Seasonal physiological responses of Argania spinosa tree from Mediterranean to semi-arid climate

Argania spinosa (the argan tree) is a slow-growing tree endemic of Morocco, growing on semi-arid areas where no other tree species can live. With the aim of predicting temporal changes in A. spinosa woodlands under a probable increase in aridity, we set off to investigate these questions: how do A. spinosa physiological attributes respond to variations in climatic conditions and seasonality, and which is the set of attributes that most affects tree response to environmental conditions? In three study sites, Beni Snassen (North), High-Atlas (Mountain) and Admine Forest in Agadir (Coastal), gas exchange measurements, photochemical efficiency, leaf water potential and different leaf attributes were monitored in February, July and November of 2006. The Mountain site presents the most continental climate. Trees in this site were the most stressed in summer, having the lowest midday leaf water potential values, photochemical efficiency and assimilation rates. We found a Ψ_md threshold around -4 MPa, below which stomatal conductance responds linearly to Ψ_md. Plants from the North area never reached this threshold during the study period. Although leaf pigments presented a clear seasonal pattern, leaves from Coastal trees exhibit the highest content for each season. The three study sites were separated by two discriminate functions obtained by canonical discriminant analysis. In summer, the Mountain population is separated from the other sites mainly by assimilation rate and F_v/F_m, while in winter transpiration rates and chlorophyll content are the main discriminant variables. Our study shows that A. spinosa trees adjust their physiological status and leaf attributes to environmental conditions allowing plants to thrive under a dry climate. Under a scenario of global change, the distribution of the argan tree likely shifts to milder areas.     

Design of a Wide Ranging Highly Sensitive Pressure Sensor Based on Two-Dimensional Photonic Crystals

Plasmonics - A highly sensitive pressure sensor operating over a wide pressure range based on two-dimensional photonic crystals having a Mach-Zehnder interferometer structure has been developed....     

Polyploidy does not control all: Lineage‐specific average chromosome length constrains genome size evolution in ferns

Recent studies investigating the evolution of genome size diversity in ferns have shown that they have a distinctive genome profile compared with other land plants. Ferns are typically characterized by possessing medium‐sized genomes, although a few lineages have evolved very large genomes. Ferns are different from other vascular plant lineages as they are the only group to show evidence for a correlation between genome size and chromosome number. In this study, we aim to explore whether the evolution of fern genome sizes is not only shaped by chromosome number changes arising from polyploidy but also by constraints on the average amount of DNA per chromosome. We selected the genus Asplenium L. as a model genus to study the question because of the unique combination of a highly conserved base chromosome number and a high frequency of polyploidy. New genome size data for Asplenium taxa were combined with existing data and analyzed within a phylogenetic framework. Genome size varied substantially between diploid species, resulting in overlapping genome sizes among diploid and tetraploid spleenworts. The observed additive pattern indicates the absence of genome downsizing following polyploidy. The genome size of diploids varied non‐randomly and we found evidence for clade‐specific trends towards larger or smaller genomes. The 578‐fold range of fern genome sizes have arisen not only from repeated cycles of polyploidy but also through clade‐specific constraints governing accumulation and/or elimination of DNA.     

Unwanted Horse Population in Illinois: Perceptions of Horse Owners,Non-Horse Owners,and Equine Industry Stakeholders

This paper presents the results of an investigation to determine perceptions, awareness, and knowledge of the unwanted horse population in Illinois from the viewpoint of horse owners, non-horse owners, and equine industry stakeholders. A questionnaire included items that pertained to knowledge of current legislation, equine background, current methods of controlling the unwanted horse population, and methods that respondents believe would reduce the unwanted horse population in Illinois. Results indicated that 58% of horse owners viewed horses as companion animals. Respondents perceived financial hardship to be the major reason why horses become unwanted. Current methods of managing unwanted horse populations were found to be ineffective. Reducing the costs of euthanasia and carcass disposal, allowing processing facilities to reopen in Illinois, and increasing the availability of gelding programs emerged as the most effective ways to manage the unwanted horse population. Results of this survey may lead to greater awareness of the unwanted horse population in Illinois. Furthermore, these results may lead to discussions about future legislation in the State designed to support and manage unwanted horses.     

Implication of Nitric Oxide Under Salinity Stress: The Possible Interaction with Other Signaling Molecules

Journal of Plant Growth Regulation - It is a well-established fact that nitric oxide (NO) is a multifaceted signaling molecule, which plays diverse role in organisms. In the past two decades,...     

Supramolecular interaction of 18‐crown‐6 ether with mesalazine and spectrofluorimetric determination of mesalazine in pharmaceutical formulations

The supramolecular interaction of protonated mesalazine (MSZ) and 18‐crown‐6 ether (18C6) has been examined by Ultraviolet–visible, FT‐IR and fluorescence spectroscopy. The formation of the inclusion complex has been confirmed based on the changes of the spectral properties. The MSZ–18C6 host–guest complex formed in (1:1) stoichiometry and the inclusion constant (K = 1.411 × 10² L mol^–1) was ascertained by the typical double reciprocal plots. Furthermore, the thermodynamic parameters (ΔG°, ΔH° and ΔS°) of (MSZ‐18C6) were obtained. Based on the remarkable enhancement of the fluorescence intensity of MSZ produced through complex formation, a simple, accurate, rapid and highly sensitive spectrofluorometric method for the determination of MSZ in aqueous solution in the presence of 18C6 was developed. The measurement of relative fluorescence intensity was carried with excitation at 298 nm, emission 410 nm. All variables affecting the reactions were studied and optimized. Beer's law was obeyed in the concentration range of 0.1–0.9 µg/mL. The absorbance was found to increase linearly with increasing concentration of MSZ. The molar absorptivity, Sandell sensitivity, limit of detection (LOD) and limit of quantification (LOQ) were calculated. The validity of the described method was assessed, and the method was successfully applied to the determination of MSZ in its pharmaceutical formulation. In addition, a solid inclusion complex was synthesized by the coprecipitation method. Copyright © 2015 John Wiley & Sons, Ltd.     

Intravoxel Incoherent Motion Diffusion Weighted MR Imaging at 3.0 T: Assessment of Steatohepatitis and Fibrosis Compared with Liver Biopsy in Type 2 Diabetic Patients

ObjectiveTo evaluate the capability of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) to assess steatohepatitis and fibrosis determined by histopathology in type 2 diabetic patients.MethodsFifty-nine type 2 diabetic patients (49 women, 10 men; mean age, 54 ± 9 years) were submitted to liver biopsy for the evaluation of non-alcoholic fatty liver disease (NAFLD) and underwent DWI on a 3.0T MR system using 10 b values. Institutional approval and patient consent were obtained. Pure molecular-based (D), perfusion-related (D*), and vascular fraction (f) were calculated using a double exponential model and least squares curve fitting. D, D*, and f were compared between patients with and without steatohepatitis and between patients with and without fibrosis. The variables were compared by using the Ranksum test and Student t-test.ResultsSteatohepatitis was observed in 22 patients and fibrosis in 16 patients. A lower D median (0.70 s/mm² vs. 0.83 s/mm², p<0.05) and a lower D* median (34.39 s/mm² vs. 45.23 s/mm², p<0.05) were observed among those with steatohepatitis. A lower D median (0.70 s/mm² vs. 0.82 s/mm², p<0.05) and a lower D* median (35.01 s/mm² vs. 44.76 s/mm², p=0.05) were also observed among those with fibrosis.ConclusionIVIM-DWI has the potential to aid in the characterization of steatohepatitis and fibrosis.     

High Prevalence of Severe Food Insecurity and Malnutrition among HIV-Infected Adults in Senegal,West Africa

Background

Malnutrition and food insecurity are associated with increased mortality and poor clinical outcomes among people living with HIV/AIDS; however, the prevalence of malnutrition and food insecurity among people living with HIV/AIDS in Senegal, West Africa is unknown. The objective of this study was to determine the prevalence and severity of food insecurity and malnutrition among HIV-infected adults in Senegal, and to identify associations between food insecurity, malnutrition, and HIV outcomes.

Methods

We conducted a cross-sectional study at outpatient clinics in Dakar and Ziguinchor, Senegal. Data were collected using participant interviews, anthropometry, the Household Food Insecurity Access Scale, the Individual Dietary Diversity Scale, and chart review.

Results

One hundred and nine HIV-1 and/or HIV-2 participants were enrolled. The prevalence of food insecurity was 84.6% in Dakar and 89.5% in Ziguinchor. The prevalence of severe food insecurity was 59.6% in Dakar and 75.4% in Ziguinchor. The prevalence of malnutrition (BMI <18.5) was 19.2% in Dakar and 26.3% in Ziguinchor. Severe food insecurity was associated with missing clinic appointments (p = 0.01) and not taking antiretroviral therapy due to hunger (p = 0.02). Malnutrition was associated with lower CD4 cell counts (p = 0.01).

Conclusions

Severe food insecurity and malnutrition are highly prevalent among HIV-infected adults in both Dakar and Ziguinchor, and are associated with poor HIV outcomes. Our findings warrant further studies to determine the root causes of malnutrition and food insecurity in Senegal, and the short- and long-term impacts of malnutrition and food insecurity on HIV care. Urgent interventions are needed to address the unacceptably high rates of malnutrition and food insecurity in this population.     

Macrophage autophagy protects against liver fibrosis in mice

Autophagy is a lysosomal degradation pathway of cellular components that displays antiinflammatory properties in macrophages. Macrophages are critically involved in chronic liver injury by releasing mediators that promote hepatocyte apoptosis, contribute to inflammatory cell recruitment and activation of hepatic fibrogenic cells. Here, we investigated whether macrophage autophagy may protect against chronic liver injury. Experiments were performed in mice with mutations in the autophagy gene Atg5 in the myeloid lineage (Atg5^fl/fl LysM-Cre mice, referred to as atg5^−/−) and their wild-type (Atg5^fl/fl, referred to as WT) littermates. Liver fibrosis was induced by repeated intraperitoneal injection of carbon tetrachloride. In vitro studies were performed in cultures or co-cultures of peritoneal macrophages with hepatic myofibroblasts. As compared to WT littermates, atg5^−/− mice exposed to chronic carbon tetrachloride administration displayed higher hepatic levels of IL1A and IL1B and enhanced inflammatory cell recruitment associated with exacerbated liver injury. In addition, atg5^−/− mice were more susceptible to liver fibrosis, as shown by enhanced matrix and fibrogenic cell accumulation. Macrophages from atg5^−/− mice secreted higher levels of reactive oxygen species (ROS)-induced IL1A and IL1B. Moreover, hepatic myofibroblasts exposed to the conditioned medium of macrophages from atg5^−/− mice showed increased profibrogenic gene expression; this effect was blunted when neutralizing IL1A and IL1B in the conditioned medium of atg5^−/− macrophages. Finally, administration of recombinant IL1RN (interleukin 1 receptor antagonist) to carbon tetrachloride-exposed atg5^−/− mice blunted liver injury and fibrosis, identifying IL1A/B as central mediators in the deleterious effects of macrophage autophagy invalidation. These results uncover macrophage autophagy as a novel antiinflammatory pathway regulating liver fibrosis.