3,667 research outputs found
Delineation of RAID1, the RACK1 interaction domain located within the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5
Background
The cyclic AMP specific phosphodiesterase, PDE4D5 interacts with the β-propeller protein RACK1 to form a signaling scaffold complex in cells. Two-hybrid analysis of truncation and mutant constructs of the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5 were used to define a domain conferring interaction with the signaling scaffold protein, RACK1.
Results
Truncation and mutagenesis approaches showed that the RACK1-interacting domain on PDE4D5 comprised a cluster of residues provided by Asn-22/Pro-23/Trp-24/Asn-26 together with a series of hydrophobic amino acids, namely Leu-29, Val-30, Leu-33, Leu-37 and Leu-38 in a 'Leu-Xaa-Xaa-Xaa-Leu' repeat. This was done by 2-hybrid analyses and then confirmed in biochemical pull down analyses using GST-RACK1 and mutant PDE4D5 forms expressed in COS cells. Mutation of Arg-34, to alanine, in PDE4D5 attenuated its interaction with RACK1 both in 2-hybrid screens and in pull down analyses. A 38-mer peptide, whose sequence reflected residues 12 through 49 of PDE4D5, bound to RACK1 with similar affinity to native PDE4D5 itself (Ka circa 6 nM).
Conclusions
The RACK1 Interaction Domain on PDE4D5, that we here call RAID1, is proposed to form an amphipathic helical structure that we suggest may interact with the C-terminal β-propeller blades of RACK1 in a manner akin to the interaction of the helical G-γ signal transducing protein with the β-propeller protein, G-β
Controlling the uncontrolled: Are there incidental experimenter effects on physiologic responding?
The degree to which experimenters shape participant behavior has long been of interest in experimental social science research. Here, we extend this question to the domain of peripheral psychophysiology, where experimenters often have direct, physical contact with participants, yet researchers do not consistently test for their influence. We describe analytic tools for examining experimenter effects in peripheral physiology. Using these tools, we investigate nine data sets totaling 1,341 participants and 160 experimenters across different roles (e.g., lead research assistants, evaluators, confederates) to demonstrate how researchers can test for experimenter effects in participant autonomic nervous system activity during baseline recordings and reactivity to study tasks. Our results showed (a) little to no significant variance in participants' physiological reactivity due to their experimenters, and (b) little to no evidence that three characteristics of experimenters that are well known to shape interpersonal interactions-status (using five studies with 682 total participants), gender (using two studies with 359 total participants), and race (in two studies with 554 total participants)-influenced participants' physiology. We highlight several reasons that experimenter effects in physiological data are still cause for concern, including the fact that experimenters in these studies were already restricted on a number of characteristics (e.g., age, education). We present recommendations for examining and reducing experimenter effects in physiological data and discuss implications for replication
SEASONALITY OF BIRD STRIKES: TOWARDS A BEHAVIOURAL EXPLANATION
It is well known that, at least in the Northern Hemisphere, there is a strong seasonal element in the annual pattern of bird strikes. This study undertakes a statistical analysis of an 11year data set collected at Dublin Airport, Ireland. It attempts to identify statistically significant trends in the seasonal trajectories of bird strikes, both in general and in respect of individual species and in comparison with seasonal trends in the abundance of birds generally and at Dublin Airport in particular. Hypotheses relating to the idea of âopenâ (i.e. intervals of through-put of naĂŻve and young birds) and âclosedâ (i.e. intervals when throughput is declining or at a minimum) periods are tested. The results are discussed in the context of the probable ability of birds to learn to avoid aircraft. If birds possess a spatio-temporal memory then it is likely that this ability, or the lack of it, may explain some of the observed trends in the seasonal distribution of bird strikes
Age, Growth and Diet of the brown trout Salmo Trutta L. in the Roundwood Reservoir System
From April to October 1983 monthly samples, totalling 343 trout, were taken from the two reservoirs at Roundwood, Co.
Wicklow, using a range of gill nets. In 1984 an extensive electro-fishing programme was carried out in the Vartry River and three
other feeder streams, in which 605 trout were obtained. The age data, determined from the scales, showed that there were six
year classes in the South Lake and five in the North Lake. The fish from the river and feeder streams were less than 4 years old,
90% belonging to 0 + and 1 + age groups. Trout from the South Lake showed faster growth, attaining 28.7 cm at year 5, compared
to 23.2 cm in the North Lake. Only six trout were over over five years old. Sexual maturity was reached during the third year.
The dominant food organisms were trichopteran larvae and pupae (Limnephilus vittatus) molluscs (Potamopyrgus jenkinsi and
Sphaerium corneum) and chironomid larvae (Endochironomus sp. and Tanytarsus sp.).
The species composition of the fauna of both lakes was almost identical, but biomass was greater in the South Lake where
the trout populations appeared to be numerically smaller.
The high female to male ratios in the lakes, varying between 1.37 and 1.67 to 1 did not appear to be age related. In the Vartry
River and other feeder streams the fish were young, immature and predominantly male. These fish contained many more
ephemeropteran nymphs than the lake trout.
The oligotrophic state of the lakes, combined with the fluctuations in water level make it unlikely that any steps can be taken
to improve the sport fishery using the native trout. Development of a put and take fishery is recommended
Studies on the Minnow Phoxinus Phoxinus (L.) from an Upland Irish Reservoir System
The paper deals with the population structure and biology of the minnow, Phoxinus phoxinus (L.), in the Roundwood Reservoir system. A total of 4,342 minnow were taken during the study period from three locations, 2,796 fish were used to calculate the age distributions and 3,013 were examined for gut contents. The age data, determined from the otoliths, showed that there are five age classes present. The mean length at the end of the first year (O-Group fish), was 3.41 cm, at the end of the second year (I-Group fish) it was 5.32 cm and 6.68 cm at the end of the third year (II-Group). Only thirteen minnow were found to be older than three years. The breeding season is later than normal and peaks in August and September. Sexual maturity is reached by the majority in their second year and all older fish are mature. Egg diameters were shown to be smaller than for fish from midland Irish waters. In the North and South Lakes the dominant food organisms were found to be chironomid and
trichopteran larvae, molluscs and Cladocera. The diet of the fish from the Vartry River contained more ephemeropteran nymphs. Seasonal differences in the diet are noted. The influence of the minnow on the associated fish species is discussed. An account of the distribution of the minnow in Ireland is included as an Appendix
Studies on the Three-Spined Stickleback Gasterosteus aculeatus L. from an Upland Irish Reservoir System
Monthly samples were taken using a small-meshed beach seine. A total of 1092 sticklebacks were captured, 725 fish were used
to calculate the age distributions and 699 were examined for gut contents. The age data, determined from the otoliths, showed that
there were four age classes present. The mean length of first year fish (O-Group fish) was 2.24cm, of second year fish (I-Group)
3.36 and 4.47cm and 5.72cm for II-Group and III-Group fish respectively. The breeding season was June-July. Sex ratios were similar
in both lakes and did not differ significantly from 1 : 1. Sexual maturity was reached by all fish above 3cm. The smallest maturing
virgin was 2.6cm in length. Egg diameters varied between 1.0 and 1.5mm. The diet was similar in the two lakes studied. In the North
Lake Cladocera, chironomid larvae, copepods and molluscs dominated while in the South Lake Cladocera, copepods, chironomid
larvae and surface insects were dominant.
Sticklebacks were extremely scarce in the Vartry River and feeder streams entering both lakes and would not pose a threat to
egg production by trout and minnow in these streams. The influence of sticklebacks is discussed in relation to other fish species
USING BIRD STRIKE DATA TO MONITOR BIRD-HAZARD CONTROL
An effective definition of a bird strike is the basis for quantifying the scale of bird hazard problems. Here we present a working definition of a bird strike, which in turn forms the basis of an analysis of 32 yearsâ data collected at Dublin Airport, Ireland. A variety of datasets are analysed including the number of bird strikes per ten thousand aircraft movements, the mass of the bird species being struck, the time of year at which bird strikes occur and the dimensions of the aircraft utilising the airfield. In addition, we have analysed the mean number of strikes per year and the mean number of birds struck per bird strike. Following a very serious incident involving a Boeing 737-200 which struck a flock of gulls in the mid -1980âs, a new regime of control measures was put in place. Therefore our study permits us to evaluate the effectiveness of this management programme. The results suggest that the most significant impact of control measures is to reduce the number of birds being struck per bird strike
Polychromatic gap solitons and breathers in nonlinear waveguide arrays
We predict the spatial localization of multiple wavelength components in the form of stationary polychromatic gap solitons and dynamic multi-gap breathers, and observe experimentally tunable spatio-spectral trapping of supercontinuum radiation in nonlinear periodic photonic structures
Nonlinear spectral-spatial control and localization of supercontinuum radiation
We present the first observation of spatiospectral control and localization of supercontinuum light through the nonlinear interaction of spectral components in extended periodic structures. We use an array of optical waveguides in a LiNbO3 crystal and employ the interplay between diffraction and nonlinearity to dynamically control the output spectrum of the supercontinuum radiation. This effect presents an efficient scheme for optically tunable spectral filtering of supercontinua
Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being
This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parentsâ own mental distress influences their childâs life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and childrenâs well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to childâs life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of childâs life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the childâs own life satisfaction is related with their fatherâs distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction
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