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1.
Poult Sci ; 101(12): 102194, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36274436

RESUMO

For many producers, introduction of improved animal welfare systems is a turning point in their future production strategies as it increases production costs. The increase in egg retail prices is of growing concern not only for producers, but also for retailers and consumers. However, no report has calculated the estimated production costs or retail prices associated with introducing practices that support improved animal welfare in poultry farms in Japan. Therefore, this study aimed to estimate the production costs and table egg prices of 6 types of laying hen systems: conventional cage (CC): 8- and 12-tiers (CC8, CC12), enriched cage (EC): 8- and 12-tiers (EC8, EC12), aviary (AV), and barn systems (BR). Production costs include land purchases, construction costs of facilities, equipment and machinery, quantity of feed provided, farming materials invested, and wages. As a result, farm gate prices were estimated as CC8 = 12.19, CC12 = 12.19, EC8 = 14.52, EC12 = 14.52, AV = 21.14, and BR = 28.74 [yen/egg], and the production cost, including building the new farm, increased by EC8 = 19.1%, EC12 = 19.1%, AV = 73.4%, and BR = 135.7%, respectively, referring to the value of CC. The results show that the prices increase in systems between CC and BN. The retail price or table egg price was estimated to be CC8 = 24.68, CC12 = 24.68, EC8 = 28.07, EC12 = 28.07, AV = 37.27, and BR = 48.53 [yen/egg]. The retail price of BR is approximately twice that of CC. In addition, assuming that all of Japan's eggs were produced in the BR system, the soaring cost of eggs would likely affect the prices of factory eggs, such as liquid eggs and other products, thus affecting the prices of various food products. Understanding the significant management costs that affect the retail price of eggs would facilitate improved policies and practical approaches to support poultry farms and sustainable farming activities while addressing public concerns.


Assuntos
Criação de Animais Domésticos , Abrigo para Animais , Animais , Feminino , Criação de Animais Domésticos/métodos , Galinhas , Aves Domésticas , Japão , Óvulo
3.
Phys Rev Lett ; 122(15): 159903, 2019 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-31050523

RESUMO

This corrects the article DOI: 10.1103/PhysRevLett.117.127202.

4.
Sci Adv ; 4(12): eaat9989, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30539144

RESUMO

Multiferroic materials with both ferroelectric and ferromagnetic orders provide a promising arena for the electrical manipulation of magnetization through the mutual correlation between those ferroic orders. Such a concept of multiferroics may expand to semiconductor with both broken symmetries of spatial inversion and time reversal, that is, polar ferromagnetic semiconductors. Here, we report the observation of current-driven magnetization switching in one such example, (Ge,Mn)Te thin films. The ferromagnetism caused by Mn doping opens an exchange gap in original massless Dirac band of the polar semiconductor GeTe with Rashba-type spin-split bands. The anomalous Hall conductivity is enhanced with increasing hole carrier density, indicating that the contribution of the Berry phase is maximized as the Fermi level approaches the exchange gap. By means of pulse-current injection, the electrical switching of the magnetization is observed in the (Ge,Mn)Te thin films as thick as 200 nm, pointing to the Rashba-Edelstein effect of bulk origin. The efficiency of this effect strongly depends on the Fermi-level position owing to the efficient spin accumulation at around the gap. The magnetic bulk Rashba system will be a promising platform for exploring the functional correlations among electric polarization, magnetization, and current.

5.
Clin Radiol ; 73(12): 1059.e1-1059.e8, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30245069

RESUMO

AIM: To assess potential prognostic factors in pharynx squamous cell carcinoma (SCC) patients by quantitative morphological and intratumoural characteristics obtained by 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT). MATERIALS AND METHODS: The cases of 54 patients with pharynx SCC who underwent chemoradiation therapy were analysed retrospectively. Using their FDG-PET data, the quantitative morphological and intratumoural characteristics of 14 parameters were calculated. The progression-free survival (PFS) and overall survival (OS) information was obtained from patient medical records. Univariate and multivariate analyses were performed to assess the 14 quantitative parameters as well as the T-stage, N-stage, and tumour location data for their relation to PFS and OS. When an independent predictor was suggested in the multivariate analysis, the parameter was further assessed using the Kaplan-Meier method. RESULTS: In the assessment of PFS, the univariate and multivariate analyses indicated the following as independent predictors: the texture parameter of homogeneity and the morphological parameter of sphericity. In the Kaplan-Meier analysis, the PFS rate was significantly improved in the patients who had both a higher value of homogeneity (p=0.01) and a higher value of sphericity (p=0.002). With the combined use of homogeneity and sphericity, the patients with different PFS rates could be divided more clearly. CONCLUSION: The quantitative parameters of homogeneity and sphericity obtained by FDG-PET can be useful for the prediction of the PFS of pharynx SCC patients, especially when used in combination.


Assuntos
Neoplasias Laríngeas/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Carcinoma de Células Escamosas de Cabeça e Pescoço/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Idoso , Quimiorradioterapia , Feminino , Humanos , Neoplasias Laríngeas/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Taxa de Sobrevida , Carga Tumoral
6.
Phys Chem Chem Phys ; 20(7): 4962-4969, 2018 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-29387834

RESUMO

Cationic disorder in the MgAl2O4 spinel induced by swift heavy ions was investigated using the X-ray absorption near edge structure. With changes in the irradiation fluences of 200 MeV Xe ions, the Mg K-edge and Al K-edge spectra were synchronously changed. The calculated spectra based on density function theory indicate that the change in the experimental spectra was due to cationic disorder between Mg in tetrahedral sites and Al in octahedral sites. These results suggest a high inversion degree to an extent that the completely random configuration is achieved in MgAl2O4 induced by the high density electronic excitation under swift heavy ion irradiation.

7.
Diabet Med ; 35(5): 602-611, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29444352

RESUMO

AIMS: To assess the predictive ability of a genetic risk score for the incidence of Type 2 diabetes in a general Japanese population. METHODS: This prospective case-control study, nested within a Japan Public Health Centre-based prospective study, included 466 participants with incident Type 2 diabetes over a 5-year period (cases) and 1361 control participants, as well as 1463 participants with existing diabetes and 1463 control participants. Eleven susceptibility single nucleotide polymorphisms, identified through genome-wide association studies and replicated in Japanese populations, were analysed. RESULTS: Most single nucleotide polymorphism loci showed directionally consistent associations with diabetes. From the combined samples, one single nucleotide polymorphism (rs2206734 at CDKAL1) reached a genome-wide significance level (odds ratio 1.28, 95% CI 1.18-1.40; P = 1.8 × 10-8 ). Three single nucleotide polymorphisms (rs2206734 in CDKAL1, rs2383208 in CDKN2A/B, and rs2237892 in KCNQ1) were nominally significantly associated with incident diabetes. Compared with the lowest quintile of the total number of risk alleles, the highest quintile had a higher odds of incident diabetes (odds ratio 2.34, 95% CI 1.59-3.46) after adjusting for conventional risk factors such as age, sex and BMI. The addition to the conventional risk factor-based model of a genetic risk score using the 11 single nucleotide polymorphisms significantly improved predictive performance; the c-statistic increased by 0.021, net reclassification improved by 6.2%, and integrated discrimination improved by 0.003. CONCLUSIONS: Our prospective findings suggest that the addition of a genetic risk score may provide modest but significant incremental predictive performance beyond that of the conventional risk factor-based model without biochemical markers.


Assuntos
Povo Asiático/genética , Diabetes Mellitus Tipo 2/genética , Adulto , Idoso , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Estudos de Casos e Controles , Inibidor de Quinase Dependente de Ciclina p15/genética , Inibidor p16 de Quinase Dependente de Ciclina , Inibidor de Quinase Dependente de Ciclina p18/genética , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Predisposição Genética para Doença , Proteínas de Homeodomínio/genética , Humanos , Incidência , Proteínas Substratos do Receptor de Insulina/genética , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Japão/epidemiologia , Canal de Potássio KCNQ1/genética , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares/genética , PPAR gama/genética , Canais de Potássio Corretores do Fluxo de Internalização/genética , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , Fatores de Transcrição/genética , Enzimas de Conjugação de Ubiquitina/genética , tRNA Metiltransferases/genética
8.
Equine Vet Educ ; 30(3): 151-160, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32313396

RESUMO

While certainly not a novel concept, faecal microbiota transplant (FMT) has recently garnered renewed interest in veterinary medicine due to its remarkable success in treating recurrent Clostridium difficile infection (CDI) in man. There is a dearth of information on indications and efficacy of FMT for the treatment of gastrointestinal disorders in the horse; however, based on evidence in man and other veterinary species, and anecdotal reports in horses, FMT may be a useful treatment for selected cases of acute and chronic diarrhoea and inflammatory bowel disease (IBD) in the horse. In the absence of evidence, expert opinion is offered on case selection and FMT procedure. More research is needed to explore the efficacy, indications and optimal preparation, storage and delivery of FMT to horses.

9.
Science ; 358(6368): 1311-1314, 2017 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-29217573

RESUMO

Electronic ordering in magnetic and dielectric materials forms domains with different signs of order parameters. The control of configuration and motion of the domain walls (DWs) enables nonvolatile responses against minute external fields. Here, we realize chiral edge states (CESs) on the magnetic DWs of a magnetic topological insulator. We design and fabricate the magnetic domains in the quantum anomalous Hall state with the tip of a magnetic force microscope and prove the existence of the chiral one-dimensional edge conduction along the prescribed DWs through transport measurements. The proof-of-concept devices based on reconfigurable CESs and Landauer-Büttiker formalism are realized for multiple-domain configurations with well-defined DW channels. Our results may lead to the realization of low-power-consumption spintronic devices.

10.
Transl Psychiatry ; 7(2): e1047, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28244984

RESUMO

In understanding the mechanism of schizophrenia pathogenesis, a significant finding is that drug abuse of phencyclidine or its analog ketamine causes symptoms similar to schizophrenia. Such drug effects are triggered even by administration at post-adolescent stages. Both drugs are N-methyl-d-aspartate receptor (NMDAR) antagonists, leading to a major hypothesis that glutamate hypofunction underlies schizophrenia pathogenesis. The precise region that depends on NMDAR function, however, is unclear. Here, we developed a mouse strain in which NMDARs in the intralaminar thalamic nuclei (ILN) were selectively disrupted. The mutant mice exhibited various schizophrenia-like phenotypes, including deficits in working memory, long-term spatial memory, and attention, as well as impulsivity, impaired prepulse inhibition, hyperlocomotion and hyperarousal. The electroencephalography analysis revealed that the mutant mice had a significantly reduced power in a wide range of frequencies including the alpha, beta and gamma bands, both during wake and rapid eye movement (REM) sleep, and a modest decrease of gamma power during non-REM sleep. Notably, restoring NMDARs in the adult ILN rescued some of the behavioral abnormalities. These findings suggest that NMDAR dysfunction in the ILN contributes to the pathophysiology of schizophrenia-related disorders. Furthermore, the reversal of inherent schizophrenia-like phenotypes in the adult mutant mice supports that ILN is a potential target site for a therapeutic strategy.


Assuntos
Comportamento Animal , Núcleos Intralaminares do Tálamo/metabolismo , Proteínas do Tecido Nervoso/genética , Receptores de N-Metil-D-Aspartato/genética , Esquizofrenia/genética , Animais , Nível de Alerta , Atenção , Modelos Animais de Doenças , Eletroencefalografia , Terapia Genética , Comportamento Impulsivo , Locomoção , Masculino , Aprendizagem em Labirinto , Memória de Curto Prazo , Camundongos , Camundongos Transgênicos , Mutação , Fenótipo , Inibição Pré-Pulso , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Memória Espacial
11.
Phys Rev Lett ; 119(13): 137204, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-29341677

RESUMO

The current-nonlinear Hall effect or second harmonic Hall voltage is widely used as one of the methods for estimating charge-spin conversion efficiency, which is attributed to the magnetization oscillation by spin-orbit torque (SOT). Here, we argue the second harmonic Hall voltage under a large in-plane magnetic field with an in-plane magnetization configuration in magnetic-nonmagnetic topological insulator (TI) heterostructures, Cr_{x}(Bi_{1-y}Sb_{y})_{2-x}Te_{3}/(Bi_{1-y}Sb_{y})_{2}Te_{3}, where it is clearly shown that the large second harmonic voltage is governed not by SOT but mainly by asymmetric magnon scattering without macroscopic magnetization oscillation. Thus, this method does not allow an accurate estimation of charge-spin conversion efficiency in TI. Instead, the SOT contribution is exemplified by current pulse induced nonvolatile magnetization switching, which is realized with a current density of 2.5×10^{10} A m^{-2}, showing its potential as a spintronic material.

12.
Phys Rev Lett ; 117(12): 127202, 2016 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-27689294

RESUMO

We report current-direction dependent or unidirectional magnetoresistance (UMR) in magnetic or nonmagnetic topological insulator (TI) heterostructures, Cr_{x}(Bi_{1-y}Sb_{y})_{2-x}Te_{3}/(Bi_{1-y}Sb_{y})_{2}Te_{3}, that is several orders of magnitude larger than in other reported systems. From the magnetic field and temperature dependence, the UMR is identified to originate from the asymmetric scattering of electrons by magnons. In particular, the large magnitude of UMR is an outcome of spin-momentum locking and a small Fermi wave number at the surface of TI. In fact, the UMR is maximized around the Dirac point with the minimal Fermi wave number.

13.
Nat Commun ; 7: 12246, 2016 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-27435028

RESUMO

Magnetic interactions in topological insulators cause essential modifications in the originally mass-less surface states. They offer a mass gap at the Dirac point and/or largely deform the energy dispersion, providing a new path towards exotic physics and applications to realize dissipation-less electronics. The nonequilibrium electron dynamics at these modified Dirac states unveil additional functions, such as highly efficient photon to spin-current conversion. Here we demonstrate the generation of large zero-bias photocurrent in magnetic topological insulator thin films on mid-infrared photoexcitation, pointing to the controllable band asymmetry in the momentum space. The photocurrent spectra with a maximal response to the intra-Dirac-band excitations can be a sensitive measure for the correlation between Dirac electrons and magnetic moments.

14.
Colorectal Dis ; 18(8): O278-82, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27354363

RESUMO

AIM: Ulcerative colitis (UC) is considered to be a disease of continuous mucosal inflammation extending proximally from the rectum. However, appendiceal orifice inflammation (AOI) is a skip lesion with segments of continuous involvement from the rectum. The aim of this study was to examine the clinical characteristics and clinical course, particularly focused on proximal extension, of UC in patients with AOI. METHOD: A retrospective evaluation of patients with UC who underwent total colonoscopy at the Department of Surgical Oncology, The University of Tokyo, from 2004 to 2014. The degree of AOI was graded endoscopically as follows: 0 (no inflammation); 1 (slight oedema); 2 (moderate inflammation); and 3 (marked inflammation). A total of 189 patient records were reviewed retrospectively. The presence of AOI was analysed with regard to the clinical information of each patient, and its association with proximal extension of proctitis or left-sided colitis was evaluated. RESULTS: Of 189 patients with UC who underwent total colonoscopy at our institution, 92 were diagnosed with pancolitis, 50 with left-sided colitis and 47 with proctitis. Endoscopic findings of AOI were observed in 26 patients, including 11 (12.0%) with pancolitis, six (12.0%) with left-sided colitis and nine (19.1%) with proctitis. During follow up, proximal extension of the disease occurred in all nine patients with proctitis AOI. CONCLUSION: AOI is more frequently observed in patients with proctitis. Our results showed correlations between AOI and subsequent proximal extension of mucosal inflammation in patients with proctitis.


Assuntos
Apendicite/patologia , Colite Ulcerativa/patologia , Colo/patologia , Colonoscopia , Proctite/patologia , Reto/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Apêndice/patologia , Criança , Colo Descendente/patologia , Colo Sigmoide/patologia , Feminino , Humanos , Inflamação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
15.
Diabetes Metab ; 42(5): 368-371, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27161346

RESUMO

AIM: As a low-pigment skin type is prevalent in men and women with type 1 diabetes, it is possible that skin pigmentation may be associated with insulin resistance. This study aimed to cross-sectionally examine this association in healthy women. METHODS: Study participants were 792 Japanese women who attended a health examination and were not taking any medication for diabetes. Skin pigmentation on the inner upper and lower arms and forehead was measured using a Mexameter® skin colorimeter, a narrow-band reflective spectrophotometer. Data are expressed as a melanin index, which quantifies melanin content. Fasting blood glucose and insulin levels were also measured, and homoeostasis model assessment for insulin resistance (HOMA-IR) scores were calculated. Information on medical history and lifestyle factors were obtained by a self-administered questionnaire, while data on sun exposure were collected through interviews. Plasma 25-hydroxyvitamin D levels were measured in a subsample of women (n=464). RESULTS: Melanin indices at the inner upper and lower arms were significantly and inversely associated with fasting insulin levels and HOMA-IR after controlling for age, body mass index, smoking status, indicators for rater effects, cumulative sun exposure and season at the time of measurement. Additional adjustment for plasma 25-hydroxyvitamin D levels did not alter the results. CONCLUSION: These data suggest that skin pigmentation is associated with insulin resistance, and encourage future studies into the potential role of melanin and related factors in glucose homoeostasis.


Assuntos
Povo Asiático/estatística & dados numéricos , Resistência à Insulina/fisiologia , Pigmentação da Pele/fisiologia , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Análise de Regressão , Luz Solar , Vitamina D/sangue , Adulto Jovem
16.
J Clin Pharm Ther ; 41(1): 19-25, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26678686

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Antimicrobial stewardship is required to ensure the appropriate use of antimicrobials. However, no reports have been published on clinical outcomes of implementation of antimicrobial stewardship in patients receiving pathogen-specific antibiotics. METHOD: To evaluate the clinical outcomes of patients who received drugs, we conducted a single-centre, retrospective study of the effects of an antimicrobial stewardship programme targeting methicillin-resistant Staphylococcus aureus (MRSA). RESULTS: The time to administer effective antimicrobials was significantly (median number of days, 3 before vs. 0 after, P < 0·001) shortened, and the rate of de-escalation was significantly elevated (47·1% vs. 96·2%, P < 0·001) after implementation of daily review. The 60-day clinical failure associated with Gram-positive bacterial infection was significantly reduced (33·3% vs. 17·6%, P = 0·007) after intervention. WHAT IS NEW AND CONCLUSIONS: Daily review of administration of antimicrobials targeting MRSA was highly effective in improving clinical outcomes by optimizing early antimicrobial therapy.


Assuntos
Antibacterianos/administração & dosagem , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Idoso , Antibacterianos/uso terapêutico , Revisão de Uso de Medicamentos , Feminino , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Estafilocócicas/microbiologia , Fatores de Tempo , Resultado do Tratamento
18.
Nat Commun ; 6: 8530, 2015 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-26497065

RESUMO

By breaking the time-reversal symmetry in three-dimensional topological insulators with the introduction of spontaneous magnetization or application of magnetic field, the surface states become gapped, leading to quantum anomalous Hall effect or quantum Hall effect, when the chemical potential locates inside the gap. Further breaking of inversion symmetry is possible by employing magnetic topological insulator heterostructures that host non-degenerate top and bottom surface states. Here we demonstrate the tailored-material approach for the realization of robust quantum Hall states in the bilayer system, in which the cooperative or cancelling combination of the anomalous and ordinary Hall responses from the respective magnetic and non-magnetic layers is exemplified. The appearance of quantum Hall states at filling factor 0 and +1 can be understood by the relationship of energy band diagrams for the two independent surface states. The designable heterostructures of magnetic topological insulator may explore a new arena for intriguing topological transport and functionality.

19.
Eur J Clin Nutr ; 69(4): 462-6, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25469462

RESUMO

BACKGROUND/OBJECTIVES: Although adipokines and insulin resistance are known to be correlated with body fatness, it is unclear whether they are independently related to weight gain experience. We examined the associations of serum adipokines and marker of insulin resistance with past weight gain during adulthood by taking the degree of attained body mass index (BMI) level into consideration. SUBJECTS/METHODS: Subjects were 399 Japanese municipal employees, aged ⩾ 30 years, who participated in a health survey. Serum adipokines were measured using a Luminex suspension bead-based multiplexed array. Weight change during adulthood was calculated as the difference between measured current weight and recalled weight at the age of 20 years. Multiple regression was performed to calculate mean adipokine levels and homeostasis model assessment of insulin resistance (HOMA-IR) according to weight gain (< 5 kg, 5-9.9 kg, or ⩾ 10 kg) with adjustment for current BMI. RESULTS: Weight gain from the age of 20 years was significantly and positively associated with leptin levels even after adjustment for current BMI (P for trend < 0.001), whereas it was significantly and inversely associated with adiponectin levels in a BMI-adjusted model among subjects aged ⩾ 40 years (P for trend=0.03). Weight gain was associated with HOMA-IR in a BMI-unadjusted model (P for trend < 0.001), but this association was largely attenuated after adjustment for BMI. Resistin, plasminogen activator inhibitor-1 and visfatin were not associated with past weight gain. CONCLUSIONS: Results suggest that a large weight gain during adulthood is associated with higher leptin and lower adiponectin levels independently of the degree of attained BMI level.


Assuntos
Adiponectina/sangue , Resistência à Insulina , Leptina/sangue , Aumento de Peso , Tecido Adiposo/metabolismo , Adulto , Povo Asiático , Biomarcadores/sangue , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Estilo de Vida , Modelos Lineares , Masculino , Nicotinamida Fosforribosiltransferase/sangue , Inibidor 1 de Ativador de Plasminogênio/sangue , Resistina/sangue , Adulto Jovem
20.
J Econ Entomol ; 107(4): 1662-73, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25195460

RESUMO

The preferences of the West Indian sweet potato weevil, Euscepes postfasciatus (Fairmaire), to tubers of sweet potato, Ipomoea batatas (L.), for food and for oviposition were evaluated, and correlated to sweet potato's resistance to immatures. Adults (parent) were released in a plastic box containing tubers of sweet potato cultivars and maintained for 5 d, after which the adults on each tuber were counted. All adults were then removed and each tuber was maintained separately. New adults that emerged from the tubers were counted. Cultivars were grouped by cluster analyses using the number of parent adults on the tubers and the number of new adults emerging from the tubers, adjusted for the weight of each tuber. Cultivars were divided into five groups: average level of preference, preferred, preferred for oviposition but not for food, preferred for food but not for oviposition, and not preferred. New adults from the first two groups took less time to eclose than those from the other groups, and their body size was smaller. In a second experiment, one to five cultivars were selected from each group and inoculated each tuber with 10 weevil eggs on each cultivar. Although the proportion of eclosed adults was not significantly different between cultivars, the time to eclosion was shorter and body size was smaller on preferred cultivars. The selection of tubers by parent adults was not linearly related with larval development, and did not reduce the survival of the immatures.


Assuntos
Preferências Alimentares , Herbivoria , Ipomoea batatas/fisiologia , Oviposição , Gorgulhos/fisiologia , Animais , Análise por Conglomerados , Larva/fisiologia , Distribuição Aleatória
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