A population genetic study of the Banks and Torres Islands (Vanuatu) and of the Santa Cruz Islands and polynesian outliers (Solomon Islands)

As part of a multidisciplinary survey of populations in the Banks and Torres Islands of Vanuatu and the Southern and Central Districts of the Solomon Islands, nearly 2,400 persons have been tested for ABO blood groups and a number of serum protein and red cell enzyme genetic marker systems. For the ABO system, the populations are characterized in general by high gene O and low gene B frequencies except in two of the Polynesian Outlier Islands, Rennell and Bellona, which have high frequencies of B. Among the serum proteins, several alleles have distributions indicating significant movement of people between islands. These include Albumin ^{New Guinea} and the transferrin alleles Tf, and Tf, and Tf. Similar specific alleles for red cell enzymes also show distributions reflecting interisland population movement as well as contact with persons from outside the southern Pacific region. Examples are ACP in the acid phosphatase system, PGM and PGM, PGM and PGM, PGK⁴ and also HbJ^Tongariki. The data available for 11 polymorphic systems were used to generate genetic distances. Of the four Polynesian Outlier Islands, Anuta is most remote genetically, with Rennell and Bellona also relatively isolated. The fourth Polynesian Outlier, Tikopia, occupies a position genetically close to the Melanesian populations of the Banks and Torres Islands and the southern Solomons. The history of early European contact and voyaging in the Pacific, as well as archaeological and linguistic evidence and local legends, indicate that significant movements of people occurred between islands and provided opportunities for genes to be introduced from Europeans, Africans, and Asians. The genetic marker studies give evidence for genes from all these sources, though at a low level. Despite this admixture, the Polynesian Outlier and Melanesian populations have preserved their own distinctive genetic patterns.     

Effects of storage on microbial loads of two commercially important shellfish species, Crassostrea virginica and Mercenaria campechiensis.

The effects of storage on the microbial load in two commercially important species of shellfish were examined. Oysters (Crassostrea virginica) were stored as shellstock, shucked meats, and fully processed meats at four temperatures for up to 21 days, and clams (Mercenaria campechiensis) were stored only as shellstock. The concentrations of most microbiological groups of organisms increased with the duration and temperature of storage in both shellfish species, although the increases were significantly lower in claims. Concentrations of Vibrio cholerae rose by approximately 1 log in oysters stored as shellstock after 7 days at 2 degrees C, and Lac+ vibrios increased 2 logs at 8 degrees C. Total counts of bacteria, fungi, coliforms, fecal streptococci, Aeromonas hydrophila, and clostridia were significantly higher in shucked oysters than in those stored as shellstock. Fecal coliforms were statistically the same, but V. cholerae, Vibrio parahaemolyticus, and the Lac+ vibrios were higher in oysters stored as shellstock. The concentrations of all microbial groups were higher in fully processed oysters than in shucked meats, with the exception of the vibrios, which showed no significant difference among the treatments. The results showed that although traditional methods of storing shellfish resulted in an overall increase in the microbial load, vibrio levels increased only in oysters stored as shellstock. Although fecal coliform and total bacterial counts did not correlate with those for vibrios in fresh oysters, strong correlations were observed in oysters stored for 7 days, suggesting that these indicators may be useful in monitoring oyster quality when meats are stored for a limited time as shellstock.     

Effect of pinealectomy on seasonal changes in antler growth and concentrations of testosterone and prolactin in white-tailed deer

A 2-year study was conducted to determine under controlled conditions the role of the pineal gland in regulating the seasonal changes in antler growth and reproduction of male white-tailed deer. Blood samples were drawn from 6 pinealectomized (PX) and 18 control (C) deer at intervals of 2 weeks and analyzed for testosterone (T) and prolactin (Prl). Relative scrotal circumference and main beam antler length were recorded. Relative scrotal circumference was similar in PX and C groups, but the normal pattern was delayed 1 to 3 months in the PX deer relative to the C deer. The mean dates of beginning antler growth, velvet shedding, antler casting and pelage changes were significantly later in both years for PX deer than in C deer. Testosterone concentrations peaked 1 month later in the PX deer than in the C deer for both yearling and 2-year-old deer. Prl concentrations in C deer, but not in PX deer, were correlated highly with day length, and the PX deer were delayed relative to the C deer in showing the normal Prl pattern. Increasing levels of Prl in both groups coincided with beginning antler growth in both years. These results indicate that the pineal gland does not originate the seasonal cycles of male white-tailed deer but may synchronize cycles among individual deer, and regulate the circannual rhythm of Prl concentrations which may in turn influence other hormonal cycles.     

Relationship among fecal coliforms, Escherichia coli, and Salmonella spp. in shellfish.

The relationship of fecal coliforms, Escherichia coli, and Salmonella spp. was examined in freshly harvested and stored shellfish. In 16 of 40 freshly collected oyster samples, fecal coliform levels were above the recommended wholesale level suggested by the National Shellfish Sanitation Program (less than or equal to 230/100 g), and Salmonella spp. were present in three of these samples. Salmonella spp. were not, however, present in any sample containing less than 230 fecal coliforms per 100 g. Analysis of the data suggests that low fecal coliform levels in both fresh and stored oysters are good indicators of the absence of Salmonella spp., but that high levels of fecal coliforms are somewhat limited in predicting the presence of Salmonella spp. E. coli levels correlated very strongly with fecal coliform levels in both fresh and stored oysters and clams, suggesting that there is no advantage in replacing fecal coliforms with E. coli as an indicator of shellfish quality.     

Mechanics of gliding in birds with special reference to the influence of the ground effect

A model of the mechanics of gliding without loss of altitude (horizontal gliding) is developed. The model can be employed to assess the influence of the principal drag components (induced, profile and parasite drag), choice of initial and final glide velocities and height above the ground on glide distance. For birds gliding near to the ground the ground effect acts to decrease the induced drag and increase the lift to drag ratio of the wings. Minimum drag speed is reduced for birds gliding near to the ground. The model is applied to the gliding flight of the black skimmer (Rhyncops nigra). Glide distances for given initial and final velocities are significantly increased in the influence of the ground effect over out of ground effect values.     

The Parodi-Irgens feline sarcoma virus and simian sarcoma virus have homologous oncogenes, but in different contexts of the viral genomes

We have identified the oncogene and the putative transforming protein of the Parodi-Irgens feline sarcoma virus (PI-FeSV). The PI-FeSV is defective and needs a helper virus for its replication. The v-onc sequences in the PI-FeSV were found to be related to the v-sis sequences of the simian sarcoma virus (SSV). PI-FeSV nonproducer cells express two viral RNAs, a 6.8-and a 3.3-kilobase RNA. The 6.8-kilobase RNA contains gag, sis, and env sequences but lacks the pol gene. The 3.3-kilobase RNA, on the other hand, contains only env sequences. We have detected one feline leukemia virus-related protein product in these cells, namely, a 76-kilodalton protein which contains determinants of the feline leukemia virus gag proteins p15 and p30. The v-sis sequences in the PI-FeSV have been located near the 5' end of the viral genome. Taken together, these results imply that the p76 protein contains both feline leukemia virus gag and sis sequences and probably is the transforming protein of this virus. In contrast, in SSV the sis sequences are located towards the 3' end of the viral genome, and the sis protein is thought to be expressed via a subgenomic RNA. PI-FeSV and SSV therefore use different schemes to express their onc-related sequences. The v-sis sequences in the PI-FeSV contain restriction sites which reflect the different origin of the v-sis sequences in the PI-FeSV and SSV. The homologous oncogenes of the PI-FeSV and SSV thus were transduced by two different retroviruses, feline leukemia virus and the simian sarcoma-associated virus, apparently from the genomes of different species.     

Postnatal Changes in Cathepsin D in Rat Neural Tissue

Cathepsin D, an aspartyl endopeptidase, was analyzed in cortex from forebrain and cerebellum, spinal cord, and optic and sciatic nerves, and in the liver of rats from 1 to 120 days of age. Cathepsin D was quantitated in tissue extracts by measurement of enzyme specific activity on a substrate of [methyl-¹⁴C]-methylated hemoglobin and by radioimmunoassay. Immunocytochemistry was used to ascertain the identity of the mixed cell types that contributed to the cathepsin D detected. As quantitated by radioimmunoassay, immunoreactive cathepsin D varied between 0.2 and 1 ng/μg of total protein. Maximum activity occurred at approximately the 15th postnatal day; the least amount of immunoreactive cathepsin D was found at 30 or 60 days of age. A subsequent increase of varying magnitude occurred at postnatal day 120. There was good correspondence between immunoreactive enzyme and enzyme specific activity, which ranged from 1 to 4 ng/μg of total protein, and the activities determined by the two methods provided similar, but not identical, developmental profiles. Cathepsin D was demonstrated by immunocytochemistry to be present in most neurons, in all choroid plexus epithelium, and in certain oligodendrocytes from the first postnatal day. Cathepsin D was present in oligodendrocytes in cord lateral funiculi and optic nerve by the first postnatal day, and by the sixth postnatal day many oligodendrocytes were abundantly stained. In contrast, oligodendrocytes in the corpus callosum and in the cerebellar white matter did not contain demonstrable cathepsin D until postnatal days 10 and 15, respectively. These results indicate a role for cathepsin D during the postnatal development of rat CNS and suggest that this proteinase may be involved in the steps of myelination.     

A simple sensitive radioreceptor assay for calcium antagonist drugs

A radioreceptor assay for calcium channel antagonist drugs described here is based on the ability of these drugs to affect ³H-nitrendipine binding to calcium channels. All the known calcium channel antagonists may be assayed in this manner. The assay can detect 10–100 nM (4 – 40 ng/ml) nimodipine, 10–100 nM (3.5 – 35 ng/ml) nifedipine, 3–30 μM (1.2 – 12 μm/ml) prenylamine, 0.1 – 1.0 μM (49 – 490 ng/ml) verapamil and 3–30 μM (1.2 – 12 μg/ml) diltiazem. These values cover the range of concentrations of calcium channel antagonists that are clinically important. As the radioreceptor assay detects active metabolites as well as the parent drugs, it should prove a useful adjunct in cardiovascular therapy. The method is more reproducible, simpler and less expensive than other methods such as high pressure liquid chromatography.     

Gibberellins and Heterosis in Maize : II. Response to Gibberellic Acid and Metabolism of [H]Gibberellin A(20)

Two maize inbreds, CM7 and CM49, and CM7 × CM49, their F₁ hybrid (which displayed significant heterosis), were examined with regard to response to exogenous gibberellin A₃ (GA₃), and in their ability to metabolize GA₂₀, a native GA of maize. The leaf sheath elongation response to GA₃ was far greater for the imbreds than for their hybrid. The inbreds also displayed significant elongation of the leaf blades in response to GA₃, whereas the hybrid was unaffected. Promotion of cell division in the leaf sheath of CM7 and the hybrid was effected by GA₃, but no promotion of cell elongation was observed in CM49, even though significant leaf sheath elongation occurred. Shoot dry weight of both inbreds was significantly increased by GA₃, but response by the hybrid in this parameter was slight and variable. Root dry weight of CM7 was significantly increased by GA₃, but was unchanged in CM49 and the hybrid. Thus, inbred shoot dry weight increases effected by GA₃ were not at the expense of the root system. Rapid metabolism of [2,3-³H]GA₂₀ occurred in all genotypes, although genotypic differences were observed. The hybrid had the highest rates of metabolism to GA glucosyl conjugate-like substances. Oxidative metabolism was also fastest in the hybrid, followed by CM7, and slowest in CM49, the slowest-growing inbred. Thus, rate of GA₂₀ metabolism is under genetic control in normal (i.e. not dwarfed) maize genotypes. These results, taken together with previous reports that the hybrid has significantly enhanced levels of endogenous GA-like substances, suggest that GA play a role in the expression of heterosis in maize.     

Experimental infection of some North American wild ruminants and domestic sheep with Mycobacterium paratuberculosis: clinical and bacteriological findings

Mycobacterium paratuberculosis originally isolated from bighorn sheep (Ovis canadensis) with spontaneous paratuberculosis was used to orally inoculate Rocky Mountain elk (Cervus elaphus nelsoni) calves, mule deer (Odocoileus hemionus) fawns, white-tailed deer (Odocoileus virginianus) fawns, bighorn X mouflon (Ovis musimon) hybrid lambs, and domestic lambs. All experimentally exposed animals became infected. During the first year of infection, hybrid and domestic sheep were able to control the infection but infection was progressive in elk and deer. Clinical paratuberculosis occurred only in mule deer.