Hyperspectral Imaging as an Early Biomarker for Radiation Exposure and Microcirculatory Damage

BACKGROUND: Radiation exposure can lead to detrimental effects in skin microcirculation. The precise relationship between radiation dose received and its effect on cutaneous perfusion still remains controversial. Previously, we have shown that hyperspectral imaging (HSI) is able to demonstrate long-term reductions in cutaneous perfusion secondary to chronic microvascular injury. This study characterizes the changes in skin microcirculation in response to varying doses of ionizing radiation and investigates these microcirculatory changes as a possible early non-invasive biomarker that may correlate with the extent of long-term microvascular damage.METHODS: Immunocompetent hairless mice (n=66) were exposed to single fractions of superficial beta-irradiation in doses of 0, 5, 10, 20, 35, or 50 Gy. A HSI device was utilized to measure deoxygenated hemoglobin levels in irradiated and control areas. HSI measurements were performed at baseline before radiation exposure and for the first three days post-irradiation. Maximum macroscopic skin reactions were graded, and histological assessment of cutaneous microvascular densities at four weeks post-irradiation was performed in harvested tissue by CD31 immunohistochemistry.RESULTS: CD31 immunohistochemistry demonstrated a significant correlation (r=0.90, p<0.0001) between dose and vessel density reduction at four weeks. Using HSI analysis, early changes in deoxygenated hemoglobin levels were observed during the first three days post-irradiation in all groups. These deoxygenated hemoglobin changes varied proportionally with dose (r=0.98, p<0.0001) and skin reactions (r=0.98, p<0.0001). There was a highly significant correlation (r= 0.91, p<0.0001) between these early changes in deoxygenated hemoglobin and late vascular injury severity assessed at the end of four weeks.CONCLUSIONS: Radiation dose is directly correlated with cutaneous microvascular injury severity at four weeks in our model. Early post-exposure measurement of cutaneous deoxygenated hemoglobin levels may be a useful biomarker for radiation dose reconstruction and predictor for chronic microvascular injury

Assessment of capacity for Health Policy and Systems Research and Analysis in seven African universities: results from the CHEPSAA project

The importance of health policy and systems research and analysis (HPSR+A) is widely recognised. Universities are central to strengthening and sustaining the HPSR+A capacity as they teach the next generation of decision-makers and health professionals. However, little is known about the capacity of universities, specifically, to develop the field. In this paper we report results of capacity self-assessments by seven universities within five African countries, conducted through the Consortium for Health Policy and Systems Analysis in Africa (CHEPSAA). The capacity assessments focused on both capacity assets and needs, and covered the wider context, as well as organisational and individual capacity levels. Six thematic areas of capacity were examined: leadership and governance, organisation’s resources, scope of HPSR+A teaching and research, communication, networking and GRIPP, demand for HPRS+A, and resource environment. The self-assessments by each university used combinations of document reviews, semi-structured interviews and staff surveys, followed by comparative analysis. A Framework Approach, guided by the six thematic areas, was used to analyse data. We found that HPSR+A is an international priority, and an existing activity in Africa, though still neglected field with challenges including its reliance on unpredictable international funding. All universities have capacity assets, such as on-going HPSR+A teaching and research. There are, however, varying levels of assets (such as differences in staff numbers, group sizes and amount of HPSR+A teaching and research), which, combined with different capacity needs at all three levels (such as individual training, improvement in systems for quality assurance and fostering demand for HPSR+A work), can shape a future agenda for HPSR+A capacity strengthening. Capacity assets and needs at different levels appear related. Possible integrated strategies for strengthening universities’ capacity include: refining HPSR+A vision, mainstreaming the subject into under- and post-graduate teaching, developing emerging leaders and aligning HPSR+A capacity strengthening within the wider organisational development

The effect of professional development on elementary science teachers’ understanding, confidence, and classroom implementation of reform‐based science instruction

Through a randomized controlled trial, this mixed‐methods study evaluated changes in elementary science teachers’ understandings, confidence, and classroom implementation of problem‐based learning (PBL), inquiry, and nature of science (NOS) instruction following participation in a professional development (PD) as well as the components of the PD that teachers perceived facilitated these changes. Results indicated that following the PD, treatment teacher (n = 139) understandings of and confidence for teaching inquiry, NOS, and PBL were significantly greater than control teachers (n = 98) after controlling for preunderstandings and confidence. The effect sizes were large. Treatment teachers also incorporated significantly more PBL, inquiry, and NOS into their instruction. Modeling, microteaching with feedback and reflection, and in‐classroom coaching facilitated teachers’ confidence, understanding, and intention to implement the reform‐based practices they learned. Implications for the understanding of the relationship between knowledge, confidence, and practice as well as elementary science teacher PD design are discussed

A new methodology for assessing health policy and systems research and analysis capacity in African universities.

BACKGROUND: The importance of health policy and systems research and analysis (HPSR+A) has been increasingly recognised, but it is still unclear how most effectively to strengthen the capacity of the different organisations involved in this field. Universities are particularly crucial but the expansive literature on capacity development has little to offer the unique needs of HPSR+A activity within universities, and often overlooks the pivotal contribution of capacity assessments to capacity strengthening. METHODS: The Consortium for Health Policy and Systems Analysis in Africa 2011-2015 designed and implemented a new framework for capacity assessment for HPSR+A within universities. The methodology is reported in detail. RESULTS: Our reflections on developing and conducting the assessment generated four lessons for colleagues in the field. Notably, there are currently no published capacity assessment methodologies for HPSR+A that focus solely on universities - we report a first for the field to initiate the dialogue and exchange of experiences with others. Second, in HPSR+A, the unit of assessment can be a challenge, because HPSR+A groups within universities tend to overlap between academic departments and are embedded in different networks. Third, capacity assessment experience can itself be capacity strengthening, even when taking into account that doing such assessments require capacity. CONCLUSIONS: From our experience, we propose that future systematic assessments of HPSR+A capacity need to focus on both capacity assets and needs and assess capacity at individual, organisational, and systems levels, whilst taking into account the networked nature of HPSR+A activity. A genuine partnership process between evaluators and those participating in an assessment can improve the quality of assessment and uptake of results in capacity strengthening

Pattern of childhood burn injuries and their management outcome at Bugando Medical Centre in Northwestern Tanzania

Burn injuries constitute a major public health problem and are the leading cause of childhood morbidity and mortality worldwide. There is paucity of published data on childhood burn injuries in Tanzania, particularly the study area. This study was conducted to describe the pattern of childhood burn injuries in our local setting and to evaluate their management outcome. A cross sectional study was conducted at Bugando Medical Centre (in Northwestern Tanzania) over a 3-year period from January 2008 to December 2010. Data was collected using a pre-tested coded questionnaire and statistical analyses performed using SPSS software version 15.0. A total of 342 burned children were studied. Males were mainly affected. Children aged = 2 were the majority accounting for 45.9% of cases. Intentional burn injuries due to child abuse were reported in 2.9% of cases. Scald was the most common type of burns (56.1%). The trunk was the most commonly involved body region (57.3%). Majority of patients (48.0%) sustained superficial burns. Eight (2.3%) patients were HIV positive. Most patients (89.8%) presented to the hospital later than 24 h. The rate of burn wound infection on admission and on 10th day were 32.4% and 39.8% respectively.Staphylococcus aureus were more common on admission wound swabs, with Pseudomonas aeruginosa becoming more evident after 10th day. MRSA was detected in 19.2% of Staphylococcus aureus. Conservative treatment was performed in 87.1% of cases. Surgical treatment mainly skin grafting (65.9%) was performed in 44 (12.9%) of patients. The overall average of the length of hospital stay (LOS) was 22.12 ± 16.62 days. Mortality rate was 11.7%. Using multivariate logistic regression analysis; age of the patient, type of burn, delayed presentation, clothing ignition, %TBSA and severity of burn were found to be significantly associated with LOS (P < 0.001), whereas mortality rate was found to be independently and significantly related to the age of the patient, type of burn, HIV positive with stigmata of AIDS, CD4 count, inhalation injury, %TBSA and severity of burn (P < 0.001). Childhood burn injuries still remain a menace in our environment with virtually unacceptable high morbidity and mortality. There is need for critical appraisal of the preventive measures and management principles currently being practiced

Measurement of jet fragmentation in Pb+Pb and pp collisions at √s NN =5.02 TeV with the ATLAS detector

This paper presents a measurement of jet fragmentation functions in 0.49 nb −1 of Pb+Pb collisions and 25 pb −1 of pp collisions at √ sNN =5.02 TeV collected in 2015 with the ATLAS detector at the LHC. These measurements provide insight into the jet quenching process in the quark-gluon plasma created in the aftermath of ultra-relativistic collisions between two nuclei. The modifications to the jet fragmentation functions are quantified by dividing the measurements in Pb+Pb collisions by baseline measurements in pp collisions. This ratio is studied as a function of the transverse momentum of the jet, the jet rapidity, and the centrality of the collision. In both collision systems, the jet fragmentation functions are measured for jets with transverse momentum between 126 GeV and 398 GeV and with an absolute value of jet rapidity less than 2.1. An enhancement of particles carrying a small fraction of the jet momentum is observed, which increases with centrality and with increasing jet transverse momentum. Yields of particles carrying a very large fraction of the jet momentum are also observed to be enhanced. Between these two enhancements of the fragmentation functions a suppression of particles carrying an intermediate fraction of the jet momentum is observed in Pb+Pb collisions. A small dependence of the modifications on jet rapidity is observed

Search for Higgs bosons produced via vector-boson fusion and decaying into bottom quark pairs in √s =13 TeV pp collisions with the ATLAS detector

A search for the bb ¯ decay of the Standard Model Higgs boson produced through vector-boson fusion is presented. Three mutually exclusive channels are considered: two all-hadronic channels and a photon-associated channel. Results are reported from the analysis of up to 30.6 fb −1 of pp data at s √ =13 TeV collected with the ATLAS detector at the LHC. The measured signal strength relative to the Standard Model prediction from the combined analysis is 2.5 +1.4 −1.3 for inclusive Higgs boson production and 3.0 +1.7 −1.6 for vector-boson fusion production only

Search for pair production of heavy vector-like quarks decaying into high-pT W bosons and top quarks in the lepton-plus-jets final state in pp collisions at √s = 13 TeV with the ATLAS detector

A search is presented for the pair production of heavy vector-like B quarks, primarily targeting B quark decays into a W boson and a top quark. The search is based on 36.1 fb −1 of pp collisions at √s = 13 TeV recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Data are analysed in the lepton-plus-jets final state, characterised by a high-transverse-momentum isolated electron or muon, large missing transverse momentum, and multiple jets, of which at least one is b -tagged. No significant deviation from the Standard Model expectation is observed. The 95% confidence level lower limit on the B mass is 1350 GeV assuming a 100% branching ratio to Wt. In the SU(2) singlet scenario, the lower mass limit is 1170 GeV. This search is also sensitive to a heavy vector-like B quark decaying into other final states (Zb and Hb ) and thus mass limits on B production are set as a function of the decay branching ratios. The 100% branching ratio limits are found to be also applicable to heavy vector-like X production, with charge +5/3, that decay into Wt

Searches for exclusive Higgs and Z boson decays into J/ψγ,ψ(2S)γ,and Υ(nS)γ at √s=13 TeV with the ATLAS detector

Searches for the exclusive decays of the Higgs and Z bosons into a J/ψ,ψ(2S), or Υ(nS)(n=1,2,3) meson and a photon are performed with a pp collision data sample corresponding to an integrated luminosity of 36.1 fb −1 collected at √s =13 TeV with the ATLAS detector at the CERN Large Hadron Collider. No significant excess of events is observed above the expected backgrounds, and 95% confidence-level upper limits on the branching fractions of the Higgs boson decays to J/ψγ, ψ(2S)γ,and Υ(nS)γ of 3.5×10 −4, 2.0×10−3,and(4.9,5.9,5.7)×10 −4,respectively, are obtained assuming Standard Model production. The corresponding 95% confidence-level upper limits for the branching fractions of the Z boson decays are 2.3×10 −6, 4.5×10 −6 and (2.8,1.7,4.8)×10 −6, respectively

Search for supersymmetry in final states with charm jets and missing transverse momentum in 13 TeV pp collisions with the ATLAS detector

A search for supersymmetric partners of top quarks decaying as t ~ 1 →cχ ~ 0 1 and supersymmetric partners of charm quarks decaying as c ~ 1 →cχ ~ 0 1, where χ ~ 0 1 is the lightest neutralino, is presented. The search uses 36.1 fb −1 pp collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider and is performed in final states with jets identified as containing charm hadrons. Assuming a 100% branching ratio to cχ ~ 0 1, top and charm squarks with masses up to 850 GeV are excluded at 95% confidence level for a massless lightest neutralino. For m t ~ 1 ,c ~ 1 −m χ ~ 0 1 < 100 GeV, top and charm squark masses up to 500 GeV are excluded