184 research outputs found
East-West Asymmetry in Coastal Temperatures of Hudson Bay as a Proxy for Sea Ice
Hudson Bay experiences a complete cryogenic cycle, which has been well documented since 1971. We developed a temperature proxy method to extend the sea ice record back to 1944, using mean temperatures for Churchill and Inukjuak and the difference between these means at two different seasonal periods. This method proved to reproduce the 1971 to 2011 ice-free season length record with an error just over eight days (6%). This relationship was used to hindcast ice-free season length to 1944. This hindcast was subsequently appended to the existing 1971–2011 record to form a 68-year sea ice record. This extended record shows that the recent statistically significant increase in length of the ice-free season was not the result of a natural oscillation of less than 68 years and is consistent with a net warming due to increasing greenhouse gases.La baie d’Hudson connaît un cycle cryogénique complet, et celui-ci est bien répertorié depuis 1971. Nous avons élaboré une méthode d’obtention de données indirectes des températures afin d’étendre les données des températures jusqu’à 1944, en nous servant des températures moyennes pour Churchill et Inukjuak et de la différence entre ces moyennes à deux périodes saisonnières différentes. Cette méthode avait pour but de reproduire le registre des durées de saisons sans glace de 1971 à 2011, avec une marge d’erreur d’un peu plus de huit jours (6 %). Cette méthode a permis de faire la simulation rétrospective de la durée des saisons sans glace jusqu’en 1944. Par la suite, la simulation rétrospective a été appliquée au registre actuel de 1971–2011, ce qui a donné lieu à un registre sur la glace de mer réparti sur 68 années. Ce registre prolongé a permis de démontrer que la récente augmentation statistiquement différente en matière de durée de la saison sans glace ne découlerait pas d’une oscillation naturelle de moins de 68 ans, et qu’elle correspond à un réchauffement net attribuable à l’augmentation des gaz à effet de serre
Multiple Pregnancy after Gonadotropin-Intrauterine Insemination: An Unavoidable Event?
Objective. Determine which factors predict multiple pregnancy in gonadotropin-intrauterine insemination cycles so that cancellation criteria might be developed. Study Design. Retrospective chart review of all patients undergoing gonadotropin-intrauterine insemination over a continuous 36 month period. Results. No factors examined were able to predict the occurrence of multiple pregnancy. Conclusion. Multiple pregnancy is an unavoidable complication of gonadotropin-intrauterine insemination treatment
Characterisation of Potential Landing Sites for the European Space Agency's Lunar Lander Project
This article describes the characterization activities of the landing sites
currently envisaged for the Lunar Lander mission of the European Space Agency.
These sites have been identified in the South Pole Region (-85{\deg} to
-90{\deg} latitude) based on favourable illumination conditions, which make it
possible to have a long-duration mission with conventional power and thermal
control subsystems, capable of enduring relatively short periods of darkness
(in the order of tens of hours), instead of utilising Radioisotope Heating
Units. The illumination conditions are simulated at the potential landing sites
based on topographic data from the Lunar Orbiter Laser Altimeter (LOLA), using
three independent tools. Risk assessment of the identified sites is also being
performed through independent studies. Long baseline slopes are assessed based
on LOLA, while craters and boulders are detected both visually and using
computer tools in Lunar Reconnaissance Orbiter Camera (LROC) images, down to a
size of less than 2 m, and size-frequency distributions are generated. Shadow
hazards are also assessed via LROC images. The preliminary results show that
areas with quasi-continuous illumination of several months exist, but their
size is small (few hundred metres); the duration of the illumination period
drops quickly to less than one month outside the areas, and some areas present
gaps with short illumination periods. Concerning hazard distributions, 50 m
slopes are found to be shallow (few degrees) based on LOLA, whereas at the
scale of the lander footprint (~5 m) they are mostly dominated by craters,
expected to be mature (from geological context) and shallow (~11{\deg}). The
preliminary conclusion is that the environment at the prospective landing sites
is within the capabilities of the Lander design
Forced Smoking Abstinence: Not Enough for Smoking Cessation
Importance: Millions of Americans are forced to quit smoking as they enter tobacco-free prisons and jails, but most return to smoking within days of release. Interventions are needed to sustain tobacco abstinence after release from incarceration.
Objective: To evaluate the extent to which the WISE intervention (Working Inside for Smoking Elimination), based on motivational interviewing (MI) and cognitive behavioral therapy (CBT), decreases relapse to smoking after release from a smoke-free prison.
Design: Participants were recruited approximately 8 weeks prior to their release from a smoke-free prison and randomized to 6 weekly sessions of either education videos (control) or the WISE intervention.
Setting: A tobacco-free prison in the United States.
Participants: A total of 262 inmates (35% female).
Main Outcome Measure: Continued smoking abstinence was defined as 7-days point-prevelance abstinence validated by urine cotinine measurement.
Results: At the 3-week follow-up, 25% of the participants in the WISE intervention (31 of 122) and 7% of the control participants (9 of 125) continued to be tobacco-abstinent (odds ration [OR], 4.4; 95% CI, 2.0-9.7). In addition to the intervention, Hispanic ethnicity, a plan to remain abstinent, and being incarcerated for more than 6 months were all associated with increased likelihood of remaining abstinent. In the logistical regression analysis, participants randomized to the WISE intervention were 6.6 times more likely to remain tobacco abstinent at the 3-week follow up than those randomized to the control condition (95% CI, 2.5-17.0). Nonsmokers at the 3-week follow-up had an additional follow-up 3 months after release, and overall 12% of the participants in the WISER intervention (14 of 122) and 2% of the control participants (3 of 125) were tobacco free at 3 months, as confirmed by urine cotinine measurement (OR, 5.3; 95% CI, 1.4-23.8).
Conclusions and Relevance: Forced tobacco abstinence alone during incarceration has little impact on postrelease smoking status. A behavioral intervention provided prior to release greatly improves cotinine-confirmed smoking cessation in the community.
Trial Registration: clinicaltrials.gov Identifier: NCT0112258
Serum hCG Levels following the Ovulatory Injection: Associations with Patient Weight and Implantation Time
Objective. To test if serum hCG levels the morning after the ovulatory hCG injection correlate with (1) retrieval efficiency, (2) oocyte maturity, (3) embryo quality, (4) pregnancy, and/or (5) time to implantation in patients undergoing in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). Design. Retrospective cohort analysis. Setting. University-based IVF clinic. Patient(s). All IVF/ICSI cycles from April 2005 to February 2008 whose hCG administration was confirmed ( = 472 patients). Intervention(s). Serum hCG was measured the morning following the ovulatory injection, on the 16th day following retrieval, and repeated on day 18 for those with positive results. Main Outcome Measure(s). Number of follicles on the day of hCG injection, number of oocytes retrieved, maturity of oocytes, embryo quality, pregnancy outcome, and time to implantation. Result(s). hCG levels did not correlate with retrieval efficiency, oocyte maturity, embryo quality, or pregnancy. Postinjection hCG levels were inversely associated with patient weight and time to implantation. Conclusion (s). No correlation was found between hCG level and any parameter of embryo quality. Patient weight affected hCG levels following hCG injection and during the early period of pregnancy following implantation. No association between postinjection hCG level and time of implantation (adjusted for patient weight) was apparent
Serum hCG Levels following the Ovulatory Injection: Associations with Patient Weight and Implantation Time
Objective. To test if serum hCG levels the morning after the ovulatory hCG injection correlate with (1) retrieval efficiency, (2) oocyte maturity, (3) embryo quality, (4) pregnancy, and/or (5) time to implantation in patients undergoing in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). Design. Retrospective cohort analysis. Setting. University-based IVF clinic. Patient(s). All IVF/ICSI cycles from April 2005 to February 2008 whose hCG administration was confirmed (n=472 patients). Intervention(s). Serum hCG was measured the morning following the ovulatory injection, on the 16th day following retrieval, and repeated on day 18 for those with positive results. Main Outcome Measure(s). Number of follicles on the day of hCG injection, number of oocytes retrieved, maturity of oocytes, embryo quality, pregnancy outcome, and time to implantation. Result(s). hCG levels did not correlate with retrieval efficiency, oocyte maturity, embryo quality, or pregnancy. Postinjection hCG levels were inversely associated with patient weight and time to implantation. Conclusion(s). No correlation was found between hCG level and any parameter of embryo quality. Patient weight affected hCG levels following hCG injection and during the early period of pregnancy following implantation. No association between postinjection hCG level and time of implantation (adjusted for patient weight) was apparent
Clomiphene, Metformin, or Both for Infertility in the Polycystic Ovary Syndrome
Background
The polycystic ovary syndrome is a common cause of infertility. Clomiphene and insulin sensitizers are used alone and in combination to induce ovulation, but it is unknown whether one approach is superior. Methods We randomly assigned 626 infertile women with the polycystic ovary syndrome to receive clomiphene citrate plus placebo, extended-release metformin plus placebo, or a combination of metformin and clomiphene for up to 6 months. Medication was discontinued when pregnancy was confirmed, and subjects were followed until delivery.
Results
The live-birth rate was 22.5% (47 of 209 subjects) in the clomiphene group, 7.2% (15 of 208) in the metformin group, and 26.8% (56 of 209) in the combinationtherapy group (P\u3c0.001 for metformin vs. both clomiphene and combination therapy; P=0.31 for clomiphene vs. combination therapy). Among pregnancies, the rate of multiple pregnancy was 6.0% in the clomiphene group, 0% in the metformin group, and 3.1% in the combination-therapy group. The rates of first-trimester pregnancy loss did not differ significantly among the groups. However, the conception rate among subjects who ovulated was significantly lower in the metformin group (21.7%) than in either the clomiphene group (39.5%, P=0.002) or the combinationtherapy group (46.0%, P\u3c0.001). With the exception of pregnancy complications, adverse-event rates were similar in all groups, though gastrointestinal side effects were more frequent, and vasomotor and ovulatory symptoms less frequent, in the metformin group than in the clomiphene group.
Conclusions
Clomiphene is superior to metformin in achieving live birth in infertile women with the polycystic ovary syndrome, although multiple birth is a complication. (ClinicalTrials.gov number, NCT00068861.
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Ulcerative colitis-risk loci on chromosomes 1p36 and 12q15 found by genome-wide association study.
Ulcerative colitis is a chronic inflammatory disease of the colon that presents as diarrhea and gastrointestinal bleeding. We performed a genome-wide association study using DNA samples from 1,052 individuals with ulcerative colitis and preexisting data from 2,571 controls, all of European ancestry. In an analysis that controlled for gender and population structure, ulcerative colitis loci attaining genome-wide significance and subsequent replication in two independent populations were identified on chromosomes 1p36 (rs6426833, combined P = 5.1 x 10(-13), combined odds ratio OR = 0.73) and 12q15 (rs1558744, combined P = 2.5 x 10(-12), combined OR = 1.35). In addition, combined genome-wide significant evidence for association was found in a region spanning BTNL2 to HLA-DQB1 on chromosome 6p21 (rs2395185, combined P = 1.0 x 10(-16), combined OR = 0.66) and at the IL23R locus on chromosome 1p31 (rs11209026, combined P = 1.3 x 10(-8), combined OR = 0.56; rs10889677, combined P = 1.3 x 10(-8), combined OR = 1.29)
Multicentre evaluation of the Boehringer Mannheim/Hitachi 917 analysis system
The new selective access analysis system BM/Hitachi 917 was evaluated in an international multicentre study, mainly according to the ECCLS protocol for the evaluation of analysers in clinical chemistry. Forty-three different analytes, covering 56 different methods enzymes, substrates, electrolytes, specific proteins, drugs and urine applications were tested in seven European clinical chemistry laboratories. Additionally, the practicability of the BM/ Hitachi 917 was tested according to a standardized questionnaire. Within-run CVs (median of 3 days) for enzymes, substrates and electrolytes were <2% except for creatine-kinase MB isoform and lipase at low concentration. For proteins, drugs and urine analytes the within-run CVs were < 4% except for digoxin and albumin in urine. Between-day median CVs were generally < 3% for enzymes, substrates and electrolytes, and < 6% for proteins, drugs and urine analytes, except for lipase, creatine kinase and MB isoform, D-dimer, glycosylated haemoglobin, rheumatoid factors, digoxin, digitoxin, theophylline and albumin in urine in some materials. Linearity was found according to the test specifications or better and there were no relevant effects seen in drift and carry-over testing. The interference results clearly show that also for the BM/Hitachi 917 interference exists sometimes, as could be expected because of the chemistries applied. It is a situation that can be found in equivalent analysers as well. The accuracy is acceptable regarding a 95–105% recovery in standard reference material, with the exception of the creatinine Jaffé method. Most of the 160 method comparisons showed acceptable agreement according to our criteria: enzymes, substrates, urine analytes deviation of slope ± 5%, electrolytes ± 3%, and proteins and drugs ± 10%. The assessment of practicability for 14 groups of attributes resulted in a grading of one–three scores better for the BM/Hitachi 917 than the present laboratory situation. In conclusion, the results of the study showed good analytical performance and confirmed the usefulness of the system as a consolidated workstation in medium-sized to large clinical chemistry laboratories
Piperidinols that show anti-tubercular activity as inhibitors of arylamine N-acetyltransferase: an essential enzyme for mycobacterial survival inside macrophages
Latent M. tuberculosis infection presents one of the major obstacles in the global eradication of tuberculosis (TB). Cholesterol plays a critical role in the persistence of M. tuberculosis within the macrophage during latent infection. Catabolism of cholesterol contributes to the pool of propionyl-CoA, a precursor that is incorporated into cell-wall lipids. Arylamine N-acetyltransferase (NAT) is encoded within a gene cluster that is involved in the cholesterol sterol-ring degradation and is essential for intracellular survival. The ability of the NAT from M. tuberculosis (TBNAT) to utilise propionyl-CoA links it to the cholesterol-catabolism pathway. Deleting the nat gene or inhibiting the NAT enzyme prevents intracellular survival and results in depletion of cell-wall lipids. TBNAT has been investigated as a potential target for TB therapies. From a previous high-throughput screen, 3-benzoyl-4-phenyl-1-methylpiperidinol was identified as a selective inhibitor of prokaryotic NAT that exhibited antimycobacterial activity. The compound resulted in time-dependent irreversible inhibition of the NAT activity when tested against NAT from M. marinum (MMNAT). To further evaluate the antimycobacterial activity and the NAT inhibition of this compound, four piperidinol analogues were tested. All five compounds exert potent antimycobacterial activity against M. tuberculosis with MIC values of 2.3-16.9 µM. Treatment of the MMNAT enzyme with this set of inhibitors resulted in an irreversible time-dependent inhibition of NAT activity. Here we investigate the mechanism of NAT inhibition by studying protein-ligand interactions using mass spectrometry in combination with enzyme analysis and structure determination. We propose a covalent mechanism of NAT inhibition that involves the formation of a reactive intermediate and selective cysteine residue modification. These piperidinols present a unique class of antimycobacterial compounds that have a novel mode of action different from known anti-tubercular drugs
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