of CF. We find that although CF contributes to the improvement of farmers' income by introducing new crops and production methods, there is room for strengthening its effects on poverty reduction through policy.

Agricultural training is a potentially effective method to diffuse relevant new technologies to increase productivity and alleviate rural poverty in Sub-Saharan Africa (SSA). However, since it is prohibitively expensive to provide direct training to all the farmers in SSA, it is critically important to examine the extent to which technologies taught to a small number of farmers disseminate to non-trained farmers. This paper investigates the technology dissemination pathways among smallholder rice producers within a rural irrigation scheme in Tanzania. As an innovative feature, we compare the performance of three categories of farmers: key farmers, who receive intensive pre-season training at a local training center; intermediate farmers, who are trained by the key farmers; and other ordinary farmers. By collecting and analyzing a unique five-year household-level panel data set, we estimate difference-indifferences models to assess how the gap in performance evolve as the technologies spill over from the trained farmers to the ordinary farmers. To disentangle the technology spillover process, we also examine the extent to which social and geographical network with the key and intermediate farmers influences the adoption of technologies by the ordinary farmers, by incorporating social relationship variables into spatial econometric models. We found that the ordinary farmers who were a relative or residential neighbor of a key or intermediate farmer were more likely to adopt new technologies than those who were not. As a result, while the key farmers' technology adoption rates rose immediately after the training, those of the non-trained ordinary farmers caught up belatedly. As the technologies disseminated, the paddy yield of the key farmers increased from 3.1 to 5.3 tons per hectare, while the yield of the ordinary farmers increased from 2.6 to 3.7 tons per hectare. Our results suggest the effectiveness and practical potential of farmer-to-farmer extension programs for smallholders in SSA as a cost effective alternative to the conventional farmer training approach.

The formation of a sitting-atop (SAT) complex of Cu(II) ion with 5,10,15,20-tetraphenylporphyrin (H(2)tpp) in acetonitrile has been observed, and the kinetic parameters for the formation were determined as follows: k(S0) = (3.6 +/- 0.1) x 10(5) mol(-)(1) dm(3) s(-)(1) at 25.0 degrees C, DeltaH(S0)() = 56 +/- 5 kJ mol(-)(1), and DeltaS(S0)() = 46 +/- 19 J mol(-)(1) K(-)(1). The (1)H NMR spectrum of the SAT complex (Cu(H(2)tpp)(2+)) indicated that two pyrrolenine nitrogens coordinate to the Cu(II) ion and that two protons bound to the pyrrole nitrogens remain. The protons were abstracted by the addition of pyridine (py) as the Brønsted base to give the Cu(tpp) metalloporphyrin. In the presence of py, the product for the reaction of the Cu(II) ion with H(2)tpp was Cu(tpp) instead of the SAT complex. The observed conditional rates for the formation of Cu(H(2)tpp)(2+) and Cu(tpp) were interpreted by the contribution of Cu(2+), Cu(py)(2+), and Cu(py)(2)(2+) species, and the second-order rate constants of the SAT complex formation were k(S1) = (3.5 +/- 0.3) x 10(4) mol(-)(1) dm(3) s(-)(1) for Cu(py)(2+) and k(S2) = 90 +/- 2 mol(-)(1) dm(3) s(-)(1) for Cu(py)(2)(2+). Deprotonation rates were measured by following the reaction between the SAT complex and py as a function of the py concentration, and the second-order rate constant was determined to be (2.3 +/- 0.1) x 10(2) mol(-)(1) dm(3) s(-)(1). The present kinetic results have indicated that the SAT complex exists during the course of the metalation process and that the SAT complex formation is a rate-determining step.

The UV-vis absorption spectra and the formation kinetics of sitting-atop (SAT) complexes (M(H2tpp)2+) of 5,10,15,20-tetraphenylporphyrin (H2tpp) with a series of divalent metal ions (M2+ = Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) in acetonitrile have been investigated. The structural characteristics of the SAT complexes for a series of M2+ ions are discussed on the basis of the UV-vis absorption spectra. The structure parameters around Cu2+ in the Cu(II)-SAT complex were determined by a fluorescent EXAFS method: the coordination number is 6 with three kinds of Cu-N interactions having bond lengths of 2.05, 1.98, and 2.32 A for pyrrolenine nitrogens of H2tpp, acetonitrile nitrogens at equatorial sites, and acetonitrile nitrogens at axial sites, respectively. The rate constants at 25 degrees C for the formation of the SAT complex in acetonitrile are as follows: kf/mol-1 kg s-1 = 3.4 x 10(2) for Mn2+, 0.18 for Co2+, 1.6 x 10(-3) for Ni2+, and 61 for Zn2+. The finding that the variation trends in the rate constants for a series of M2+ ions for the SAT complex formation and the solvent exchange reaction in various solvents are very similar indicates that the rate-determining step for the SAT complex formation is the interchange between the coordinating nitrogen of a bound acetonitrile and the pyrrolenine nitrogen of H2tpp. The fact that the values of kf are smaller by 4-6 orders of magnitude in comparison with those of the solvent exchange suggests that there is a large energetic loss due to the fast preequilibria prior to the rate-determining step, such as deformation of a porphyrin ring and outer-sphere encounter formation due to an electrostatic interaction between M2+ and the local negative charge on the pyrrolenine nitrogens. We observed the subsequent formation of the corresponding metalloporphyrins by deprotonation of the SAT complex and oxidation of the M2+ center, of which the dynamic behavior was significantly different for the different M2+ ions.

ObjectivesSeveral instruments for evaluating patient complexity have been developed from a biopsychosocial perspective. Although relationships between the results obtained by these instruments and the length of stay in hospital have been examined, many instruments are complicated and not easy to use. The Patient Centred Assessment Method (PCAM) is a candidate for practical use. This study aimed to test the validity and reliability of the PCAM and examine the correlations between length of hospital stay and PCAM scores in a regional secondary care hospital in Japan.DesignProspective cohort study.Participants and settingTwo hundred and one patients admitted to Ouji Coop Hospital between July 2014 and September 2014.Main predictorPCAM total score in initial phase of hospital admission.Main outcomeLength of stay in hospital.ResultsAmong 201 patients (Female/Male=98/103) with mean (SD) age of 77.4±11.9 years, the mean PCAM score was 25±7.3 and mean (SD) length of stay in hospital (LOS) 34.1±40.9 days. Using exploratory factor analysis to examine construct validity, PCAM evidently has a two-factor structure, comprising medicine-oriented and patient-oriented complexity. The Spearman rank correlation coefficient for evaluating criterion-based validity between PCAM and INTERMED was 0.90. For reliability, Cronbach’s alpha was 0.85. According to negative binomial regression analyses, PCAM scores are a statistically significant predictor (p<0.001) of LOS after adjusting for age, gender, Mini Nutritional Assessment Short-Form, Charlson Comorbidity Index, serum sodium concentration, total number of medications and whether public assistance was required. In another model, each factor in PCAM was independently correlated with length of stay in hospital after adjustment (medicine-oriented complexity: p=0.001, patient-oriented complexity: p=0.014).ConclusionPCAM is a reliable and valid measurement of patient complexity and PCAM scores have a significant correlation with hospital length of stay.

Abstract-Cardiomyocyte death plays an important role in the pathogenesis of heart failure. The nuclear factor (NF)-B signaling pathway regulates cell death, however, the effect of NF-B pathway on cell death can vary in different cells or stimuli. The purpose of the present study was to clarify the in vivo role of the NF-B pathway in response to pressure overload. First, we subjected C57Bl6/J mice to pressure overload by means of transverse aortic constriction (TAC) and examined the activity of the NF-B pathway in response to pressure overload. IB kinase (IKK) and NF-B were activated after TAC. Then, we investigated the role of the activation using cardiac-specific IKK␤-deficient mice (CKO). CKO displayed normal global cardiac structure and function compared with control littermates. We subjected CKO and control mice to pressure overload. One week after TAC, CKO showed cardiac dilation, dysfunction, and lung congestion, which are characteristics of heart failure. The number of apoptotic cells in the hearts of CKO mice increased significantly after TAC. The levels of manganese superoxide dismutase mRNA and protein expression in CKO after TAC were significantly attenuated compared with control mice. The levels of oxidative stress and c-Jun N-terminal kinase (JNK) activation in CKO after TAC were significantly greater than those in control mice. Isoproterenol-induced cell death of isolated adult CKO cardiomyocytes was inhibited by treatment with either a manganese superoxide dismutase mimetic or a JNK inhibitor. Thus, the IKK␤/NF-B signaling pathway plays a protective role in cardiomyocytes because of the attenuation of oxidative stress and JNK activation in a setting of acute pressure overload. Key Words: heart failure Ⅲ apoptosis Ⅲ NF-B C ardiac remodeling is generally accepted as a determinant of the clinical course of heart failure. Cardiomyocyte apoptotic death plays an important role in the progression of cardiac remodeling. [1][2][3][4] The loss of cardiomyocytes caused by apoptosis is predicted to reduce contractility and promote slippage of muscle bundles, wall thinning, and dilatation, which are commonly observed during heart failure. Neurohumoral factors and cytokines that are induced by mechanical stress on cardiomyocytes activate various intracellular signaling pathways, which regulate apoptotic cell death.The nuclear factor (NF)-B transcription factors (p50, p52, RelA, c-Rel, and RelB) play important roles in many physiological and pathological conditions. These transcriptional factors are kept inactive in the cytoplasm by binding of inhibitory proteins, the IB (inhibitor of NF-B) family. On stimulation, IBs are phosphorylated at serine residues, leading to their ubiquitination and degradation by the 26S proteasome. The freed NF-B components dimerize and translocate to nucleus, where they bind to specific sequences in either the promoter or enhancer regions of target genes. 5 Activation process is dependent on phosphorylation of IB proteins, which is mediated by the IKK complex. The IKK complex is comp...

Here we show that laboratory of genetics and physiology 2 (LGP2) virus sensor protein regulates gene expression network of endogenous genes mediated by TAR-RNA binding protein (TRBP)-bound microRNAs (miRNAs). TRBP is an enhancer of RNA silencing, and functions to recruit precursor-miRNAs (pre-miRNAs) to Dicer that processes pre-miRNA into mature miRNA. Viral infection activates the antiviral innate immune response in mammalian cells. Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), including RIG-I, melanoma-differentiation-associated gene 5 (MDA5), and LGP2, function as cytoplasmic virus sensor proteins during viral infection. RIG-I and MDA5 can distinguish between different types of RNA viruses to produce antiviral cytokines, including type I interferon. However, the role of LGP2 is controversial. We found that LGP2 bound to the double-stranded RNA binding sites of TRBP, resulting in inhibition of pre-miRNA binding and recruitment by TRBP. Furthermore, although it is unclear whether TRBP binds to specific pre-miRNA, we found that TRBP bound to particular pre-miRNAs with common structural characteristics. Thus, LGP2 represses specific miRNA activities by interacting with TRBP, resulting in selective regulation of target genes. Our findings show that a novel function of LGP2 is to modulate RNA silencing, indicating the crosstalk between RNA silencing and RLR signaling in mammalian cells.

RNA interference (RNAi) is a powerful tool for post-transcriptional gene silencing. However, the siRNA guide strand may bind unintended off-target transcripts via partial sequence complementarity by a mechanism closely mirroring micro RNA (miRNA) silencing. To better understand these off-target effects, we investigated the correlation between sequence features within various subsections of siRNA guide strands, and its corresponding target sequences, with off-target activities. Our results confirm previous reports that strength of base-pairing in the siRNA seed region is the primary factor determining the efficiency of off-target silencing. However, the degree of downregulation of off-target transcripts with shared seed sequence is not necessarily similar, suggesting that there are additional auxiliary factors that influence the silencing potential. Here, we demonstrate that both the melting temperature (Tm) in a subsection of siRNA non-seed region, and the GC contents of its corresponding target sequences, are negatively correlated with the efficiency of off-target effect. Analysis of experimentally validated miRNA targets demonstrated a similar trend, indicating a putative conserved mechanistic feature of seed region-dependent targeting mechanism. These observations may prove useful as parameters for off-target prediction algorithms and improve siRNA ‘specificity’ design rules.