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1.
J Forensic Sci ; 65(1): 84-89, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31454431

RESUMO

Impressions of friction ridges left on a surface are important evidence for identifying an individual and can be used to confirm his or her presence at the scene of an incident. Factors influencing the durability of fingerprints include the physiological characteristics and cleanliness of the individual, environmental factors, and time. The aim of the study was to determine the effect of atmospheric factors, gender, hand cleanliness and time on the width of friction ridge impressions and the amount of material forming the print. The research shows that factors such as gender, ambient conditions, and hand cleanliness affect the width of the ridge impressions and the quantity of material forming the print. The passage of time significantly reduces both the width of the ridge impressions and the quantity of the material forming the print.


Assuntos
Dermatoglifia , Higiene das Mãos , Manejo de Espécimes , Adulto , Escuridão , Exposição Ambiental , Feminino , Humanos , Luz , Masculino , Microscopia , Fatores Sexuais , Creme para a Pele , Temperatura Ambiente , Fatores de Tempo , Adulto Jovem
2.
Zootaxa ; 4560(2): zootaxa.4560.2.2, 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-31716579

RESUMO

Land leeches in the family Haemadipsidae are mostly from the humid tropical rainforest habitats and habitually take blood from the body of human and other animals. In the present study, we report a new species, Sinospelaeobdella wulingensis sp. n., from caves in the northern subtropical Wuling Mountains of central-south China that feeds blood exclusively on cave-dwelling bats. Based on morphological characteristics, COI gene sequence divergence, and phylogenetic analysis, a new genus Sinospelaeobdella gen. n. is established for the new species, to which a previously described species Haemadipsa cavatuses Yang et al., 2009 is transferred as S. cavatuses comb. n. We also provided extended discussion on phylogenetic relationship within the "Tritetrabdellinae" clade uncovered in a previous study, DNA taxonomy, morphological and behavioral adaptions, biogeography, and possible involvement of Sinospelaeobdella gen. n. in bat transmitted diseases of public concerns.


Assuntos
Quirópteros , Sanguessugas , Animais , China , Escuridão , Humanos , Filogenia
3.
Plant Mol Biol ; 101(4-5): 487-498, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31560104

RESUMO

KEY MESSAGE: The transcriptional profile of roots is highly affected by shoot illumination. Transcriptogram analysis allows the identification of cellular processes that are not detected by DESeq. Light is a key environmental factor regulating plant growth and development. Arabidopsis thaliana seedlings grown under light display a photomorphogenic development pattern, showing short hypocotyl and long roots. On the other hand, when grown in darkness, they display skotomorphogenic development, with long hypocotyls and short roots. Although many signals from shoots might be important for triggering root growth, the early transcriptional responses that stimulate primary root elongation are still unknown. Here, we aimed to investigate which genes are involved in the early photomorphogenic root development of dark grown roots. We found that 1616 genes 4 days after germination (days-old), and 3920 genes 7 days-old were differently expressed in roots when the shoot was exposed to light. Of these genes, 979 were up regulated in 4 days and 2784 at 7 days-old. We compared the functional categorization of differentially regulated processes by two methods: GO term enrichment and transcriptogram analysis. Expression analysis of nine selected candidate genes in roots confirmed the data observed in the RNA-seq analysis. Loss-of-function mutants of these selected differentially expressed genes suggest the involvement of these genes in root development in response to shoot illumination. Our findings are consistent with the observation that dark grown roots respond to the shoot-perceived aboveground light environment.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Transcriptoma , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Escuridão , Iluminação , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/efeitos da radiação , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/efeitos da radiação , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/efeitos da radiação
4.
Adv Gerontol ; 32(3): 347-356, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31512420

RESUMO

We studied the effect of prolonged absence of a photoperiodic signal (constant lighting and constant darkness) on the changes of digestive enzymes' activity in late postnatal ontogenesis of rats. Age-related alterations are characterized as a change in activity of enzymes, as well as a redistribution of the functional activity between the amylo- and lipolytic links, the upper and lower divisions of the gastrointestinal tract. It was shown that along with age, the activity of enzymes is affected both by the absence of photoperiodism and by the level of melatonin associated with the light regime. In conditions of light deprivation the age-related changes characterizing the «aging¼ of the digestive system are observed later compared with standard illumination and especially constant illumination.


Assuntos
Escuridão , Enzimas , Trato Gastrointestinal , Melatonina , Fotoperíodo , Fatores Etários , Animais , Ritmo Circadiano , Ativação Enzimática , Enzimas/metabolismo , Trato Gastrointestinal/enzimologia , Trato Gastrointestinal/crescimento & desenvolvimento , Luz , Melatonina/metabolismo , Ratos
5.
Acta Psychol (Amst) ; 199: 102901, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31398623

RESUMO

Based on theories of grounded cognition, we assumed that the experience of social exclusion is grounded in a concept of darkness. Specifically, we hypothesized that social exclusion causes perceptual judgments of darkness and a preference for brightness as a compensatory response. To investigate these hypotheses, we conducted four studies using different manipulations and measurements. In Studies 1a and 1b, excluded participants judged a picturized room as darker and drew more attention to its brightest part than included participants. In Study 2, excluded participants judged a surface as darker and decided for brighter clothing than included participants. In Study 3, excluded participants judged their lab room as darker and expressed a higher preference for brightness than included participants. Providing consistent support for our hypotheses, these findings confirm the idea that the experience of social exclusion is grounded in multiple ways that share a common representational system.


Assuntos
Escuridão , Relações Interpessoais , Julgamento/fisiologia , Distância Social , Adolescente , Adulto , Feminino , Humanos , Luz , Masculino , Distribuição Aleatória , Adulto Jovem
6.
Mar Pollut Bull ; 146: 85-91, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426228

RESUMO

In order to understand how darkness/irradiance and low nighttime temperature might alter physiology of Ulva prolifera under lower salinity conditions, we analyzed the growth rates, water content, superoxide dismutase (SOD) activity, total soluble proteins (SPs) and carbohydrates content at the end of dark and light period under three temperature levels (25-25 °C treatment: 25 °C for day and night; 15-15 °C treatment: 15 °C for day and night; 25-15 °C treatment: 25 °C for day with 15 °C for night) and two salinity conditions (15, 25), meanwhile, the pigment content (chlorophyll a and b), chlorophyll fluorescence and photosynthetic oxygen evolution also were determined during light phase. We found that the U. prolifera showed higher growth rate and SOD activity during dark phase at 25 °C, but this dark-induced increase could not be observed at 15 °C. The reasons for this increase varied, however, maybe not included water content and SPs for no significant difference in water content observed under all the treatments, as well as lower SPs content for dark period aside that at 15 °C and salinity 15. Compared to other two temperature treatments, the thalli grown at 25-15 °C showed higher growth rate and the photosynthetic oxygen evolution rate in light phase under salinity 15 conditions, although the maximum relative electron transport rate (rETRmax) showed higher value under 25 °C treatment. These results indicate that the darkness and the lower nighttime temperature maybe responsible reason for the rapid growth of these green tide algae.


Assuntos
Ulva/fisiologia , Clorofila/metabolismo , Escuridão , Oxigênio/metabolismo , Fotossíntese/fisiologia , Proteínas de Plantas/metabolismo , Salinidade , Superóxido Dismutase/metabolismo , Temperatura Ambiente , Ulva/crescimento & desenvolvimento
7.
Arch Insect Biochem Physiol ; 102(4): e21605, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31328825

RESUMO

The pathways of insect melatonin (MEL) biosynthesis apparently follow the same routes as those identified in vertebrates but information on MEL synthesis variations related with serotonin (5-HT), 5-hydroxy-indole acetic acid (5HIAA), and N-acetylserotonin (NAS) levels, as well as 5-HT N-acetyltransferase (NAT) activity throughout the day, is very limited in the insect nervous system. In the present study, the levels of MEL, metabolites (5-HT, NAS, and 5-HIAA) and enzyme NAT were determined in the optic lobes and the midbrain of the grasshopper Oedipoda caerulescens, in conditions of light and darkness. In both tissues, a different pattern of MEL synthesis was observed over the light/dark cycle. Variations in the levels of 5-HT, NAS and NAT activity related to the synthesis of cerebral MEL follow a pattern very similar to that observed in the pineal of mammals, with a peak of synthesis in the first half of the scotophase. Also, we observed differences in the metabolism of 5-HT between the optic lobes and the midbrain light/dark-dependent.


Assuntos
Encéfalo/metabolismo , Gafanhotos/metabolismo , Melatonina/biossíntese , Animais , Arilalquilamina N-Acetiltransferase/metabolismo , Escuridão , Gafanhotos/efeitos da radiação , Ácido Hidroxi-Indolacético/metabolismo , Luz , Masculino , Melatonina/efeitos da radiação , Serotonina/análogos & derivados , Serotonina/metabolismo
8.
ScientificWorldJournal ; 2019: 1030236, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31346323

RESUMO

The unicellular halotolerant cyanobacterium Aphanothece halophytica is a potential dark fermentative producer of molecular hydrogen (H2) that produces very little H2 under illumination. One factor limiting the H2 photoproduction of this cyanobacterium is an inhibition of bidirectional hydrogenase activity by oxygen (O2) obtained from splitting water molecules via photosystem II activity. The present study aimed to investigate the effects of the photosystem II inhibitors carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) on H2 production of A. halophytica under light and dark conditions and on photosynthetic and respiratory activities. The results showed that A. halophytica treated with CCCP and DCMU produced H2 at three to five times the rate of untreated cells, when exposed to light. The highest H2 photoproduction rates, 2.26 ±â€Š0.24 and 3.63 ±â€Š0.26 µmol H2 g-1 dry weight h-1, were found in cells treated with 0.5 µM CCCP and 50 µM DCMU, respectively. Without inhibitor treatment, A. halophytica incubated in the dark showed a significant increase in H2 production compared with cells that were incubated in the light. Only CCCP treatment increased H2 production of A. halophytica during dark incubation, because CCCP functions as an uncoupling agent of oxidative phosphorylation. The highest dark fermentative H2 production rate of 39.50 ±â€Š2.13 µmol H2 g-1 dry weight h-1 was found in cells treated with 0.5 µM CCCP after 2 h of dark incubation. Under illumination, CCCP and DCMU inhibited chlorophyll fluorescence, resulting in a low level of O2, which promoted bidirectional hydrogenase activity in A. halophytica cells. In addition, only CCCP enhanced the respiration rate, further reducing the O2 level. In contrast, DCMU reduced the respiration rate in A. halophytica.


Assuntos
Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Cianobactérias/efeitos dos fármacos , Cianobactérias/metabolismo , Diurona/farmacologia , Hidrogênio/metabolismo , Complexo de Proteína do Fotossistema II/antagonistas & inibidores , Respiração Celular/efeitos dos fármacos , Respiração Celular/efeitos da radiação , Clorofila A/metabolismo , Escuridão , Hidrogenase/metabolismo , Fotossíntese/efeitos dos fármacos
9.
J Physiol Sci ; 69(5): 791-798, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31301005

RESUMO

Serum testosterone concentration decreases with age in humans and rodents. Accordingly, old male mice show changes in locomotor activity rhythms: a lengthened free-running period and decreased activity levels among others. To investigate whether testosterone replacement improves the age-related decline in circadian rhythmicity, we examined the effects of testosterone on the circadian rhythms of wheel running activity in old male mice. Intact male C57BL/6J mice (18-22 months old) were subcutaneously implanted with silicone tubes packed with testosterone propionate (TP) or cholesterol. TP treatment significantly decreased the daily wheel running revolutions in a normal light/dark (LD) cycle and in constant darkness (DD), but did not affect the free-running period. The same experiment performed on young male gonadectomized mice (3-5 months old) demonstrated that TP treatment significantly increased activity levels in both LD and DD. These results suggest that testosterone replacement exacerbates the age-related decline in circadian rhythmicity.


Assuntos
Ritmo Circadiano/efeitos dos fármacos , Testosterona/farmacologia , Animais , Escuridão , Luz , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Fotoperíodo
10.
PLoS Genet ; 15(7): e1007655, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31356596

RESUMO

Circadian clocks control the timing of animal behavioral and physiological rhythms. Fruit flies anticipate daily environmental changes and exhibit two peaks of locomotor activity around dawn and dusk. microRNAs are small non-coding RNAs that play important roles in post-transcriptional regulation. Here we identify Drosophila miR-210 as a critical regulator of circadian rhythms. Under light-dark conditions, flies lacking miR-210 (miR-210KO) exhibit a dramatic 2 hrs phase advance of evening anticipatory behavior. However, circadian rhythms and molecular pacemaker function are intact in miR-210KO flies under constant darkness. Furthermore, we identify that miR-210 determines the evening phase of activity through repression of the cell adhesion molecule Fasciclin 2 (Fas2). Ablation of the miR-210 binding site within the 3' UTR of Fas2 (Fas2ΔmiR-210) by CRISPR-Cas9 advances the evening phase as in miR-210KO. Indeed, miR-210 genetically interacts with Fas2. Moreover, Fas2 abundance is significantly increased in the optic lobe of miR-210KO. In addition, overexpression of Fas2 in the miR-210 expressing cells recapitulates the phase advance behavior phenotype of miR-210KO. Together, these results reveal a novel mechanism by which miR-210 regulates circadian locomotor behavior.


Assuntos
Moléculas de Adesão Celular Neuronais/genética , Drosophila melanogaster/fisiologia , Locomoção , MicroRNAs/genética , Regiões 3' não Traduzidas , Animais , Sistemas CRISPR-Cas , Ritmo Circadiano , Escuridão , Drosophila melanogaster/genética , Técnicas de Inativação de Genes , Mutação
11.
Genes (Basel) ; 10(7)2019 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-31252693

RESUMO

The sea slug Onchidium reevesii inhabits the intertidal zone, which is characterized by a changeable environment. Although the circadian modulation of long-term memory (LTM) is well documented, the interaction of the circadian clock with light-dark masking in LTM of intertidal animals is not well understood. We characterized the LTM of Onchidium and tested the expression levels of related genes under a light-dark (LD) cycle and constant darkness (i.e., dark-dark, or DD) cycle. Results indicated that both learning behavior and LTM show differences between circadian time (CT) 10 and zeitgeber time (ZT) 10. In LD, the cry1 gene expressed irregularly, and per2 expression displayed a daily pattern and a peak expression level at ZT 18. OnCREB1 (only in LD conditions) and per2 transcripts cycled in phase with each other. In DD, the cry1 gene had its peak expression at CT 10, and per2 expressed its peak level at CT 18. OnCREB1 had two peak expression levels at ZT 10 or ZT 18 which correspond to the time node of peaks in cry1 and per2, respectively. The obtained results provide an LTM pattern that is different from other model species of the intertidal zone. We conclude that the daily transcriptional oscillations of Onchidium for LTM were affected by circadian rhythms and LD cycle masking.


Assuntos
Relógios Circadianos/genética , Ritmo Circadiano/genética , Gastrópodes/metabolismo , Memória de Longo Prazo/fisiologia , Animais , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Criptocromos/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Escuridão , Gastrópodes/genética , Proteínas Circadianas Period/metabolismo , Fotoperíodo
12.
Neural Plast ; 2019: 7624837, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31178904

RESUMO

Recent studies conducted on kittens have revealed that the reduced visual acuity of the deprived eye following a short period of monocular deprivation imposed in early life is reversed quickly following a 10-day period spent in total darkness. This study explored the contribution of the fellow eye to the darkness-induced recovery of the acuity of the deprived eye. Upon emergence of kittens from darkness, the fellow eye was occluded for different lengths of time in order to investigate its effects on either the speed or the extent of the recovery of acuity of the deprived eye. Occlusion of the fellow eye for even a day immediately following the period spent in darkness blocked any recovery of the acuity of the deprived eye. Moreover, occlusion of the fellow eye two days after the period of darkness blocked any further visual recovery beyond that achieved in the short period when both eyes were open. The results imply that the darkness-induced recovery of the acuity of the deprived eye depends upon, and is guided by, neural activity in the mature neural connections previously established by the fellow eye.


Assuntos
Ambliopia/fisiopatologia , Fenômenos Fisiológicos Oculares , Privação Sensorial/fisiologia , Visão Ocular/fisiologia , Animais , Gatos , Escuridão , Olho
13.
Forensic Sci Int ; 301: 331-340, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31202146

RESUMO

The structural identification and the monitoring of the relative concentrations of a wide range of major (3) and minor secondary (16) metabolites used as marker substances for profiling of cannabis resin using GC-FID at the Swedish National Forensic Centre (NFC) has facilitated the mapping of their chemical and physical behaviors over a period of 48months whilst stored under different conditions (exposure to light, exposure to air, temperature). In all cases the behavior of this group of sesquiterpenes, sesquiterpenoids, cannabinoids and waxes could be directly related to their chemical lability/functionality. In particular, the identification of homologue triads for both Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) together with a group of seemingly chemically inert substances (for example, cannabicyclol(CBL) and the waxes (n-alkanes)) has created new tools for the establishment of common origins between samples of cannabis resins aged under different conditions. Since sampling of the resin blocks in NFC's method for profiling of cannabis resin is made below the surface, the effects of light incursion were found to be negligible. The effects of exposure to air (and indirectly temperature) were found to be more significant, not unexpectedly as many of the observed transformations were based on oxidation or rearrangement processes.


Assuntos
Canabinoides/química , Cannabis/química , Resinas Vegetais/química , Manejo de Espécimes/métodos , Cromatografia Gasosa , Escuridão , Luz , Temperatura Ambiente
14.
Int J Mol Sci ; 20(12)2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31212732

RESUMO

Light influences a wide range of physiological processes from prokaryotes to mammals. Neurospora crassa represents an important model system used for studying this signal pathway. At molecular levels, the WHITE COLLAR Complex (WCC), a heterodimer formed by WC-1 (the blue light photo-sensor) and WC-2 (the transcriptional activator), is the critical positive regulator of light-dependent gene expression. GATN (N indicates any other nucleotide) repeats are consensus sequences within the promoters of light-dependent genes recognized by the WCC. The distal GATN is also known as C-box since it is involved in the circadian clock. However, we know very little about the role of the proximal GATN, and the molecular mechanism that controls the transcription of light-induced genes during the dark/light transition it is still unclear. Here we showed a first indication that mutagenesis of the proximal GATA sequence within the target promoter of the albino-3 gene or deletion of the WC-1 zinc finger domain led to a rise in expression of light-dependent genes already in the dark, effectively decoupling light stimuli and transcriptional activation. This is the first observation of cis-/trans-acting repressive machinery, which is not consistent with the light-dependent regulatory mechanism observed in the eukaryotic world so far.


Assuntos
Sítios de Ligação , Escuridão , Fatores de Transcrição GATA/metabolismo , Regulação da Expressão Gênica/efeitos da radiação , Luz , Elementos de Resposta , Fatores de Transcrição/metabolismo , Sequência de Bases , Cromatina/genética , Cromatina/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fatores de Transcrição GATA/química , Mutação , Neurospora/genética , Neurospora/metabolismo , Neurospora/efeitos da radiação , Motivos de Nucleotídeos , Fenótipo , Regiões Promotoras Genéticas , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Ativação Transcricional , Dedos de Zinco/genética
15.
Plant Sci ; 285: 44-54, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203893

RESUMO

Although the involvement of ROS (reactive oxygen species) in leaf senescence is well known, the factors governing this accumulation of ROS are not fully characterized. In this study, analysis of transgenic overexpressing and knock out lines of AtWDS1 (encoding a WD repeat protein), indicates that AtWDS1 negatively regulates age-dependent and dark-induced leaf senescence. Furthermore, we observed ROS accumulation and altered tolerance of oxidative stress in atwds1 plants, as well as upregulated expression of oxidative stress-responsive genes. The location of an EGFP-AtWDS1 fusion protein in the nucleus of transformed cells and plants indicates that AtWDS1 is a nuclear protein, and, using a Dual-Luciferase assay, we showed that AtWDS1 can act as a transcription activator. However, the lack of a nuclear localization sequence in AtWDS1 suggests that its presence in the nucleus must depend on interactions with other proteins. Indeed, we found that AtWDS1 interacts directly with AtRanBPM, and that mutation of the AtRanBPM gene results in partial mislocalization of AtWDS1 in the cytoplasm. Together, these results suggest a role for AtWDS1 as a novel modulator of redox homeostasis, which responds to developmental and stress signals to regulate leaf senescence.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Arabidopsis/fisiologia , Clorofila/metabolismo , Escuridão , Microscopia Confocal , Folhas de Planta/fisiologia , Protoplastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transcriptoma
16.
Parasit Vectors ; 12(1): 213, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064400

RESUMO

BACKGROUND: The poultry red mite (PRM), Dermanyssus gallinae, is one of the most economically deleterious ectoparasites affecting egg-laying hens worldwide. It may be possible to control D. gallinae populations by manipulating lighting regimes within poultry units. However, no studies have clearly shown the effects of darkness on the population growth rate of D. gallinae. METHODS: The effect of darkness on the population growth rate of D. gallinae was investigated, together with the first description of the molecular identity of the mite from China. Mite variables under two lighting regimens (1:23 h L:D and 12:12 h L:D) were compared, including number of mites and eggs, survival and feeding rates, engorgement, oviposition, hatchability and the life-cycle of D. gallinae. RESULTS: The results showed that the number of mites (13,763 ± 956) and eggs (5424 ± 317) in the rearing system with prolonged darkness of 1:23 h L:D at 4th week were 2.4- and 3.6-fold higher than those under a conventional lighting regimen of 12:12 h L:D, respectively. The feeding rates of mites under prolonged darkness ranged from 36.7 ± 1.1% to 52.0 ± 7.0%, which were significantly higher than those under conventional lighting regimen (ranging from 22.6 ± 1.9% to 37.3 ± 1.6%). The mean weight of engorged females (0.26 ± 0.01 mg) and the mean number of eggs per female (on average 5.87 ± 0.36) under prolonged darkness were significantly higher than those under conventional lighting regimen (0.22 ± 0.01 mg and 3.62 ± 0.31, respectively). However, the survival rate ranging from 98.07 ± 0.10% to 98.93 ± 0.19%, hatchability of 97.93 ± 0.01% and the life-cycle of D. gallinae (9 days) was not affected by the lighting period. CONCLUSIONS: Our findings demonstrated that prolonged darkness significantly promoted the proliferation levels of D. gallinae, resulting in increased number of mites and eggs in the rearing system. The promoted population growth of D. gallinae was found to be related to the increased feeding rate, engorgement level and oviposition level of mites under prolonged darkness. The egg hatchability, the survival rates and the duration of life-cycle of D. gallinae were not affected by the light regimes.


Assuntos
Escuridão , Ácaros/efeitos da radiação , Animais , Galinhas , DNA Intergênico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Comportamento Alimentar/efeitos da radiação , Feminino , Estágios do Ciclo de Vida , Luz , Infestações por Ácaros/veterinária , Ácaros/genética , Ácaros/crescimento & desenvolvimento , Oviposição/efeitos da radiação , Fotoperíodo , Crescimento Demográfico , Doenças das Aves Domésticas/parasitologia , Reprodução/efeitos da radiação , Fatores de Tempo
17.
Malar J ; 18(1): 179, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31118028

RESUMO

BACKGROUND: Identifying efficient and effective strategies to reach and monitor populations at greatest risk of malaria in low-transmission settings is a key challenge for malaria elimination. In Namibia's Zambezi Region, transmission is ongoing yet its drivers remain poorly understood. A growing literature suggests that night-time social activities may lead to malaria exposure that is beyond the reach of conventional preventive interventions, such as insecticide treated bed nets and indoor residual spraying. METHODS: Formative research was conducted with community members in March, 2015 in the catchment areas of six randomly selected health facilities in the western Zambezi Region to identify night-time locations where large numbers of individuals regularly congregate. Using time-location sampling, a survey was conducted between March and May, 2015 at community-identified venues (bars and evening church services) to develop representative estimates of the prevalence of parasite infection and risk factors among venue-goers. RESULTS: When compared to a contemporaneous household survey of the general population aged 15 and older (N = 1160), venue-goers (N = 480) were more likely to have spent the night away from their home recently (17.3% vs. 8.9%, P = 0.008), report recent fever (65.2% vs. 36.9%, P < 0.001), and were less likely to have sought care for fever (37.9% vs. 52.1%, P = 0.011). Venue-goers had higher, but not significantly different, rates of malaria infection (4.7% vs. 2.8%, P = 0.740). Risk factors for malaria infection among venue-goers could not be determined due to the small number of infections identified, however self-reported fever was positively associated with outdoor livelihood activities (adjusted odds ratio [AOR] = 1.9, 95% CI 1.0-3.3), not wearing protective measures at the time of the survey (AOR = 6.8, 9% CI 1.4-33.6) and having been bothered by mosquitos at the venue (AOR = 2.7, 95% CI 1.5-4). CONCLUSIONS: Prevention measures and continued surveillance at night-time venues may be a useful complement to existing malaria elimination efforts.


Assuntos
Escuridão , Malária/transmissão , Controle de Mosquitos/métodos , Adolescente , Adulto , Animais , Anopheles/parasitologia , Feminino , Humanos , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Atividades de Lazer , Malária/prevenção & controle , Masculino , Pessoa de Meia-Idade , Namíbia/epidemiologia , Prevalência , Medição de Risco , Fatores de Risco , Amostragem , Inquéritos e Questionários , Adulto Jovem
18.
J Opt Soc Am A Opt Image Sci Vis ; 36(4): B35-B43, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31044953

RESUMO

Visual detection of small black objects surrounded by a light background depends on background luminance, pupil size, optical blur, and object size. Holding pupil and optics fixed, we measured the minimum background luminance needed for foveal detection of small black targets as a function of target size. For all three observers, absolute threshold varied inversely with target area when disk diameter subtended less than 10' of visual angle. For target diameter ≥10', threshold remained constant at about 0.3 Td, which was also the absolute threshold for detecting light spots 10' or larger in diameter on a black background. These results are consistent with Ricco's law of spatial summation: a "black hole" is just detectable when the background luminance is sufficiently high for its absence inside the Ricco area to reduce 555 nm photon flux by 7500 photons/s, which is the same change needed to detect light spots on a black surround. These results can be accounted for by a differential pair of Ricco detectors, each about the size of the receptive field center of magocellular retinal ganglion cells when projected into object space through the eye's weakly aberrated optical system. Statistical analysis of the model suggests the quantum fluctuations due to internal, biological noise (i.e., "scotons") are a greater handicap than the photon fluctuations inherent in the light stimulus at absolute foveal threshold.


Assuntos
Escuridão , Fóvea Central/fisiologia , Limiar Sensorial/efeitos da radiação , Fóvea Central/efeitos da radiação , Modelos Biológicos , Estimulação Luminosa
19.
Behav Processes ; 164: 157-166, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31059764

RESUMO

Sensory substitution refers to a process whereby an agent, by means of a removable specialized instrumentation, becomes capable of exploiting an available sensory modality in order to perceive properties of the environment which are normally accessible by means of a different modality. We describe a situation of visual-auditory sensory substitution in the rat. Rats were placed in complete darkness, and trained to follow a virtual path whose position was signalled by a sound activated by a video-tracking device. Our hypothesis was that the rats would be able to succeed in this task of spatial navigation, following the sound contour by means of sensory-motor coupling based on seeking the sound (all-or-none) and mastering the relation between their own actions and the expected sensory feedback. Our results confirm this hypothesis and show the progressive structuring of meaningful exploratory activity, leading from the appearance of stopping behaviour when the sound is lost or acceleration when the sound is discovered, up to a veritable sensory-motor strategy which maximizes the possibilities for discovering and following the sound path. Thus, the animals seem to have developed a new form of perception which translates in particular into motor behaviour adapted to the search for sound.


Assuntos
Percepção Auditiva , Ratos , Navegação Espacial , Estimulação Acústica , Animais , Escuridão , Retroalimentação , Feminino , Masculino , Recompensa
20.
BMC Plant Biol ; 19(1): 184, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31060496

RESUMO

BACKGROUND: Since their discovery, vacuolar processing enzymes (VPEs) have consistently been investigated as programmed cell death (PCD) initiators and participants in plant development and responses to biotic or abiotic stresses, in part due to similarities with the apoptosis regulator caspase-1. However, recent studies show additional functions of VPE in tomatoes, specifically in sucrose accumulation and fruit ripening. RESULTS: Herein, we evaluated the functions of VPE from sweetpotato, initially in expression pattern analyses of IbVPE1 during development and senescence. Subsequently, we identified physiological functions by overexpressing IbVPE1 in Arabidopsis thaliana, and showed reduced leaf sizes and numbers and early flowering, and elucidated the underlying molecular mechanisms. CONCLUSIONS: The present data demonstrate functions of the VPE gene family in development and senescence and in regulation of flowering times, leaf sizes and numbers, and senescence phenotypes in Arabidopsis thaliana.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Clorofila/metabolismo , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Ipomoea batatas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Escuridão , Especificidade de Órgãos/genética , Fenótipo , Complexo de Proteína do Fotossistema II/metabolismo , Filogenia , Folhas de Planta/anatomia & histologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Fatores de Transcrição/metabolismo
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