2,202 research outputs found
Tracing Uganda’s global primary organic pineapple value chain
The organic sector is one of the fastest growing sectors globally. The sector provides an opportunity for developing countries to export high value products in the global market. One such opportunity for Uganda is the export of organic pineapples. The organic pineapple enterprise is relatively new, having existed for approximately 10 years. This paper traces the organic pineapple value chain, characterises and explains the functions of the actors in the chain. The study used the Global Value Chain Analysis Framework, using data obtained from 140 organic farmers, 10 exporters and 3 support institutions in Uganda. It is clear from the study that the chain is private- sector-driven, has relatively young smallholder farmers, and comprises of 10 small scale export companies. Only 45% of the organic pineapples produced by farmers reach the organic consumers. Reasons for this included limited processing capacity of exporters, competition from conventional buyers and the few local organic consumers. Other reasons were declining soil fertility, limited regulative institutional support and poor infrastructure. We recommend increased use of soil amendments, favourable legislations and investment environment, increased horizontal coordination among exporters and increasing the range of the organic export products in order to increase organic pineapple sales.Keywords: Certification, organic consumer value strea
Microbial sulfate reduction and metal attenuation in pH 4 acid mine water
Sediments recovered from the flooded mine workings of the Penn Mine, a Cu-Zn mine abandoned since the early 1960s, were cultured for anaerobic bacteria over a range of pH (4.0 to 7.5). The molecular biology of sediments and cultures was studied to determine whether sulfate-reducing bacteria (SRB) were active in moderately acidic conditions present in the underground mine workings. Here we document multiple, independent analyses and show evidence that sulfate reduction and associated metal attenuation are occurring in the pH-4 mine environment. Waterchemistry analyses of the mine water reveal: (1) preferential complexation and precipitation by H2S of Cu and Cd, relative to Zn; (2) stable isotope ratios of 34S/32S and 18O/16O in dissolved SO4 that are 2–3 ‰ heavier in the mine water, relative to those in surface waters; (3) reduction/oxidation conditions and dissolved gas concentrations consistent with conditions to support anaerobic processes such as sulfate reduction. Scanning electron microscope (SEM) analyses of sediment show 1.5-micrometer, spherical ZnS precipitates. Phospholipid fatty acid (PLFA) and denaturing gradient gel electrophoresis (DGGE) analyses of Penn Mine sediment show a high biomass level with a moderately diverse community structure composed primarily of iron- and sulfate-reducing bacteria. Cultures of sediment from the mine produced dissolved sulfide at pH values near 7 and near 4, forming precipitates of either iron sulfide or elemental sulfur. DGGE coupled with sequence and phylogenetic analysis of 16S rDNA gene segments showed populations of Desulfosporosinus and Desulfitobacterium in Penn Mine sediment and laboratory cultures
Absence of Spontaneous Magnetic Fields Due to Time-Reversal Symmetry Breaking in Bulk Superconducting UTe2
We have investigated the low-temperature local magnetic properties in the
bulk of molten salt-flux (MSF) grown single crystals of the candidate
odd-parity superconductor UTe2 by zero-field muon spin relaxation (muSR). In
contrast to previous muSR studies of UTe2 single crystals grown by a chemical
vapour transport (CVT) method, we find no evidence of magnetic clusters or
electronic moments fluctuating slow enough to cause a discernible relaxation of
the zero-field muSR asymmetry spectrum. Consequently, our measurements on
MSF-grown single crystals rule out the generation of spontaneous magnetic
fields in the bulk that would occur near impurities or lattice defects if the
superconducting state of UTe2 breaks time-reversal symmetry. This result
suggests UTe2 is characterized by a single-component superconducting order
parameter.Comment: 5 pages, 3 figure
The Impact of Acceptance and Commitment Training and Multicultural Training on the stigmatizing attitudes and professional burnout of substance abuse counselors
Empirically validated methods for reducing stigma and prejudice toward recipients of behavioral healthcare services are badly needed. In the present study, two packages presented in one day workshops were compared to a biologically oriented Educational Control condition in the alleviation of stigmatizing attitudes in drug abuse counselors. One, Acceptance and Commitment Training (ACT), utilized acceptance, defusion, mindfulness, and values methods. The other, Multicultural Training, sensitized participants to group prejudices and biases. Measures of stigma and burnout were taken pre-training, post-training, and after a three month follow-up. Results showed that Multicultural Training had an impact on stigmatizing attitudes and burnout post-intervention but not at follow-up, but showed better gains in a sense of personal accomplishment as compared to the Educational Control at follow-up. ACT had a positive impact on stigma at follow-up and on burnout at post-treatment and follow-up and follow-up gains in burnout exceeded those of Multicultural Training. ACT also significantly changed the believability of stigmatizing attitudes. This process mediated the impact of ACT but not Multicultural Training on follow-up stigma and burnout. This preliminary study opens new avenues for reducing stigma and burnout in behavioral health counselors
Structural Plasticity and Noncovalent Substrate Binding in the GroEL Apical Domain. A study using electrospray ionization mass spectrometry and fluorescence binding studies
Advances in understanding how GroEL binds to non-native proteins are reported. Conformational flexibility in the GroEL apical domain, which could account for the variety of substrates that GroEL binds, is illustrated by comparison of several independent crystallographic structures of apical domain constructs that show conformational plasticity in helices H and I. Additionally, ESI-MS indicates that apical domain constructs have co-populated conformations at neutral pH. To assess the ability of different apical domain conformers to bind co-chaperone and substrate, model peptides corresponding to the mobile loop of GroES and to helix D from rhodanese were studied. Analysis of apical domain-peptide complexes by ESI-MS indicates that only the folded or partially folded apical domain conformations form complexes that survive gas phase conditions. Fluorescence binding studies show that the apical domain can fully bind both peptides independently. No competition for binding was observed, suggesting the peptides have distinct apical domain-binding sites. Blocking the GroES-apical domain-binding site in GroEL rendered the chaperonin inactive in binding GroES and in assisting the folding of denatured rhodanese, but still capable of binding non-native proteins, supporting the conclusion that GroES and substrate proteins have, at least partially, distinct binding sites even in the intact GroEL tetradecamer
Environmental pH and a Glu364 to Gln mutation in the chlorophyll-binding CP47 protein affect redox-active TyrD and charge recombination in Photosystem II
In Photosystem II, loop E of the chlorophyll-binding CP47 protein is located near a redox-active tyrosine, Y-D, forming a symmetrical analog to loop E in CP43, which provides a ligand to the oxygen-evolving complex (OEC). A Glu364 to Gln substitution in CP47, near Y-D, does not affect growth in the cyanobacterium Synechocystis sp. PCC 6803; however, deletion of the extrinsic protein PsbV in this mutant leads to a strain displaying a pH-sensitive phenotype. Using thermoluminescence, chlorophyll fluorescence, and flash-induced oxygen evolution analyses, we demonstrate that Glu364 influences the stability of Y-D and the redox state of the OEC, and highlight the effects of external pH on photosynthetic electron transfer in intact cyanobacterial cells
Acute scrotum as a complication of Thiersch operation for rectal prolapse in a child
BACKGROUND: We report a case of acute scrotal condition that presented in a four year old male child one year after being treated for an idiopathic rectal prolapse utilizing Thiersch wire. CASE PRESENTATION: The acute scrotum had resulted from spreading perianal infection due to erosion of the circlage wire. The condition was treated with antibiotics and removal of the wire. The child made an uneventful recovery. CONCLUSION: This case highlights that patients with Thiersch wire should be followed until the wire is removed. Awareness of anal lesions as a cause of acute scrotal conditions, and history and physical examination are emphasized
Quantum transport in ultracold atoms
Ultracold atoms confined by engineered magnetic or optical potentials are
ideal systems for studying phenomena otherwise difficult to realize or probe in
the solid state because their atomic interaction strength, number of species,
density, and geometry can be independently controlled. This review focuses on
quantum transport phenomena in atomic gases that mirror and oftentimes either
better elucidate or show fundamental differences with those observed in
mesoscopic and nanoscopic systems. We discuss significant progress in
performing transport experiments in atomic gases, contrast similarities and
differences between transport in cold atoms and in condensed matter systems,
and survey inspiring theoretical predictions that are difficult to verify in
conventional setups. These results further demonstrate the versatility offered
by atomic systems in the study of nonequilibrium phenomena and their promise
for novel applications.Comment: 24 pages, 7 figures. A revie
DNA methylation changes in response to neoadjuvant chemotherapy are associated with breast cancer survival
Background: Locally advanced breast cancer is a heterogeneous disease with respect to response to neoadjuvant chemotherapy (NACT) and survival. It is currently not possible to accurately predict who will benefit from the specific types of NACT. DNA methylation is an epigenetic mechanism known to play an important role in regulating gene expression and may serve as a biomarker for treatment response and survival. We investigated the potential role of DNA methylation as a prognostic marker for long-term survival (> 5 years) after NACT in breast cancer.
Methods: DNA methylation profiles of pre-treatment (n = 55) and post-treatment (n = 75) biopsies from 83 women with locally advanced breast cancer were investigated using the Illumina HumanMethylation450 BeadChip. The patients received neoadjuvant treatment with epirubicin and/or paclitaxel. Linear mixed models were used to associate DNA methylation to treatment response and survival based on clinical response to NACT (partial response or stable disease) and 5-year survival, respectively. LASSO regression was performed to identify a risk score based on the statistically significant methylation sites and Kaplan–Meier curve analysis was used to estimate survival probabilities using ten years of survival follow-up data. The risk score developed in our discovery cohort was validated in an independent validation cohort consisting of paired pre-treatment and post-treatment biopsies from 85 women with locally advanced breast cancer. Patients included in the validation cohort were treated with either doxorubicin or 5-FU and mitomycin NACT.
Results: DNA methylation patterns changed from before to after NACT in 5-year survivors, while no significant changes were observed in non-survivors or related to treatment response. DNA methylation changes included an overall loss of methylation at CpG islands and gain of methylation in non-CpG islands, and these changes affected genes linked to transcription factor activity, cell adhesion and immune functions. A risk score was developed based on four methylation sites which successfully predicted long-term survival in our cohort (p = 0.0034) and in an independent validation cohort (p = 0.049).
Conclusion: Our results demonstrate that DNA methylation patterns in breast tumors change in response to NACT. These changes in DNA methylation show potential as prognostic biomarkers for breast cancer survival.publishedVersio
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