scholarly journals Two closely linked genes in the mouse

1960 ◽  
Vol 1 (1) ◽  
pp. 69-90 ◽  
Author(s):  
H. Grüneberg ◽  
G. M. Truslove
Keyword(s):  
Primordial Germ Cells ◽  
Dilution Effect ◽  
Coat Colour ◽  
Detectable Effect ◽  
Appreciable Effect ◽  
Double Heterozygote ◽  
Macrocytic Anaemia ◽  
Heterozygous Condition ◽  
Group Iii ◽  
The Face

(1) In heterozygous condition, the gene for Patch (symbol Ph) produces spotting with sharply defined pigmented and white areas. The extent of the spotting is under the control of the genetic background.(2) The Ph/Ph homozygote is inviable and dies before birth. In 9-day embryos, clear liquid is found flanking the notochord; in addition, there may be excessive amounts of liquid in the pericardium, the circulation, the tissues, and under the epidermis. The more extremely affected Ph/Ph embryos die at about 10 days. About one-third survive to later stages of pregnancy. Such ‘cleft-face’ embryos have a large bleb of liquid in the middle of the face which interferes mechanically with the formative movements of the nose and palate, and many subepidermal blebs elsewhere.(3) Ph is closely linked to the gene for dominant spotting with macrocytic anaemia (W, Wv) in linkage group III, the crossover percentage being 0·077. There is a striking interaction in the double heterozygote Ph + / + Wv which is almost white, but nearly equally striking interactions occur with other spotting genes (s, bt and Miwh).(4) By itself, Ph has no detectable effect on the coat colour, but in the double heterozygote with Wv, it slightly increases the dilution effect of the latter in the regions which remain pigmented. Similarly, Ph by itself has no appreciable effect on the red-blood picture of 13–14-day-old animals, but in the double heterozygote with Wv, it probably slightly increases the mild macrocytic anaemia produced by that gene. It remains unknown whether the Ph/Ph homozygote has an effect on the blood. Unlike W/W and Wv/Wv, Ph/Ph has no appreciable effect on the primordial germ cells.(5) The relationship between Ph and the W-series is discussed.

A VALVE FOR RESPIRATORY STUDIES IN INFANTS

PEDIATRICS ◽  
1961 ◽  
Vol 27 (4) ◽  
pp. 645-647
Author(s):  
Richard J. Golinko ◽  
Abraham M. Rudolph
Keyword(s):  
Dead Space ◽  
Newborn Infants ◽  
Dilution Effect ◽  
Face Mask ◽  
The Body ◽  
Large Head ◽  
The Face ◽  
Residual Capacity ◽  
Respiratory Valve ◽  
Body Plethysmograph

PULMONARY function studies in small infants have been limited in the past by failure to develop practical methods for collecting expired gas samples. Adaption of a respiratory valve suitable for use in small subjects with small tidal volumes has been difficult and has led to the use of techniques with the body plethysmograph, contour face mask and large head chamber. The body plethysmograph offers only indirect data and requires considerable prepration before each study. In addition, it has the disadvantage that once the infant is placed in the plethysmograph chamber further manipulations of the infant are not possible. Systems using the contour face mask on head chamber involve a large dead space which may be quite significant when one considers the small volumes dealt with. In order to overcome the problem of large dead space, Cayler et al., similar to others, circulated air across the face of the contour mask. However, because of the dilution effect, differences in the composition of the inspired and expired gases were very small and therefore the chance for error in the calculations was increased. Berglund and Karlberg, and Geubelle et al., while studying functional residual capacity in infants, found that practically all quiet, healthy newborn infants breathe through the nose and can also tolerate the insertion of small tubes in their nostrils for varying periods. On the basis of these observations, a respiratory valve has been designed for insertion directly into the nostrils, permitting collection of total expired air. The valve, especially adapted for use in small infants, offers minimal resistance to respiration and has a dead space of 0.8 ml.

scholarly journals Group I, II, and III mGluR Compounds Affect Rhythm Generation in the Gastric Circuit of the Crustacean Stomatogastric Ganglion

2000 ◽  
Vol 83 (3) ◽  
pp. 1188-1201 ◽  
Author(s):  
Wulf D. Krenz ◽  
Don Nguyen ◽  
Nivia L. Pérez-Acevedo ◽  
Allen I. Selverston
Keyword(s):  
Metabotropic Glutamate Receptor ◽  
Stomatogastric Ganglion ◽  
Detectable Effect ◽  
Consistent Difference ◽  
Rhythm Generation ◽  
Group Iii ◽  
Group I ◽  
Specific Antagonist ◽  
Group Ii

We have studied the effects of group I, II, and III metabotropic glutamate receptor (mGluR) agonists on rhythm generation by the gastric circuit of the stomatogastric ganglion (STG) of the Caribbean spiny lobster Panulirus argus. All mGluR agonists and some antagonists we tested in this study had clear and distinct effects on gastric rhythm generation when superfused over combined oscillating or blocked silent STG preparations. A consistent difference between group I agonists and group II and III agonists was that group I agonists acted excitatory. The group I-specific agonists l-quisqualic acid and ( S)-3,5-dihydroxyphenylglycine, as well as the nonspecific agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid accelerated ongoing rhythms and could induce gastric rhythms in silent preparations. The group II agonist (2S,1′S,2′S)-2-(carboxycyclopropyl)glycine (L-CCG-I) and the group III agonist l(+)-2-amino-4-phosphonobutyric acid (l-AP4) slowed down or completely blocked ongoing gastric rhythms and were without detectable effect on silent preparations. The action of L-CCG-I was blocked partially by the group-II-specific antagonist, (RS)-1-amino-5-phosphonoindan-1-carboxylic acid [(RS)APICA], and the group-III-specific antagonist (RS)-α-methyl-4-phosphonophenylglycine completely blocked the action of l-AP4. Besides its antagonistic action, the group-II-specific antagonist (RS)APICA had a remarkably strong apparent inverse agonist action when applied alone on oscillating preparations. The action of all drugs was dose dependent and reversible, although recovery was not always complete. In our experiments, the effects of none of the mGluR-specific agonists were antagonized or amplified by the N-methyl-d-aspartate (NMDA)-receptor-specific antagonistd(−)-2-amino-5-phosphonopentanoic acid, excluding the contamination of responses to mGluR agonists by nonspecific cross-reactivity with NMDA receptors. Picrotoxin did not prevent the inhibitory action of L-CCG-I and l-AP4. We conclude that mGluRs, probably similar to those belonging to groups I, II, and III described in mammals, may play a role as modulators of gastric circuit rhythm generation in vivo.

Morphometric characteristics and present status of Ponwar cattle breed in India

2004 ◽  
Vol 34 ◽  
pp. 17-25 ◽  
Author(s):  
G.K. Gaur ◽  
Avtar Singh ◽  
P.K. Singh ◽  
R.K. Pundir
Keyword(s):  
Present Status ◽  
Uttar Pradesh ◽  
Cattle Breed ◽  
Coat Colour ◽  
The Body ◽  
Lactation Period ◽  
Body Measurements ◽  
Service Period ◽  
The Face ◽  
Average Body

SummaryThis study was undertaken in order to characterize the Ponwar breed and to establish its present status so that suitable breeding strategies and conservation models could be suggested for the overall improvement of the breed.The Ponwar is a draught cattle breed and is native to the Pilibhit District of Uttar Pradesh. The breeding tract lies between latitude 28°4' and 28°8' North and between longitude 79°0' and 80°4' East. The coat colour of these animals is brown or black with white patches in varying proportions. The tail switch is white in black animals and black in those having a greater proportion of white patches. The body is small, compact and non-fleshy, the face is small and narrow and the ears are small. The horns are small to medium and curve inward with pointed tips. The hump is small in females and developed in males. The tail is long and reaches to below the hock. Cows have small udders and teats. The animals of this breed possess an aggressive temperament.The milk production of the Ponwar cows is low, i.e. about 0.5 to 2.5 kg per day for a lactation period of 8 to 10 (average 8.9±0.1) months. Lactation milk yield averaged 462.5±12.1 kg. The age at first calving ranged from 40 to 60 months and the inter-calving period averaged 12.6±0.1 months. The service period in Ponwar cattle varied from 60 to 100 days. The cows remained dry for average of 110.0±2.6 days. Bullocks of this breed can transport an 800 to 1 000 kg load up to 10 kilometres easily. They can plough 0.4 hectares of land in a day working for 6 to 8 hours. Body length, height at wither and heart girth in adult cows averaged 97.1±0.5, 109.0±0.4 and 140.6±0.5 cm, respectively. The animals recorded in the different villages had similar average body measurements corresponding to their category. The survey revealed that about 21% of total cattle population was of Ponwar breed in Puranpur Tehsil. The approximate Ponwar population in the entire breeding tract was estimated as 10 667.

Genetic activity of sex chromosomes in germinal cells

1970 ◽  
Vol 259 (828) ◽  
pp. 53-58 ◽  
Keyword(s):  
Germ Cells ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Germ Line ◽  
Sampling Error ◽  
Primordial Germ Cells ◽  
Coat Colour ◽  
Chromosome Constitution ◽  
Y Chromosomes ◽  
Genetic Activity

If I adhere strictly to the title proposed for me and speak only of the genetic activity of the sex chromosomes in germ cells, there is very little to say. The evidence is necessarily indirect and includes, first, examples of differential behaviour of germ cells of different sex chromosome constitution in situations where competitive proliferation is a possibility, as in some mosaics and chimaeras; and secondly, exceptional species in which the sex chromosome constitution is normally different in germ cells and soma. The species concerned are all mammals. An instance of the first kind is provided by observations made on a 39,X /41,XYY mosaic mouse discovered by chance in the course of an irradiation experiment (Evans, Ford & Searle 1969). All the spermatogonia and spermatocytes examined contained 41 chromosomes, including two Y chromosomes, whereas bone marrow (the only other tissue examined) was mosaic, the probability of difference being due to sampling error being very low. The question, then, was whether the failure to detect mosaicism among the germ cells was a consequence of chance exclusion of the 39, X cell type from the germ line during development, or of differential proliferation and/or survival of 41,XYY germ cells in the testicular environment. The latter interpretation was favoured on the grounds: (1) A 39,X /41,XYY mosaic is likely to have originated by non-disjunction of the Y chromosome at the first cleavage division of a 40,XY zygote, since other theoretically possible modes of origin would require the combination of rare events or other implausible assumptions. (2) Primordial germ cells of the constitution 39, X are capable of reaching the developing gonad and subsequently forming functional oocytes as evidenced by the fertility of 39, X female mice (Russell, Russell & Gower 1959). (3) Nearly all half-and-half coat colour mosaic mutants are also germ cell mosaics (Russell 1964), implying that when two distinct cell lines are present very early in development both lines are likely to be represented among the germ cells

Why do people believe in a zero-sum economy?

2018 ◽  
Vol 41 ◽  
Author(s):  
Samuel G. B. Johnson
Keyword(s):  
Perspective Taking ◽  
Evolutionary Model ◽  
Everyday Experience ◽  
Coalitional Psychology ◽  
The Face ◽  
Zero Sum

AbstractZero-sum thinking and aversion to trade pervade our society, yet fly in the face of everyday experience and the consensus of economists. Boyer & Petersen's (B&P's) evolutionary model invokes coalitional psychology to explain these puzzling intuitions. I raise several empirical challenges to this explanation, proposing two alternative mechanisms – intuitive mercantilism (assigning value to money rather than goods) and errors in perspective-taking.

Mars: was There an Ancient Eden?

1997 ◽  
Vol 161 ◽  
pp. 203-218 ◽  
Author(s):  
Tobias C. Owen
Keyword(s):  
Positive Answer ◽  
Biogenic Elements ◽  
Habitable Zones ◽  
The Face ◽  
The Origin Of Life ◽  
Early Mars ◽  
Favorable Conditions ◽  
Open Question ◽  
Rocky Planets ◽  
Impact Erosion

AbstractThe clear evidence of water erosion on the surface of Mars suggests an early climate much more clement than the present one. Using a model for the origin of inner planet atmospheres by icy planetesimal impact, it is possible to reconstruct the original volatile inventory on Mars, starting from the thin atmosphere we observe today. Evidence for cometary impact can be found in the present abundances and isotope ratios of gases in the atmosphere and in SNC meteorites. If we invoke impact erosion to account for the present excess of129Xe, we predict an early inventory equivalent to at least 7.5 bars of CO2. This reservoir of volatiles is adequate to produce a substantial greenhouse effect, provided there is some small addition of SO2(volcanoes) or reduced gases (cometary impact). Thus it seems likely that conditions on early Mars were suitable for the origin of life – biogenic elements and liquid water were present at favorable conditions of pressure and temperature. Whether life began on Mars remains an open question, receiving hints of a positive answer from recent work on one of the Martian meteorites. The implications for habitable zones around other stars include the need to have rocky planets with sufficient mass to preserve atmospheres in the face of intensive early bombardment.

Ultrastructural Lesions Produced by Alcohol and Sucrose in the Heart and Liver of C57BL Mice

1970 ◽  
Vol 28 ◽  
pp. 208-209
Author(s):  
K.K. SEKHRI ◽  
C.S. ALEXANDER ◽  
H.T. NAGASAWA
Keyword(s):  
Osmium Tetroxide ◽  
Male Mice ◽  
Alcohol Group ◽  
Group Iii ◽  
Group I ◽  
C57bl Mice ◽  
Group Ii

C57BL male mice (Jackson Lab., Bar Harbor, Maine) weighing about 18 gms were randomly divided into three groups: group I was fed sweetened liquid alcohol diet (modified Schenkl) in which 36% of the calories were derived from alcohol; group II was maintained on a similar diet but alcohol was isocalorically substituted by sucrose; group III was fed regular mouse chow ad lib for five months. Liver and heart tissues were fixed in 2.5% cacodylate buffered glutaraldehyde, post-fixed in 2% osmium tetroxide and embedded in Epon-araldite.

Evidence for a shear mechanism for the precipitation of γ-zirconium hydride in zirconium

1978 ◽  
Vol 36 (1) ◽  
pp. 658-659
Author(s):  
G.J.C. Carpenter
Keyword(s):  
Elevated Temperature ◽  
Strain Field ◽  
Zirconium Hydride ◽  
Zirconium Atom ◽  
Atom Diffusion ◽  
Solvus Temperature ◽  
Hexagonal Close Packed ◽  
Partial Dislocations ◽  
The Face

In zirconium-hydrogen alloys, rapid cooling from an elevated temperature causes precipitation of the face-centred tetragonal (fct) phase, γZrH, in the form of needles, parallel to the close-packed <1120>zr directions (1). With low hydrogen concentrations, the hydride solvus is sufficiently low that zirconium atom diffusion cannot occur. For example, with 6 μg/g hydrogen, the solvus temperature is approximately 370 K (2), at which only the hydrogen diffuses readily. Shears are therefore necessary to produce the crystallographic transformation from hexagonal close-packed (hep) zirconium to fct hydride.The simplest mechanism for the transformation is the passage of Shockley partial dislocations having Burgers vectors (b) of the type 1/3<0110> on every second (0001)Zr plane. If the partial dislocations are in the form of loops with the same b, the crosssection of a hydride precipitate will be as shown in fig.1. A consequence of this type of transformation is that a cumulative shear, S, is produced that leads to a strain field in the surrounding zirconium matrix, as illustrated in fig.2a.

A study of interface sliding at F.C.C.-B.C.C. boundaries in a Cu-Zn alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 422-423
Author(s):  
F. Monchoux ◽  
A. Rocher ◽  
J.L. Martin
Keyword(s):  
Face Centered Cubic ◽  
Creep Tests ◽  
High Voltage Electron Microscopy ◽  
Diffusion Treatment ◽  
Voltage Electron ◽  
The Face ◽  
Face Centered ◽  
Interface Sliding ◽  
Zn Alloy ◽  
Made In

Interphase sliding is an important phenomenon of high temperature plasticity. In order to study the microstructural changes associated with it, as well as its influence on the strain rate dependence on stress and temperature, plane boundaries were obtained by welding together two polycrystals of Cu-Zn alloys having the face centered cubic and body centered cubic structures respectively following the procedure described in (1). These specimens were then deformed in shear along the interface on a creep machine (2) at the same temperature as that of the diffusion treatment so as to avoid any precipitation. The present paper reports observations by conventional and high voltage electron microscopy of the microstructure of both phases, in the vicinity of the phase boundary, after different creep tests corresponding to various deformation conditions.Foils were cut by spark machining out of the bulk samples, 0.2 mm thick. They were then electropolished down to 0.1 mm, after which a hole with thin edges was made in an area including the boundary

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