125 research outputs found
Skeleton Islands of New Zealand and elsewhere
Skeleton Islands are a variety of the class of islands resulting from subsidence of dissected land, subcategory 4a of a classification of islands here offered. Such islands are characterised by development of a sprawling outline with a narrow axial ridge from which slender lateral spurs, or ribs, extend more or less at right angles. Extreme skeletonisation is associated with development before a final drowning, or redrowning, of amphitheatre heads in valleys already heading in the main divide. This may be a climatically induced change of the valley form related, in the case of the New Zealand example, Arapawa Island, to cryergic (periglacial) activity in the Pleistocene glacial ages.
Kakeroma Island (Ryukyu Group), an example of a skeleton island described by W. M. Davis, has quite possibly a history different from that of Arapawa Island as regards both the development of the relief of the subsiding lands and. being in a low latitude, the possibly climatic process responsible for shaping its now submerged valley heads and thus emaciating the ribs of the island
Pared-down landscapes in Antarctica
The frigid-arid climate that now prevails in ice-free parts of Victoria Land, Antarctica, inhibits glacial erosion. If certain landscapes, more or less remote from the great troughs of outlet glaciers, have been glaciated in the past, as seems very probable, landforms that resulted from glaciation have been replaced by surfaces of different origin.
A widespread landscape glaciation was probably contemporaneous with the excavation of large cirques which still survive in mountain summit areas.
Replacement of glaciated landforms by others, in a general paring down of the land surface to forms of moderate relief, seems to have resulted from the process of gravity removal of debris from precipitous rock outcrops that were retreating because of disintegration by salt weathering and were eventually eliminated, in most cases, so that the landscape became a mosaic of smooth denudation slopes inclined at 33° to 350.
In the Darwin Mountains ice-free area (80ºS) an advanced stage of such denudation with respect to a base level some 400 m above the present level of surrounding glaciers has produced some pyramidal landforms. Just above the present ice level, however, narrow Richter denudation slopes that border weathering rock faces are at only a juvenile stage of development. Thus the ice level appears to have stood alternately at about its present position and 400 m higher in Pleistocene interglacials and glacial ages respectively. The higher ice levels must have been due to extensions of the ice sheet seaward caused by groundings of the shelf ice during low glacio-eustatic stands of sea leve
Trajectory and predictors of quality of life in first episode psychotic mania.
BACKGROUND: Little is known about the trajectory of quality of life (QoL) following a first episode of psychotic mania in bipolar disorder (BD). This 18-month longitudinal study investigated the trajectory of QoL, and the influence of premorbid adjustment and symptoms on 18-month QoL in a cohort of young people experiencing a first episode of psychotic mania.
METHODS: As part of an overarching clinical trial, at baseline, sixty participants presenting with a first episode of psychotic mania (BD Type 1 - DSM-IV) completed symptomatic and functional assessments in addition to the Premorbid Adjustment Scale - General Subscale. Symptom measures were repeated at 18-month follow up. QoL was rated using the Quality of Life Scale (QLS) at designated time points.
RESULTS: Mean QLS scores at initial measurement (8 weeks) were 61% of the maximum possible score, increasing significantly to 70% at 12 months, and 71.2% at 18-month follow-up. Premorbid adjustment and 18-month depressive symptoms were significantly associated with QoL at 18-month follow-up.
LIMITATIONS: Study limitations include the small sample size, inclusion of participants with psychotic mania only, use of measures originally designed for use with schizophrenia spectrum disorders, and lack of premorbid or baseline measurement of QoL.
CONCLUSIONS: Results suggest that QoL can be maintained early in BD, and reinforce the importance of assertively treating depressive symptoms throughout the course of this disorder. The emergence of a link between premorbid adjustment and poorer QoL in this cohort highlights the importance of assessing facets of adjustment when planning psychological interventions
Personality disorder among youth with first episode psychotic mania: An important target for specific treatment?
Personality disorder is a common co-occurrence ('comorbidity') among patients with bipolar disorder and appears to affect outcome negatively. However, there is little knowledge about the impact of this comorbidity in the early phases of bipolar disorder. We examined the prevalence and effect of personality disorder co-occurrence on outcome in a cohort of youth with first episode mania with psychotic features.
Seventy-one first episode mania patients, aged 15-29, were assessed at baseline, 6, 12, and 18 months as part of a randomized controlled trial of olanzapine and chlorpromazine as add-on to lithium in first episode mania with psychotic features. The current study involved secondary analysis of trial data.
A co-occurring clinical personality disorder diagnosis was present in 16.9% of patients. Antisocial and narcissistic personality disorders were the most common diagnoses. Patients with co-occurring personality disorder had higher rates of readmission to hospital, lower rates of symptomatic recovery and poorer functional levels at 6 months, but these differences disappeared after 12 and 18 months.
In the early phase of bipolar disorder, patients with personality disorder comorbidity display delayed symptomatic and functional recovery and increased likelihood to need hospital readmissions. These observations suggest that routine assessment for personality disorder and specific interventions are important in order to improve short-term treatment efficacy in this subgroup
Multi-wavelength interferometry of evolved stars using VLTI and VLBA
We report on our project of coordinated VLTI/VLBA observations of the
atmospheres and circumstellar environments of evolved stars. We illustrate in
general the potential of interferometric measurements to study stellar
atmospheres and envelopes, and demonstrate in particular the advantages of a
coordinated multi-wavelength approach including near/mid-infrared as well as
radio interferometry. We have so far made use of VLTI observations of the near-
and mid-infrared stellar sizes and of concurrent VLBA observations of the SiO
maser emission. To date, this project includes studies of the Mira stars S Ori
and RR Aql as well as of the supergiant AH Sco. These sources all show strong
silicate emission features in their mid-infrared spectra. In addition, they
each have relatively strong SiO maser emission. The results from our first
epochs of S Ori measurements have recently been published and the main results
are reviewed here. The S Ori maser ring is found to lie at a mean distance of
about 2 stellar radii, a result that is virtually free of the usual uncertainty
inherent in comparing observations of variable stars widely separated in time
and stellar phase. We discuss the status of our more recent S Ori, RR Aql, and
AH Sco observations, and present an outlook on the continuation of our project.Comment: 9 pages, to appear in the proceedings of the ESO workshop "The Power
of Optical/IR Interferometry: Recent Scientific Results and 2nd Generation
VLTI Instrumentation", ESO Astrophysics Symposi
AD51B in Familial Breast Cancer
Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
Background:
Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.
Findings:
Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79).
Interpretation:
In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
Cytomorphological patterns of M. bovis BCG and M. tuberculosis on fine needle aspiration biopsies: Does HIV make a difference?
To determine if fine needle aspiration (FNAB) of mycobacterial lymphadenopathy can differentiate infection with M. bovis BCG (BCG) from M. tuberculosis (TB) and whether HIV status affects discriminatory cytological features. A retrospective study of culture positive, fine needle aspiration biopsies of lymph nodes in children (<13 years) between 2003 and 2008. A total of 77 aspirates were available for evaluation with 67 (87%) patients having known HIV status. BCG occurred at a younger age (6 months), predominantly axillary lymph nodes (90%) compared with TB (5 years and 20% axillary lymph nodes). Amorphous necrosis was only seen in aspirates fromTB lymph nodes, while in HIV negative children with TB, foamy macrophages were absent. OnZN staining there were more organisms in the BCG group and in HIV positive patients the organisms were present in both extra- and intracellular locations, whereas in the HIV negative patients the organisms were predominantly extracellular in location. Demographic and cytomorphologic features that can assist in distinguishing between thetwo mycobacterial species include: age of patient, location of the lymph node, and presence/absence of amorphous necrosis and foamy macrophages on FNAB. However the only reliable method to identify the mycobacterial species is by mycobacterial culture and/orPCR. © 2010 Wiley-Liss, Inc.Articl
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