Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 247
Filtrar
1.
Proc Biol Sci ; 291(2018): 20232522, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38444337

RESUMEN

Pesticides have well-documented negative consequences to control crop pests, and natural predators are alternatives and can provide an ecosystem service as biological control agents. However, there remains considerable uncertainty regarding whether such biological control can be a widely applicable solution, especially given ongoing climatic variation and climate change. Here, we performed a meta-analysis focused on field studies with natural predators to explore broadly whether and how predators might control pests and in turn increase yield. We also contrasted across studies pest suppression by a single and multiple predators and how climate influence biological control. Predators reduced pest populations by 73% on average, and increased crop yield by 25% on average. Surprisingly, the impact of predators did not depend on whether there were many or a single predator species. Precipitation seasonality was a key climatic influence on biological control: as seasonality increased, the impact of predators on pest populations increased. Taken together, the positive contribution of predators in controlling pests and increasing yield, and the consistency of such responses in the face of precipitation variability, suggest that biocontrol has the potential to be an important part of pest management and increasing food supplies as the planet precipitation patterns become increasingly variable.


Asunto(s)
Ecosistema , Plaguicidas , Cambio Climático , Incertidumbre
2.
J Adv Nurs ; 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38752602

RESUMEN

AIMS: Research capacity strengthening (RCS) is crucial in enhancing healthcare outcomes, particularly in low- and middle-income countries (LMICs), which face challenges due to limited resources, unequal access to care and the need for evidence-based decision-making. We seek to move beyond a surface-level understanding of RCS, unearthing the core attributes, the factors that precede its implementation and the transformative outcomes it generates within the LMIC healthcare landscape. DESIGN: This study employs the Walker and Avant approach to concept analysis to comprehensively explore the dimensions and attributes of RCS as it pertains to allied and public health professionals in LMICs, propose empirical referents and suggest an operational definition. DATA SOURCES: Ovid MEDLINE, Embase, CINAHL and Cochrane CENTRAL were searched from inception to 27 July 2023, to identify studies on RCS in LMICs. The Walker and Avant approach to concept analysis was selected because it provides a framework for systematically examining and clarifying the meaning and implications of RCS. This method involves a structured process of defining RCS, identifying its attributes, antecedents, consequences and cases, and ultimately providing a clear understanding of its meaning and implications. Identifying empirical referents offers measurable indicators that researchers and policymakers can use to assess the effectiveness of RCS initiatives in LMICs. CONCLUSION: RCS for health professionals in LMICs involves a sustainable process that equips them with essential research skills, fostering the ability to conduct high-quality research and improve healthcare delivery in resource-constrained settings. IMPLICATIONS: RCS aims to empower health professionals to apply evidence-based practices, reduce disparities and enhance the well-being of populations in LMICs. IMPACT: Ultimately, a concept analysis of RCS empowers us to harness the full potential of research to enhance healthcare delivery, improve patient outcomes and advance the well-being of populations worldwide.

3.
Am J Hum Genet ; 104(2): 229-245, 2019 02 07.
Artículo en Inglés | MEDLINE | ID: mdl-30665704

RESUMEN

Primary ciliary dyskinesia (PCD) is a genetic disorder in which impaired ciliary function leads to chronic airway disease. Exome sequencing of a PCD subject identified an apparent homozygous frameshift variant, c.887_890delTAAG (p.Val296Glyfs∗13), in exon 5; this frameshift introduces a stop codon in amino acid 308 of the growth arrest-specific protein 2-like 2 (GAS2L2). Further genetic screening of unrelated PCD subjects identified a second proband with a compound heterozygous variant carrying the identical frameshift variant and a large deletion (c.867_∗343+1207del; p.?) starting in exon 5. Both individuals had clinical features of PCD but normal ciliary axoneme structure. In this research, using human nasal cells, mouse models, and X.laevis embryos, we show that GAS2L2 is abundant at the apical surface of ciliated cells, where it localizes with basal bodies, basal feet, rootlets, and actin filaments. Cultured GAS2L2-deficient nasal epithelial cells from one of the affected individuals showed defects in ciliary orientation and had an asynchronous and hyperkinetic (GAS2L2-deficient = 19.8 Hz versus control = 15.8 Hz) ciliary-beat pattern. These results were recapitulated in Gas2l2-/- mouse tracheal epithelial cell (mTEC) cultures and in X. laevis embryos treated with Gas2l2 morpholinos. In mice, the absence of Gas2l2 caused neonatal death, and the conditional deletion of Gas2l2 impaired mucociliary clearance (MCC) and led to mucus accumulation. These results show that a pathogenic variant in GAS2L2 causes a genetic defect in ciliary orientation and impairs MCC and results in PCD.


Asunto(s)
Cilios/patología , Trastornos de la Motilidad Ciliar/genética , Trastornos de la Motilidad Ciliar/fisiopatología , Proteínas de Microfilamentos/deficiencia , Proteínas Asociadas a Microtúbulos/deficiencia , Proteínas de Xenopus/deficiencia , Animales , Trastornos de la Motilidad Ciliar/patología , Modelos Animales de Enfermedad , Exones/genética , Femenino , Eliminación de Gen , Genes Letales , Humanos , Masculino , Ratones , Ratones Noqueados , Proteínas de Microfilamentos/genética , Proteínas Asociadas a Microtúbulos/genética , Fenotipo , Rotación , Xenopus/embriología , Xenopus/genética , Proteínas de Xenopus/genética
4.
Proc Biol Sci ; 289(1970): 20212487, 2022 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-35232241

RESUMEN

Predation is a fundamental ecological process that shapes communities and drives evolutionary dynamics. As the world rapidly urbanizes, it is critical to understand how human perturbations alter predation and meat consumption across taxa. We conducted a meta-analysis to quantify the effects of urban environments on three components of trophic ecology in predators: dietary species richness, dietary evenness and stable isotopic ratios (IRs) (δ13C and δ15N IR). We evaluated whether the intensity of anthropogenic pressure, using the human footprint index (HFI), explained variation in effect sizes of dietary attributes using a meta-regression. We calculated Hedges' g effect sizes from 44 studies including 11 986 samples across 40 predatory species in 39 cities globally. The direction and magnitude of effect sizes varied among predator taxa with reptilian diets exhibiting the most sensitivity to urbanization. Effect sizes revealed that predators in cities had comparable diet richness, evenness and nitrogen ratios, though carbon IRs were more enriched in cities. We found that neither the 1993 nor 2009 HFI editions explained effect size variation. Our study provides, to our knowledge, the first assessment of how urbanization has perturbed predator-prey interactions for multiple taxa at a global scale. We conclude that the functional role of predators is conserved in cities and urbanization does not inherently relax predation, despite diets broadening to include anthropogenic food sources such as sugar, wheat and corn.


Asunto(s)
Conducta Predatoria , Urbanización , Animales , Ciudades , Dieta , Cadena Alimentaria , Humanos , Vertebrados
5.
Cryobiology ; 106: 160-163, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35413361

RESUMEN

Dimethyl sulphoxide (DMSO) used in haematopoietic stem cell (HSC) cryopreservation has been linked to an increased incidence of adverse reactions following transplantation. In the interest of reducing the required DMSO concentrations, we have evaluated the use of unilamellar liposomes to internalize the non-toxic, cell-impermeable disaccharide, trehalose into HSCs and characterized the cryoprotective efficacy of this strategy. A fluorescent marker, 5(6)-carboxyfluorescein (200 µmol/L), was used for trehalose internalization following a 5 h incubation at 37 °C with liposome concentrations ranging from 0.5 mM to 4 mM. Cells were frozen (1 °C/min to -80 °C) following treatment with either 3 mM or 4 mM of liposomes (5 h, 37 °C) containing 0.2 mol/L trehalose either in the presence or absence of 0.2 mol/L extracellular trehalose. Increasing the liposome concentration from 3 mM to 4 mM corresponded to a significant (p = 0.046) increase in the mean fluorescent intensity (MFI) (3 mM 512 ± 7.07; 4 mM: 916 ± 28.3). Post-thaw membrane integrity indicated that the presence of trehalose both inside and outside when internalized using a liposome concentration of 4 mM significantly improved survival relative to the sole presence of extracellular trehalose (p = 0.02). However, viability was diminished relative to a standard DMSO control (trehalose: 32.5% ± 1.7%; DMSO: 85.0% ± 4.6%). This study confirms that the protective efficacy of trehalose is enhanced when it is present on both sides of the membrane; however, it reinforces concerns surrounding the efficiency of using liposomes as a vehicle to transfer trehalose into cells.


Asunto(s)
Células Madre Hematopoyéticas , Trehalosa , Línea Celular , Supervivencia Celular , Criopreservación/métodos , Crioprotectores/metabolismo , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Humanos , Liposomas , Trehalosa/metabolismo , Trehalosa/farmacología
6.
Br J Dermatol ; 184(6): 1023-1032, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32961599

RESUMEN

BACKGROUND: Palmoplantar pustulosis (PPP) is a chronic inflammatory disease in which sterile and relapsing pustules appear on the palms and soles. OBJECTIVES: To assess the effects of interventions for chronic PPP to induce and maintain complete remission. METHODS: We searched for randomized controlled trials (RCTs), including people with PPP or chronic palmoplantar pustular psoriasis, in the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase, LILACS and eight trials registers up to July 2020. Study selection, data extraction and risk-of-bias assessment were carried out independently by two review authors. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method. RESULTS: We included 37 RCTs (1663 participants, 76% women, mean age 50 years). Mean treatment duration was 11 weeks. Topical vitamin D derivative may be more effective than placebo in achieving clearance [risk ratio (RR) 7·83, 95% confidence interval (CI) 1·85-33·12; low-certainty evidence from two trials]. Concerning biological therapies, there was little or no difference between etanercept and placebo in achieving clearance (low-certainty evidence from one trial), ustekinumab is less effective than placebo in reducing severity (low-certainty evidence from one trial), and guselkumab (RR 2·88, 95% CI 1·24-6·69) and secukinumab (RR 1·55, 95% CI 1·02-2·35) are probably better in reducing disease severity (moderate-certainty evidence from two and one trial(s), respectively) but may cause more serious adverse events than placebo. CONCLUSIONS: Evidence is lacking for or against major chronic PPP treatments. Risk of bias and imprecision limit our confidence in the results.


Asunto(s)
Exantema , Psoriasis , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psoriasis/tratamiento farmacológico , Inducción de Remisión , Ustekinumab
8.
Nano Lett ; 16(5): 3309-13, 2016 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-27124722

RESUMEN

A novel concept of utilizing nanoporous coatings as effective nanovalves on microporous adsorbents was developed for high capacity natural gas storage at low storage pressure. The work reported here for the first time presents the concept of nanovalved adsorbents capable of sealing high pressure CH4 inside the adsorbents and storing it at low pressure. Traditional natural gas storage tanks are thick and heavy, which makes them expensive to manufacture and highly energy-consuming to carry around. Our design uses unique adsorbent pellets with nanoscale pores surrounded by a coating that functions as a valve to help manage the pressure of the gas and facilitate more efficient storage and transportation. We expect this new concept will result in a lighter, more affordable product with increased storage capacity. The nanovalved adsorbent concept demonstrated here can be potentially extended for the storage of other important gas molecules targeted for diverse relevant functional applications.

9.
Br J Dermatol ; 175(1): 172-4, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27484276

RESUMEN

Malignant melanoma is a high-risk skin cancer that, in potential transplant recipients, is considered a substantial contraindication to solid organ transplantation due to significant risk of recurrence with immunosuppression. Current guidelines stipulate waiting between 3 and 10 years after melanoma diagnosis. However, in young patients with end-stage organ failure and malignant melanoma, complex ethical and moral issues arise. Assessment of the true risk associated with transplantation in these patients is difficult due to lack of prospective data, but an autonomous patient can make a decision that clinicians may perceive to be high risk. The national and worldwide shortage of available organs also has to be incorporated into the decision to maximize the net benefit and minimize the risk of graft failure and mortality. The incidence of malignant melanoma worldwide is increasing faster than that of any other cancer and continues to pose ethically challenging decisions for transplant specialists evaluating recipients for solid organ transplantation.


Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Nefropatías Diabéticas/complicaciones , Trasplante de Riñón/ética , Melanoma/complicaciones , Trasplante de Páncreas/ética , Neoplasias Cutáneas/complicaciones , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/cirugía , Trasplante de Riñón/métodos , Masculino , Persona de Mediana Edad , Trasplante de Páncreas/métodos
11.
Am J Respir Crit Care Med ; 192(2): 182-90, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-25909230

RESUMEN

RATIONALE: Chronic bronchitis (CB) is characterized by persistent cough and sputum production. Studies were performed to test whether mucus hyperconcentration and increased partial osmotic pressure, in part caused by abnormal purine nucleotide regulation of ion transport, contribute to the pathogenesis of CB. OBJECTIVES: We tested the hypothesis that CB is characterized by mucus hyperconcentration, increased mucus partial osmotic pressures, and reduced mucus clearance. METHODS: We measured in subjects with CB as compared with normal and asymptomatic smoking control subjects indices of mucus concentration (hydration; i.e., percentage solids) and sputum adenine nucleotide/nucleoside concentrations. In addition, sputum partial osmotic pressures and mucus transport rates were measured in subjects with CB. MEASUREMENTS AND RESULTS: CB secretions were hyperconcentrated as indexed by an increase in percentage solids and total mucins, in part reflecting decreased extracellular nucleotide/nucleoside concentrations. CB mucus generated concentration-dependent increases in partial osmotic pressures into ranges predicted to reduce mucus transport. Mucociliary clearance (MCC) in subjects with CB was negatively correlated with mucus concentration (percentage solids). As a test of relationships between mucus concentration and disease, mucus concentrations and MCC were compared with FEV1, and both were significantly correlated. CONCLUSIONS: Abnormal regulation of airway surface hydration may slow MCC in CB and contribute to disease pathogenesis.


Asunto(s)
Bronquitis Crónica/fisiopatología , Depuración Mucociliar/fisiología , Moco/química , Moco/fisiología , Presión Osmótica/fisiología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
12.
Parallel Comput ; 55: 17-27, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27274603

RESUMEN

The cellular process responsible for providing energy for most life on Earth, namely photosynthetic light-harvesting, requires the cooperation of hundreds of proteins across an organelle, involving length and time scales spanning several orders of magnitude over quantum and classical regimes. Simulation and visualization of this fundamental energy conversion process pose many unique methodological and computational challenges. We present, in two accompanying movies, light-harvesting in the photosynthetic apparatus found in purple bacteria, the so-called chromatophore. The movies are the culmination of three decades of modeling efforts, featuring the collaboration of theoretical, experimental, and computational scientists. We describe the techniques that were used to build, simulate, analyze, and visualize the structures shown in the movies, and we highlight cases where scientific needs spurred the development of new parallel algorithms that efficiently harness GPU accelerators and petascale computers.

13.
Mol Psychiatry ; 19(4): 511-8, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23478745

RESUMEN

5-Lipoxygenase (5LO) is upregulated in Alzheimer's disease (AD) and in vivo modulates the amyloidotic phenotype of amyloid precursor protein transgenic mice. However, no data are available on the effects that 5LO has on synaptic function, integrity and cognition. To address this issue, we used a genetic and a pharmacological approach by generating 3 × Tg mice deficient for 5LO and administering 3 × Tg mice with a 5LO inhibitor. Compared with controls, we found that even before the development of overt neuropathology, both animals manifested significant memory improvement, rescue of their synaptic dysfunction and amelioration of synaptic integrity. In addition, later in life, these mice had a significant reduction of Aß and tau pathology. Our findings support a novel functional role for 5LO in regulating synaptic plasticity and memory. They establish this protein as a pleiotropic contributor to the development of the full spectrum of the AD phenotype, making it a valid therapeutic target for the treatment of AD.


Asunto(s)
Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/patología , Araquidonato 5-Lipooxigenasa/metabolismo , Encéfalo/patología , Trastornos de la Memoria/terapia , Sinapsis/fisiología , Factores de Edad , Enfermedad de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animales , Araquidonato 5-Lipooxigenasa/genética , Condicionamiento Clásico/efectos de los fármacos , Condicionamiento Clásico/fisiología , Modelos Animales de Enfermedad , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/genética , Miedo/psicología , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/genética , Humanos , Hidroxiurea/análogos & derivados , Hidroxiurea/farmacología , Hidroxiurea/uso terapéutico , Técnicas In Vitro , Inhibidores de la Lipooxigenasa/farmacología , Inhibidores de la Lipooxigenasa/uso terapéutico , Trastornos de la Memoria/etiología , Ratones , Ratones Transgénicos , Mutación/genética , Presenilina-1/genética , Sinapsis/efectos de los fármacos , Sinapsis/genética , Proteínas tau/genética
14.
Hum Genet ; 133(9): 1075-82, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24850140

RESUMEN

Turner syndrome is a sex chromosome aneuploidy with characteristic malformations. Amniotic fluid, a complex biological material, could contribute to the understanding of Turner syndrome pathogenesis. In this pilot study, global gene expression analysis of cell-free RNA in amniotic fluid supernatant was utilized to identify specific genes/organ systems that may play a role in Turner syndrome pathophysiology. Cell-free RNA from amniotic fluid of five mid-trimester Turner syndrome fetuses and five euploid female fetuses matched for gestational age was extracted, amplified, and hybridized onto Affymetrix(®) U133 Plus 2.0 arrays. Significantly differentially regulated genes were identified using paired t tests. Biological interpretation was performed using Ingenuity Pathway Analysis and BioGPS gene expression atlas. There were 470 statistically significantly differentially expressed genes identified. They were widely distributed across the genome. XIST was significantly down-regulated (p < 0.0001); SHOX was not differentially expressed. One of the most highly represented organ systems was the hematologic/immune system, distinguishing the Turner syndrome transcriptome from other aneuploidies we previously studied. Manual curation of the differentially expressed gene list identified genes of possible pathologic significance, including NFATC3, IGFBP5, and LDLR. Transcriptomic differences in the amniotic fluid of Turner syndrome fetuses are due to genome-wide dysregulation. The hematologic/immune system differences may play a role in early-onset autoimmune dysfunction. Other genes identified with possible pathologic significance are associated with cardiac and skeletal systems, which are known to be affected in females with Turner syndrome. The discovery-driven approach described here may be useful in elucidating novel mechanisms of disease in Turner syndrome.


Asunto(s)
Líquido Amniótico , Aneuploidia , Cromosomas Humanos X/genética , Regulación del Desarrollo de la Expresión Génica/genética , ARN Mensajero/genética , Síndrome de Turner/genética , Líquido Amniótico/química , Estudios de Casos y Controles , ADN Complementario/genética , Regulación hacia Abajo , Femenino , Perfilación de la Expresión Génica , Humanos , Cariotipo , Análisis de Secuencia por Matrices de Oligonucleótidos , Especificidad de Órganos , Fenotipo , Proyectos Piloto , Embarazo , Transcriptoma , Regulación hacia Arriba
16.
J Aerosol Med Pulm Drug Deliv ; 37(4): 167-170, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38687136

RESUMEN

Background: Recent studies show e-cigarette (EC) users have increased rates of chronic bronchitic symptoms that may be associated with depressed mucociliary clearance (MCC). Little is known about the acute or chronic effects of EC inhalation on in vivo MCC. Methods: In vivo MCC was measured in young adult vapers (n = 5 males, mean age = 21) after controlled inhalation of a radiolabeled (Tc99m sulfur colloid) aerosol. Whole-lung clearance of radiolabeled deposited particles was measured over a 90-minute period for baseline MCC and associated with controlled periodic vaping over the first 60 minutes of MCC measurements. The vaping challenge was administered from a fourth generation box mod EC containing unflavored e-liquid (65% propylene glycol/35% vegetable glycerin, 3 mg/mL freebase nicotine). The challenge was administered at the start of each 10-minute interval of MCC measurements and consisted of 1 puff every 30 seconds for 5 minutes (i.e., 10 puffs for each 10-minute period for a total of 60 puffs during the initial 60 minutes of MCC measurements). Results: Compared with baseline, peripheral lung average clearance (%) over the 90 minutes of MCC measures was enhanced, associated with EC challenge, 12 (±6) versus 24 (±6), respectively (p < 0.05 by Wilcoxon signed-rank test). Conclusions: Acute enhancement of in vivo MCC during EC challenge is contrary to recent studies showing nicotine-associated slowing of ciliary beat and mucus transport at higher nicotine levels than those used here. However, our findings are consistent with an acute increase in fluid volume and mucin secretion to the bronchial airway surface that is likely short lived. Research reported in this publication was supported by the National Institutes of Health R01HL139369 and registered with ClinicalTrials.gov (NCT03700892).


Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Pulmón , Depuración Mucociliar , Nicotina , Vapeo , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto Joven , Administración por Inhalación , Aerosoles , Glicerol/administración & dosificación , Pulmón/metabolismo , Pulmón/fisiopatología , Depuración Mucociliar/efectos de los fármacos , Nicotina/administración & dosificación , Nicotina/farmacocinética , Nicotina/efectos adversos , Propilenglicol/administración & dosificación , Azufre Coloidal Tecnecio Tc 99m/administración & dosificación , Factores de Tiempo , Vapeo/efectos adversos
17.
Ecol Evol ; 14(9): e70208, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39247168

RESUMEN

Because it can lead to retaliatory killing, livestock depredation by large carnivores is among the foremost threats to carnivore conservation, and it severely impacts human well-being worldwide. Ongoing climate change can amplify these human-wildlife conflicts, but such issues are largely unexplored, though are becoming increasingly recognized. Here, we assessed how the availability of primary resources and wild prey interact to shape large carnivore selection for livestock rather than wild prey (i.e., via prey switching or apparent competition). Specifically, we combined remotely sensed estimates of primary resources (i.e., water availability and primary productivity), wild prey movement, and 7 years (2015-2021) of reports for livestock depredation by African lions (Panthera leo) in the Makgadikgadi Pans ecosystem, Botswana. Although livestock depredation did not vary between wet versus dry seasons, analyses at finer temporal scales revealed higher incidences of livestock depredation when primary production, water availability, and wild prey availability were lower, though the effects of wild prey availability were mediated by water availability. Increased precipitation also amplified livestock depredation events despite having no influence on wild prey availability. Our results suggest that livestock depredation is influenced by the diverse responses of livestock, wild prey, and lions to primary resource availability, a driver that is largely overlooked or oversimplified in studies of human-carnivore conflict. Our findings provide insight into tailoring potential conflict mitigation strategies to fine-scale changes in resource conditions to efficiently reduce conflict and support human livelihoods.

18.
Philos Trans R Soc Lond B Biol Sci ; 379(1909): 20230180, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39034695

RESUMEN

Comparative studies suggest remarkable similarities among food webs across habitats, including systematic changes in their structure with diversity and complexity (scale-dependence). However, historic aboveground terrestrial food webs (ATFWs) have coarsely grouped plants and insects such that these webs are generally small, and herbivory is disproportionately under-represented compared to vertebrate predator-prey interactions. Furthermore, terrestrial herbivory is thought to be structured by unique processes compared to size-structured feeding in other systems. Here, we present the richest ATFW to date, including approximately 580 000 feeding links among approximately 3800 taxonomic species, sourced from approximately 27 000 expert-vetted interaction records annotated as feeding upon one of six different resource types: leaves, flowers, seeds, wood, prey and carrion. By comparison to historical ATFWs and null ecological hypotheses, we show that our temperate forest web displays a potentially unique structure characterized by two properties: (i) a large fraction of carnivory interactions dominated by a small number of hyper-generalist, opportunistic bird and bat predators; and (ii) a smaller fraction of herbivory interactions dominated by a hyper-rich community of insects with variably sized but highly specific diets. We attribute our findings to the large-scale, even resolution of vertebrate, insect and plant guilds in our food web.This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.


Asunto(s)
Cadena Alimentaria , Herbivoria , Insectos , Animales , Insectos/fisiología , Bosques , Aves/fisiología
19.
FASEB J ; 26(2): 533-45, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21990373

RESUMEN

Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Pulmón/metabolismo , Fumar/efectos adversos , Fumar/metabolismo , Adulto , Anciano , Animales , Secuencia de Bases , Transporte Biológico Activo , Agua Corporal/metabolismo , Bronquitis Crónica/etiología , Bronquitis Crónica/metabolismo , Estudios de Casos y Controles , Células Cultivadas , Cricetinae , Fibrosis Quística/etiología , Fibrosis Quística/metabolismo , Fibrosis Quística/terapia , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Cartilla de ADN/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Depuración Mucociliar , Mucosa Respiratoria/metabolismo , Solución Salina Hipertónica/farmacología , Humo/efectos adversos , Solubilidad
20.
Prenat Diagn ; 33(9): 873-83, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23640821

RESUMEN

OBJECTIVE: The objective of this study was to understand the biological pathways involved in twin-twin transfusion syndrome (TTTS) by performing global gene expression analysis of amniotic fluid (AF) cell-free RNA. METHODS: A prospective whole transcriptome microarray study analyzing cell-free RNA in AF from TTTS recipient twins and singleton controls was carried out. Significantly differentially regulated genes in TTTS cases (N = 8) versus matched controls (N = 8) were identified and pathways analyses performed. Significant gene expression differences between stage II TTTS recipients (N = 5) and stage III TTTS recipients with abnormal Doppler measurements (N = 5) were also analyzed. RESULTS: Analysis of paired data from TTTS cases and controls revealed differential expression of 801 genes, which were significantly enriched for neurological disease and cardiovascular system pathways. We also identified cardiovascular genes and pathways associated with the presence of critically abnormal Doppler measurements in stage III TTTS recipients. CONCLUSIONS: This study provides the first transcriptome-wide data on the impact of TTTS on fetal development. Our results show that gene expression involving neurological and cardiovascular pathways are altered in recipient fetuses prior to surgical treatment. This has relevance for the origins of long-term complications seen in survivors and for the development of future fetal biomarkers.


Asunto(s)
Líquido Amniótico/química , Transfusión Feto-Fetal/genética , Perfilación de la Expresión Génica , ARN/análisis , Líquido Amniótico/metabolismo , Estudios de Casos y Controles , Femenino , Transfusión Feto-Fetal/metabolismo , Humanos , Masculino , Análisis por Micromatrices , Embarazo , ARN/metabolismo , Transcriptoma , Trasplante , Gemelos
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda