Juvenile development of Douglas-fir, red alder and snowbrush associations in Western Oregon

The juvenile development of Douglas-fir, red alder and snowbrush associations was investigated in western Oregon. The relationship between Douglas-fir and red alder was studied and compared in the Coast, Willamette Valley and Cascade regions. Snowbrush- Douglas-fir stands were sampled in the western Cascades. Alder- Douglas-fir relationships were studied on clearcuts supporting at the same time mixtures of alder and Douglas-fir and open-grown Douglas-fir. Sites where snowbrush and Douglas-fir grew together were selected on the same basis. Total heights of alder and Douglas-fir were expressed as cumulative one-year growth measurements. Canopy height of snowbrush was measured at various ages to determine growth rate. Information pertaining to moisture, vegetation, slope, aspect, elevation and stand structure was recorded at each sample plot. The data were analyzed with the aid of a multiple regression program. Height and (height)² were treated as independent variables, and annual height increment as the dependent variable. Results indicate that early establishment of Douglas-fir is expected to aid its dominance-takeover and allow it to evade suppression by red alder. Douglas-fir trees growing on wet sites need to be established earlier than those on drier habitats for the same degree of suppression evasion. The rapid juvenile growth rate of red alder is a major threat for the successful establishment of Douglas-fir. Height growth curves of the two species intersected at an earlier age on non-wet as compared to wet sites. The two trees grow in direct competition up to about age 40 years on wet habitats, with alder able to suppress Douglas-fir during this period. Douglas-fir has virtually no chance áf survival when it is established concurrently with red alder or after its appearance. Snowbrush retards the growth of Douglas-fir trees during their first ten years of development. Trees that are delayed more than five years in establishment suffer a loss of more than 50% in total height as a result of the suppressive effect of the shrub. It is expected that the trees will compensate for some of this loss, but their growth may never equal that of comparable open-grown Douglas-fir developing under similar conditions

The impact of three stocking intensities and four grazing treatments on the carbohydrate reserves of perennial ryegrass (Lolium perenne L.)

A study was conducted during 1974 and 1975 to evaluate the impact of stocking intensity and season of grazing upon carbohydrate concentration, biomass of storage organs, and total carbohydrate per plant in the roots and crowns of perennial ryegrass (Lolium perenne L.) in improved rangelands in Western Oregon. The stocking intensities were 7.4 ewes per hectare (moderate), 9.9 ewes per hectare (heavy), and 12.4 ewes per hectare (overstocking). The grazing treatments were Complete Protection, Fall Protection, Fall Grazing, and Yearlong Grazing. Another study was established during the same period to relate the seasonal carbohydrate reserve cycle and plant growth to phenological stages of development. The influence of stocking intensity on carbohydrate concentration was significant for both roots and crowns. Effects of season of grazing on the concentration in these plant parts were also significant. Ryegrass plants under the moderate stocking intensity had a significantly higher concentration of total available carbohydrate (TAC) than those under each of the other two higher stocking rates. Fall grazing resulted in higher total available carbohydrate concentration than the other seasonal grazing treatments. Stocking intensity impact was significant on the crown biomass, but not on root biomass. Plants under moderate stocking intensity had significantly greater biomass than those under heavy and overstocking rates. Season of grazing as well as interaction among year and season of grazing had a significant effect on both crown and root biomass. Stocking intensity had a significant effect on total carbohydrate per plant. The TAC per perennial ryegrass plant was higher in moderately stocked pastures than in pastures with heavy or overstocking rates. A significant effect was shown for the season of grazing treatments on root TAC per plant, but not for the crowns. Perennial ryegrass displayed clearly defined seasonal trends in TAC concentration during the period of data collection. The crowns maintained greater TAC levels than the roots at all phenological stages. The carbohydrate reserve curve for different phases of development displayed the expected spring and winter depletion of reserves for meeting growth initiation and further development. It had its greatest slope during these phenological stages, concurrent with sharp reserve depletion. Fall regrowth did not result in a sharp decline in reserve level as did spring and winter growth. The management implications were discussed. Ryegrass showed a high tolerance to season of grazing. Grazing during the early phase of spring is recommended to be at moderate intensity, since the combination of high grazing pressure and early defoliation is detrimental to the carbohydrate reserves. Winter grazing at overstocking rates may be potentially harmful to perennial ryegrass. Moderate to heavy stocking intensities are recommended, if yearlong grazing is considered. Grazing at overstocking rates is possible through a program that considers deferment during one or two seasons of grazing

ACCREDITATION OF THE FACULTY OF MEDICINE UNIVERSITY OF GEZIRA (FMUG), PILOT STUDY

The Faculty of Medicine University of Khartoum was founded in 1924 and has graduated the majority of doctors in the Sudan. In recent years the government invested heavily in higher education and 26 new medical schools have been established and are now functioning and graduating doctors. Those new schools adopted different models of curricula, however most of them benefited from the Gezira medical school experience and hence their curricula are innovative. The large number of schools and the diversity in their curricular models fueled interest in the Sudan General Medical Council and the Ministry of Higher Education to establish a national mechanism for evaluating those schools and ensuring the society that they graduate doctors with optimum standard

Spatial and temporal distribution of the malaria mosquito Anopheles arabiensis in northern Sudan: influence of environmental factors and implications for vector control

BACKGROUND: Malaria is an important public health problem in northern Sudan, but little is known about the dynamics of its transmission. Given the characteristic low densities of Anopheles arabiensis and the difficult terrain in this area, future vector control strategies are likely to be based on area-wide integrated pest management (AW-IPM) that may include the sterile insect technique (SIT). To support the planning and implementation of future AW-IPM activities, larval surveys were carried out to provide key data on spatial and seasonal dynamics of local vector populations. METHODS: Monthly cross-sectional larval surveys were carried out between March 2005 and May 2007 in two localities (Dongola and Merowe) adjacent to the river Nile. A stratified random sampling strategy based on the use of Remote Sensing (RS), Geographical Information Systems (GIS) and the Global Positioning System (GPS) was used to select survey locations. Breeding sites were mapped using GPS and data on larval density and breeding site characteristics were recorded using handheld computers. Bivariate and multivariate logistic regression models were used to identify breeding site characteristics associated with increased risk of presence of larvae. Seasonal patterns in the proportion of breeding sites positive for larvae were compared visually to contemporaneous data on climate and river height. RESULTS: Of a total of 3,349 aquatic habitats sampled, 321 (9.6%) contained An. arabiensis larvae. The frequency with which larvae were found varied markedly by habitat type. Although most positive sites were associated with temporary standing water around the margins of the main Nile channel, larvae were also found at brickworks and in areas of leaking pipes and canals - often far from the river. Close to the Nile channel, a distinct seasonal pattern in larval populations was evident and appeared to be linked to the rise and fall of the river level. These patterns were not evident in vector populations breeding in artificial water sources away from the river. CONCLUSION: The GIS-based survey strategy developed in this study provides key data on the population dynamics of An. arabiensis in Northern State. Quantitative estimates of the contributions of various habitat types and their proximity to settlements provide a basis for planning a strategy for reducing malaria risk by elimination of the vector population

Medication Sector in Qatar: Hand in Hand Facing the Blockade

Conference agend

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87–1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98–1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87–1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication

Satellite Navigation Systems: Policy, Commercial and Technical Interaction Testing The DVRS National GPS-RTK Network

Abstract In this study, the Dubai Virtual Reference System (DVRS), a national RTK network, is examined. The network started its service in March 2002 with the objective of obtaining the cmlevel positioning accuracy throughout the Emirate of Dubai, UAE. The DVRS network architecture is first addressed. The estimation technique of processing the observables in a state space mode transferred to the observation domain is next described, followed by presenting procedure and results of comprehensive testing of the DVRS system. The system absolute accuracy was first tested by surveying a set of points of well known coordinates and comparing the known and DVRS results. Relative positioning accuracy was tested by studying differences between distances derived from the DVRS estimated points against their pre-determined precise values. Precision and repeatability were investigated by comparing results of point coordinates determined by the DVRS in different sessions with varying conditions. System availability, reliability, and robustness, particularly in case of failure of one of the reference stations, were also investigated. In addition, the performance of the network approach against that of employing a single reference station was investigated. Results prove system reliability and show its advantages and positioning accuracy, which is typically 1-5 cm