316 research outputs found
\u3csup\u3e40\u3c/sup\u3eAr-\u3csup\u3e39\u3c/sup\u3eAr Age constraints on volcanism and tectonism in the Terror Rift of the Ross Sea, Antarctica
Volcanic sills and dikes inferred from seismic reflection profiles and geophysical studies of the Ross Sea are thought to be related to the rift basins in the region, and their emplacement to be coeval with extension. However, lack of precise geochronology in the Terror Rift of the Ross Sea region has left these inferred relationships poorly constrained and has hindered neotectonic studies, because of the large temporal gaps between seismic reflectors of known ages. New 40Ar/39Ar geochronology presented here for submarine volcanic rocks provides better age constraints for neotectonic interpretations within the Terror Rift. Several samples from seamounts yielded young ages between 156 ± 21 and 122 ± 26 Ka. These ages support interpretations that extension within the Terror Rift was active at least through the Pleistocene. Three evenly spaced samples from the lowermost 100 m of Franklin Island range in age from 3.28 ± 0.04 to 3.73 ± 0.05 Ma. These age determinations demonstrate that construction of a small volcanic edifice such as Franklin Island took at least several hundred thousand years, and therefore that much larger ones in the Erebus Volcanic Province are likely to have taken considerably longer than previously inferred. This warrants caution in applying a limited number of age determinations to define the absolute ages of events in the Ross Sea region
New radiometric evidence for the age and thermal history of the metamorphic rocks of the Ruby and Nixon Fork Terranes, West-Central Alaska
https://deepblue.lib.umich.edu/bitstream/2027.42/155805/1/Dillon_et_al_1985_New_radiometric.pd
Estimating the costs of induced abortion in Uganda: A model-based analysis
<p>Abstract</p> <p>Background</p> <p>The demand for induced abortions in Uganda is high despite legal and moral proscriptions. Abortion seekers usually go to illegal, hidden clinics where procedures are performed in unhygienic environments by under-trained practitioners. These abortions, which are usually unsafe, lead to a high rate of severe complications and use of substantial, scarce healthcare resources. This study was performed to estimate the costs associated with induced abortions in Uganda.</p> <p>Methods</p> <p>A decision tree was developed to represent the consequences of induced abortion and estimate the costs of an average case. Data were obtained from a primary chart abstraction study, an on-going prospective study, and the published literature. Societal costs, direct medical costs, direct non-medical costs, indirect (productivity) costs, costs to patients, and costs to the government were estimated. Monte Carlo simulation was used to account for uncertainty.</p> <p>Results</p> <p>The average societal cost per induced abortion (95% credibility range) was 140-64 million in annual national costs. Of this, the average direct medical cost was 49-86) and the average direct non-medical cost was 16-92 (139). Patients incurred 46-14 (20) on average.</p> <p>Conclusion</p> <p>Induced abortions are associated with substantial costs in Uganda and patients incur the bulk of the healthcare costs. This reinforces the case made by other researchers--that efforts by the government to reduce unsafe abortions by increasing contraceptive coverage or providing safe, legal abortions are critical.</p
Use of timelapse photography to determine flower opening time and pattern in banana (Musa spp.) for efficient hand pollination
Open Access Journal; Published online: 30 Sep 2021Sterility and low seed set in bananas is the main challenge to their conventional genetic improvement. The first step to seed set in a banana breeding program depends on pollination at the right time to ensure effective fertilization. This study aimed at determining bract opening time (BOT) to enhance efficient pollination and seed set in bananas. A Nikon D810 digital camera was set-up to take pictures of growing banana inflorescences at five-minute intervals and time-lapse movies were developed at a speed of 30 frames per second to allow real-time monitoring of BOT. Genotypes studied included wild banana (1), Mchare (2), Matooke (4), Matooke hybrid (1), and plantain (1). Events of bract opening initiated by bract lift for female flowers (P < 0.01) started at 16:32 h and at 18:54 h for male flowers. Start of bract rolling was at 18:51 h among female flowers (P < 0.001) and 20:48 h for male flowers. Bracts ended rolling at 02:33 h and 01:16 h for female and flowers respectively (P < 0.05). Total time of bract opening (from lift to end of rolling) for female flowers was significantly longer than that of male flowers (P < 0.001). On average, the number of bracts subtending female flowers opening increased from one on the first day, to between one and four on the fourth day. The number regressed to one bract on day eight before start of opening of bracts subtending male flowers. There was a longer opening interval between bracts subtending female and male flowers constituting spatial and temporal separation. Bract rolling increased from partial to complete rolling from proximal to the distal end of the inflorescence among female flower. On the other hand, bracts subtending male flowers completely rolled. Differences in BOT of genotypes with the same reference time of assessment may be partly responsible for variable fertility. Hand pollination time between 07:00 and 10:00 h is slightly late thus an early feasible time should be tried
Poor birth weight recovery among low birth weight/preterm infants following hospital discharge in Kampala, Uganda
<p>Abstract</p> <p>Background</p> <p>Healthy infants typically regain their birth weight by 21 days of age; however, failure to do so may be due to medical, nutritional or environmental factors. Globally, the incidence of low birth weight deliveries is high, but few studies have assessed the postnatal weight changes in this category of infants, especially in Africa. The aim was to determine what proportion of LBW infants had not regained their birth weight by 21 days of age after discharge from the Special Care Unit of Mulago hospital, Kampala.</p> <p>Methods</p> <p>A cross sectional study was conducted assessing weight recovery of 235 LBW infants attending the Kangaroo Clinic in the Special Care Unit of Mulago Hospital between January and April 2010. Infants aged 21 days with a documented birth weight and whose mothers gave consent to participate were included in the study. Baseline information was collected on demographic characteristics, history on pregnancy, delivery and postnatal outcome through interviews. Pertinent infant information like gestation age, diagnosis and management was obtained from the medical records and summarized in the case report forms.</p> <p>Results</p> <p>Of the 235 LBW infants, 113 (48.1%) had not regained their birth weight by 21 days. Duration of hospitalization for more than 7 days (AOR: 4.2; 95% CI: 2.3 - 7.6; p value < 0.001) and initiation of the first feed after 48 hours (AOR: 1.9; 95% CI 1.1 - 3.4 p value 0.034) were independently associated with failure to regain birth weight. Maternal factors and the infant's physical examination findings were not significantly associated with failure to regain birth weight by 21 days of age.</p> <p>Conclusion</p> <p>Failure to regain birth weight among LBW infants by 21 days of age is a common problem in Mulago Hospital occurring in almost half of the neonates attending the Kangaroo clinic. Currently, the burden of morbidity in this group of high-risk infants is undetected and unaddressed in many developing countries. Measures for consideration to improve care of these infants would include; discharge after regaining birth weight and use of total parenteral nutrition. However, due to the pressure of space, keeping the baby and mother is not feasible at the moment hence the need for a strong community system to boost care of the infant. Close networking with support groups within the child's environment could help alleviate this problem.</p
Preliminary Integrated Chronostratigraphy of the AND-2A Core, ANDRILL Southern McMurdo Sound Project, Antarctica
We use all available chronostratigraphic constraints – biostratigraphy, magnetostratigraphy,
radioisotopic dates, strontium-isotope stratigraphy, and correlation of compositional and physical properties
to well-dated global or regional records – to construct a preliminary age model for ANDRILL SMS Project’s
AND-2A drillcore (77°45.488’S, 165°16.605’E, 383.57 m water depth). These diverse chronostratigraphic
constraints are consistent with each other and are distributed throughout the 1138.54 m-thick section,
resulting in a well-constrained age model. The sedimentary succession comprises a thick early and middle
Miocene section below 224.82 mbsf and a condensed middle/late Miocene to Recent section above
this. The youngest sediments are Brunhes age (<0.781 Ma), as confirmed by a radioisotopic age of
0.691±0.049 Ma at 10.23 mbsf and the occurrence of sediments that have normal magnetic polarity down
to ~31.1 mbsf, which is interpreted to be the Brunhes/Matuyama reversal (0.781 Ma). The upper section
is punctuated by disconformities resulting from both discontinuous deposition and periods of extensive
erosion typical of sedimentary environments at the margin of a dynamic ice sheet. Additional breaks in
the section may be due to the influence of tectonic processes. The age model incorporates several major
hiatuses but their precise depths are still somewhat uncertain, as there are a large number of erosional
surfaces identified within the stratigraphic section. One or more hiatuses, which represent a total 7 to 8
million years of time missing from the sedimentary record, occur between about 50 mbsf and the base of
Lithostratigraphic Unit (LSU) 3 at 122.86 mbsf. Similarly, between about 145 mbsf and the base of LSU
4 at 224.82 mbsf, one or more hiatuses occur on which another 2 to 3 million years of the sedimentary
record is missing. Support for the presence of these hiatuses comes from a diatom assemblage that
constrains the age of the core from 44 to 50 mbsf to 2.06-2.84 Ma, two radioisotopic dates (11.4 Ma)
and a Sr‑isotope date (11.7 Ma) that indicate the interval from 127 to 145 mbsf was deposited between
11.4 and 11.7 Ma, and three diatom occurrence datums from between 225.38 and 278.55 mbsf that
constrain the age of this upper part of Lithostratigraphic Unit (LSU) 5 to 14.29 - 15.89 Ma. Below the
boundary between LSU 5 and 6 sedimentation was relatively continuous and rapid and the age model is
well-constrained by 9 diatom datums, seven 40Ar-39Ar dates, one Sr-isotope date, and 19 magnetozones.
Even so, short hiatuses (less than a few hundred thousand years) undoubtedly occur but are beyond
the resolution of current chronostratigraphic age constraints. Diatom first and last occurrence datums
provide particularly good age control from the top of LSU 6 down to 771.5 mbsf (in LSU 10), where
the First Occurrence (FO) of Thalassiosira praefraga (18.85 Ma) is observed. The diatom datum ages
are supported by radioisotopic dates of 17.30±0.31 Ma at 640.14 mbsf (in LSU 9) and 18.15±0.35 and
17.93±0.40 Ma for samples from 709.15 and 709.18 mbsf (in LSU 10), respectively, and 18.71±0.33 Ma
for a sample from 831.67 mbsf (in LSU 11). The sediments from 783.69 mbsf to the base of the hole
comprise two thick normal polarity magnetozones that bound a thinner reversed polarity magnetozone
(958.59 - 985.64 mbsf). This polarity sequence most likely encompasses Chrons C5En, C5Er, and C6n
(18.056 - 19.772 Ma or slightly older given uncertainties in this section of the geomagnetic polarity
timescale), but could be also be Chrons C6n, C6r, and C6An.1n (18.748 - 20.213 Ma). Either polarity
sequence is compatible with the 40Ar–39Ar age of 20.01±0.35 Ma obtained from single-grain analyses of
alkali feldspar from a tephra sample from a depth of 1093.02 mbsf, although the younger interpretation
allows a better fit with chronostratigraphic data up-core. Given this age model, the mean sedimentation
rate is about 18 cm/k.y. from the top of LSU 6 to the base of the hole.Published221-2202.2. Laboratorio di paleomagnetismoN/A or not JCRreserve
Injury characteristics and outcome of road traffic crash victims at Bugando Medical Centre in Northwestern Tanzania
<p>Abstract</p> <p>Background</p> <p>Road traffic crash is of growing public health importance worldwide contributing significantly to the global disease burden. There is paucity of published data on road traffic crashes in our local environment. This study was carried out to describe the injury characteristics and outcome of road traffic crash victims in our local setting and provide baseline data for establishment of prevention strategies as well as treatment protocols.</p> <p>Methods</p> <p>This was a prospective hospital based study of road traffic crash victims carried out at Bugando Medical Centre in Northwestern Tanzania between March 2010 and February 2011. After informed consent to participate in the study, all patients were consecutively enrolled into the study. Data were collected using a pre-tested questionnaire and analyzed using SPSS computer software version 15.0.</p> <p>Results</p> <p>A total of 1678 road traffic crash victims were studied. Their male to female ratio was of 2.1:1. The patients ages ranged from 3 to 78 years with the mean and median of 29.45 (± 24.22) and 26.12 years respectively. The modal age group was 21-30 years, accounting for 52.1% patients. Students (58.8%) and businessmen (35.9%) were the majority of road traffic crash victims. Motorcycle (58.8%) was responsible for the majority of road traffic crashes. Musculoskeletal (60.5%) and the head (52.1%) were the most common body region injured. Open wounds (65.9%) and fractures (26.3%) were the most common type of injuries sustained. The majority of patients (80.3%) were treated surgically. Wound debridement was the most common procedure performed in 81.2% of the patients. The complication rate was 23.7%. The overall average length of hospital stay (LOS) was 23.5 ± 12.3 days. Mortality rate was 17.5%. According to multivariate logistic regression analysis, patients who had severe trauma (Kampala Trauma Score II ≤ 6) and those with long bone fractures stayed longer in the hospital and this was significant (P < 0.001) whereas the age of the patient, severe trauma (Kampala Trauma Score II ≤ 6), admission Systolic Blood Pressure < 90 mmHg and severe head injury (Glasgow Coma Score = 3-8) significantly influenced mortality (P < 0.001).</p> <p>Conclusion</p> <p>Road traffic crashes constitute a major public health problem in our setting and contribute significantly to unacceptably high morbidity and mortality. Urgent preventive measures targeting at reducing the occurrence of road traffic crashes is necessary to reduce the morbidity and mortality resulting from these injuries. Early recognition and prompt treatment of road traffic injuries is essential for optimal patient outcome.</p
Behaviour change strategies for reducing blood pressure-related disease burden: findings from a global implementation research programme.
The Global Alliance for Chronic Diseases comprises the majority of the world's public research funding agencies. It is focussed on implementation research to tackle the burden of chronic diseases in low- and middle-income countries and amongst vulnerable populations in high-income countries. In its inaugural research call, 15 projects were funded, focussing on lowering blood pressure-related disease burden. In this study, we describe a reflexive mapping exercise to identify the behaviour change strategies undertaken in each of these projects.Using the Behaviour Change Wheel framework, each team rated the capability, opportunity and motivation of the various actors who were integral to each project (e.g. community members, non-physician health workers and doctors in projects focussed on service delivery). Teams then mapped the interventions they were implementing and determined the principal policy categories in which those interventions were operating. Guidance was provided on the use of Behaviour Change Wheel to support consistency in responses across teams. Ratings were iteratively discussed and refined at several group meetings.There was marked variation in the perceived capabilities, opportunities and motivation of the various actors who were being targeted for behaviour change strategies. Despite this variation, there was a high degree of synergy in interventions functions with most teams utilising complex interventions involving education, training, enablement, environmental restructuring and persuasion oriented strategies. Similar policy categories were also targeted across teams particularly in the areas of guidelines, communication/marketing and service provision with few teams focussing on fiscal measures, regulation and legislation.The large variation in preparedness to change behaviour amongst the principal actors across these projects suggests that the interventions themselves will be variably taken up, despite the similarity in approaches taken. The findings highlight the importance of contextual factors in driving success and failure of research programmes. Forthcoming outcome and process evaluations from each project will build on this exploratory work and provide a greater understanding of factors that might influence scale-up of intervention strategies
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