Audition: hearing     

Durlach NI  Weiss TF 《Science (New York, N.Y.)》1984,224(4653):1090-1091

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Regulation of interleukin-2 gene enhancer activity by the T cell accessory molecule CD28.   总被引：85，自引：0，他引：85  

J D Fraser  B A Irving  G R Crabtree  A Weiss 《Science (New York, N.Y.)》1991,251(4991):313-316

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Conductance-controlled point functionalization of single-walled carbon nanotubes     

Goldsmith BR  Coroneus JG  Khalap VR  Kane AA  Weiss GA  Collins PG 《Science (New York, N.Y.)》2007,315(5808):77-81

We used covalent attachments to single-walled carbon nanotubes (SWNTs) to fabricate single-molecule electronic devices. The technique does not rely on submicrometer lithography or precision mechanical manipulation, but instead uses circuit conductance to monitor and control covalent attachment to an electrically connected SWNT. Discrete changes in the circuit conductance revealed chemical processes happening in real time and allowed the SWNT sidewalls to be deterministically broken, reformed, and conjugated to target species. By controlling the chemistry through electronically controlled electrochemical potentials, we were able to achieve single chemical attachments. We routinely functionalized pristine, defect-free SWNTs at one, two, or more sites and demonstrated three-terminal devices in which a single attachment controls the electronic response.  相似文献   

Slow fertilization of stickleback eggs: the result of sexual conflict?     

Theo CM Bakker  Marc Zbinden  Joachim G Frommen  Alexander Weiss  Carlo R Largiadèr 《BMC ecology》2006,6(1):7-8

Background  

The fertilization success in sperm competition in externally fertilizing fish depends on number and quality of sperm. The time delay between sequential ejaculations may further influence the outcome of sperm competition. Such a time interval can load the raffle over fertilization if fertilization takes place very fast. Short fertilization times are generally assumed for externally fertilizing fish such as the three-spined stickleback (Gasterosteus aculeatus). In this pair-spawning fish, territorial males often try to steal fertilizations in nests of neighbouring males. This sneaking behaviour causes sperm competition. Sneakers will only get a share of paternity when eggs are not fertilized immediately after sperm release. Contrary to males, females may be interested in multiple paternity of their clutch of eggs. There thus may be a sexual conflict over the speed of fertilization.  相似文献   

Distribution of Trypanosoma congolense in infected multimammate rats (Mastomys coucha): light and electron microscopical studies     

Ojok L  Kaeufer-Weiss I  Weiss E 《Veterinary parasitology》2002,105(4):327-336

In an attempt to determine whether Trypanosoma congolense occurs both within and outside the blood vessels in an infected animal host, multimammate rats (Mastomys coucha) were infected with T. congolense and samples from spleen, lymph nodes, bone marrow, liver, kidney, lungs, brain, heart, intestines, ovaries and testes were collected. The tissue samples were fixed and processed for light and electron microscopical examination. In all the tissues examined, trypanosomes were found only within the lumen of large and small blood vessels, capillaries and sinuses. It is concluded that following entry into the blood circulation after intra-peritoneal infection of M. coucha, T. congolense remains restricted to the bloodstream.  相似文献   

Reproductive Performance of Gilts with Similar Age but with Different Growth Rate at the Onset of Puberty Stimulation   总被引：1，自引：0，他引：1  

R Kummer  ML Bernardi  AC Schenkel  WS Amaral Filha  I Wentz  FP Bortolozzo 《Reproduction in domestic animals》2009,44(2):255-259

The aim of this study was to evaluate the reproductive performance of gilts that had a similar age but different weights at the onset of puberty stimulation by boar exposure at 144 days. Gilts were divided into two groups according to their lifetime growth rate from birth to approximately 144 days of age. Mean growth rates at this moment were 577 and 724 g/day for group 1 (G1; n = 58) and group 2 (G2; n = 58), respectively. After selection, gilts were weighed at approximately 155, 165 and 175 days of age, on the insemination day and at slaughter. Gilts were inseminated, on average, at 193 days of age and were slaughtered 32 days after insemination, when the number of corpora lutea and embryos were recorded. Higher growth rate gilts (G2) reached puberty earlier (155.3 vs 164.1 days; p < 0.01). More gilts of G2 group attained puberty by 190 days of age (p = 0.004) than G1 gilts (95%; 55/58 vs 76%; 44/58). The anoestrous rate, until 60 days after the onset of boar exposure was higher (p < 0.01) in G1 (19.0%; 11/58) than in G2 (3.4%; 2/58) group. However, there were no differences in the pregnancy rate (90.7 vs 94.5), ovulation rate (15.9 vs 16.5), total embryos (12.9 vs 11.7), viable embryos (12.0 vs 11.1) and embryo survival (73.7% vs 68.5%), between G1 gilts and G2 gilts, respectively (p > 0.05). High growth rate gilts attain puberty earlier and have a lower anoestrous rate than low growth rate gilts.  相似文献   

Response of resident brown trout, Salmo trutta L., and rainbow trout, Oncorhynchus mykiss (Walbaum), to the stocking of hatchery-reared brown trout     

S. Weiss  & S. Schmutz 《Fisheries Management and Ecology》1999,6(5):365-376

Two strains of hatchery-reared adult brown trout, Salmo trutta L., [208–334 mm total length (TL); n =  591] were individually marked and released into a limestone stream. The estimated survival after one month (86%; n =  508) was comparable to that for resident brown trout and rainbow trout, Oncorhynchus mykiss (Walbaum), (89%; n =  771), but declined to 14% ( n =  83) after 8 months compared with 52% ( n =  451) for resident trout. The movement of resident trout out of stocked stretches was higher (14%) than from control sites (5%), but the population size in both individual sites and the overall study area were unaffected. The growth of resident brown trout was unaffected by stocking, but rainbow trout showed lower growth rates in stocked versus unstocked stretches both one and 8 months after stocking ( P <  0.002).  相似文献   

The potential of liposomes as a nutrient supplement in first-feeding marine fish larvae     

Koven  Barr  Hadas  Ben-Atia  Chen  Weiss  & Tandler 《Aquaculture Nutrition》1999,5(4):251-256

The ingestion rate (ng liposome larva^–1 h^–1) of extruded [1–¹⁴C] palmitic acid-labelled liposomes containing physiological saline (PHS) or cod fish extract (CFE), was tested in 5-day-old gilthead seabream Sparus aurata and white grouper Epinephelus aeneus larvae. A follow-up study compared the assimilation of radioactive free fatty acid (FFA) label of these two liposome treatments into six phospholipid and neutral lipid fractions as well as the nonlipid fraction in 5-day-old seabream. In seabream larvae, there was a 50-fold ( P  < 0.05) increase in the net consumption rate when fed CFE liposomes (2305.8 ng liposome larva^–1 h^–1) compared with liposomes containing physiological saline (42.7 ng liposome larva^–1 h^–1). A similarly significant ( P  < 0.05) but less marked pattern was also observed in the grouper larvae where the CFE treatment larvae ingested 238.5 ng liposome larva^–1 h^–1 compared with 54.3 ng liposome larva^–1 h^–1 in larvae fed the PHS liposomes. In seabream larvae ingesting CFE and PHS liposomes, radioactivity was found in all larval fractions analysed. However, marked treatment differences ( P  > 0.05) in assimilation were found only in the triacylglycerol fraction (3.4 and 0.6 dpm larva^–1 h^–1, respectively) and nonlipid fraction (11.2 and 15 dpm larva^–1 h^–1, respectively).  相似文献   

Antioxidant 1 copper chaperone gene expression and copper levels in dog osteosarcoma patients     

Pedro L. Rivera  William T. Li  Sumail Bhogal  Jonathan B. Mandell  Rebekah Belayneh  Margaret L. Hankins  John T. Payne  Rebecca J. Watters  Kurt R. Weiss 《Veterinary and comparative oncology》2023,21(3):559-564

Twenty-four dogs with OS underwent limb amputation. Serum, OS tumour, and normal bone were harvested at time of surgery. RNA was extracted and gene expression was performed using quantitative polymerase chain reaction (qPCR). Tissue and blood copper concentrations were also determined with spectrophotometry. Compared to bone, tumour samples had significantly higher expressions of antioxidant 1 copper chaperone (ATOX1, p = .0003). OS tumour copper levels were significantly higher than that of serum (p < .010) and bone (p = .038). Similar to our previous observations in mouse and human OS, dog OS demonstrates overexpression of genes that regulate copper metabolism (ATOX1), and subsequent copper levels. Dogs with OS may provide a robust comparative oncology platform for the further study of these factors, as well as potential pharmacologic interventions.  相似文献