Return Date Research Articles

Long-Term Compliance and Side Effects of Oral Appliances Used for the Treatment of Snoring and Obstructive Sleep Apnea Syndrome

This study, by means of a mail survey, quantified the compliance with and side effects of the use of an oral appliance for more than five years in patients with snoring or obstructive sleep apnea. A questionnaire was mailed to 544 patients who used an oral appliance for the treatment of snoring or obstructive sleep apnea. Some 46.1% of the patients returned the questionnaire, 37.8% did not, 15% had an invalid address, and 0.9% were deceased. The mean time period between oral appliance insertion and the return date of these surveys was 5.7 +/- 3.5 years. Of the returned sample, 64.1% were wearing their oral appliance (users). There was no significant difference in the baseline and post-titration respiratory disturbance index between the returned and not-returned groups or between patients who had stopped wearing the oral appliance (nonusers) and users. Within the users group, 93.7% used the oral appliance more than 4 nights per week, 100% wore it more than half of each night, and 95% were satisfied with the treatment. The most frequent reasons why patients discontinued wear were uncomfortable (44.4%), had little or no effect (33.6%), or switched to nasal continuous positive airway pressure (23.3%). Snoring was satisfactorily controlled in 75.6% of users and in 43.2% of nonusers. Side effects, such as dry mouth and tooth and/or jaw discomfort, were more frequent and more severe in the nonusers (P < .05). With oral appliance usage, both users and nonusers reported an increase in temporomandibular joint symptoms, but there was no difference in the degree of change. Subjects who were compliant with oral appliance therapy reported long periods of use and adequate control of snoring.

모바일 기술을 활용한 도서관 정보서비스에 대한 고찰

Since mobile internet technology emerging from late 1990`s provides anytime and anywhere accessibility to information, mobile is adapted in the various field to increase efficiency of work. After looking into the trend of mobile contents services, case studies of information services using mobile were investigated in this paper. Library information services are providing retrieval of library OPAC and verifications of circulation and return date using mobile internet technology. In addition, various notice services using short message service(SMS) of mobile are available. Considering growing mobile users and advancement of related technology, more information services utilizing mobile should be developed in near future.

Projections of Australian obstetricians ceasing practice and the reasons

To assess the intentions of Australia's specialist obstetricians to cease practice and their reasons for abandoning this specialty. A structured questionnaire posted to Fellows of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG), issued 11 July 2001 with a return date of 31 July 2001 (in practice, responses were accepted up to 31 August 2001). Australian specialists holding a Fellowship of the RANZCOG. Demographic data (eg, age, sex); type and location of practice; past, current and intended future obstetric practice; reasons for stopping practice; cost of indemnity premiums; experience of litigation and its influence on practice; and experience in giving medicolegal opinion. The response rate was 74% (829/1116), with 826 responses fulfilling our selection criteria. The median number of years since admission as a Fellow was 17 (range, 1-47 years), and 19% (158/817) of respondents were women (9 people did not specify their sex). Of the 826 respondents, 596 (72%) were currently practising obstetrics, 548 (66%) intended to still be practising after one year, 365 (44%) intended to be practising after five years, and 196 (24%) intended to be practising after 10 years. The median indemnity premium in 2001-02 was $35,515 (range, nil to $156,000) for practising obstetricians. The main reasons given for ceasing obstetrics were intention to specialise in gynaecology, fear of litigation, high indemnity costs, family disruption, and long working hours. About two-thirds of respondents (557/818) had experienced the threat of litigation, and almost all (768/803) desired some type of "no-fault" indemnity scheme. Thirty-three of the 314 respondents who had given medicolegal opinions accounted for 71% of the total number of opinions. Many of these were non-practising obstetricians who were not accredited RANZCOG expert witnesses. There will soon be a shortage of experienced practising obstetricians in Australia.

Assessment of launch vehicle advances to enable human mars excursions

A mathematical model is developed for the assessment of the launch mass of a vehicle designed for a human mission to Mars. The mission involves six stages: (i) ascent from Earth surface to low Earth orbit, (ii) outgoing trip from low Earth orbit to low Mars orbit, (iii) descent and landing on Mars, (iv) ascent from Mars surface to low Mars orbit, (v) return trip from low Mars orbit to low Earth orbit, (vi) descent and landing on Earth. The basic objective is to minimize the launch mass while containing the total flight time. The mathematical model includes two parts: interplanetary flight and planetary flight. The interplanetary flight model is based on the restricted four-body scheme and covers the spacecraft transfer from a low Earth orbit to a low Mars orbit and back. The planetary flight model concerns the spacecraft ascent from Earth surface to low Earth orbit and from Mars surface to low Mars orbit. The sequential gradient-restoration algorithm is employed to solve optimal trajectory problems of interplanetary flight in mathematical programming format and optimal trajectory problems of planetary flight in optimal control format. The planetary flight study shows that, due to the large gravitational constant of Earth, it is best to assemble the spacecraft in low Earth orbit and launch it from there, rather than from the Earth surface. To reduce the ratio of outgoing LEO mass to return LEO mass, it is best to design the spacecraft as consisting of three modules: Earth return module, habitation module, Mars excursion module. The interplanetary flight study shows that, for minimum energy LEO–LMO–LEO transfer, the total characteristic velocity is 11.30 km/ s . The round-trip time is 970 days, including a stay of 454 days on Mars while waiting for an optimal return date. For a fast transfer mission with a stay of 30 days on Mars, the round-trip time can be reduced to less than half at the cost of nearly doubling the characteristic velocity, thereby resulting into a mass ratio 10 times higher than that of a minimum energy mission, if chemical propellants are used. To decrease the total mass ratio, use of advanced techniques is indispensable. First, aerobraking techniques can contribute considerably to the reduction of mass ratios: excess velocity on arrival to Mars (outgoing trip) and excess velocity on arrival to Earth (return trip) can be depleted via aerobraking maneuvers instead of propulsive maneuvers. Second, the development of engine/propellant combinations with high specific impulse can be another key factor for reducing the mass ratio. Third, cargo transportation can be used: equipment and propellant not required for the outgoing trip can be sent before the crew leaves Earth via a cargo spacecraft using a low-thrust engine having high specific impulse. Numerical computation shows that, if both aerobraking techniques and cargo transportation techniques are employed, the mass ratio for a minimum energy mission can be brought down by a factor of 5, while the mass ratio for a fast transfer mission can be brought down by a factor of 20. To sum up, the mathematical model developed for a launch vehicle can help the engineer to assess proper development directions. Numerical results are highly dependent on certain factors characterizing hardware and propellant such as engine specific impulse, spacecraft structural factor, and aerobraking structural factor. At this time, we must look at a round trip Earth–Mars–Earth by humans as a formidable undertaking. This paper merely indicates some useful directions.

Modeling Demand for Recreational Trips of Differing Lengths: A Competing Risks Duration Model with Censoring and Time-varying Covariates

In this paper we characterize seasonal recreational participation with a model of between-trip durations, a variation on seasonal participation models that provides certain advantages relative to modeling total trip counts directly. Employing a competing risk framework, we are able to model anglers? demands for trips of different lengths. The duration framework also allows us to model the effect on total trips of intra-seasonal variations in explanatory variables such as fish catch rates. Further we develop the model for a context where the available data are limited to detailed information on the most recent trip, supplemented by the return date of the survey. The proposed resolution to the challenges of left- and right-censored duration data employs the ?memoryless? exponential distribution for the duration model, which implies a Poisson count model. With another dataset, we provide an external validation test of the predicted number of angler trips from the model.

IS A LIBERAL ARTS EDUCATION STILL RELEVANT? SURVEY RESULTS FROM GRADUATES AND UNDERGRADUATES

This research evaluates the support for eight liberal arts goals: thinking clearly; knowing the physical universe; cultural awareness; moral awareness; valuing thought; thought/feeling relationships; independent action; and tolerance and concern for others. (1) The survey of 1,014 consists of 541 graduates and 473 undergraduates of a small southern liberal arts university. A low response rate for graduates led to comparisons of returns to the original sample frame in terms of: year graduated, sex composition, and ratings by survey return date. (2) the GER scale consists of 8 subscales and 33 items. Each item is rated by importance and gains in college. Cronbach's Alpha for subscales ranged from .67 to .82 with an overall ∝ =.928. (3) Results. All goals were rated as Very Important to Extremely Important. GER goals were rated more important by undergraduates who were: women, leaders, community volunteers, and those with out‐of‐class experience. Tolerance and Concern for Others was the most important goal. Greatest gains were in thinking clearly. Support of the liberal arts program, defined as a combination of gains and importance, increased from freshman to senior class. Support was unexpectedly strong for more affective components of the program. Limitations of this research are used to suggest future areas of study.

An Experimental Study of Incubation Effort in High-Arctic Barnacle Geese

We examined the cost of reproduction in high-Arctic barnacle geese (Branta leucopsis Bechstein) by manipulating the length of the incubation period by ± 5 days. Unmanipulated clutches were used as controls. Nests with prolonged incubation suffered a higher egg loss to predators than control nests and nests with shortened incubation. Among females with prolonged incubation, body condition at hatching was significant lower than among females with shortened incubation. These, however, did not increase their feeding effort to compensate for mass loss. Increased levels of parental effort did not affect adult return rate or date of arrival to the breeding ground the following season. Accordingly, there is no evidence from this study that barnacle geese invest in young at the expense of their own survival or future fecundity. We propose that breeding females retain some reserves at the end of laying in order to (i) incubate more continuously, thus shortening the incubation period and minimizing the risk of egg predation, and/or (ii) have a buffer against weight loss due to increased energy expenditure during inclement weather.

Home Ranges of Sloth Bears in Nepal: Implications for Conservation

Sloth bears (Melursus ursinus) are the only myrmecophagous ursid. Ursids generally have large home ranges, often with widely separated seasonal ranges, whereas myrmecophagous mammals tend to have relatively small ranges for their body size. During 1990-93, we captured and radiocollared 18 sloth bears in Royal Chitwan National Park, Nepal, and tracked their movements for ≤3 years to assess whether sloth bears have large ranges like other bears, or if, as a result of their myrmecophagous foraging habits, their home ranges are smaller. Six of 8 males tracked ≥1 year exhibited seasonal home range shifts from grasslands and riverine forests of the alluvial floodplain to upland sal (Shorea robusta)-dominated forest during the onset of the monsoon (median movement date = 1 Jun); however, the 2 smallest males and most females did not make seasonal range shifts to sal forest. After the wet season (May-Nov), males returned to the alluvium (median return date = 14 Nov). Alluvial dry season ranges were smaller (P < 0.05) than wet season ranges, for bears that had moved to the sal and for those that did not, suggesting that alluvium offered a plentiful food supply during the dry season. We propose that digging for termites (sloth bears' primary food) was difficult in alluvium when the ground was saturated, prompting large males to move to better drained uplands. Home ranges of sloth bears in Chitwan were small compared with those of other ursids, and unlike typical ursids, sloth bears were not attracted to croplands outside the park, where they would have been subjected to risks of human-related mortality. Sloth bear populations may subsist in sanctuaries smaller than would be expected for an ursid, given sufficient alluvial habitat

Biological characteristics of the upstream migration of naturally and hatchery-reared Baltic salmon, Salmo salar L.

Daily returns of all hatchery- and naturally reared Baltic salmon, Salmo salar L., to the Umealven (Sweden) were examined for an 18-year period, 1974–1991. Returns of naturally reared fish to the Norrfors fish ladder were more abundant than returns of hatchery fish with little obvious trend since the mid-seventies. Arrival date and median return date to the Norrfors fish ladder were consistently different by rearing type and sex with no overall trend since 1974. Hatchery-reared fish passed through the ladder later than naturally reared fish of the same sex and size. Males migrated later than females of the same size and rearing type. Larger, and presumably older, fish migrated earlier than smaller fish. There was little trend in the timing of the run since 1974. There was no simple relationship with river flows or river temperatures to explain the variation in most characteristics of the run. Pre-midsummer mean river temperatures were negatively correlated with arrival date but this was only significant for hatchery-reared males. The fishery catch data in the estuary indicated that the proportion of hatchery-reared adults decreased between the Umeätilven estuary and the fish ladder. There is evidence that larger fish took longer to travel from the estuary to the fish ladder.

Spawning migratory behaviour of coastal-released Baltic salmon (Salmo salar). Effects on straying frequency and time of river ascent

As a part of a risk analysis, we have studied straying frequency and seasonal river ascent of coastal-released Baltic salmon (Salmo salar L.) juveniles in the Baltic.In a number of release experiments Baltic salmon smolts were transferred to the Baltic Sea and retained in cages during 2–24 weeks before release. Control releases were made from the hatcheries directly into the rivers of origin. The experimental design included release experiments that can be used to mimic escapes from salmon net-pen farming. From the coastal releases we report data from five different release areas in the main Baltic and in the Fothnian Sea. Of about 33 000 individually tagged fish, a mean of 30% were reported recaptured. In the Baltic, the main part of recaptures have been reported from the sea fishery, and in this experiment a total of only about 0.3% were reported as recaptured in rivers.Coastal-released salmon showed a temporal delay in river ascent relative to river-released fish. The straying frequency (i.e. proportion of the river recaptured caught is a non-natal river) among non-river-released fish seemed to be increased. On the other hand, the non-river-released fish showed an overall reduced return date. Thus, comparing straying frequency based on the total number of released fish, the coastal- and river-released fish do not seem to show any significant difference in number of straying fish.

Gaining Respondent Cooperation in Mail Surveys Through Prior Commitment

To derive the benefits associated with mail surveys, researchers have studied many techniques designed to elicit increased cooperation, including prior contact of survey participants. Prior contact has generally taken the form of an advance or preliminary letter and has been found in research conducted by Heaton (1965), Stafford (1966), Ford (1967), and Myers and Haug (1969) to have a positive effect on survey response rates. The use of prior contact to obtain a commitment to respond to a survey before the actual mailing has received much less attention in the literature. Prior commitment to participate in a survey has the same advantages as the advance letter (see Heaton, 1965). But, as noted by Cannell et al. (1977), its major effect is to obligate the respondent, presumably to respond initially and also to report more accurate information. It also has the advantage of identifying subgroups of participants who may be less likely to respond, allowing for a possible oversampling of these subgroups or the consideration of additional steps to encourage their response. In the only published study found that was designed to measure the effect of prior commitment on response to a mailed questionnaire, Hinrichs (1975) reported that prior commitment increased response rate, but at the expense of initially depressing speed of response. The present study was designed to measure the effect of prior commitment in persuading recipients of a mail survey to: (1) participate in the study, thereby increasing response rate; (2) commit to a return date, thereby increasing speed of response; and (3) to determine if these behavioral intentions to respond are translated into actual response.

Forecasting the incidence of parasitic gastroenteritis in lambs in England and Wales.

An empirical method for forecasting the incidence of parasitic gastroenteritis in sheep in England and Wales is described. The level of disease in lambs in late summer depends on the date soil moisture returns to field capacity (the autumn return date) in the previous year together with rainfall from May to July in the current year. The importance of a late autumn return date and winter weather in relation to disease in stock at other times of the year is also discussed.

MAIL SURVEY RESPONSE BY SMOKING STATUS

A detailed smoking history questionnaire was mailed to a series of 1987 white male veterans participating in the Normative Aging Study of the Veterans' Administration Outpatient Clinic in Boston, Mass. Response time from mailing date to return date was determined and then compared by various smoker categories. Although a total response rate of 96 percent was achieved after six months, the results showed that cigarette smoker response rates were considerably lower than the other smoker categories withing 30 days and within 60 days of the original mailing date. Cigarette smokers would therefore be under-represented if the data collection had ended within these spans of time; and even to some extent after six months had elapsed from time of original mailing. A relationship was also found between amounts of cigaretts smoked and rate of response with heavier smokers being slowest to respound. The implications of the findings with respect to cohort studies of smoking and heath are discussed.