Interactions of Ar(9+) and metastable Ar(8+) with a Si(100) surface at velocities near the image acceleration limit

Auger LMM spectra and preliminary model simulations of Ar(9+) and metastable Ar(8+) ions interacting with a clean monocrystalline n-doped Si(100) surface are presented. By varying the experimental parameters, several yet undiscovered spectroscopic features have been observed providing valuable hints for the development of an adequate interaction model. On our apparatus the ion beam energy can be lowered to almost mere image charge attraction. High data acquisition rates could still be maintained yielding an unprecedented statistical quality of the Auger spectra.Comment: 34 pages, 11 figures, http://pikp28.uni-muenster.de/~ducree

Kidney Donor Profile Index and allograft outcomes: interactive effects of estimated post-transplant survival score and ischaemic time

Background. The Kidney Donor Profile Index (KDPI) is routinely reported by the donation agencies in Australia.We determined the association between KDPI and short-term allograft loss and assessed if this association was modified by the estimated post-transplant survival (EPTS) score and total ischaemic time. Methods. Using data from the Australia and New Zealand Dialysis and Transplant Registry, the association between KDPI (in quartiles) and 3-year overall allograft loss was examined using adjusted Cox regression analysis. The interactive effects between KDPI, EPTS score and total ischaemic time on allograft loss were assessed. Results. Of 4006 deceased donor kidney transplant recipients transplanted between 2010 and 2015, 451 (11%) recipients experienced allograft loss within 3 years post-transplant. Compared with recipients of kidneys with a KDPI of 0–25%, recipients who received donor kidneys with a KDPI >75% experienced a 2-fold increased risk of 3-year allograft loss {adjusted hazard ratio [HR] 2.04 [95% confidence interval (CI) 1.53–2.71]}. The adjusted HRs for kidneys with a KDPI of 26–50% and 51–75% were 1.27 (95% CI 0.94–1.71) and 1.31 (95% CI 0.96–1.77), respectively. There were significant interactions between KDPI and EPTS scores (P-value for interaction <.01) and total ischaemic time (P-value for interaction <.01) such that the associations between higher KDPI quartiles and 3-year allograft loss were strongest in recipients with the lowest EPTS scores and longest total ischaemic time. Conclusion. Recipients with higher post-transplant expected survival and transplants with longer total ischaemia who received donor allografts with higher KDPI scores experienced a greater risk of short-term allograft loss compared with those recipients with reduced post-transplant expected survival and with shorter total ischemia.Janelle Prunster, Germaine Wong, Nicholas Larkins, Kate Wyburn, Ross Francis, William R. Mulley, Esther Ooi, Helen Pilmore, Christopher E. Davies and Wai H. Li

The Indigenous Australian Human Papillomavirus (HPV) Cohort Study 2, Continuation for 5 to 10 Years: Protocol for a Longitudinal Study

Background: Human papillomavirus (HPV) infection, a common sexually transmitted disease, is associated with cancers of the cervix, vulva, vagina, penis, anus, and head and neck. Oropharyngeal squamous cell carcinoma (OPSCC; throat cancer) is a type of cancer involving the head and neck area that is rapidly increasing across the globe. There are higher rates of OPSCC among Indigenous populations relative to non–Indigenous Australian populations, although the HPV-attributable fraction remains unknown. For the first time at a global level, we plan to extend an Indigenous Australian adult cohort to monitor, screen, and ultimately prevent HPV-associated OPSCC and to undertake extensive cost-effectiveness modelling around HPV vaccination. Objective: This study aims to (1) extend follow-up to a minimum of 7 years post recruitment to describe the prevalence, incidence, clearance, and persistence of oral HPV infection; and (2) conduct clinical examinations of the head and neck, oral cavity, and oropharynx and collect saliva samples for early-stage OPSCC testing. Methods: We will continue to implement a longitudinal design for the next study phase, where we will ascertain the prevalence, incidence, clearance, and persistence of oral HPV infection at 48, 60, and 72 months; undertake clinical examinations/saliva assessments to detect early-stage OPSCC; and refer for treatment. The primary outcome measures are changes in oral HPV infection status, biomarker measures of early HPV-related cancer, and clinical evidence of early-stage OPSCC. Results: Participant 48-month follow-up will commence in January 2023. The first results are expected to be submitted for publication 1 year after 48-month follow-up begins. Conclusions: Our findings have potential to change the way in which OPSCC among Australian Indigenous adults is managed, with desired impacts including cost-savings on expensive cancer treatments; improved nutritional, social, and emotional outcomes; and improved quality of life for both Indigenous adults and the Indigenous community more broadly. Continuing a large, representative Indigenous adult cohort to track oral HPV infection and monitor early OPSCC is essential to yield critical information to include in the management armamentarium of health and well-being recommendations for Australia’s First Nations.Joanne Hedges, Sneha Sethi, Gail Garvey, Lisa J Whop, Karen Canfell, Zell Dodd, Priscilla Larkins, Annika Antonsson, Megan A Smith, Murthy Mittinty, Catherine Leane, Nicolas Reid, Eng H Ooi, Xiangqun Ju, Richard Logan, Lisa Jamieso

Interactions between donor age and 12-month estimated glomerular filtration rate on allograft and patient outcomes after kidney transplantation

Reduced estimated glomerular filtration rate (eGFR) at 12-months after kidney transplantation is associated with increased risk of allograft loss, but it is uncertain whether donor age and types modify this relationship. Using Australia and New Zealand registry data, multivariable Cox proportional modelling was used to examine the interactive effects between donor age, types and 12-month eGFR on overall allograft loss. We included 11,095 recipients (4,423 received live-donors). Recipients with lowest 12-month eGFR (60 ml/min/1.73 m²) was 0.67 [0.62–0.74]. The association of 12-month eGFR and allograft loss was modified by donor age (but not donor types) where a higher risk of allograft loss in recipients with lower compared with higher 12-month eGFR being most pronounced in the younger donor age groups (p 60 ml/min/1.73 m², and the magnitude of the increased risk is most marked among recipients with younger donors. Careful deliberation of other factors including donor age when considering eGFR as a surrogate for clinical endpoints is warranted.Wai H. Lim, Esther Ooi, Helen L. Pilmore, David W. Johnson, Stephen P. McDonald, Philip Clayton, Carmel Hawley, William R. Mulley, Ross Francis, Michael G. Collins, Bryon Jaques, Nicholas G. Larkins, Christopher E. Davies, Kate Wyburn, Steve J. Chadban and Germaine Won

Disclosure experience and associated factors among HIV positive men and women clinical service users in southwest Ethiopia

BACKGROUND: Disclosing HIV test results to one's sexual partner allows the partner to engage in preventive behaviors as well as the access of necessary support for coping with serostatus or illness. It may motivate partners to seek testing or change behavior, and ultimately decrease the transmission of HIV. The present study was undertaken to determine the rate, outcomes and factors associated with HIV positive status disclosure in Southwest Ethiopia among HIV positive service users. METHODS: A cross-sectional study was carried out from January 15, 2007 to March 15, 2007 in Jimma University Specialized Hospital. Data were collected using a pre-tested interviewer-administered structured questionnaire. RESULTS: A total of 705 people (353 women and 352 men), participated in the study of which 71.6% were taking ART. The vast majority (94.5%) disclosed their result to at least one person and 90.8% disclosed to their current main partner. However, 14.2% of disclosure was delayed and 20.6% did not know their partner's HIV status. Among those who did not disclose, 54% stated their reason as fear of negative reaction from their partner. Among those disclosures however, only 5% reported any negative reaction from the partner. Most (80.3%) reported that their partners reacted supportively to disclosure of HIV status. Disclosure of HIV results to a sexual partner was associated with knowing the partner's HIV status, advanced disease stage, low negative self-image, residing in the same house with partner, and discussion about HIV testing prior to seeking services. CONCLUSION: Although the majority of participants disclosed their test results, lack of disclosure by a minority resulted in a limited ability to engage in preventive behaviors and to access support. In addition, a considerable proportion of the participants did not know their partner's HIV status. Programmatic and counseling efforts should focus on mutual disclosure of HIV test results, by encouraging individuals to ask their partner's HIV status in addition to disclosing their own

Systematics and plastid genome evolution of the cryptically photosynthetic parasitic plant genus Cuscuta (Convolvulaceae)

<p>Abstract</p> <p>Background</p> <p>The genus <it>Cuscuta </it>L. (Convolvulaceae), commonly known as dodders, are epiphytic vines that invade the stems of their host with haustorial feeding structures at the points of contact. Although they lack expanded leaves, some species are noticeably chlorophyllous, especially as seedlings and in maturing fruits. Some species are reported as crop pests of worldwide distribution, whereas others are extremely rare and have local distributions and apparent niche specificity. A strong phylogenetic framework for this large genus is essential to understand the interesting ecological, morphological and molecular phenomena that occur within these parasites in an evolutionary context.</p> <p>Results</p> <p>Here we present a well-supported phylogeny of <it>Cuscuta </it>using sequences of the nuclear ribosomal internal transcribed spacer and plastid <it>rps2</it>, <it>rbcL </it>and <it>matK </it>from representatives across most of the taxonomic diversity of the genus. We use the phylogeny to interpret morphological and plastid genome evolution within the genus. At least three currently recognized taxonomic sections are not monophyletic and subgenus <it>Cuscuta </it>is unequivocally paraphyletic. Plastid genes are extremely variable with regards to evolutionary constraint, with <it>rbcL </it>exhibiting even higher levels of purifying selection in <it>Cuscuta </it>than photosynthetic relatives. Nuclear genome size is highly variable within <it>Cuscuta</it>, particularly within subgenus <it>Grammica</it>, and in some cases may indicate the existence of cryptic species in this large clade of morphologically similar species.</p> <p>Conclusion</p> <p>Some morphological characters traditionally used to define major taxonomic splits within <it>Cuscuta </it>are homoplastic and are of limited use in defining true evolutionary groups. Chloroplast genome evolution seems to have evolved in a punctuated fashion, with episodes of loss involving suites of genes or tRNAs followed by stabilization of gene content in major clades. Nearly all species of <it>Cuscuta </it>retain some photosynthetic ability, most likely for nutrient apportionment to their seeds, while complete loss of photosynthesis and possible loss of the entire chloroplast genome is limited to a single small clade of outcrossing species found primarily in western South America.</p