Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation

Late Cretaceous (Cenomanian) fossils discovered in the Kem Kem region of Morocco include large predatory dinosaurs that inhabited Africa as it drifted into geographic isolation. One, represented by a skull approximately 1.6 meters in length, is an advanced allosauroid referable to the African genus Carcharodontosaurus. Another, represented by a partial skeleton with slender proportions, is a new basal coelurosaur closely resembling the Egyptian genus Bahariasaurus. Comparisons with Cretaceous theropods from other continents reveal a previously unrecognized global radiation of carcharodontosaurid predators. Substantial geographic differentiation of dinosaurian faunas in response to continental drift appears to have arisen abruptly at the beginning of the Late Cretaceous.     

Effects of high-pressure processing at low temperature on the molecular structure and surface properties of beta-lactoglobulin

High-pressure processing (HPP) was utilized to induce unfolding of beta-lactoglobulin (beta-LG). beta-Lactoglobulin solutions at concentrations of 0.5 mg/mL, in pH 7.5 phosphate buffer, were pressure treated at 510 MPa for 10 min at either 8 or 24 degrees C. The secondary structure, as determined by circular dichroism (CD), of beta-LG processed at 8 degrees C appeared to be unchanged, whereas beta-LG processed at 24 degrees C lost alpha-helix structure. Tertiary structures for beta-LG, as determined by near-UV CD, intrinsic protein fluorescence spectroscopy, hydrophobic fluorescent probe binding, and thiol group reactivity, were changed following processing at either temperature. The largest changes to tertiary structure were observed for the samples processed at 24 degrees C. Model solutions containing the pressure-treated beta-LG showed significant decreases in surface tension at liquid-air interfaces with values of 54.00 and 51.69 mN/m for the samples treated at 24 and 8 degrees C, respectively. In comparison, the surface tension for model solutions containing the untreated control was 60.60 mN/m. Changes in protein structure during frozen and freeze-dried storage were also monitored, and some renaturation was observed for both storage conditions. Significantly, the sample pressure-treated at 8 degrees C continued to display the lowest surface tension.     

Nutrient and persistent pollutant deposition on the Bothnian Bay ice and snow fields

A study of atmospheric deposited nutrients and some persistent pollutants has been carried out on the ice and snow fields of the subarctic Bothnian Bay, the northernmost basin of the Baltic Sea. Total amounts of 600, 500 and 400 tons NO₃-N, NH₄-N and N_org-N, respectively are deposited in the snow while the corresponding amounts for P_tot-P is 40 tons. The corresponding amount for PCB and lindane are 1.0 and 0.2 kg, respectively. The measurements were carried out on the snow-covered ice four to six weeks old. A part of the deposited snow has been incorporated -into the snow-ice and an attempt to estimate its mean thickness and its amount of nutrients has been made. The total amounts now reach 1700, 1300 and 1100 tons of NO₃-N and NH₄-N and N_org-N, respectively in the snow and ice together. The results obtained support the use of land-based stations in estimates of seasonal atmospheric nutrient deposition to the Bothnian Bay. The observed concentrations of chloroorganic compounds correspond to those land-based observations reported from the same latitude in the northern hemisphere and reported in literature.     

Primary bovine viral diarrhoea virus infection in calves following direct contact with a persistently viraemic calf.

Six calves, aged 24 to 58 days and not previously exposed to bovine viral diarrhoea virus (BVDV), were infected with this agent by nose-to-nose contact with a persistently BVDV viraemic calf. The study was conducted in two trials, using 3 calves in each. All 6 calves showed a peak interferon level in serum at 4 days post infection (dpi), and they seroconverted to BVDV at 16-21 dpi. The calves in trial 1 had diarrhoea for 2 or 3 days between 2 and 6 dpi and one calf again from 9 to 11 dpi. During the periods of fever, the calves were slightly depressed. Those in trial 2 were more depressed and their oral and nasal mucous membranes were reddened but they never had diarrhoea. In both trials, fever (up to 41.3 degrees C) was a prominent symptom at 8 to 9 dpi and 2 calves showed a diphasic fever course. Respiratory affection was mild and no medical treatment was required. Haematological assessment demonstrated a transient but significant leukopenia and lymphopenia at 4 dpi (P less than 0.01 and P less than 0.05 respectively) and 11 dpi (P less than 0.05 and P less than 0.01 respectively). A significant decrease in thrombocyte count was seen at 4 dpi (P less than 0.05, n = 3). This study has demonstrated that nose-to-nose contact is an effective way of transmitting BVDV from persistently infected to susceptible cattle.     

Sperm localization in the oviducts of artificially inseminated dairy cattle

Eight animals, 3 heifers and 5 primiparous cows, were artificially inseminated by intrauterine deposition of frozen-thawed semen. The insemination dose comprised 20×10⁶ or 200 × 10⁶ spermatozoa, frozen in French mini straws. Four animals were inseminated at fixed time interval (72 or 84 h) after cloprostenol injection. The remaining 4 animals were inseminated in spontaneous oestrus. Slaughter took place 2 or 12 h after insemination. After fixation the oviducts were cut into segments, which were serial-sectioned and stained. Six sections per segment were examined under the microscope for sperm recovery.The number of spermatozoa recovered from the oviducts varied considerably among animals. Recovery was poor (less than 50 spermatozoa) in 4 animals. Recovery was low when insemination took place in induced oestrus and with the lower sperm number (20×10⁶). In animals in which more than 50 spermatozoa were found the distribution varied both between animals and between oviducts within the same animal. Overall, more spermatozoa were found in the lower (UTJ, isthmus and AIJ) than in the upper (ampulla) parts of the oviducts. In 3 out of 4 animals more spermatozoa were recovered from the left than from the right oviduct. Only in 1 animal were the majority of spermatozoa found in the oviduct ipsilateral to the follicle-bearing ovary.     

Bovine virus diarrhoea virus induces in vitro a proliferative response of peripheral blood mononuclear cells from cattle immunized by infection.

The ability of bovine peripheral blood mononuclear cells (PBMC) to mount a proliferative response to bovine virus diarrhoea virus (BVDV) in vitro was examined. After culturing PBMC in the presence of a non-cytopathic strain of BVDV for 6 days, the magnitude of PBMC proliferation was measured as incorporation of radiolabelled thymidine, present during the last 18 h. Live, but not heat-inactivated, BVDV evoked a proliferative response of PBMC obtained from cattle seropositive to the virus. However, PBMC from seronegative or persistently BVDV-infected animals were not stimulated by BVDV. The presence of live BVDV did not alter the proliferative response of PBMC to stimulation with concanavalin A.     

2-Mercaptoethanol influences the in vitro function of bovine peripheral blood mononuclear cells.

The effects of 2-mercaptoethanol (2-ME) on some in vitro functions of bovine peripheral blood mononuclear cells (PBMC) were examined. It was shown that 2-ME enhanced, in a dose-dependent manner, the production of antibodies to bovine coronavirus. In this test the optimal concentration of 2-ME was 50 microM. This molarity of 2-ME was also optimal for the pokeweed mitogen (PWM)-induced proliferation of PBMC obtained from the 7 cattle tested. Similarly, the spontaneous proliferation of PBMC from 4 out of these cattle was enhanced. Thus, 2-ME evoked an increase (up to 2.5 times) or a decrease (at most 10 times) of the quota between the PWM-induced and the spontaneous proliferation (stimulation index). In general, the presence of 50 microM 2-ME enhanced the in vitro production of interferon by bovine PBMC. On the contrary, the highest proliferative response of PBMC to stimulation with bovine virus diarrhoea virus was achieved in cultures without 2-ME or in cultures with 0.5 or 5 microM 2-ME. Since the effects of 2-ME varied, for different tests as well as for cattle tested, attention should be paid to the use of 2-ME in cultures of bovine PBMC.     

Grain Yield and Drought Resistance Indices of Oat Cultivars in Field Rain Shelter and Laboratory Experiments

Oat cultivars (n = 22) varying in origin were examined in laboratory and field tests at Svalöv and Ultuna, Sweden, in 1985 and 1986. Comparisons were made between drought resistance characteristics of juvenile plants and drought responses in yield of crops grown in field. By using automatic, movable rain shelters in combination with drip irrigation systems, both high and low irrigation regimes could be effected in the field experiments.
Black oat cultivars were more stable under water deficiency conditions, particularly on sandy soil. They possessed the highest drought resistance indices both in the laboratory and field. Modern white oat cultivars were found to be most drought sensitive.
Drought resistance index (DRI) and seminal root length (RL), as assessed in seedling stage, were strongly correlated with field drought susceptibility index (S). It is suggested that DRI and RL could be used as selection criteria to increase drought resistance of oats.     

The effect of mastitis on milk progesterone concentration in dairy cows

A within cow comparison was made between milk progesterone levels in healthy and mastitic quarters. Material was collected from cows with mastitis induced by bacterial inoculation, or by inoculation with bacterial endotoxin. Furthermore material from cows with spontaneous subclinical mastitis was used. Milk progesterone levels were lowered due to mastitis. However, the decrease was not large enough to cause misinterpretation of where in the oestrous cycle (luteal phase or non-luteal phase) the samples were taken.     

Sperm Distribution and Its Relation to Ovulation in Artificially Inseminated Heifers

Contents: Blood samples were taken in ten heifers every two hours during prooestrus and oestrus for determination of the LH peak, which was used to calculote the time of expected ovulation. Artificial insemination with frozen/thawed semen was performed at different times from the beginning of oestrus and the animals were slaughtered two, twelve or 24 hours after insemination. The genital tract was flushed and the spermatozoa recovered from the flushing solution by microscopic investigation. Heifers slaughtered two hours after insemination and more than 19 hours before ovulation had more spermatozoa in the uterotubal junction (UTJ) than in the isthmus and ampulla. This sperm distribution differed from that in the other animals. In animals which were slaughtered closer to ovulation and in those who had already ovulated at slaughter, approximately the same number of spermatozoa were recovered from the UTJ and isthmus and only a few spermatozoa were recovered from the ampulla. Motile spermatozoa were found in both the isthmus, UTJ and uterus at two and twelve hours after insemination and approximately ten hours before ovulation. Their number decreased with time but some motile spermatozoa were also recovered 24 hours after insemination and after ovulation. The distribution of spermatozoa in the oviducts ipsi-and contralateral to the corpus haemorrhagicum-bearing ovary was compared in heifers that had ovulated. There were no differences in the number of oviductal segments containing spermatozoa, nor were there any differences within animal in the number of spermatozoa in the oviducts. It was concluded that ovulation does not seem to cause great changes in the distribution of spermatozoa in the oviducts. Inhalt: Spermienverteilung und deren Beziehung zur Ovulation bei kunstlich besamten Jungrindern Von 10 Färsen wurden wahrend des Diöstrus und Östrus Blutproben im Abstand von 2 Std. entnommen, um den LH-Gipfel festzustellen. Dieser wurde jür die Bestimmung des erwarteten Ovulationstermins herangezogen. Inseminationen mit Gefriersperma wurden von Brunstbeginn an in verschiedenen Intervallen vorgenommen. Die Tiere wurden 2, 12 oder 24 Std. nach der Besamung getötet, die Geschlechtsorgane gespült und die Spermien in den Spülflüssigkeiten mikroskopisch nachgewiesen. Färsen, die 2 Std. nach der Besamung und mehr als 19 Std. vor der Ovulation getötet wurden, hat-ten mehr Spermien im Ostium uterinum des Eileiters (OU) als im Isthmus und Ampulle. Diese Verteilung war von jener der anderen Tiere verschieden. Tiere, die kürzere Zeit vor der Ovulation getötet wurden, oder bei der Schlachtung schon ovuliert hatten, zeigten etwa dieselbe Anzahl von Spermien in OU und Isthmus, in der Ampulle wurden nur wenig Spermien gefunden. Bei Färsen, die ovuliert hatten, wurde die Sper-mienverteilung in den ipsi- und contralateralen Eileitern zum Corpus haemowhagicum des Ovars verglichen. Die Spermienxahlen in den Eileitersegmenten waren nicht verschieden und auch im rechten und linken Eileiter gleich. Es wurde gefolgert, daβ die Ovulation keinen groβen Einfluβ auf die Spermienverteilung in den Eileitern bewirkt.