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1.
Proc Biol Sci ; 290(1990): 20221658, 2023 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-36629113

RESUMEN

Human-induced biodiversity loss negatively affects ecosystem function, but the interactive effects of biodiversity change across trophic levels remain insufficiently understood. We sampled arboreal spiders and lepidopteran larvae across seasons in 2 years in a subtropical tree diversity experiment, and then disentangled the links between tree diversity and arthropod predator diversity by deconstructing the pathways among multiple components of diversity (taxonomic, phylogenetic and functional) with structural equation models. We found that herbivores were major mediators of plant species richness effects on abundance, species richness, functional and phylogenetic diversity of predators, while phylogenetic, functional and structural diversity of trees were also important mediators of this process. However, the strength and direction differed between functional, structural and phylogenetic diversity effects, indicating different underlying mechanisms for predator community assembly. Abundance and multiple diversity components of predators were consistently affected by tree functional diversity, indicating that the variation in structure and environment caused by plant functional composition might play key roles in predator community assembly. Our study highlights the importance of an integrated approach based on multiple biodiversity components in understanding the consequences of biodiversity loss in multitrophic communities.


Asunto(s)
Artrópodos , Arañas , Animales , Humanos , Ecosistema , Filogenia , Biodiversidad , Plantas
2.
J Anim Ecol ; 92(2): 442-453, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36507573

RESUMEN

Global biodiversity decline and its cascading effects through trophic interactions pose a severe threat to human society. Establishing the impacts of biodiversity decline requires a more thorough understanding of multi-trophic interactions and, more specifically, the effects that loss of diversity in primary producers has on multi-trophic community assembly. Within a synthetic conceptual framework for multi-trophic beta-diversity, we tested a series of hypotheses on neutral and niche-based bottom-up processes in assembling herbivore and carnivore communities in a subtropical forest using linear models, hieratical variance partitioning based on linear mixed-effects models (LMMs) and simulation. We found that the observed taxonomic, phylogenetic and functional beta-diversity of both herbivorous caterpillars and carnivorous spiders were significantly and positively related to tree dissimilarity. Linear models and variance partitioning for LMMs jointly suggested that as a result of bottom-up effects, producer dissimilarities were predominant in structuring consumer dissimilarity, the strength of which highly depended on the trophic dependencies on producers, the diversity facet examined, and data quality. Importantly, linear models for standardized beta-diversities against producer dissimilarities implied a transition between niche-based processes such as environmental filtering and competitive exclusion, which supports the role of bottom-up effect in determining consumer community assembly. These findings enrich our mechanistic understanding of the 'Diversity Begets Diversity' hypothesis and the complexity of higher-trophic community assembly, which is fundamental for sustainable biodiversity conservation and ecosystem management.


Asunto(s)
Ecosistema , Herbivoria , Humanos , Animales , Filogenia , Biodiversidad , Bosques
3.
Oecologia ; 203(1-2): 205-218, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37831151

RESUMEN

There are many factors known to drive species turnover, although the mechanisms by which these operate are less clear. Based on comprehensive datasets from the largest tree diversity experiment worldwide (BEF-China), we used shared herbivore species (zeta diversity) and multi-site generalized dissimilarity modelling to investigate the patterns and determinants of species turnover of Lepidoptera herbivores among study plots across a gradient in tree species richness. We found that zeta diversity declined sharply with an increasing number of study plots, with complete changes in caterpillar species composition observed even at the fine spatial scale of our study. Plant community characteristics rather than abiotic factors were found to play key roles in driving caterpillar compositional turnover, although these effects varied with an increasing number of study plots considered, due to the varying contributions of rare and common species to compositional turnover. Our study reveals details of the impact of phylogeny- and trait-mediated processes of trees on herbivore compositional turnover, which has implications for forest management and conservation and shows potential avenues for maintenance of heterogeneity in herbivore communities.


Asunto(s)
Herbivoria , Árboles , Biodiversidad , Bosques , Plantas
4.
Inorg Chem ; 61(41): 16325-16332, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36198195

RESUMEN

A dimeric dithiolate-bridged species, [Fe(NO)(PS2)]2 (1) containing two {FeNO}7 units, can be isolated by treating [Fe(CO)2(NO)2] with PS2H2 (PS2H2 = bis(2-dimercaptophenyl)phenylphosphine). Crystallographic studies reveal the syn-configuration of NO units and the bridging thiolates in the butterfly shape of the 2Fe2S core. Addition of PPh3 to the solution of dinuclear 1 leads to the formation of mononuclear {FeNO}7 [Fe(NO)(PS2)(PPh3)] (2) that shows electrochemical responses similar to those of 1. One-electron reduction of 1 with Cp*2Co or KC8 results in the isolation of thiolate-bridged bimetallic DNIC, [(PS2)Fe(µ-PS2)Fe(NO)2]- ([3]-), confirmed by several spectroscopies including single-crystal X-ray diffraction studies. The bimetallic DNIC [3]- is a rare example obtained from the one-electron reduction of a dinuclear Fe-NO {FeNO}7 model complex. With the assistance of redox behaviors of 2, electrochemical studies imply that the reduction of 1 leads to the formation of a mononuclear {FeNO}8 [Fe(NO)(PS2)(THF)]- intermediate, which involves disproportionation or NO- transfer to yield [3]-. Based on IR data and magnetic properties, the electronic structure of [3]- can be described as a FeII/{Fe(NO)2}9 state. Isolation of the {Fe(NO)2}9 moiety coordinated by the Fe ancillary complex lends strong support to the NO scrambling behavior in the effectiveness of the activity of flavodiiron nitric oxide reductases (FNORs).


Asunto(s)
Hierro , Óxido Nítrico , Cristalografía por Rayos X , Compuestos Ferrosos , Hierro/química , Óxido Nítrico/química , Oxidorreductasas/química
5.
Toxicol Appl Pharmacol ; 288(3): 359-73, 2015 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-26298006

RESUMEN

Gefitinib is the first-line chemotherapeutic drug for treating non-small cell lung cancer (NSCLC), which comprises nearly 85% of all lung cancer cases worldwide. However, most patients eventually develop drug resistance after 12-18 months of treatment. Hence, investigating the drug resistance mechanism and resistance-associated biomarkers is necessary. Two lung adenocarcinoma cell lines, PC9 and gefitinib-resistant PC9/Gef, were established for examining resistance mechanisms and identifying potential therapeutic targets. Two-dimensional differential gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were used for examining global protein expression changes between PC9 and PC9/Gef. The results revealed that 164 identified proteins were associated with the formation of gefitinib resistance in PC9 cells. Additional studies using RNA interference showed that progesterone receptor membrane component 1 and pericentrin proteins have major roles in gefitinib resistance. In conclusion, the proteomic approach enabled identifying of numerous proteins involved in gefitinib resistance. The results provide useful diagnostic markers and therapeutic candidates for treating gefitinib-resistant NSCLC.


Asunto(s)
Adenocarcinoma/patología , Carcinoma de Pulmón de Células no Pequeñas/patología , Resistencia a Antineoplásicos , Neoplasias Pulmonares/tratamiento farmacológico , Quinazolinas/farmacología , Adenocarcinoma/metabolismo , Adenocarcinoma del Pulmón , Antígenos/genética , Antígenos/metabolismo , Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Receptores ErbB/genética , Receptores ErbB/metabolismo , Gefitinib , Silenciador del Gen , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteómica/métodos , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Transducción de Señal , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
6.
Insects ; 13(12)2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36555010

RESUMEN

Nutritional content of host plants is expected to drive caterpillar species assemblages and their trait composition. These relationships are altered by tree richness-induced neighborhood variation and a seasonal decline in leaf quality. We tested how key functional traits related to the growth and defenses of the average caterpillar hosted by a tree species are shaped by nutritional host quality. We measured morphological traits and estimated plant community-level diet breadth based on occurrences from 1020 caterpillars representing 146 species in a subtropical tree diversity experiment from spring to autumn in one year. We focused on interspecific caterpillar trait variation by analyzing presence-only patterns of caterpillar species for each tree species. Our results show that tree richness positively affected caterpillar species-sharing among tree species, which resulted in lowered trait variation and led to higher caterpillar richness for each tree species. However, community-level diet breadth depended more on the nutritional content of host trees. Higher nutritional quality also supported species-poorer but more abundant communities of smaller and less well-defended caterpillars. This study demonstrates that the leaf nutritional quality of trees shapes caterpillar trait composition across diverse species assemblages at fine spatial scales in a way that can be predicted by ecological theory.

7.
Ecol Evol ; 11(11): 6153-6166, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34141209

RESUMEN

Herbivorous insects acquire microorganisms from host plants or soil, but it remains unclear how the diversity and functional composition of host plants contribute to structuring herbivore microbiomes. Within a controlled tree diversity setting, we used DNA metabarcoding of 16S rRNA to assess the contribution of Lepidoptera species and their local environment (particularly, tree diversity, host tree species, and leaf traits) to the composition of associated bacterial communities. In total, we obtained 7,909 bacterial OTUs from 634 caterpillar individuals comprising 146 species. Tree diversity was found to drive the diversity of caterpillar-associated bacteria both directly and indirectly via effects on caterpillar communities, and tree diversity was a stronger predictor of bacterial diversity than diversity of caterpillars. Leaf toughness and dry matter content were important traits of the host plant determining bacterial species composition, while leaf calcium and potassium concentration influenced bacterial richness. Our study reveals previously unknown linkages between trees and their characteristics, herbivore insects, and their associated microbes, which contributes to developing a more nuanced understanding of functional dependencies between herbivores and their environment, and has implications for the consequences of plant diversity loss for trophic interactions.

8.
Kaohsiung J Med Sci ; 32(5): 267-75, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27316586

RESUMEN

Coronary heart disease (CHD) is a major cause of morbidity and mortality in developed countries. Metabolic syndrome (MetS) is associated with increased risk of CHD. Cardiac rehabilitation is considered an effective intervention and a Class I indication in patients with CHD. This study was designed to evaluate the effects of home-based, integrated cardiac rehabilitation (HBICR) of patients with CHD in modifiable risk-factor control and exercise capacity. Sixty-four patients with CHD were investigated and randomized into intervention and control groups. The intervention group received a HBICR containing medication use, exercise program, smoking-cessation counseling, and education regarding risk factors, nutrition, and the necessity of continuing the program, whereas the control group received traditional care. Baseline and follow-up assessments at 3 months and 12 months, including body composition, metabolic syndrome risk score, and biochemical tests were performed in all patients. Additionally, cardiopulmonary function tests were also performed at baseline and 3-month follow-up assessments. There was a significant between-group, within-group, and interaction effect found in the MetS Z scores. Significant within-group effects were also observed in modified Adult Treatment Panel III score, waist circumference, high-density lipoprotein, and low-density lipoprotein. However, several cardiopulmonary parameters did not differ significantly at 3-month follow-up between the two groups, including peak V̇O2, peak heart rate, peak respiratory exchange ratio, anaerobic threshold V̇O2, heart-rate reserve, and heart-rate recovery after 1 min and after 2 min. Our results showed that HBICR exhibited significant positive effects on modifiable risk-factor control in CHD patients.


Asunto(s)
Rehabilitación Cardiaca , Enfermedad de la Arteria Coronaria/metabolismo , Enfermedad de la Arteria Coronaria/rehabilitación , Servicios de Atención de Salud a Domicilio , Metaboloma , Estudios de Casos y Controles , Enfermedad de la Arteria Coronaria/complicaciones , Ejercicio Físico , Femenino , Humanos , Masculino , Síndrome Metabólico/complicaciones , Persona de Mediana Edad , Factores de Riesgo
9.
Kaohsiung J Med Sci ; 31(7): 337-43, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26162813

RESUMEN

We investigated the effects of extracorporeal shockwave therapy (ESWT) on the rehabilitation of cervical spondylosis with nuchal ligament (NL) calcification under X-ray and ultrasound guidance. Sixty patients with cervical spondylosis and calcification of NL were selected and randomly assigned to three groups: A, B, and C. Patients in Group A received rehabilitation with 20 minutes of hot packs and underwent 15 minutes of intermittent cervical traction three times/week for 6 weeks. Patients in Group B received the same rehabilitation as those in Group A and ESWT (2000 impulses, 0.27 mJ/mm(2)) over the calcified NL guided by X-ray image. Patients in Group C received the same treatment as those in Group B, but the ESWT was guided by musculoskeletal sonography. The therapeutic effects were evaluated by: changes in range of motion (ROM) of the cervical spine including flexion, extension, lateral bending, and rotation; visual analog pain scale; and Neck Disability Index before and after treatment and at follow up 3 months later. We found a significant reduction in pain in each treated group after treatment and at follow up. However, patients in Groups B and C showed more improvements in ROM and neck pain relief after treatment and a decrease in Neck Disability Index. Furthermore, patients in Group C showed better cervical ROM at follow up than Group B. ESWT is an adjuvant treatment in the management of cervical spondylosis with calcification of NL and ultrasound-guided ESWT results in more functional improvements.


Asunto(s)
Calcinosis/diagnóstico por imagen , Calcinosis/terapia , Ligamentos/diagnóstico por imagen , Litotricia , Espondilosis/diagnóstico por imagen , Espondilosis/terapia , Calcinosis/fisiopatología , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiopatología , Estudios de Seguimiento , Humanos , Ligamentos/fisiopatología , Dolor de Cuello/diagnóstico por imagen , Dolor de Cuello/fisiopatología , Dolor de Cuello/terapia , Dimensión del Dolor , Radiografía , Rango del Movimiento Articular , Espondilosis/fisiopatología , Resultado del Tratamiento , Ultrasonografía
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