Frequency of Hospital Use Before and After Home-Delivery Meal by Meals On Wheels, of Tarrant County, Texas.

BACKGROUND: Patients recently discharged from the hospital are vulnerable and are at high risk for readmission. Home-delivered meals may be beneficial in improving their health and facilitating independent living in the community. The purpose of this study was to identify the association between home-delivered meals and use of hospital services. METHODS: This study includes 120 clients recently discharged from an inpatient hospital stay or from an emergency department (ED) visit who received meal services from Meals On Wheels, Inc., of Tarrant County. Healthcare utilization data was extracted from the Dallas-Fort Worth Hospital Council Foundation, a regional all claims database used by over 90% of hospitals in Dallas-Fort Worth area. Signed tests and generalized linear models (GLM) were performed. RESULTS: A total of 16,959 meals were delivered from March 2013 through March 2014. Each client received an average of 6.19 meals per week. The average number of ED visits decreased from 5.03 before receipt of meals to 1.45 after receipt of meals, z = -5.23, p < .001. The average number of hospitalizations decreased from 1.33 to .83, z = -7.29, p < .001. The average length of stay per hospitalization decreased from 5.47 days to 2.34 days, z = -5.84, p < .001. Clients who received more meals were less likely to experience ED visits and hospitalizations after controlling for demographic characteristics and levels of physical functioning. CONCLUSION: The findings of this study indicate that home-delivered meals services may contribute to a reduction in hospital based care services among frail and vulnerable adults. Additional studies should consider the short and long-term effects of home-delivered meals services on healthcare utilization and the potential to decrease healthcare costs.

Single and blended maize volatiles as attractants for diabroticite corn rootworm beetles.

Synthetic maize volatiles and analogs dispensed singly and blended were tested for attractiveness to western (WCR, Diabrotica virgifera virgifera) and northern corn rootworm beetles (NCR, D. barberi) in maize fields. Newly identified attractants included syn-benzaldoxime, especially for NCR, and beta-caryophyllene for WCR females. (+/-)-Linalool was more effective than was (-)-linalool. Myrcene, (+)-beta-pinene, and (-)-beta-pinene were unattractive. Adding methyl salicylate to (+/-)-linalool, (+)-alpha-terpineol, or beta-ionone appeared to synergistically increase capture of WCR females, but dispensing the terpenes in binary blends did not. Dose-response data for methyl salicylate, (+/-)-linalool, and a blend of both compounds confirmed the synergy. beta-Caryophyllene, but not (-)-alpha-pinene, added to the latter blend produced a further synergistic increase in WCR female capture that did not vary with sesquiterpene dose from 1.0 to 100 mg. Indole addition to the same blend caused an increase in WCR female captures indicative of synergy, assuming that each did not individually lure different segments of the WCR female population. The green leaf volatiles (Z)-3-hexenyl acetate and (Z)-3-hexen-1-ol were unattractive alone and had no influence on efficacy of traps baited with 3.3 mg each of (+/-)-linalool, methyl salicylate, and beta-caryophyllene. The latter mixture captured about half as many WCR females as did 10 mg of 4-methoxycinnamaldehyde, a potent WCR attractant standard. Substituting beta-ionone for (+/-)-linalool yielded a ternary blend that captured more beetles than did the aldehyde and was unaffected by aldehyde addition. Olive oil, which has been used to sustain attractant volatilization, did not affect captures. The results show that the blending of maize volatiles has thepotential to greatly improve efficacy of lures having promising applications in corn rootworm population management.

Phenylpropanoids as attractants for adult Stomoxys calcitrans (Diptera:Muscidae).

Rate of capture of stable flies, Stomoxys calcitrans (L.), on phenylpropanoid-baited and unbaited sticky traps was determined in tests conducted in a corn field and in grasses adjacent to a dairy farm. Phenylpropanoid compounds significantly increased capture in 2 of 4 tests in corn. Captures were highest with 3-phenyl-1-propanol, followed closely by hydrocinnamaldehyde (3-phenyl-1-propanal), and more distantly by cinnamyl alcohol. Both sexes were trapped, although males predominated approximately 2:1. Compounds without apparent attractiveness were (E)-cinnamaldehyde, 4-propylphenol, and 3-(4-hydroxyphenyl)-1-propanol. In the test adjacent to a dairy, 3-phenyl-1-propanol attracted approximately 16 times more stable flies than did 3-(4-hydroxyphenyl)-1-propanol or controls. The latter 2 treatments did not differ from one another, but were significantly less effective than 3-phenyl-1-propanol, which captured 1.2 times more males than females. The results are discussed in relation to stable fly nectar- and host-seeking behaviors.

Corn volatiles as attractants for northern and western corn rootworm beetles (Coleoptera: Chrysomelidae:Diabrotica spp.).

Synthetic corn volatiles and selected analogs were tested in commercial corn fields for attractiveness to feral northern (NCR,Diabrotica barberi) and western corn rootworm beetles (WCR,D. virgifera virgifera). Two new attractants, geranylacetone and α-terpineol, were identified among corn terpenes and compared at four stages in crop development with the phenylpropanoid standards cinnamyl alcohol and 4-methoxy-cinnamaldehyde, with each component at 30 mg/trap. Dose-response relationships (0.1-100 mg/trap) and efficacy of two-component blends (30 mg/component) were also examined. More beetles were captured on traps baited with (+)- than (-)-α-terpineol, but the difference was statistically significant only for WCR. Captures with geranylacetone or (+)-α-terpineol were directly proportional to the logarithm of the attractant dose. WCR females were attracted to as little as 0.1 mg of either compound. WCR males required ≥ 1.0 mg of (+)-α-terpineol and were not attracted to geranylacetone at any dose. NCR required ≥0.3 mg of either attractant and showed less marked response differences between the sexes than did WCR. Geranylacetone and cinnamyl alcohol were equally effective attractants, whereas (+)-α-terpineol was significantly less attractive to WCR but more attractive to NCR than was 4-methoxycinnamaldehyde. Corn terpenes and phenylpropanoid standards produced similar seasonal response patterns in that captures tended to rise in each case as the season progressed, except during silking when no compound was attractive. Mixing corn terpenes or phenylpropanoid standards synergized responses of WCR females, but (+)-α-terpineol suppressed attraction of NCR females to geranylacetone.

Identification of compounds in an HPLC fraction from female extracts that elicit mating responses in male screwworm flies,Cochliomyia hominivorax.

When hexane extracts of mature screwworm females were chromatographed on a silica gel column, mating stimulant activity was concentrated in a fraction that eluted with hexane-ether (94∶6, v/v). Separation of this fraction with HPLC (acetonitrile-acetone; 60∶40, isocratic) resulted in a chromatogram of some 20 peaks. Only peaks 4-11 elicited mating responses. Peaks 5-10 had most of the activity, with peak 8 producing the highest response. Sixteen compounds were characterized from peak 8 by gas chromatography-mass spectrometry: six unbranched secondary acetates (C31H62O2); seven previously unreported methyl-branched secondary acetates (C32H64O2); one unbranched ketone (C31H62O); and one methyl-branched ketone (C32H64O). The isomeric acetates were not completely resolved from each other by capillary gas chromatography (CGC) on methyl silicone columns. The sixteenth compound was an aldehyde (C30H60O) that was present only in occasional peak 8 preparations. These compounds and several derivatives were characterized by capillary gas chromatography-mass spectrometry (CGC-MS). The position of the acetate group was ascertained by conversion to a keto group or by replacement of the acetate with a methyl group. Pheromone activity was not observed in peaks trapped either from CGC or by recombination of the trapped CGC peaks from HPLC peak 8. This apparent loss of activity from CGC peaks or from TLC cannot currently be explained.

Intra- and interspecific sex pheromone responses of screwworm and secondary screwworm flies.

A laboratory behavioral assay examined intra- and interspecific responses to sex pheromone by screwworms,Cochliomyia hominivorax, and secondary screwworms,C. macellaria, in relation to the duration of colonization ofC. hominivorax test males. Females ofC. macellaria, like those ofC. hominivorax, were found to produce a pheromone that stimulates male copulatory attempts on contact. Newly colonized (<22 generations)C. hominivorax males did not respond toC. macellaria pheromone, indicating that pheromone contributes to reproductive isolation between these two closely related species. Although long-colonized (>200 generations)C. hominivorax males did respond toC. macellaria females or their extract, this behavior was infrequent and significantly less common than intraspecific responses. DeprivingC. macellaria adults of dietary protein did not affect the potency of female extracts, but did reduce male responsiveness to pheromone. These results provided little evidence that colonization reduces the ability ofC. hominivorax males to differentiate betweenC. hominivorax andC. macellaria females using sex pheromones.

Reproductive compatibility and mitochondrial DNA restriction site analysis of New World screwworm, Cochliomyia hominivorax, from North Africa and Central America.

The reproductive compatibility of New World screwworms, Cochliomyia hominivorax (Coquerel), from North Africa and a strain being mass produced for the Mexican eradication programme was examined to assess the feasibility of using flies from the Mexican screwworm mass production facility for a sterile insect technique eradication programme in North Africa. Males from the production strain mated randomly with females from North Africa and from the production strain when both were present. Neither strain of males discriminated between cuticular extracts of North African and production strain females containing a contact sex pheromone. Interstrain crosses between North African flies and production flies were fertile and produced fertile progeny. Chromosome morphology did not differ significantly between the two strains and homologue pairing was normal in hybrid meiotic and polytene nuclei. Mitochondrial DNA restriction site analyses indicated that the genetic divergence of the North African strain from Mexican and Central American strains was within the range of the diversity observed in Central American, Mexican and Caribbean populations. Test results indicate that New World screwworms from North Africa are reproductively compatible with the strain currently being mass produced in Mexico. Mating barriers should not impede the progress of an eradication programme using the sterile insect technique in North Africa with sterile screwworms from the Mexican mass production facility.

Oviposition by screwworm flies (Diptera: Calliphoridae) on contact with host fluids.

Factor affecting oviposition by screwworm flies, Cochliomyia hominivorax (Coquerel), contacting different host fluids were examined in a laboratory bioassay. Fresh bovine blood, which does not release the attractive odors involved in host finding, nevertheless stimulated as many or more females to oviposit than did the other fluids tested. These other fluids included attractive fluid from screwworm-infected wounds (a favored oviposition site in nature) and cultures of Providencia rettgeri (a bacterium implicated in attractant production). Oviposition did not vary with batch of fresh blood or frozen storage, making blood a useful standard for comparing oviposition rates among studies. Oviposition did vary with the substrate to which the blood was applied, suggesting that an interaction between tactile and chemical stimuli is important for host recognition. Both insemination and darkness during bioassay increased oviposition rates, but the magnitude of these effects was small compared with that due to substrate. Age had no effect for at least 1 wk after females became gravid.

Sex pheromone communication in the screwworm,Cochliomyia hominivorax: Ontogenetic and strain effects.

A laboratory behavioral assay was used to examine ontogenetic and strain effects on sex pheromone production and reception in the screwworm, which employs a female-produced contact pheromone to stimulate male copulatory attempts. Pheromone levels peaked between three and six days after adult emergence in females of two strains that had been colonized fewer than 50 generations. Pheromone was detectable at low levels in newly emerged flies of both sexes but disappeared from males by two days of age, when males first became responsive to females. A similar decline in pheromone with ontogenetic age was previously described for females of a strain colonized over 100 generations. Interstrain tests between the two newer strains, which differed by 35 generations in duration of colonization, demonstrated lower female pheromone activity but higher male responsiveness to pheromone in the older strain, despite the similar shape within these strains of curves relating female age and pheromone activity. The data suggest that conditions of screwworm colonization result in gradual loss of the pheromone peak that develops three to six days after emergence in newly colonized females. Higher male responsiveness associated with longer colonization involved change in both thresholds and dose dependency and may be relevant to control of the screwworm via the sterile insect technique.

Multicomponent attractant for female screwworm flies,Cochliomyia hominivorax, in bovine blood.

An olfactometer bioassay was used to follow attractant for screwworm flies,Cochliomyia hominivorax, in steam distillates of bovine blood under different distillation and storage conditions and after HPLC separation of components in a water-methanol gradient. In addition, fly responsiveness was examined in relation to sex and ovarian stage. Gravid and vitellogenic nullipars were attracted to the blood, although the former predominated four to one. Males did not respond at a dose that attracted 76% of gravid females. Maximum attractiveness occurred when distillate was stored in sealed glass ampoules. An argon atmosphere made storage at ambient temperatures feasible, but offered no advantage during storage at ca. -60°C or during distillation. The HPLC separation produced four fractions that duplicated the attractiveness of the distillate when recombined but showed little activity when presented as two-fraction, and most three-fraction, mixtures. Availability of the HPLC fractions for combination with other samples will facilitate location via bioassay of attractant components in samples obtained from subsequent or alternate isolations that preserve only one or two elements of the multicomponent mixture.

Chemical basis for asymmetric mating isolation between strains of screwworm fly,Cochliomyia hominivorax.

Laboratory mating tests and bioassays for a contact, mating-stimulant pheromone were conducted within and between two strains of the screwworm fly,Cochliomyia hominivorax. No strain or sex difference in pheromone activity occurred at emergence. However, the pheromone activity of females increased with age in one strain but declined in the other. Activity also declined in males of both strains but more steeply than in the females. Thus, sexual dimorphism in pheromone activity developed with age in both strains but to differing degrees. The decline in female pheromone activity was partly compensated for within that strain by a higher male responsiveness to pheromone. Female pheromone activity and mating success were positively correlated. Virgin females and those inseminated 24-48 hr previously were equally stimulatory. It appears that the strain differences arose from selection for reduced pheromone activity during laboratory colonization.

Pheromone-mediated copulatory responses of the screwworm fly,Cochliomyia hominivorax.

A bioassay based on male copulatory responses occurring on contact with dead decoy insects was used to confirm the existence of a sex pheromone in the screwworm fly,Cochliomyia hominivorax. Males responded to female but not male decoys. Mated and virgin females were equally stimulatory. Activity was abolished when females were washed with hexane but partially restored by treatment with crude hexane extract of females. Responses decreased when extracts were diluted and when the number of females extracted per milliliter of hexane was decreased from 20 to 1 in the preparation of extracts concentrated to 0.4 female/µl. Sexually mature female decoys of the 009 strain, the most laboratory-adapted of three strains examined in intrastrain tests, produced few copulatory attempts compared with those of Aricruz or DE-9 strains. However, newly emerged 009 as well as Aricruz females elicited responses from about 80% of sexually mature males. Those of the DE-9 strain stimulated fewer than 1%. The observation that 009 females were maximally stimulatory before becoming receptive to mating suggests that these strain differences resulted from laboratory colonization.

Responses of gravid screwworm flies,Cochliomyia hominivorax, to whole wounds, wound fluid, and a standard blood attractant in olfactometer tests.

Laboratory olfactometer bioassays were used to study attractiveness of whole animal wounds, wound fluid, and reconstituted dried blood to gravid screwworm flies,Cochliomyia hominivorax (Coquerel). Flies were attracted to odors from whole wounds that were infested with screwworm larvae but not to those from uninfested wounds that were 0-2 days old. A maximum of 59% of females were attracted to fluid from screwworminfested wounds, and the response changed little over fluid concentrations from 3.3 to 100%. However, blood tested over a similar concentration range yielded a significant linear relationship between log dose and response. Peak attraction was 82%. Attractancy of fluid collected from infested wounds declined when the fluid was stored at - 20 °C for more than four weeks but attractancy of a stored blood sample remained unchanged for three months. The blood attractant(s) was also heat stable and is suitable for use as a reference standard in bioassays.