bluuebunny/crossref_metadata_2025_split huggingface dataset:
Late Quaternary ecotone change between sub‐alpine and montane forest zone on the leeward northern slope of Mt. Kilimanjaro
Authors: Montade Vincent , Schüler Lisa , Hemp Andreas , Bremond Laurent , Salamanca Duarte Angela Maria , Behling Hermann 
Published: April 2018

AbstractQuestionsHow did the montane forest of the leeward northern slopes on Mt. Kilimanjaro respond to climate fluctuation during the late Quaternary?LocationMt. Kilimanjaro, Tanzania.MethodsPollen, phytolith and macro‐charcoal analyses from a palaeosol.ResultsPalaeoecological analyses indicate that vegetation was mainly characterized by Ericaceae with Poaceae dominated by cold‐adapted C3 highland grasses during the pre‐LGM and the LGM. From the last deglaciation onwards, the previous assemblage was progressively replaced by Podocarpus forest associated with Clematis and later the expansion of ferns, then Araliaceae, Hagenia abyssinica, Ilex mitis and Olea started in the early Holocene.ConclusionVegetation dynamics reveal that open sub‐alpine vegetation associated with some components of afro‐alpine grassland was located at a lower elevation than today, related to cold and dry conditions during the Late Glacial. In contrast to Mt. Kenya, our results show an absence of C4 grass expansion on the northern slope of Mt. Kilimanjaro during the LGM. From the last deglaciation to the early Holocene, under temperature and precipitation increase, the vegetation zones moved upward, as indicated by the development of upper montane forest at the expense of the sub‐alpine vegetation. Although we confirm the altitudinal movements of vegetation zones generally observed from the Late Glacial to the Holocene in East African mountains, our results also reveal the importance of local environmental conditions in mountain vegetation response.
Light availability impacts structure and function of phototrophic stream biofilms across domains and trophic levels
Authors: Bengtsson Mia M. , Wagner Karoline , Schwab Clarissa , Urich Tim , Battin Tom J. 
Published: April 2018

AbstractPhototrophic biofilms are ubiquitous in freshwater and marine environments where they are critical for biogeochemical cycling, food webs and in industrial applications. In streams, phototrophic biofilms dominate benthic microbial life and harbour an immense prokaryotic and eukaryotic microbial biodiversity with biotic interactions across domains and trophic levels. Here, we examine how community structure and function of these biofilms respond to varying light availability, as the crucial energy source for phototrophic biofilms. Using metatranscriptomics, we found that under light limitation‐dominant phototrophs, including diatoms and cyanobacteria, displayed a remarkable plasticity in their photosynthetic machinery manifested as higher abundance of messenger RNAs (mRNAs) involved in photosynthesis and chloroplast ribosomal RNA. Under higher light availability, bacterial mRNAs involved in phosphorus metabolism, mainly from Betaproteobacteria and Cyanobacteria, increased, likely compensating for nutrient depletion in thick biofilms with high biomass. Consumers, including diverse ciliates, displayed community shifts indicating preferential grazing on algae instead of bacteria under higher light. For the first time, we show that the functional integrity of stream biofilms under variable light availability is maintained by structure–function adaptations on several trophic levels. Our findings shed new light on complex biofilms, or “microbial jungles”, where in analogy to forests, diverse and multitrophic level communities lend stability to ecosystem functioning. This multitrophic level perspective, coupling metatranscriptomics to process measurements, could advance understanding of microbial‐driven ecosystems beyond biofilms, including planktonic and soil environments.
Mitochondria and Wolbachia titers are positively correlated during maternal transmission
Authors: Henry Lucas P. , Newton Irene L. G. 
Published: April 2018

AbstractMothers provide their offspring with symbionts. Maternally transmitted, intracellular symbionts must disperse from mother to offspring with other cytoplasmic elements, like mitochondria. Here, we investigated how the intracellular symbiont Wolbachia interacts with mitochondria during maternal transmission. Mitochondria and Wolbachia may interact antagonistically and compete as each population tries to ensure its own evolutionary success. Alternatively, mitochondria and Wolbachia may cooperate as both benefit from ensuring the fitness of the mother. We characterized the relationship between mitochondria and Wolbachia titers in ovaries of Drosophila melanogaster. We found that mitochondria and Wolbachia titers are positively correlated in common laboratory genotypes of D. melanogaster. We attempted to perturb this covariation through the introduction of Wolbachia variants that colonize at different titers. We also attempted to perturb the covariation through manipulating the female reproductive tract to disrupt maternal transmission. Finally, we also attempted to disrupt the covariation by knocking down gene expression for two loci involved in mitochondrial metabolism: NADH dehydrogenase and a mitochondrial transporter. Overall, we find that mitochondria and Wolbachia titers are commonly positively correlated, but this positive covariation is disrupted at high titers of Wolbachia. Our results suggest that mitochondria and Wolbachia have likely evolved mechanisms to stably coexist, but the competitive dynamics change at high Wolbachia titers. We provide future directions to better understand how their interaction influences the maintenance of the symbiosis.
o‐Phthalate derived from plastics’ plasticizers and a bacterium's solution to its anaerobic degradation
Authors: Sawers R. G. 
Published: April 2018

SummaryPhthalic acid esters (phthalates) are anthropogenic compounds that are used as plasticizers. Unfortunately, because phthalates are non‐covalently intercalated into plastic polymers they leach into the environment, accumulating in anoxic sediments. This has negative consequences for animal and human health. Denitrifying Betaproteobacteria, such as Aromatoleum aromaticum, can use ortho‐phthalate, derived by ester hydrolysis, as a carbon and energy source. Mergelsberg et al. () deconstruct the pathway whereby ortho‐phthalic acid is converted, via the highly unstable phthaloyl‐CoA, to the central intermediate of anaerobic aromatic degradation, benzoyl‐CoA. The latter reaction is catalysed by UbiD‐like phthaloyl‐CoA decarboxylase (PCD). Succinyl‐CoA:o‐phthalate CoA‐transferase (SPT) generates phthaloyl‐CoA, which accumulates at only sub‐micromolar concentrations, while the Km of PCD for phthaloyl‐CoA is two‐orders of magnitude higher. This seemingly insurmountable kinetic barrier is overcome because A. aromatoleum massively over‐produces PCD and because the decarboxylation reaction is irreversible. These features of the pathway facilitate capture of phthaloyl‐CoA as it is released from SPT without the need for direct substrate‐channelling. The authors provide strong evidence from both in vivo and in vitro studies to support their conclusions. This work reveals how these anaerobic bacteria have rapidly evolved a stop‐gap measure to allow them to completely degrade an otherwise recalcitrant aromatic xenobiotic.
TbLpn, a key enzyme in lipid droplet formation and phospholipid metabolism, is essential for mitochondrial integrity and growth of Trypanosoma brucei
Authors: Dawoody Nejad Ladan , Serricchio Mauro , Jelk Jennifer , Hemphill Andrew , Bütikofer Peter 
Published: April 2018

SummaryMammalian phosphatidic acid phosphatases, also called lipins, show high amino acid sequence identity to Saccharomyces cerevisiae Pah1p and catalyze the dephosphorylation of phosphatidic acid (PA) to diacylglycerol. Both the substrate and product of the reaction are key precursors for the synthesis of phospholipids and triacylglycerol (TAG). We now show that expression of the Trypanosoma brucei lipin homolog TbLpn is essential for parasite survival in culture. Inducible down‐regulation of TbLpn in T. brucei procyclic forms increased cellular PA content, decreased the numbers of lipid droplets, reduced TAG steady‐state levels and inhibited in vivo [3H]TAG formation after labeling trypanosomes with [3H]glycerol. In addition, fluorescence and transmission electron microscopy revealed that depletion of TbLpn caused major alterations in mitochondrial morphology and function, i.e., the appearance of distorted mitochondrial matrix, and reduced ATP production via oxidative phosphorylation. Effects of lipin depletion on mitochondrial integrity have previously not been reported. N‐ and C‐terminally tagged forms of TbLpn were localized in the cytosol.
A nonmyeloablative chimeric mouse model accurately defines microglia and macrophage contribution in glioma
Authors: Yu K. , Youshani A. S. , Wilkinson F. L. , O'Leary C. , Cook P. , Laaniste L. , Liao A. , Mosses D. , Waugh C. , Shorrock H. , Pathmanaban O. , Macdonald A. , Kamaly‐Asl I. , Roncaroli F. , Bigger B. W. 
Published: April 2018

AimsResident and peripherally derived glioma associated microglia/macrophages (GAMM) play a key role in driving tumour progression, angiogenesis, invasion and attenuating host immune responses. Differentiating these cells’ origins is challenging and current preclinical models such as irradiation‐based adoptive transfer, parabiosis and transgenic mice have limitations. We aimed to develop a novel nonmyeloablative transplantation (NMT) mouse model that permits high levels of peripheral chimerism without blood‐brain barrier (BBB) damage or brain infiltration prior to tumour implantation.MethodsNMT dosing was determined in C57BL/6J or Pep3/CD45.1 mice conditioned with concentrations of busulfan ranging from 25 mg/kg to 125 mg/kg. Donor haematopoietic cells labelled with eGFP or CD45.2 were injected via tail vein. Donor chimerism was measured in peripheral blood, bone marrow and spleen using flow cytometry. BBB integrity was assessed with anti‐IgG and anti‐fibrinogen antibodies. Immunocompetent chimerised animals were orthotopically implanted with murine glioma GL‐261 cells. Central and peripheral cell contributions were assessed using immunohistochemistry and flow cytometry. GAMM subpopulation analysis of peripheral cells was performed using Ly6C/MHCII/MerTK/CD64.ResultsNMT achieves >80% haematopoietic chimerism by 12 weeks without BBB damage and normal life span. Bone marrow derived cells (BMDC) and peripheral macrophages accounted for approximately 45% of the GAMM population in GL‐261 implanted tumours. Existing markers such as CD45 high/low proved inaccurate to determine central and peripheral populations while Ly6C/MHCII/MerTK/CD64 reliably differentiated GAMM subpopulations in chimerised and unchimerised mice.ConclusionNMT is a powerful method for dissecting tumour microglia and macrophage subpopulations and can guide further investigation of BMDC subsets in glioma and neuro‐inflammatory diseases.
Down‐regulation of natural resistance‐associated macrophage protein‐1 (Nramp1) is associated with 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)/1‐methyl‐4‐phenylpyridinium (MPP+)‐induced α‐synuclein accumulation and neurotoxicity
Authors: Wu K.‐C. , Liou H.‐H. , Lee C.‐Y. , Lin C.‐J. 
Published: April 2018

AimsThe accumulation of α‐synuclein is a hallmark in the pathogenesis of Parkinson′s disease (PD). Natural resistance‐associated macrophage protein‐1 (Nramp1) was previously shown to contribute to the degradation of extracellular α‐synuclein in microglia under conditions of iron overload. This study was aimed at investigating the role of Nramp1 in α‐synuclein pathology in the neurone under 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)/1‐methyl‐4‐phenylpyridinium (MPP+) treatment.MethodsThe expression of Nramp1 and pathological features (including iron and α‐synuclein accumulation) were examined in the dopaminergic neurones of humans (with and without PD) and of mice [with and without receiving chronic MPTP intoxication]. The effects of Nramp1 expression on low‐dose MPP+‐induced α‐synuclein expression and neurotoxicity were determined in human dopaminergic neuroblastoma SH‐SY5Y cells.ResultsSimilar to the findings in the substantia nigra of human PD, lower expression of Nramp1 but higher levels of iron and α‐synuclein were identified in the dopaminergic neurones of mice receiving chronic MPTP intoxication, compared to controls. In parallel to the loss of dopaminergic neurones, the numbers of glial fibrillary acidic protein‐ and ionized calcium‐binding adapter molecule‐1‐positive cells were significantly increased in the substantia nigra of MPTP‐treated mice. Likewise, in human neuroblastoma SH‐SY5Y cells exposed to low‐dose MPP+, Nramp1 expression and cathepsin D activity were decreased, along with an increase in α‐synuclein protein expression and aggregation. Overexpression of functional Nramp1 restored cathepsin D activity and attenuated α‐synuclein up‐regulation and neuronal cell death caused by MPP+ treatment.ConclusionsThese data suggest that the neuronal expression of Nramp1 is important for protecting against the development of MPTP/MPP+‐induced α‐synuclein pathology and neurotoxicity.
Obesity and the food system transformation inLatin America
Authors: Popkin B. M. , Reardon T. 
Published: April 2018

SummaryThe Latin America and the Caribbean (LAC) region faces a major diet‐related health problem accompanied by enormous economic and social costs. The shifts in diet are profound: major shifts in intake of less‐healthful low‐nutrient‐density foods and sugary beverages, changes in away‐from‐home eating and snacking and rapid shifts towards very high levels of overweight and obesity among all ages along with, in some countries, high burdens of stunting. Diet changes have occurred in parallel to, and in two‐way causality with, changes in the broad food system – the set of supply chains from farms, through midstream segments of processing, wholesale and logistics, to downstream segments of retail and food service (restaurants and fast food chains). An essential contribution of this piece is to marry and integrate the nutrition transition literature with the literature on the economics of food system transformation. These two literatures and debates have been to date largely ‘two ships passing in the night’.This review documents in‐depth the recent history of rapid growth and transformation of that broad food system in LAC, with the rapid rise of supermarkets, large processors, fast food chains and food logistics firms. The transformation is the story of a ‘double‐edged sword’, showing its links to various negative diet side trends, e.g. the rise of consumption of fast food and highly processed food, as well as in parallel, to various positive trends, e.g. the reduction of the cost of food, de‐seasonalization, increase of convenience of food preparation reducing women's time associated with that and increase of availability of some nutritious foods like meat and dairy. We view the transformation of the food system, as well as certain aspects of diet change linked to long‐run changes in employment and demographics (e.g. the quest for convenience), as broad parameters that will endure for the next decades without truly major regulatory and fiscal changes.We then focus in on what are the steps that are being and can be taken to curb the negative effects on diet of these changes. We show that countries in LAC are already among the global leaders in initiating demand‐related solutions via taxation and marketing controls. But we also show that this is only a small step forward. To shift LAC's food supply towards prices that incentivize consumption of healthier diets and demand away from the less healthy component is not simple and will not happen immediately. We must be cognizant that ultimately, food industry firms must be incentivized to market the components of healthy diets. This will primarily need to be via selective taxes and subsidies, marketing controls, as well as food quality regulations, consumer education and, in the medium term, consumers' desires to combine healthier foods with their ongoing quest for convenience in the face of busy lives. In the end, the food industry in LAC will orient itself towards profitable solutions, ie those demanded by the broad mass of consumers.
Longitudinal urinary metabolomic profiling reveals metabolites for asthma development in early childhood
Authors: Chiu Chih‐Yung , Lin Gigin , Cheng Mei‐Ling , Chiang Meng‐Han , Tsai Ming‐Han , Su Kuan‐Wen , Hua Man‐Chin , Liao Sui‐Ling , Lai Shen‐Hao , Yao Tsung‐Chieh , Yeh Kuo‐Wei , Huang Jing‐Long 
Published: April 2018

AbstractBackgroundSeveral metabolites and altered metabolic pathways have been reported to be associated with asthma. However, longitudinal analysis of the dynamics of metabolites contributing to the development of asthma has not yet been fully clarified.MethodsWe sought to identify the metabolic mechanisms underlying asthma development in early childhood. Thirty children with asthma and paired healthy controls from a prospective birth cohort were enrolled. Time series analysis of urinary metabolites collected at ages 1, 2, 3, and 4 years was assessed using 1H nuclear magnetic resonance (NMR) spectroscopy coupled with partial least squares discriminant analysis (PLS‐DA). Metabolites identified were studied in relation to changes over time in a linear mixed model for repeated measures.ResultsA total of 172 urine samples collected from the enrolled children were analyzed. Urinary metabolomics identified four metabolites significantly associated with childhood asthma development, with longitudinal analysis. Among them, dimethylamine, a metabolite produced by intestinal bacteria, appeared to shift from higher to lower level during asthma development. A persistent lower level of 1‐methylnicotinamide and allantoin was found in children with asthma, with a peak difference at age 3 years (P = .032 and P = .021, respectively). Furthermore, a significant inverse correlation was found between allantoin and house dust mite sensitization (Spearman’s r = −.297 P = .035).ConclusionsLongitudinal urinary metabolomic profiling provides a link of microbe‐environment interactions in the development of childhood asthma. 1‐Methylnicotinamide and allantoin may participate in allergic reactions in response to allergen exposure, potentially serving as specific biomarkers for asthma.
Associations of ultra‐processed food and drink products with asthma and wheezing among Brazilian adolescents
Authors: Melo B. , Rezende L. , Machado P. , Gouveia N. , Levy R. 
Published: April 2018

AbstractBackgroundAlthough both consumptions of ultra‐processed products and asthma are common during adolescence, the epidemiological evidence in regarding their association is unclear. We investigated the associations of ultra‐processed products consumption with asthma and wheezing in a representative sample of Brazilian adolescents.MethodsWe used data from a representative sample of 109 104 Brazilian adolescents enrolled in the National Survey of School Health, 2012. The consumption of ultra‐processed products was based on the weekly consumption (0‐2, 3‐4, ≥5 d/wk) of sweet biscuits, salty biscuits, ultra‐processed meats, sweets/candies, soft drinks, and packaged snacks over the previous 7 days. We also calculated an ultra‐processed consumption score by adding partial scores corresponding to weekly frequency intake of each ultra‐processed product. The ultra‐processed consumption score ranged from 0 to 42, the higher score, the higher the intake of these products. The presence of wheezing in the previous 12 months and asthma at any time in the past was self‐reported.ResultsThe adjusted odds ratios of asthma comparing the extreme categories ranged from 1.08 (95% CI 1.03‐1.13) for sweets/candies to 1.30 (1.21‐1.40) for ultra‐processed meats. Similar magnitude of associations was found for wheezing outcome. The ultra‐processed consumption score was positively associated with the presence of asthma and wheezing in a dose‐response manner. The adjusted OR of asthma and wheezing comparing highest to lowest quintile of ultra‐processed consumption score was 1.27 (95% CI 1.15‐1.41) and 1.42 (1.35‐1.50), respectively.ConclusionsThe consumption of ultra‐processed products was positively associated with the presence of asthma and wheezing in adolescents.
Burst Spinal Cord Stimulation in Peripherally Injured Chronic Neuropathic Rats: A Delayed Effect
Authors: Meuwissen Koen P. V. , Gu Jianwen Wendy , Zhang Tianhe C. , Joosten Elbert A. J. 
Published: April 2018

AbstractObjectiveTwo well‐known spinal cord stimulation (SCS) paradigms, conventional (Con) and burst SCS, are hypothesized to exert their antinociceptive effects through different stimulation‐induced mechanisms. We studied the course of the behavioral antinociceptive effect during 60 minutes of SCS and 30 minutes post‐SCS in a rat model of chronic neuropathic pain.MethodsAnimals underwent a unilateral partial sciatic nerve ligation, after which quadripolar electrodes were implanted into the epidural space at vertebral level T13 (n = 43 rats). While receiving either Con SCS or biphasic burst SCS, the pain behavior of the rats was assessed by means of paw withdrawal thresholds (WTs) in response to the application of von Frey monofilaments.ResultsAfter 15 minutes of Con SCS (n = 21), WTs significantly differed from baseline (P = 0.04), whereas WTs of the burst SCS group (n = 22) did not. After 30 minutes of SCS, WTs of the Con SCS and burst SCS groups reached similar levels, both significantly different from baseline, indicating a comparable antinociceptive effect for these SCS paradigms. Yet, the WTs of the burst SCS group were still significantly increased compared with baseline at 30 minutes post‐stimulation, whereas the WTs of the Con SCS group were not.ConclusionsTo conclude, biphasic burst SCS results in a delayed antinociceptive effect after onset of the stimulation, as compared with Con SCS, in a chronic neuropathic pain model. Furthermore, biphasic burst SCS seems to exhibit a delayed wash‐out of analgesia after stimulation is turned off.
Multidimensional Patient Impression of Change Following Interdisciplinary Pain Management
Authors: Gagnon Christine M. , Scholten Paul , Atchison James 
Published: April 2018

AbstractObjectivesTo assess patient impression of change following interdisciplinary pain management utilizing a newly developed Multidimensional Patient Impression of Change (MPIC) questionnaire.MethodsA heterogeneous group of chronic pain patients (N = 601) participated in an interdisciplinary treatment program. Programs included individual and group therapies (pain psychology, physical therapy, occupational therapy, relaxation training/biofeedback, aerobic conditioning, patient education and medical management). Patients completed measures of pain, mood, coping, physical functioning and pain acceptance both prior to and at completion of their treatment programs. The newly developed MPIC is an expansion to the Patient Global Impression of Change (PGIC) including seven additional domains (Pain, Mood, Sleep, Physical Functioning, Cope with Pain, Manage Pain Flare‐ups, and Medication Effectiveness). The MPIC was administered to the patients post‐treatment.ResultsThere were statistically significant pre‐ to post‐treatment improvements found on all outcome measures. The majority of these improvements were significantly correlated with all domains of the MPIC. The original PGIC item was significantly associated with all of the new MPIC domains and the MPIC domains were significantly associated with each other; but there were variations in the distribution of responses highlighting variation of perceived improvements among the domains. The MPIC accounted for greater amounts of variance among the program outcomes than did the PGIC.ConclusionOur results support the use of the MPIC as a quick and easy post‐treatment assessment screening tool. Future research is needed to examine relevant correlates to Medication Effectiveness.