Inhibitory effects of some invasive alien species leaf extracts against tomato (Lycopersicon esculentum Mill.) bacterial wilt (Ralstonia solanacearum)

The inhibitory activity of selected invasive alien species leaf extracts against tomato bacterial wilt was studied in vitro and greenhouse. In vitro inhibitory activity was undertaken in a disc diffusion sensitivity test. Furthermore, aqueous extracts of Eichhorina crassipes, Mimosa diplotricha and Lantana camara and methanolic extract of Prosopis juliflora which showed better inhibitory effect in vitro were evaluated against R. solanacearum in greenhouse on tomato. The plant extracts were applied and evaluated at three different times of application (at the time of inoculation; two days before pathogen inoculation; and two days after pathogen inoculation). The result showed that most of the treatment combinations significantly reduce disease incidence and area under disease progress curve and increase biomass of tomato plants, but the effectiveness of tested plant species depends on the type of plant species and application time. The application of plant extracts at the time of pathogen inoculation resulted in highest reduction of disease development on tomato plants. Aqueous extract of E. crassipes was found to be the most effective plant extract in disease suppression and increase above-ground biomass compared to inoculated control. The study revealed that the tested plant species have a potential of inhibiting the development of bacterial wilt on tomato.     

Concurrent Visualization of Acoustic Radiation Force Displacement and Shear Wave Propagation with 7T MRI

Manual palpation is a common and very informative diagnostic tool based on estimation of changes in the stiffness of tissues that result from pathology. In the case of a small lesion or a lesion that is located deep within the body, it is difficult for changes in mechanical properties of tissue to be detected or evaluated via palpation. Furthermore, palpation is non-quantitative and cannot be used to localize the lesion. Magnetic Resonance-guided Focused Ultrasound (MRgFUS) can also be used to evaluate the properties of biological tissues non-invasively. In this study, an MRgFUS system combines high field (7T) MR and 3 MHz focused ultrasound to provide high resolution MR imaging and a small ultrasonic interrogation region (~0.5 x 0.5 x 2 mm), as compared with current clinical systems. MR-Acoustic Radiation Force Imaging (MR-ARFI) provides a reliable and efficient method for beam localization by detecting micron-scale displacements induced by ultrasound mechanical forces. The first aim of this study is to develop a sequence that can concurrently quantify acoustic radiation force displacements and image the resulting transient shear wave. Our motivation in combining these two measurements is to develop a technique that can rapidly provide both ARFI and shear wave velocity estimation data, making it suitable for use in interventional radiology. Secondly, we validate this sequence in vivo by estimating the displacement before and after high intensity focused ultrasound (HIFU) ablation, and we validate the shear wave velocity in vitro using tissue-mimicking gelatin and tofu phantoms. Such rapid acquisitions are especially useful in interventional radiology applications where minimizing scan time is highly desirable.     

Transcriptome analysis of hen preadipocytes treated with an adipogenic cocktail (DMIOA) with or without 20(S)-hydroxylcholesterol

Background

20(S)-hydroxycholesterol (20(S)) potentially reduces adipogenesis in mammalian cells. The role of this oxysterol and molecular mechanisms underlying the adipogenesis of preadipocytes from laying hens have not been investigated. This study was conducted to 1. Analyze genes differentially expressed between preadipocytes treated with an adipogenic cocktail (DMIOA) containing 500 nM dexamethasone, 0.5 mM 3-isobutyl-1-methylxanthine, 20 μg/mL insulin and 300 μM oleic acid (OA) and control cells and 2. Analyze genes differentially expressed between preadipocytes treated with DMIOA and those treated with DMIOA + 20(S) using Affymetrix GeneChip® Chicken Genome Arrays.

Results

In experiment one, where we compared the gene expression profile of non-treated (control) cells with those treated with DMIOA, out of 1,221 differentially expressed genes, 755 were over-expressed in control cells, and 466 were over-expressed in cells treated with DMIOA. In experiment two, where we compared the gene expression profile of DMIOA treated cells with those treated with DMIOA+20(S), out of 212 differentially expressed genes, 90 were over-expressed in cells treated with DMIOA, and 122 were over-expressed in those treated with DMIOA+20(S).Genes over-expressed in control cells compared to those treated with DMIOA include those involved in cell-to-cell signaling and interaction (IL6, CNN2, ITGB3), cellular assembly and organization (BMP6, IGF1, ACTB), and cell cycle (CD4, 9, 38). Genes over-expressed in DMIOA compared to control cells include those involved in cellular development (ADAM22, ADAMTS9, FIGF), lipid metabolism (FABP3, 4 and 5), and molecular transport (MAP3K8, PDK4, AGTR1). Genes over-expressed in cells treated with DMIOA compared with those treated with DMIOA+20(S) include those involved in lipid metabolism (ENPP2, DHCR7, DHCR24), molecular transport (FADS2, SLC6A2, CD36), and vitamin and mineral metabolism (BCMO1, AACS, AR). Genes over-expressed in cells treated with DMIOA+20(S) compared with those treated with DMIOA include those involved in cellular growth and proliferation (CD44, CDK6, IL1B), cellular development (ADORA2B, ATP6VOD2, TNFAIP3), and cell-to-cell signaling and interaction (VCAM1, SPON2, VLDLR).

Conclusion

We identified important adipogenic regulators and key pathways that would help to understand the molecular mechanism of the in vitro adipogenesis in laying hens and demonstrated that 20(S) is capable of suppressing DMIOA-induced adipogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1231-z) contains supplementary material, which is available to authorized users.     

Mass Coral Bleaching in 2010 in the Southern Caribbean

Ocean temperatures are increasing globally and the Caribbean is no exception. An extreme ocean warming event in 2010 placed Tobago''s coral reefs under severe stress resulting in widespread coral bleaching and threatening the livelihoods that rely on them. The bleaching response of four reef building taxa was monitored over a six month period across three major reefs systems in Tobago. By identifying taxa resilient to bleaching we propose to assist local coral reef managers in the decision making process to cope with mass bleaching events. The bleaching signal (length of exposure to high ocean temperatures) varied widely between the Atlantic and Caribbean reefs, but regardless of this variation most taxa bleached. Colpophyllia natans, Montastraea faveolata and Siderastrea siderea were considered the most bleaching vulnerable taxa. Interestingly, reefs with the highest coral cover showed the greatest decline reef building taxa, and conversely, reefs with the lowest coral cover showed the most bleaching but lowest change in coral cover with little algal overgrowth post-bleaching.     

Men Traveling Away from Home Are More Likely to Bring Malaria into High Altitude Villages,Northwest Ethiopia

Background

Information about malaria risk factors at high altitudes is scanty. Understanding the risk factors that determine the risk of malaria transmission at high altitude villages is important to facilitate implementing sustainable malaria control and prevention programs.

Methods

An unmatched case control study was conducted among patients seeking treatment at health centers in high altitude areas. Either microscopy or rapid diagnostic tests were used to confirm the presence of plasmodium species. A generalized linear model was used to identify the predictors of malaria transmission in high altitude villages.

Results

Males (AOR = 3.11, 95%CI: 2.28, 4.23), and those who traveled away from the home in the previous month (AOR = 2.01, 95% CI: 1.56, 2.58) were strongly associated with presence of malaria in high altitude villages. Other significant factors, including agriculture in occupation (AOR = 1.41, 95% CI: 1.05, 1.93), plants used for fencing (AOR = 1.70, 95% CI: 1.18, 2.52) and forests near the house (AOR = 1.60, 95% CI: 1.15, 2.47), were found predictors for malaria in high altitude villages.

Conclusion

Travel outside of their home was an important risk of malaria infections acquisition. Targeting males who frequently travel to malarious areas can reduce malaria transmission risks in high altitude areas.     

Burden of podoconiosis in poor rural communities in Gulliso woreda, West Ethiopia

Background

Podoconiosis is an environmental lymphoedema affecting people living and working barefoot on irritant red clay soil. Podoconiosis is relatively well described in southern Ethiopia, but remains neglected in other parts of the Ethiopian highlands. This study aimed to assess the burden of podoconiosis in rural communities in western Ethiopia.

Methodology/Principal Findings

A cross-sectional study was conducted in Gulliso woreda (district), west Ethiopia. A household survey in the 26 rural kebeles (villages) of this district was conducted to identify podoconiosis patients and to measure disease prevalence. A more detailed study was done in six randomly selected kebeles to describe clinical features of the disease, patients'' experiences of foot hygiene, and shoe wearing practice. 1,935 cases of podoconiosis were registered, giving a prevalence of 2.8%. The prevalence was higher in those aged 15–64 years (5.2%) and in females than males (prevalence ratio 2.6∶1). 90.3% of patients were in the 15–64 year age group. In the detailed study, 335 cases were interviewed and their feet assessed. The majority of patients were farmers, uneducated, and poor. Two-third of patients developed the disease before the age of thirty. Almost all patients (97.0%) had experienced adenolymphangitis (ALA - red, hot legs, swollen and painful groin) at least once during the previous year. Patients experienced an average of 5.5 ALA episodes annually, each of average 4.4 days, thus 24 working days were lost annually. The incidence of ALA in podoconiosis patients was higher than that reported for filariasis in other countries. Shoe wearing was limited mainly due to financial problems.

Conclusions

We have documented high podoconiosis prevalence, frequent adenolymphangitis and high disease-related morbidity in west Ethiopia. Interventions must be developed to prevent, treat and control podoconiosis, one of the core neglected tropical diseases in Ethiopia.     

Direct Interaction between a Precursor Mature Domain and Transport Component Tha4 during Twin Arginine Transport of Chloroplasts

Proteins destined for the thylakoid lumen of chloroplasts must cross three membranes en route. The chloroplast twin arginine translocation (cpTat) system facilitates the transport of about one-half of all proteins that cross the thylakoid membrane in chloroplasts. Known mechanistic features of the cpTat system are drastically different from other known translocation systems, notably in its formation of a transient complex to transport fully folded proteins utilizing only the protonmotive force generated during photosynthesis for energy. However, key details, such as the structure and composition of the translocation pore, are still unknown. One of the three transmembrane cpTat components, Tha4, is thought to function as the pore by forming an oligomer. Yet, little is known about the topology of Tha4 in thylakoid, and little work has been done to detect precursor-Tha4 interactions, which are expected if Tha4 is the pore. Here, we present evidence of the interaction of the precursor with Tha4 under conditions leading to transport, using cysteine substitutions on the precursor and Tha4 and disulfide bond formation in pea (Pisum sativum). The mature domain of a transport-competent precursor interacts with the amphipathic helix and amino terminus of functional Tha4 under conditions leading to transport. Detergent solubilization of thylakoids post cross linking and blue-native polyacrylamide gel electrophoresis analysis shows that Tha4 is found in a complex containing precursor and Hcf106 (i.e. the cpTat translocase). Affinity precipitation of the cross-linked complex via Tha4 clearly demonstrates that the interaction is with full-length precursor. How these data suggest a role for Tha4 in cpTat transport is discussed.The thylakoid membrane of plant chloroplasts possesses two systems working in parallel for the transport of soluble proteins across the bilayer and into the lumen, namely the chloroplast secretory system and the chloroplast twin arginine translocation (cpTat) system (Müller and Klösgen, 2005; Cline and Theg, 2007; Cline and Dabney-Smith, 2008; Albiniak et al., 2012). For both systems, proteins destined for the thylakoid lumen are encoded by nuclear genes, cytoplasmically translated as higher molecular mass precursor proteins containing targeting sequences, and imported into the chloroplast. However, lumen-targeting sequences on precursors directed to the cpTat system contain obligate twin Arg residues on the amino-proximal side of the hydrophobic core, and the precursors are transported in folded conformations. Both systems require energy to drive the translocation process, but the cpTat system relies solely on the transmembrane potential generated by the protonmotive force (PMF) of photosynthesis, whereas the secretory system also relies on ATP hydrolysis (Cline and Theg, 2007). It is estimated that roughly one-half of the lumen proteins contain twin-Arg signal peptides (Peltier et al., 2004; Sun et al., 2004), several of which are involved in photosynthetic processes, such as the 23-kD subunit of the oxygen evolving complex of PSII (OE23; Ifuku et al., 2011), OE17 (Yi et al., 2006), and subunit T of PSII (Kapazoglou et al., 1995) and subunit N of PSI (Haldrup et al., 1999), making the cpTat system a vital pathway for higher plants.Twin arginine translocation (Tat) systems are also found in bacterial plasma membrane, and both thylakoid and bacteria serve as model systems for studies on the Tat pathway mechanism, each providing insight into different aspects of the mechanism and demonstrating important differences between the two. The cpTat machinery contains three membrane-bound components, Tha4, Hcf106, and cpTatC, with homologous proteins TatA, TatB, and TatC in bacteria, respectively. Tha4 and Hcf106 share sequence and structural homology. They both contain an N-terminal single-transmembrane region followed by a hinge region that connects to an amphipathic α-helix and a divergent C-terminal tail. However, they have distinct functions in the cpTat pathway (Sargent et al., 1999; Dabney-Smith et al., 2003). Hcf106 is largely found in complex with cpTatC, together composing the Tat receptor complex in the thylakoid that migrates as an approximately 700-kD complex by blue native (BN)-PAGE, whereas Tha4 is found as a separate homooligomeric complex of approximately 400 kD or less by BN-PAGE. cpTatC contains six transmembrane regions with the N and C termini on the stromal face of the membrane and serves as the initial receptor of the signal peptide in the receptor complex.Translocation occurs in a cyclical fashion. Precursor binds to the cpTatC-Hcf106 receptor complex in an energy-independent manner. Then, in the presence of the PMF, which mainly consists of ∆pH in isolated thylakoids, Tha4 assembles with the precursor-bound receptor complex to form the active translocase. At this point, transport occurs. After transport, Tha4 dissociates from the receptor complex, thus resetting the system for subsequent rounds of translocation (Mori et al., 1999; Cline and Mori, 2001; Mori and Cline, 2002). This regulated assembly of Tha4 and its tight correlation to transport of the precursor suggests that Tha4 has a critical role in the translocation step.Several models of the Tat translocase propose that Tha4 (TatA) serves as the protein-conducting channel. Several characteristics support this hypothesis, including a regulated assembly mechanism, the requirement for Tha4 only at the translocation step (Cline and Mori, 2001), the molar excess of Tha4 over cpTatC and Hcf106 (Mori et al., 2001; Celedon and Cline, 2012), oligomerization of Tha4 at the translocase (Dabney-Smith and Cline, 2009), and observations of channel-like structures of the Escherichia coli TatA in detergent extracts or even in vivo in E. coli cells (Gohlke et al., 2005; Sargent et al., 2006; Berthelmann et al., 2008). However, none of these studies demonstrate a direct interaction between precursor and Tha4 (TatA).Studies on the E. coli Tat system demonstrate weak cross links between TatA and precursor but did not follow the interaction during active transport, as the UV-inducible cross linking occurred after transport (Maurer et al., 2010). The question still remains how Tha4 (TatA) is directly involved in the translocation event itself. If Tha4 serves the role of protein-conducting channel, one would expect that as the precursor passes through the channel it would interact with Tha4. To test this hypothesis, we have employed an alternative cross-linking strategy involving disulfide exchange cross linking by generating Cys-containing variants of both precursor and Tha4 in pea (Pisum sativum). This method allows probing of the interactions between precursor and Tha4 in the steps immediately prior to and during the transport of precursor, unlike other cross-linking methods employed previously. Through one-to-one disulfide bond formation between single Cys residues placed throughout the mature domain of pOE17 and Tha4, we determined that Tha4 is in direct contact with full-length precursor after its binding the receptor and immediately prior to or during transport across the membrane. BN-PAGE demonstrated that Cys-substituted Tha4 was able to relocate into the approximately 700-kD complex in the presence of Cys-substituted precursor, demonstrating that direct interaction between the two occurs as part of the active translocase. Moreover, site-specific Cys mutations allow us to determine, to our knowledge for the first time, the region of Tha4 in contact with precursor during transport. How these data affect current models for protein transport by the cpTat pathway are discussed.     

Use of 'sense of coherence (SOC)' scale to measure resilience in Eritrea: interrogating both the data and the scale

An adapted 'sense of coherence' scale short form (SOC-13) was administered in nine languages of Eritrea with a total of 265 participants (162 women and 103 men) in order to assess 'resilience' in quantitative terms. Statistical analysis yielded significant differences in SOC scores between the displaced and non-displaced: mean=54.84 (SD=6.48) in internally displaced person (IDP) camps, compared with mean=48.94 (SD=11.99) in urban and rural settlements (t=3.831, p<0.001). Post-hoc tests revealed that the main difference is between IDP camp dwellers and urban (non-displaced) residents. Those in rural but traditionally mobile (pastoralist or transhumant) communities scored more or less the same as the urban non-displaced - i.e. significantly higher than those in IDP camps (p<0.05). Analysis of variance showed that displacement has a significantly negative effect on women compared with men (RR=0.262, p<0.001). Repeating the analysis for the three groups confirmed that urban and pastoralist/transhumant groups are similar, while women in IDP camps are lower scoring (RR=0.268, p<0.001), Hamboka women being worst affected due to their experience of serial displacement. These findings are interpreted and discussed in the light of qualitative information gleaned from the study participants' interrogation of the content of the SOC scale; and in the wider context of historical, socio-political and cultural characteristics of Eritrea. The study's implications for humanitarian and public health policy are considered.     

Demographic review of a captive colony of callitrichids (Callithrix kuhlii)

Although reports on colony demographics for a variety of callitrichid species are available in the literature, to date there has not been a detailed examination of Wied's black tufted-ear marmoset (Callithrix kuhlii). The purpose of this study is to present colony demographics for C. kuhlii from the University of Nebraska at Omaha's Callitrichid Research Center from 1991 to 2002. C. kuhlii are currently held in a number of zoological parks in the United States and abroad; however, the University of Nebraska at Omaha held the only breeding colony in North America. Here we report data on lifespan, sex ratio, litter size, and interbirth interval (IBI) for that captive breeding colony.     

Indirect genetic effects contribute substantially to heritable variation in aggression-related traits in group-housed mink (Neovison vison)

Background

Since the recommendations on group housing of mink (Neovison vison) were adopted by the Council of Europe in 1999, it has become common in mink production in Europe. Group housing is advantageous from a production perspective, but can lead to aggression between animals and thus raises a welfare issue. Bite marks on the animals are an indicator of this aggressive behaviour and thus selection against frequency of bite marks should reduce aggression and improve animal welfare. Bite marks on one individual reflect the aggression of its group members, which means that the number of bite marks carried by one individual depends on the behaviour of other individuals and that it may have a genetic basis. Thus, for a successful breeding strategy it could be crucial to consider both direct (DGE) and indirect (IGE) genetic effects on this trait. However, to date no study has investigated the genetic basis of bite marks in mink.

Result and discussion

A model that included DGE and IGE fitted the data significantly better than a model with DGE only, and IGE contributed a substantial proportion of the heritable variation available for response to selection. In the model with IGE, the total heritable variation expressed as the proportion of phenotypic variance (T²) was six times greater than classical heritability (h²). For instance, for total bite marks, T² was equal to 0.61, while h² was equal to 0.10. The genetic correlation between direct and indirect effects ranged from 0.55 for neck bite marks to 0.99 for tail bite marks. This positive correlation suggests that mink have a tendency to fight in a reciprocal way (giving and receiving bites) and thus, a genotype that confers a tendency to bite other individuals can also cause its bearer to receive more bites.

Conclusion

Both direct and indirect genetic effects contribute to variation in number of bite marks in group-housed mink. Thus, a genetic selection design that includes both direct genetic and indirect genetic effects could reduce the frequency of bite marks and probably aggression behaviour in group-housed mink.