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1.
Apidologie ; 51(5): 746-762, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33122866

RESUMO

Bees are vital pollinators, but are faced with numerous threats that include loss of floral resources and emerging parasites amongst others. Urbanisation is a rapidly expanding driver of land-use change that may interact with these two major threats to bees. Here we investigated effects of urbanisation on food store quality and colony health in honeybees (Apis mellifera) by sampling 51 hives in four different land-use categories: urban, suburban, rural open and rural wooded during two seasons (spring and autumn). We found positive effects of urban land use on colony strength and richness of stored pollen morphotypes, alongside lower late-season Nosema sp. infection in urban and suburban colonies. Our results reveal that honeybees exhibit lower colony performance in strength in rural areas, adding to the growing evidence that modern agricultural landscapes can constitute poor habitat for insect pollinators.

2.
Proc Biol Sci ; 285(1881)2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-30051852

RESUMO

Urbanization represents a rapidly growing driver of land-use change. While it is clear that urbanization impacts species abundance and diversity, direct effects of urban land use on animal reproductive success are rarely documented. Here, we show that urban land use is linked to long-term colony reproductive output in a key pollinator. We reared colonies from wild-caught bumblebee (Bombus terrestris) queens, placed them at sites characterized by varying degrees of urbanization from inner city to rural farmland and monitored the production of sexual offspring across the entire colony cycle. Our land-use cluster analysis identified three site categories, and this categorization was a strong predictor of colony performance. Crucially, colonies in the two clusters characterized by urban development produced more sexual offspring than those in the cluster dominated by agricultural land. These colonies also reached higher peak size, had more food stores, encountered fewer parasite invasions and survived for longer. Our results show a link between urbanization and bumblebee colony reproductive success, supporting the theory that urban areas provide a refuge for pollinator populations in an otherwise barren agricultural landscape.


Assuntos
Abelhas/fisiologia , Meio Ambiente , Animais , Cidades , Inglaterra , Fazendas , Londres , Reprodução
3.
Ecol Evol ; 8(11): 5598-5610, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29938077

RESUMO

Land-use change is one of the most important drivers of widespread declines in pollinator populations. Comprehensive quantitative methods for land classification are critical to understanding these effects, but co-option of existing human-focussed land classifications is often inappropriate for pollinator research. Here, we present a flexible GIS-based land classification protocol for pollinator research using a bottom-up approach driven by reference to pollinator ecology, with urbanization as a case study. Our multistep method involves manually generating land cover maps at multiple biologically relevant radii surrounding study sites using GIS, with a focus on identifying land cover types that have a specific relevance to pollinators. This is followed by a three-step refinement process using statistical tools: (i) definition of land-use categories, (ii) principal components analysis on the categories, and (iii) cluster analysis to generate a categorical land-use variable for use in subsequent analysis. Model selection is then used to determine the appropriate spatial scale for analysis. We demonstrate an application of our protocol using a case study of 38 sites across a gradient of urbanization in South-East England. In our case study, the land classification generated a categorical land-use variable at each of four radii based on the clustering of sites with different degrees of urbanization, open land, and flower-rich habitat. Studies of land-use effects on pollinators have historically employed a wide array of land classification techniques from descriptive and qualitative to complex and quantitative. We suggest that land-use studies in pollinator ecology should broadly adopt GIS-based multistep land classification techniques to enable robust analysis and aid comparative research. Our protocol offers a customizable approach that combines specific relevance to pollinator research with the potential for application to a wide range of ecological questions, including agroecological studies of pest control.

4.
Matern Child Health J ; 21(9): 1706-1712, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28707101

RESUMO

Objectives The uptake and actual use of the current guidelines from the American College of Obstetrics and Gynecology (ACOG) is unknown. Methods Family planning providers across Colorado and Iowa were surveyed as part of statewide initiatives to reduce unintended pregnancy in 2010 and 2012, both before and after the release of the guidelines. These initiatives focused on the promotion of intrauterine devices (IUDs) and implants. These surveys included questions on providers' views regarding the suitability and safety of the copper T IUD, hormonal IUD, and single rod implant for various subgroups of clients. The results are contrasted with guidelines provided in July of 2011 by ACOG. This strategy provides both baseline and follow-up models about the methods promoted in these guidelines. Results Findings show that there is some improvement in beliefs that IUDs are suitable and safe for women who are post-partum, post-abortion, have had an ectopic pregnancy, are nulliparous, teenagers, or have a history of STIs. However, these clinicians' views are not entirely in alignment with ACOG recommendations in their beliefs that these methods should not be used immediately post-partum or post-abortion. Notable percentages of these clinicians were hesitant to recommend these effective methods for other groups of patients, approved for use by ACOG. Conclusions While the cost of these methods is a barrier to adoption, these data suggest that there are continuing provider barriers to their use as well. The paper concludes with suggestions for further training for family planning providers.


Assuntos
Atitude do Pessoal de Saúde , Anticoncepção/métodos , Serviços de Planejamento Familiar , Fidelidade a Diretrizes/estatística & dados numéricos , Ginecologia , Dispositivos Intrauterinos , Obstetrícia , Médicos/psicologia , Guias de Prática Clínica como Assunto , Colorado , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Dispositivos Intrauterinos de Cobre , Dispositivos Intrauterinos Medicados , Iowa , Padrões de Prática Médica , Gravidez , Gravidez não Planejada , Sociedades Médicas , Inquéritos e Questionários , Recursos Humanos
5.
Lupus ; 25(11): 1200-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27000154

RESUMO

BACKGROUND: Memory impairment is prevalent in systemic lupus erythematosus (SLE); however, its pathogenesis is unknown. In a previous functional magnetic resonance imaging (fMRI) study we demonstrated altered brain activity dynamics and less brain deactivation in patients with SLE as compared with healthy controls, when performing a learning and memory task. Our findings localized this impairment to the default mode network (DMN), and particularly to its anterior medial prefrontal cortex node. In addition, altered networking of the hippocampal subsystem of the DMN was seen in patients with SLE when performing this task, as well as atrophy of the left hippocampus. The present study aimed to search for a structural substrate for the altered recruitment pattern observed in fMRI studies using diffusion tensor imaging (DTI). PATIENTS AND METHODS: Using DTI, we characterized brain diffusivity in 10 patients with SLE and nine healthy controls. Two tracts associated with the DMN were reconstructed: the corpus callosum (CC) and the cingulum bundle. The CC was segmented according to the Witelson segmentation scheme and the cingulum was segmented into superior and descending bundles. RESULTS: A significant increase in mean diffusivity (MD) was seen in patients with SLE without neuropsychiatric SLE (NPSLE) as compared with healthy controls in all five segments of the CC (segment 1: p = 0.043; segment 2: p = 0.005; segment 3: p = 0.003; segment 4: p = 0.012; segment 5: p = 0.023) as well as in the descending portion of the left cingulum bundle (p = 0.026). CONCLUSIONS: Increased MD values in the CC and the left cingulum may indicate impaired organization/reduced integrity of these tracts, which may underlie the abnormal pattern of brain activity recruitment of the DMN observed during a verbal learning and memory task. Taking into account the central role of the left hippocampus in verbal memory, the abnormal integrity of the left cingulum may contribute to the reduced performance of patients with SLE on verbal memory tasks.


Assuntos
Corpo Caloso/diagnóstico por imagem , Giro do Cíngulo/diagnóstico por imagem , Lúpus Eritematoso Sistêmico/diagnóstico por imagem , Lúpus Eritematoso Sistêmico/psicologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/diagnóstico por imagem , Vasculite Associada ao Lúpus do Sistema Nervoso Central/psicologia , Adulto , Mapeamento Encefálico , Corpo Caloso/patologia , Imagem de Tensor de Difusão/métodos , Feminino , Giro do Cíngulo/patologia , Humanos , Lúpus Eritematoso Sistêmico/patologia , Vasculite Associada ao Lúpus do Sistema Nervoso Central/patologia , Imageamento por Ressonância Magnética , Adulto Jovem
6.
Philos Trans A Math Phys Eng Sci ; 361(1802): 23-6, 2003 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-12626234

RESUMO

Global Altimeter Measurements by Leading Europeans (GAMBLE) is a project, funded by the European Commission, which aims to mobilize the community of specialists in radar altimetry within Europe. The main objective is to investigate how to maximize the synergy between satellite altimetry missions before launch. This makes GAMBLE unique in the annals of planning future satellite missions over the oceans and represents a notable first for Europe.


Assuntos
Planeta Terra , Radar , Cooperação Internacional , Oceanos e Mares , Astronave , Temperatura
7.
Behav Sci Law ; 19(1): 81-96, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11241682

RESUMO

The present study investigated the relationship between characteristics of a violent event, as self-reported by 82 incarcerated juvenile offenders, and personality features measured by the Millon Adolescent Clinical Inventory (MACI). The study predicted that specific personality features that have previously been associated with psychopathy would be associated with the instrumentality, emotional reactivity, and empathy or guilt reported for the incident. Results confirmed that a self-reported pattern of elevated instrumental motivation and reduced empathy or guilt was associated with higher scores on the MACI Forceful, Unruly, Substance Abuse Proneness, Impulsive Propensity, and Family Discord Scales, as well as a recently developed Psychopathy Content Scale. Self-reported elevated instrumental motivation and reduced empathy or guilt was also associated with lower scores on the Submissive, Conforming, Anxious Feelings, and Sexual Discomfort Scales. There were no significant relationships observed between emotional reactivity and personality scales.


Assuntos
Transtorno da Personalidade Antissocial/diagnóstico , Transtorno da Personalidade Antissocial/psicologia , Delinquência Juvenil/psicologia , Delinquência Juvenil/estatística & dados numéricos , Violência/psicologia , Adolescente , Afeto , Empatia , Feminino , Culpa , Humanos , Masculino , Inventário de Personalidade , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Distribuição por Sexo
8.
Cancer Res ; 60(18): 5179-86, 2000 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11016646

RESUMO

We have used diffusion-weighted proton magnetic resonance spectroscopy (DWMRS) to noninvasively selectively observe only the intracellular metabolites of breast cancer and melanoma cell lines in vitro in real time. Breast cancer cell lines representing different stages in breast cancer progression were chosen for study. Intracellular biochemical profiles of six cell lines perfused in alginate beads were obtained. Spectral differences between groups of cell lines, including choline, lactate, and threonine peaks, were investigated. We also monitored response to the antineoplastic agent, lonidamine (LND), as a function of time and drug concentration in perfused cancer cells. Previous studies reported that this drug induced intracellular acidification and lactate accumulation. Diffusion weighted proton spectra demonstrated a 2- to 9-fold increase in the intracellular lactate signal as a response to LND treatment in several cancer cell lines. These results are consistent with the hypothesis that the principal mechanism of LND in some cancer cells is marked inhibition of lactate transport. Moreover, we have shown that there is a factor of two to three between the response of melanoma cells and that of some types of breast cancer cells. The higher sensitivity of the melanoma cells, as predicted by proton DWMRS, was correlated with changes in water-suppressed magnetic resonance spectra and confirmed by a biological assay. This study demonstrates the feasibility of using DWMRS for monitoring intracellular metabolism and for studying the effects and mechanisms of action of anticancer drugs. We believe that this method can be used for noninvasive clinical applications, such as the differentiation between benign and malignant tissue, real-time monitoring of response to therapy, dose response, and toxicity effects.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/metabolismo , Indazóis/farmacologia , Espectroscopia de Ressonância Magnética/métodos , Melanoma Experimental/metabolismo , Animais , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/tratamento farmacológico , Difusão , Relação Dose-Resposta a Droga , Humanos , Isquemia/metabolismo , Melanoma Experimental/tratamento farmacológico , Camundongos , Monitorização Fisiológica/métodos , Prótons , Processamento de Sinais Assistido por Computador , Células Tumorais Cultivadas
9.
Proc Natl Acad Sci U S A ; 97(19): 10371-6, 2000 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-10984533

RESUMO

13C-selective NMR, combined with inhibitor perturbation experiments, shows that the C(epsilon)(1)H proton of the catalytic histidine in resting alpha-lytic protease and subtilisin BPN' resonates, when protonated, at 9.22 ppm and 9.18 ppm, respectively, which is outside the normal range for such protons and approximately 0.6 to 0.8 ppm further downfield than previously reported. They also show that the previous alpha-lytic protease assignments [Markley, J. L., Neves, D. E., Westler, W. M., Ibanez, I. B., Porubcan, M. A. & Baillargeon, M. W. (1980) Front. Protein Chem. 10, 31-61] were to signals from inactive or denatured protein. Simulations of linewidth vs. pH demonstrate that the true signal is more difficult to detect than corresponding signals from inactive derivatives, owing to higher imidazole pK(a) values and larger chemical shift differences between protonated and neutral forms. A compilation and analysis of available NMR data indicates that the true C(epsilon)(1)H signals from other serine proteases are similarly displaced downfield, with past assignments to more upfield signals probably in error. The downfield displacement of these proton resonances is shown to be consistent with an H-bond involving the histidine C(epsilon)(1)H as donor, confirming the original hypothesis of Derewenda et al. [Derewenda, Z. S., Derewenda, U. & Kobos, P. M. (1994) J. Mol. Biol. 241, 83-93], which was based on an analysis of literature x-ray crystal structures of serine hydrolases. The invariability of this H-bond among enzymes containing Asp-His-Ser triads indicates functional importance. Here, we propose that it enables a reaction-driven imidazole ring flip mechanism, overcoming a major dilemma inherent in all previous mechanisms, namely how these enzymes catalyze both the formation and productive breakdown of tetrahedral intermediates.


Assuntos
Histidina/química , Serina Endopeptidases/química , Catálise , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Conformação Molecular , Prótons
10.
Plant Dis ; 82(5): 569-572, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-30856990

RESUMO

A survey of more than 200 trees has documented the widespread occurrence of Xylella fastidiosa in Florida oak populations. The pathogen was detected readily via enzyme-linked immunosorbent assay in oaks exhibiting decline or leaf scorch symptoms and was infrequently detected in asymptomatic trees. It was also associated with reduced growth in Quercus laevis as measured by current-year shoot length. The occurrence of X. fastidiosa in Q. laevis and the evidence for its occurrence in Q. incana represent first reports for these oak hosts. The role of X. fastidiosa in oak decline scenarios deserves further attention.

11.
Science ; 278(5340): 1128-32, 1997 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-9353195

RESUMO

Cleland and Kreevoy recently advanced the idea that a special type of hydrogen bond (H-bond), termed a low-barrier hydrogen bond (LBHB), may account for the "missing" transition state stabilization underlying the catalytic power of many enzymes, and Frey et al. have proposed that the H-bond between aspartic acid 102 and histidine 57 in the catalytic triad of serine proteases is an example of a catalytically important LBHB. Experimental facts are here considered regarding the aspartic acid-histidine and cis-urocanic H-bonds that are inconsistent with fundamental tenets of the LBHB hypothesis. The inconsistencies between theory and experiment in these paradigm systems cast doubt on the existence of LBHBs, as currently defined, within enzyme active sites.


Assuntos
Serina Endopeptidases/química , Ácido Aspártico/química , Sítios de Ligação , Ácidos Borônicos/metabolismo , Catálise , Histidina/química , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Oligopeptídeos/metabolismo , Prótons , Serina Endopeptidases/metabolismo , Inibidores de Serina Proteinase/metabolismo , Subtilisinas/química , Temperatura , Ácido Urocânico/química
12.
ASAIO J ; 43(5): M830-8, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9360163

RESUMO

Whole body hyperthermia therapy (WBHT) is the elevation of the core body temperature to 42 degrees C. In vitro studies have confirmed that 42 degrees C is cytocidal for virally infected lymphocytes, and even more effective when heating is repeated 4 days later. The safety and efficacy of two successive sessions of WBHT (4 days apart) was evaluated in 30 patients with AIDS (not on protease inhibitors), randomized to: 1) untreated controls, 2) low temperature WBHT for 1 hour at 40 degrees C and repeated 96 hours later, and 3) high temperature WBHT for 1 hour at 42 degrees C and repeated 96 hours later. The sorbent suspension in the ThermoChem System (HemoCleanse, West Lafayette, IN) system automatically controlled blood phosphate, calcium, and other electrolyte concentrations during WBHT. In 1 year of follow-up after WBHT, there were positive effects of the therapy on frequency of AIDS defining events, Karnofsky score, and weight maintenance. However, effects on plasma HIV RNA and CD4 counts were transient. Two successive WBHT treatments were performed in four patients who were on protease inhibitor/triple drug therapy, but had suboptimal response. In follow-up for 6 months, plasma HIV RNA and CD4 improved after WBHT, and the patients remained clinically well. This WBHT may have specific advantages in patients with suboptimal response to protease inhibitor therapy.


Assuntos
Síndrome da Imunodeficiência Adquirida/terapia , Circulação Extracorpórea/métodos , Infecções por HIV/terapia , Hipertermia Induzida/métodos , Síndrome da Imunodeficiência Adquirida/fisiopatologia , Síndrome da Imunodeficiência Adquirida/virologia , Adulto , Contagem de Linfócito CD4 , Eletrólitos/sangue , Circulação Extracorpórea/instrumentação , Infecções por HIV/fisiopatologia , Infecções por HIV/virologia , Hemodinâmica , Humanos , Hipertermia Induzida/instrumentação , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue
13.
J Magn Reson B ; 113(3): 236-47, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8995843

RESUMO

HCN, a new 3D NMR technique for stepwise coherence transfer from 1H to 13C to 15N and reverse through direct spin couplings 1JCH and 1JCN, is presented as a method for detection and assignment of histidine and tryptophan side-chain 1H, 13C, and 15N resonances in uniformly 13C/15N-labeled proteins. Product-operator calculations of cross-peak volumes vs adjustable delay tau 3 were employed for determination of optimal tau 3. For the phosphatidylinositol 3-kinase (PI3K SH3 domain, MW = 9.6 kD) at pH 6, H(C)N, the 1H/15N projection, produced observable cross peaks within 20 min. and was completely selective for the single tryptophan and single histidine. The 3D HCN experiment yielded well-defined cross peaks in 20 h for the 13C/15N-labeled origin-specific DNA binding domain from simian virus 40 T-antigen (T-ag-OBD131-259, MW = 15.4 kD) at pH 5.5. Resonances from all six histidines in T-ag-OBD were observed, and 11 of the 12 1H and 13C chemical shifts and 10 of the 12 15N chemical shifts were determined. The 13C dimension proved essential in assignment of the multiply overlapping 1H and 15N resonances. From the spectra recorded at a single pH, three of the imidazoles were essentially neutral and the other three were partially protonated (22-37%). HCN yielded strong cross peaks after 18 h on a 2.0 mM sample of phenylmethanesulfonyl fluoride (PMSF)-inhibited alpha-lytic protease (MW = 19.8 kD) at pH 4.4. No spectra have been obtained, however, of native or boronic acid-inhibited alpha-lytic protease after 18 h at various temperatures ranging from 5 to 55 degrees C, probably due to efficient relaxation of active-site imidazole 1H and/or 15N nuclei.


Assuntos
Histidina/análise , Espectroscopia de Ressonância Magnética/métodos , Triptofano/análise , 1-Fosfatidilinositol 4-Quinase , Isótopos de Carbono , Histidina/química , Hidrogênio , Processamento de Imagem Assistida por Computador , Isótopos de Nitrogênio , Fosfotransferases (Aceptor do Grupo Álcool)/química , Triptofano/química
14.
J Autism Dev Disord ; 14(2): 183-9, 1984 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6086566

RESUMO

Two cases of congenital cytomegalovirus infection associated with autism are reported. The viral hypothesis of autism is discussed along with a brief review of the literature. Suggestions are made for future research.


Assuntos
Transtorno Autístico/etiologia , Infecções por Citomegalovirus/congênito , Adoção , Desenvolvimento Infantil , Pré-Escolar , Infecções por Citomegalovirus/diagnóstico , Feminino , Humanos , Lactente , Masculino
15.
Nature ; 237(5357): 510-2, 1972 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-12635200
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