Cloning of terminal transferase cDNA by antibody screening

A cDNA library was prepared from a terminal deoxynucleotidyltransferase-containing thymoma in the phage vector λgt11. By screening plaques with anti-terminal transferase antibody, positive clones were identified of which some had β-galactosidase-cDNA fusion proteins identifiable after electrophoretic fractionation by immunoblotting with anti-terminal transferase antibody. The predominant class of cross-hybridizing clones was determined to represent cDNA for terminal transferase by showing that one representative clone hybridized to a 2200-nucleotide mRNA in close-matched enzyme-positive but not to enzyme-negative cells and that the cDNA selected a mRNA that translated to give a protein of the size and antigenic characteristics of terminal transferase. Only a small amount of genomic DNA hybridized to the longest available clone, indicating that the sequence is virtually unique in the mouse genome

Long range transport of ultra cold atoms in a far-detuned 1D optical lattice

We present a novel method to transport ultra cold atoms in a focused optical lattice over macroscopic distances of many Rayleigh ranges. With this method ultra cold atoms were transported over 5 cm in 250 ms without significant atom loss or heating. By translating the interference pattern together with the beam geometry the trap parameters are maintained over the full transport range. Thus, the presented method is well suited for tightly focused optical lattices that have sufficient trap depth only close to the focus. Tight focusing is usually required for far-detuned optical traps or traps that require high laser intensity for other reasons. The transport time is short and thus compatible with the operation of an optical lattice clock in which atoms are probed in a well designed environment spatially separated from the preparation and detection region.Comment: 14 pages, 6 figure

The UK risk assessment scheme for all non-native species

1. A pest risk assessment scheme, adapted from the EPPO (European and Mediterranean Plant Protection Organisation) scheme, was developed to assess the risks posed to UK species, habitats and ecosystems by non-native taxa. 2. The scheme provides a structured framework for evaluating the potential for non-native organisms, whether intentional or unintentional introductions, to enter, establish, spread and cause significant impacts in all or part of the UK. Specialist modules permit the relative importance of entry pathways, the vulnerability of receptors and the consequences of policies to be assessed and appropriate risk management options to be selected. Spreadsheets for summarising the level of risk and uncertainty, invasive attributes and economic impact were created. In addition, new methods for quantifying economic impact and summarising risk and uncertainty were explored. 3. Although designed for the UK, the scheme can readily be applied elsewhere

CMEs at High Northern Latitudes During Solar Maximum : Ulysses and SOHO Correlated Observations.

From September through November 2001, Ulysses was almost continuously immersed in polar coronal hole (CH) flow during its northern polar pass of the Sun. For much of this time, the flow was fast (> 700 km/s) and steady, quite similar to the steady unstructured flow observed during Ulysses first polar orbit near solar minimum. During the three months Ulysses transited the northern polar CH it observed 5 coronal mass ejections (CMEs). Of these, two were clearly over-expanding and two were at least partially driven by overexpansion. The phenomenon of over-expansion was frequently observed at high latitudes during Ulysses first orbit. The recurrence of over-expanding CMEs during the second orbit at high latitudes indicates that this is a phenomenon apparently unique to and typical of CMEs embedded in polar CH flow. Ulysses was nearly above the solar limb during this three-month interval, providing an opportunity to use LASCO/SOHO observations to study the initial velocity profiles of the CMEs observed further out by Ulysses. These initial conditions were used as inputs into a hydrodynamic code, the results of which are reported here

Kinetics and Product Yields of the OH Initiated Oxidation of Hydroxymethyl Hydroperoxide

Hydroxymethyl hydroperoxide (HMHP), formed in the reaction of the C1 Criegee intermediate with water, is among the most abundant organic peroxides in the atmosphere. Although reaction with OH is thought to represent one of the most important atmospheric removal processes for HMHP, this reaction has been largely unstudied in the laboratory. Here, we present measurements of the kinetics and products formed in the reaction of HMHP with OH. HMHP was oxidized by OH in an environmental chamber; the decay of the hydroperoxide and the formation of formic acid and formaldehyde were monitored over time using CF3O- chemical ionization mass spectrometry (CIMS) and laser induced fluorescence (LIF). The loss of HMHP by reaction with OH is measured relative to the loss of 1,2-butanediol [k1;2-butanediol+OH = (27:0 5:6) 10- exp12 cm3 molecule-1s-1]. We find that HMHP reacts with OH at 295 K with a rate coefficient of (7.1 1.5) 10-12 cm3 molecule-1s-1, with the formic acid to formaldehyde yield in a ratio of 0:880:21 and independent of NO concentration (31010 1.51013 molecule cm-3). We suggest that, exclusively, abstraction of the methyl hydrogen of HMHP results in formic acid while abstraction of the hydroperoxy hydrogen results in formaldehyde. We further evaluate the relative importance of HMHP sinks and use global simulations from GEOS-Chem to estimate that HMHP oxidation by OH contributes 1.7 Tg yr-1 (1-3%) of global annual formic acid production

Outcome after steroid withdrawal in pediatric renal transplant patients receiving tacrolimus-based immunosuppression

Background. Corticosteroids have always been an integral part of immunosuppressive regimens in renal transplantation. The primary goal of this analysis was to assess the safety of steroid withdrawal in our pediatric renal transplant recipients receiving tacrolimus-based immunosuppression. Methods. Between December 1989 and December 1996, 82 renal transplantations were performed in pediatric patients receiving tacrolimus-based immunosuppression. Two of these patients lost their grafts within 3 weeks of transplantation (and were still on steroids at the time of graft loss), and were excluded from further analysis. Seventy-four patients (92.5%) were taken off prednisone a median of 5.7 months after transplantation. Of these 74, 56 (70%) remained off prednisone (OFF), and 18 (22.5%) were restarted on prednisone a median of 14.8 months after discontinuing steroids (OFF → ON). 6(7.5%) were never taken off prednisone (ON). The mean follow-up was 59±23 months. Results. The 1-, 3-, and 5-year actuarial patient survival rates in the OFF group were 100%, 98%, and 96%, respectively; in the OFF → ON group, they were 100%, 100%, and 100%, and in the ON group, they were 100%, 83%, and 83%. The 1-, 3-, and 5- year actuarial graft survival rates in the OFF group were 100%, 95%, and 82%, respectively; in the OFF → ON group, they were 100%, 89%, and 83%; and in the ON group, they were 100%, 50%, and 33%. Two of the six graft losses in the OFF group, three out of four in the OFF → ON Group, and two out of five in the ON group, were to chronic rejection. A time-dependent Cox regression analysis showed that the hazard for graft failure for those who came and stayed off prednisone was 0.178 relative to those who were never withdrawn from prednisone (P=0.005). Patients who were 10 years of age or younger were withdrawn from prednisone earlier (median: 5 months) than those older than 10 years (median: 7.3 months, P=0.02). In addition, patients who never had acute rejection were withdrawn from steroids earlier (median: 5 months) than those who had one or more episodes of acute rejection (median: 7.6 months, P=0.001). There was no effect of donor age, race, sex, recipient race, sex, cadaveric versus living donor, 48-hr graft function, panel reactive antibody, and total HLA mismatches or matches on the likelihood of being weaned off steroids. Serum creatinine at most recent follow-up in the OFF group was 1.2±0.5 mg/dl; in the OFF → ON group, it was 1.8±0.9 mg/dl, and in the ON group it was 2.0 mg/dl (P<0.003). The incidence of rejection in the OFF, OFF → ON, and ON groups was 39%, 77%, and 100%, respectively (P<0.05). Conclusion. These data suggest that steroid withdrawal in pediatric renal transplant patients receiving tacrolimus-based immunosuppression is associated with reasonable short- and medium-term patient and graft survival, and acceptable renal function. Patients who discontinue and then resume steroids had patient and graft survival rates comparable with those in patients who discontinue and stay off steroids, but had a higher serum creatinine and a higher incidence of rejection

Sexual Segregation and Flexible Mating Patterns in Temperate Bats

Social structure evolves from a trade-off between the costs and benefits of group-living, which are in turn dependent upon the distribution of key resources such as food and shelter. Males and females, or juveniles and adults, may have different priorities when selecting habitat due to differences in physiological or behavioural imperatives, leading to complex patterns in group composition. We studied social structure and mating behaviour in the insectivorous bat Myotis daubentonii along an altitudinal gradient, combining field studies with molecular genetics. With increasing altitude the proportion of males in summer roosts increased and only males were present in the highest roosts. With increasing altitude environmental temperature decreased, nightly variation in temperature increased, and bat foraging activity decreased, supporting the hypothesis that the harsher, high elevation sites cannot support breeding females. We found that offspring in female-dominated lowland roosts had a very high probability of being fathered by bats caught during autumn swarming at hibernation sites, in contrast to those in intermediate roosts, which had a high probability of being fathered by males sharing the nursery roost with the females. Whilst females normally appear to exclude males from nursery colonies, for those in marginal habitats, one explanation for the presence of males is that the thermoregulatory benefits to the females may outweigh disadvantages, such as competition for food, and give some males an opportunity to increase their breeding success. We suggest that the environment, and its effects on resource distribution, thus determine social structure, which in turn determines the mating pattern that has evolved