Heat-load simulator for heat sink design

Heat-load simulator is fabricated from 1/4-inch aluminum plate with a contact surface equal in dimensions and configuration to those of the electronic installation. The method controls thermal output to simulate actual electronic component thermal output

Consequences of Intensive Cropping on Soybean Diseases

A number of disease problems have occurred or increased since Iowa\u27s soybean acreage expanded about 6 fold in the last 30 years. With present trends indicating more intense cultivation in the future, a plant pathologist reveals some of his concerns about soybean disease and some problem areas where more knowledge is needed

Brown Stem Rot in Soybeans

Iowa soybean acreage has been increasing. So has the percentage of soybean fields found contaminated by the brown stem rot fungus. Here is a description of the symptoms plus suggestions for helping control this disease

An Economical Laminar-flow Microbe-free Chamber for Culturing Small Plants

An economical plant growth chamber, 16 cm in diameter and 50 cm high, was made from two 4-liter glass beakers. The bottom was removed from one beaker, and a 1 cm hole cut in the bottom of the other. The bottomless beaker, when placed atop the other, telescoped slightly for firm support. Sand was placed in the bottom of the chamber as a growth substrate. A polyethylene bag was placed over the two beakers and filtered air (under pressure) and nutrient solution entered the chamber through rubber tubing. Six chambers, each with an open petri dish of nutrient agar in the bottom, were tested for 2 weeks, and all dishes remained microbe-free. The laminar flow of air between the plastic bag and the glass walls of the beakers prevented microbes from entering the chamber. The chambers supported good growth of corn and soybean seedlings for 4 weeks when a sterile nutrient solution was added to the sand as needed

A Method for Determining Stem Canker Resistance in Soybean

Stem canker disease of soybean is caused by the fungus, Diaporthe phaseolorum var. caulivora, and at present there are no soybean varieties known to be highly resistant to this disease. Stem canker takes its name from the resemblance of the discolored area of an infected stem to a canker. As the infected area on a stem enlarges, the stem is girdled and the portion of the plant above the girdled area is killed. Stem canker seriously affects soybeans in the northcentral region of the United States and has been reported to cause heavy losses (Athow and Caldwell, 1954; and Dunleavy, 1954, 1955). A description of the disease and the casual organism has been published by Welch and Gilman (1948) and Athow and Caldwell (1954). Differences in varietal susceptibility have been reported by Hildebrand (1953a) and Beeson and Probst (1955)

Home accidents amongst elderly people: A locality study in Scotland

Aim The aim of this locality study was to collect information on reported and unreported accidents amongst elderly people living in one locality in Scotland. Method Postal Survey- A postal questionnaire was sent to 3,757 men and women aged 65+ years living in one locality. The questionnaire asked respondents to indicate how many accidents they had experienced in the past twelve months, plus to indicate type and location. Information was gathered on living arrangements, ethnicity, gender, age and deprivation. Respondents were asked if they would be willing to take part in an interview study. Interview Study - One hundred elders who had had at least one accident in the previous twelve months were interviewed. Results Postal Survey - Over a third of the respondents in the postal survey reported having had an accident in the previous twelve months. Bumps and drops and falls were the most common type of accident. Most accidents happened in the kitchen. Women reported more falls than men and those living alone reported more accidents than those living with others. Age was associated with the prevalence of accidents, but the association was somewhat curvilinear, with accidents decreasing with age and then increasing again. Interview Study – Interviewees found it hard to differentiate one accident from another. Considerable reluctance to visit the GP after an accident was noted, with many not attending even for serious accidents. Almost forty percent were ‘very’ distressed after their accident, and a quarter reported a loss of confidence. However, most did not worry about accidents. Few thought that their age, health or medications were a cause of their accidents

A New Disease in Iowa Corn Fields

It resembles maize dwarf mosaic found in Ohio, Symptoms vary widely and may include red or purple streaking of leaves or severe stunting. Research is underway and is being intensified

Method of Extracting Starch from Bacteria

Corynebacterium kutscheri required 10 days of growth on semisolid medium to accumulate intracellular starch, but when the same medium was used as a broth, only l day of growth was required. C. kutscheri synthesized starch when amylose was added to nutrient agar in the substrate, but did not do so when amylopectin was substituted for amylose. Dimethyl sulfoxide (DMSO) was superior to water as a cell wash for removing substrate starch from cells before chemical treatment to remove intracellular starch. Bacterial starch was extracted from C. kutscheri cells by destroying cell walls with lysozyme and sodium lauryl sulfate, removing cellular debris by centrifugation, and precipitating the starch from the supernatant with butanol. A qualitative method for the separation of this starch into amylose and amylopectin fractions is described. Use of DMSO in cell washes established that the bacterial starch molecule was too large to pass through the membrane of the bacterial cell because DMSO passes through the cell membrane and cells gave a positive test for starch after the treatment

A Source of Bacterial Blight Resistance For Soybeans

Incidence of bacterial blight of soybeans was observed from 1953 to 1959. During this period the disease was observed in 25 to 72 percent of the fields examined. A search was made for an improved source of blight resistance. A soybean introduction, P.I. 68708 was resistant to blight under natural conditions and when inoculated. It was also resistant to brown spot but was susceptible to race 8 of Peronospora manshurica as well as to Phytophthora rot. Yield, date of maturity, seed size, seed quality, and lodging resistance of the introduction were comparable to the same characters of the variety Blackhawk

Antibiotics for exacerbations of asthma.

BACKGROUND: Asthma is a chronic respiratory condition that affects over 300 million adults and children worldwide. It is characterised by wheeze, cough, chest tightness, and shortness of breath. Symptoms typically are intermittent and may worsen over a short time, leading to an exacerbation. Asthma exacerbations can be serious, leading to hospitalisation or even death in rare cases. Exacerbations may be treated by increasing an individual's usual medication and providing additional medication, such as oral steroids. Although antibiotics are sometimes included in the treatment regimen, bacterial infections are thought to be responsible for only a minority of exacerbations, and current guidance states that antibiotics should be reserved for cases in which clear signs, symptoms, or laboratory test results are suggestive of bacterial infection. OBJECTIVES: To determine the efficacy and safety of antibiotics in the treatment of asthma exacerbations. SEARCH METHODS: We searched the Cochrane Airways Trials Register, which contains records compiled from multiple electronic and handsearched resources. We also searched trial registries and reference lists of primary studies. We conducted the most recent search in October 2017. SELECTION CRITERIA: We included studies comparing antibiotic therapy for asthma exacerbations in adults or children versus placebo or usual care not involving an antibiotic. We allowed studies including any type of antibiotic, any dose, and any duration, providing the aim was to treat the exacerbation. We included parallel studies of any duration conducted in any setting and planned to include cluster trials. We excluded cross-over trials. We included studies reported as full-text articles, those published as abstracts only, and unpublished data. DATA COLLECTION AND ANALYSIS: At least two review authors screened the search results for eligible studies. We extracted outcome data, assessed risk of bias in duplicate, and resolved discrepancies by involving another review author. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs), and continuous data as mean differences (MDs), all with a fixed-effect model. We described skewed data narratively. We graded the results and presented evidence in 'Summary of findings' tables for each comparison. Primary outcomes were intensive care unit/high dependence unit (ICU/HDU) admission, duration of symptoms/exacerbations, and all adverse events. Seconday outcomes were mortality, length of hospital admission, relapse after index presentation, and peak expiratory flow rate (PEFR). MAIN RESULTS: Six studies met our inclusion criteria and included a total of 681 adults and children with exacerbations of asthma. Mean age in the three studies in adults ranged from 36.2 to 41.2 years. The three studies in children applied varied inclusion criteria, ranging from one to 18 years of age. Five studies explicitly excluded participants with obvious signs and symptoms of bacterial infection (i.e. those clearly meeting current guidance to receive antibiotics). Four studies investigated macrolide antibiotics, and two studies investigated penicillin (amoxicillin and ampicillin) antibiotics; both studies using penicillin were conducted over 35 years ago. Five studies compared antibiotics versus placebo, and one was open-label. Study follow-up ranged from one to twelve weeks. Trials were of varied methodological quality, and we were able to perform only limited meta-analysis.None of the included trials reported ICU/HDU admission, although one participant in the placebo group of a study including children with status asthmaticus experienced a respiratory arrest and was ventilated. Four studies reported asthma symptoms, but we were able to combine results for only two macrolide studies of 416 participants; the MD in diary card symptom score was -0.34 (95% confidence interval (CI) -0.60 to -0.08), with lower scores (on a 7 point scale) denoting improved symptoms. Two macrolide studies reported symptom-free days. One study of 255 adults authors reported the percentage of symptom-free days at 10 days as 16% in the antibiotic group and 8% in the placebo group. In a further study of 40 children study authors reported significantly more symptom-free days at all time points in the antibiotic group compared with the usual care group. The same study reported the duration in days of the index asthma exacerbation, again favouring the antibiotic group. One study of a penicillin including 69 participants reported asthma symptoms at hospital discharge; the between-group difference for both studies was reported as non-significant.We combined data for serious adverse events from three studies involving 502 participants, but events were rare; the three trials reported only 10 events: five in the antibiotic group and five in the placebo group. We combined data for all adverse events (AEs) from three studies, but the effect estimate is imprecise (OR 0.99, 95% CI 0.69 to 1.43). No deaths were reported in any of the included studies.Two studies investigating penicillins reported admission duration; neither study reported a between-group difference. In one study (263 participants) of macrolides, two participants in each arm were reported as experiencing a relapse, defined as a further exacerbation, by the six-week time points. We combined PEFR endpoint results at 10 days for two macrolide studies; the result favoured antibiotics over placebo (MD 23.42 L/min, 95% CI 5.23 to 41.60). One study in children reported the maximum peak flow recorded during the follow-up period, favouring the clarithromycin group, but the confidence interval includes no difference (MD 38.80, 95% CI -11.19 to 88.79).Grading of outcomes ranged from moderate to very low quality, with quality of outcomes downgraded for suspicion of publication bias, indirectness, imprecision, and poor methodological quality of studies. AUTHORS' CONCLUSIONS: We found limited evidence that antibiotics given at the time of an asthma exacerbation may improve symptoms and PEFR at follow-up compared with standard care or placebo. However, findings were inconsistent across the six heterogeneous studies included, two of the studies were conducted over 30 years ago and most of the participants included in this review were recruited from emergency departments, limiting the applicability of findings to this population. Therefore we have limited confidence in the results. We found insufficient evidence about several patient-important outcomes (e.g. hospital admission) to form conclusions. We were unable to rule out a difference between groups in terms of all adverse events, but serious adverse events were rare