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1.
J Dairy Sci ; 104(9): 10029-10039, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34099290

RESUMO

The aim of this study was to analyze time-lagged heat stress (HS) effects during late gestation on genetic co(variance) components in dairy cattle across generations for production, female fertility, and health traits. The data set for production and female fertility traits considered 162,492 Holstein Friesian cows from calving years 2003 to 2012, kept in medium-sized family farms. The health data set included 69,986 cows from calving years 2008 to 2016, kept in participating large-scale co-operator herds. Production traits were milk yield (MKG), fat percentage (fat%), and somatic cell score (SCS) from the first official test-day in first lactation. Female fertility traits were the nonreturn rate after 56 d (NRR56) in heifers and the interval from calving to first insemination (ICFI) in first-parity cows. Health traits included clinical mastitis (MAST), digital dermatitis (DD), and endometritis (EM) in the early lactation period in first-parity cows. Meteorological data included temperature and humidity from public weather stations in closest herd distance. The HS indicator was the temperature-humidity index (THI) during dams' late gestation, also defined as in utero HS. For the genetic analyses of production, female fertility, and health traits in the offspring generation, a sire-maternal grandsire random regression model with Legendre polynomials of order 3 for the production and of order 2 for the fertility and health traits on prenatal THI, was applied. All statistical models additionally considered a random maternal effect. THI from late gestation (i.e., prenatal climate conditions), influenced genetic parameter estimates in the offspring generation. For MKG, heritabilities and additive genetic variances decreased in a wave-like pattern with increasing THI. Especially for THI >58, the decrease was very obvious with a minimal heritability of 0.08. For fat% and SCS, heritabilities increased slightly subjected to prenatal HS conditions at THI >67. The ICFI heritabilities differed marginally across THI [heritability (h2) = 0.02-0.04]. For NRR56, MAST, and DD, curves for heritabilities and genetic variances were U-shaped, with largest estimates at the extreme ends of the THI scale. For EM, heritability increased from THI 25 (h2 = 0.13) to THI 71 (h2 = 0.39). The trait-specific alterations of genetic parameters along the THI gradient indicate pronounced genetic differentiation due to intrauterine HS for NRR56, MAST, DD, and EM, but decreasing genetic variation for MKG and ICFI. Genetic correlations smaller than 0.80 for NRR56, MAST, DD, and EM between THI 65 with corresponding traits at remaining THI indicated genotype by environment interactions. The lowest genetic correlations were identified when considering the most distant THI. For MKG, fat%, SCS, and ICFI, genetic correlations throughout were larger than 0.80, disproving concerns for any genotype by environment interactions. Variations in genetic (co)variance components across prenatal THI may be due to epigenetic modifications in the offspring genome, triggered by in utero HS. Epigenetic modifications have a persistent effect on phenotypic responses, even for traits recorded late in life. However, it is imperative to infer the underlying epigenetic mechanisms in ongoing molecular experiments.


Assuntos
Doenças dos Bovinos , Transtornos de Estresse por Calor , Animais , Bovinos/genética , Doenças dos Bovinos/genética , Feminino , Genótipo , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico , Lactação , Leite , Fenótipo , Gravidez
2.
Appl Opt ; 60(13): 4047-4063, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33983346

RESUMO

Small, highly absorbing points are randomly present on the surfaces of the main interferometer optics in Advanced LIGO. The resulting nanometer scale thermo-elastic deformations and substrate lenses from these micron-scale absorbers significantly reduce the sensitivity of the interferometer directly though a reduction in the power-recycling gain and indirect interactions with the feedback control system. We review the expected surface deformation from point absorbers and provide a pedagogical description of the impact on power buildup in second generation gravitational wave detectors (dual-recycled Fabry-Perot Michelson interferometers). This analysis predicts that the power-dependent reduction in interferometer performance will significantly degrade maximum stored power by up to 50% and, hence, limit GW sensitivity, but it suggests system wide corrections that can be implemented in current and future GW detectors. This is particularly pressing given that future GW detectors call for an order of magnitude more stored power than currently used in Advanced LIGO in Observing Run 3. We briefly review strategies to mitigate the effects of point absorbers in current and future GW wave detectors to maximize the success of these enterprises.

3.
J Dairy Sci ; 102(7): 6660-6671, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31128870

RESUMO

The aim of the present study was to quantify the effect of heat stress (HS) from different points in time on production, female fertility, and health traits. In this regard, on-farm measurements for temperature and relative humidity were combined into temperature-humidity indexes (THI), and merged with longitudinal cow traits from electronic recording systems. The study included traits from 22,212 Holstein cows kept in 15 large-scale dairy co-operator herds. Trait and meteorological data recording spanned a period between May 2013 and November 2015. Longitudinal production traits considered 191,911 test-day records for protein yield, protein percentage, and milk urea nitrogen (MUN). Female fertility traits were the pregnancies per AI (P/AI) and the number of daily inseminations per herd cow (INS/HCOW). Health traits considered clinical mastitis (MAST), retained placenta, puerperal disorders (PD) from d 0 to 10 postpartum, and the claw disorders digital phlegmona, digital dermatitis (DD), and interdigital hyperplasia from d 0 to 360 postpartum. For all traits, we analyzed the THI influence from the trait-recording day. In addition, we studied the time-lagged THI effect from the previous week. Linear mixed models were applied to estimate THI effects on Gaussian distributed production traits. For binary health and fertility traits, generalized linear mixed models with a logit link function were used. The continuous THI effect was either modeled linear, or via Legendre polynomials of order 4. Regression models for THI were validated via THI class effects (i.e., 5% percentiles for THI). Protein percentage decreased with increasing test-day THI, and with increasing THI from the previous week. Protein yield obviously decreased beyond THI 68 for both THI measurements (test-day THI and THI from previous week). For MUN, the visually identified test-day HS threshold was THI 70. Time-lagged THI effects on MUN were less obvious. For both THI measuring dates, INS/HCOW was highest at THI 57. Beyond THI 57, INS/HCOW substantially decreased. For P/AI, the visually identified HS threshold at the insemination date was THI 65. Temperature-humidity indexes from the previous week had a moderate detrimental effect on P/AI. Incidences for MAST, retained placenta, and PD during d 0 to 10 postpartum increased with increasing average THI from this period. Studying the whole lactation period, incidences for interdigital hyperplasia also increased with increasing THI from the previous week. An opposite THI response was identified for DD: DD decreased with increasing THI. For all health traits, associations between disease incidences and THI were almost linear. Hence, for health traits, no obvious HS thresholds were detected. Especially in early lactation, HS had a detrimental effect on cow productivity and female fertility. The influence of HS on cow health differed, depending on the disease pathogenesis.


Assuntos
Doenças dos Bovinos/fisiopatologia , Indústria de Laticínios , Fertilidade , Transtornos de Estresse por Calor/veterinária , Leite , Animais , Bovinos , Fazendas , Feminino , Umidade , Lactação , Modelos Lineares , Gravidez
4.
J Insect Sci ; 7: 1-10, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-20233099

RESUMO

Abstract We conducted field observations of physical competition for mates, in which a single male attempts to usurp a female from another male, in male Japanese beetles, Popillia japonica Newman (Coleoptera; Scarabaeidae). Physical contests for mates were relatively rare, but when they occurred the challenger male was able to successfully takeover females by dislodging the previously paired resident male in only 18% of contests, suggesting that a substantial prior residency advantage exists in this species. Challenger males that were successful in takeover attempts were significantly larger than the resident male. In contrast, no size pattern was found between intruding males and residents in unsuccessful takeover attempts. The frequency of contests for existing pairs was examined throughout the day. Pair frequency was greatest in early morning and in the evening but contest frequency was highest during the middle of the day. Contest frequency was negatively related to beetle density but not related to temperature. Overall, physical contests for mates appear to be an important part of the mating behavior in Japanese beetles. The frequency of the contests relates to the time of day and social conditions and contest outcome is related to prior residency and the size of the intruding male relative to the paired male.


Assuntos
Besouros/fisiologia , Comportamento Sexual Animal/fisiologia , Agressão/fisiologia , Animais , Tamanho Corporal/fisiologia , Feminino , Masculino , Fatores de Tempo
5.
J Insect Sci ; 5: 18, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16341250

RESUMO

The effect of the social environment on post-copulatory mate guarding duration in Japanese beetles, (Popillia japonica Newman), was examined in a laboratory experiment. The mate guarding durations of beetles in different sex ratios and densities were observed for 10 hours. Guarding duration was longer when females were larger, suggesting the presence of 'cryptic' male mate choice. Densities, but not sex ratio, affected the duration of guarding bouts, with males guarding for longer at higher densities. This result implies that males increase their guarding duration under conditions in which their female may be likely to be encountered by other males. The lack of a sex ratio effect on the duration of guarding bouts is consistent with other studies on this species that indicate males have difficulty distinguishing females from males. Consequently, because the sex ratio on food plants is typically male-biased, a paired male may react just to density, treating surrounding individuals as if they were mostly males. The total amount of time males spent guarding was lower at lower densities and at male-biased sex ratios; this suggests that after ceasing to guard one female, males were less able to find a subsequent mate under these conditions.


Assuntos
Besouros/fisiologia , Comportamento Sexual Animal/fisiologia , Meio Social , Animais , Tamanho Corporal/fisiologia , Feminino , Masculino , Densidade Demográfica , Razão de Masculinidade , Fatores de Tempo
6.
Photochem Photobiol ; 70(2): 191-8, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10461458

RESUMO

Soluble melanin precursors are present in serum and may act as skin chromophores contributing to UVR-induced oxidative damage. Our study aimed to determine whether the soluble eumelanin precursor 5,6-dihydroxy-indole-2-carboxylic acid (DHICA) photosensitizes DNA damage in human keratinocytes exposed to UVA irradiation. The HaCaT keratinocytes were incubated with and without DHICA, before irradiation with broadband UVA (320-400 nm). The DNA photodamage was assessed using the comet assay that detects frank single-strand breaks (SSB) and specific oxidative lesions with the addition of endonuclease III. Without DHICA incubation, there was no significant increase in SSB, compared to unirradiated cells, for doses up to 48.5 J/cm2 (< 1 minimum erythemal dose). Preincubation with 0.5 microM DHICA caused an increase in SSB at every UVA dose (significant from 12.1 to 48.5 J/cm2), while varying the DHICA concentration (0.125-2 microM) showed this effect to be concentration dependent such that SSB increased and endonuclease III-sensitive sites decreased with increasing DHICA concentration. The irradiation of cells in the presence of antioxidants (catalase, mannitol and histidine) suggests that DHICA-induced photosensitization is mediated via singlet oxygen and, to a lesser extent, hydroxyl radicals. These results indicate that DHICA can induce strand breaks with UVA at clinically relevant doses via a mechanism involving reactive oxygen species.


Assuntos
Dano ao DNA , Indóis/toxicidade , Antioxidantes/farmacologia , Linhagem Celular , Células Cultivadas , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Oxirredução , Fotobiologia , Raios Ultravioleta/efeitos adversos
7.
Br J Dermatol ; 140(6): 1023-30, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10354066

RESUMO

Tanning lamps, emitting predominantly ultraviolet (UV) A, are used widely throughout the U.K. and other countries, but little is known about the long-term risks associated with their use, especially with respect to skin cancer. We have exposed normal human epidermal keratinocytes to a commercial tanning lamp and used the comet assay in association with DNA repair enzymes T4 endonuclease V and endonuclease III to investigate the relative yields of directly formed cyclobutane pyrimidine dimers (CPDs) and indirectly formed types of oxidative DNA damage. To put the risk of using tanning lamps into perspective, the sunbed used in this study (five Philips Performance 80W-R UVA tubes at a distance of 35 cm) was found to be approximately 0.7 times as potent at inducing CPDs as U.K. natural sunlight around noon on a fine summer day. This compares with a relative risk for CPD induction and erythema of 0.8 and 0.7 times, respectively, calculated from the relevant action spectra of tanning lamps and British noontime sunlight. To determine the relative contribution of UVB and UVA to the induction of CPDs and oxidative DNA damage, we modified the spectral output of the tanning lamps with a series of Schott WG UVB filters. The induction of CPDs was more dependent on the UVB component of the sunbed than oxidative types of damage. Schott WG UVB filters with 50% transmission at 305 nm reduced the yield of T4 endonuclease V sites by 42% while there was only a 17% decrease in the yield of endonuclease III sites. CPD induction was not completely abolished after irradiation through WG335 and WG345 nm filters despite there being no detectable UVB. From these data, it was estimated that, although the tanning lamps emitted only 0.8% of their total output in the UVB range, these wavelengths were responsible for the induction of over 75% of CPDs and 50% of the oxidative damage to DNA.


Assuntos
Queratinócitos/efeitos da radiação , Dímeros de Pirimidina/metabolismo , Raios Ultravioleta/efeitos adversos , Células Cultivadas , Ensaio Cometa , Dano ao DNA , Relação Dose-Resposta à Radiação , Eritema/etiologia , Humanos , Queratinócitos/metabolismo , Risco
8.
Photochem Photobiol ; 67(1): 126-32, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9477770

RESUMO

Topical 6,4,4'-trimethylangelicin (TMA) plus UVA was used to induce intense epidermal pigmentation in inbred HRA.HRII-c/+/Skh hairless pigmented mice over a 13 day period. Subsequent UVB/UVA exposure was used to assess the photoprotective properties of this tan using skin tumors as an endpoint. Comparisons were always made with sibling albino mice. The TMA/UVA treatment was shown to be not carcinogenic when treated mice were compared with untreated control mice over 25 weeks. The tan faded despite daily exposure to UVB/UVA and did not afford any protection when TMA/UVA-treated mice with subsequent UVB/UVA were compared with pigmented mice treated with UVB/UVA only. In one group, the TMA-induced tan was maintained by application of TMA three times a week prior to UVB/UVA for the duration of the experiment. This treatment was associated with a significant increase in tumor risk in both pigmented and albino mice compared to groups treated with UVB/UVA alone. Although pigmented mice had a significant photoprotective advantage, it was shown to be outweighed by the carcinogenic risks of the TMA maintenance treatment when they were compared with mice that did not have this treatment. Nonpretanned pigmented mice developed mild pigmentation during UVB/UVA treatment that was shown to have no protective effect when those mice were compared with albinos. We conclude that induced epidermal tanning with or without furocoumarin enhancement is not an effective way to prevent skin cancer in the HRA.HRII-c/+/Skh mouse model.


Assuntos
Furocumarinas/farmacologia , Melanócitos/efeitos dos fármacos , Neoplasias Induzidas por Radiação/prevenção & controle , Protetores contra Radiação/farmacologia , Neoplasias Cutâneas/prevenção & controle , Animais , Feminino , Melaninas/biossíntese , Camundongos , Camundongos Pelados , Camundongos Endogâmicos , Neoplasias Cutâneas/etiologia , Raios Ultravioleta
10.
Soc Work Health Care ; 17(1): 23-37, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1440107

RESUMO

Older adults tend to avoid mental health services and rely on hospital emergency departments for medicalization of these conditions. An intervention was designed for use in emergency departments to refer older adult patients with mental and social health problems to appropriate services within the hospital and community. Most of the patients in the study used the services to which they were referred; further, the intervention was found to decrease repeat utilization of the emergency department. Social work practice and policy implications of the findings are also discussed.


Assuntos
Serviços de Emergência Psiquiátrica/estatística & dados numéricos , Mau Uso de Serviços de Saúde/estatística & dados numéricos , Serviços de Saúde Mental/organização & administração , Serviço Hospitalar de Assistência Social/organização & administração , Idoso , Florida , Acessibilidade aos Serviços de Saúde , Necessidades e Demandas de Serviços de Saúde , Pesquisa sobre Serviços de Saúde , Humanos , Relações Interdepartamentais , Planejamento de Assistência ao Paciente/normas
12.
Oecologia ; 58(3): 383-388, 1983 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28310339

RESUMO

The feeding behavior of predaceous beetle larvae (Dytiscus fasciventris) on American toad (Bufo americanus) tadpoles was investigated in the laboratory. The rate of food extraction from an individual tadpole decreases as the prey item is being depleted. Beetles hand fed single tadpoles were shown to have a significantly longer mean handling time than beetles capturing similar size tadpoles from constant prey densities of 5 or 20 tadpoles/1. Handling times were not correlated with mean intercatch intervals but were found to decrease throughout a 10-tadpole catch sequence at all prey densities. Beetles allocated less time per unit weight to large prey items than to smaller tadpoles. However, the marginal ingestion rate (amount consumed/unit of handling time) did not differ with prey size throughout a 10-tadpole catch sequence. These results support the rate expectation hypothesis (Charnov 1976) as an explanation for time allocation to patches.

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