Regular Feeding Research Articles

Sky reconstruction for the Tianlai cylinder array

We apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on spherical harmonic decomposition, and can be applied to a cylindrical array as well as dish arrays and we can compute the instrument response, synthesized beam, transfer function and noise power spectrum. We consider cylinder arrays with feed spacing larger than half a wavelength and, as expected, we find that the arrays with regular spacing have grating lobes which produce spurious images in the reconstructed maps. We show that this problem can be overcome using arrays with a different feed spacing on each cylinder. We present the reconstructed maps, and study the performance in terms of noise power spectrum, transfer function and beams for both regular and irregular feed spacing configurations.

Adult pollen diet essential for egg maturation by a solitary Osmia bee

Reproduction is a nutritionally costly activity for many insects, as their eggs are rich in lipids and proteins. That cost seems especially acute for non-social bees, which for their size, lay enormous eggs. All adult female bees visit flowers, most of them to collect pollen and nectar, or sometimes oils, to feed their progeny. For adult bees, the need for pollen feeding has only been detailed for the honey bee, Apis mellifera. To experimentally test for the reproductive value of adult pollen feeding by a non-social bee, Osmia californica (Hymenoptera: Apiformes: Megachilidae), young female bees plus males were released into large glasshouse cages provided with either a male-fertile sunflower cultivar or a pollen-less one. Females regularly visited and drank nectar from flowers of both cultivars. Abundant orange pollen was seen regularly in guts of females confined with the male-fertile sunflowers, indicative of active pollen ingestion. All females’ terminal oocytes (next egg to be laid) were small at emergence. Oocytes of females confined with the pollen-less sunflowers remained small, despite frequent nectaring and exposure to other floral stimuli. In contrast, the basal oocytes of female O. californica with access to pollen had swelled to full size within ten days following emergence, enabling them to lay eggs in provided nest tubes. Adult females of this solitary bee required dietary pollen to reproduce; nitrogen stores acquired as larvae were inadequate. Early and regular pollen feeding in part paces the onset and maximum tempo of solitary bees’ lifetime reproductive output.

Liver function as an engineering system

Process Systems Engineering has tackled a wide range of problems including manufacturing, the environment, and advanced materials design. Here we discuss how tools can be deployed to tackle medical problems which involve complex chemical transformations and spatial phenomena looking in particular at the liver system, the body's chemical factory. We show how an existing model has been developed to model distributed behavior necessary to predict the behavior of drugs for treating liver disease. The model has been used to predict the effects of suppression of de novo lipogenesis, stimulation of β‐oxidation and a combination of the two. A reduced model has also been used to explore the prediction of behavior of hormones in the blood stream controlling glucose levels to ensure that levels are kept within safe bounds using interval methods. The predictions are made resulting from uncertainty in two key parameters with oscillating input resulting from regular feeding. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3285–3297, 2016

Dietary selenium requirement and toxicity levels in juvenile Nile tilapia, Oreochromis niloticus

A 10-weeks of feeding trial was conducted to evaluate the dietary selenium (Se) requirement and toxicity levels in juvenile Nile tilapia, Oreochromis niloticus using seleno-methionine as the source of Se. Graded level of Se-Met were added to the basal diet at 0, 0.25, 0.5, 0.75, 1.0, 2.0, 4.0, 8.0 and 16.0mg Se/kg diet providing the analyzed Se of 0.30 (Se0.30), 0.55 (Se0.55), 0.73 (Se0.73), 0.82 (Se0.82), 1.04 (Se1.04), 2.06 (Se2.06), 2.95 (Se2.95), 6.31 (Se6.31) and 14.7 (Se14.7) mg Se/kg diet respectively. Twenty fish averaging 1.85±0.1g (mean±SD) were fed one of the nine experimental diets in triplicate groups. At the end of the feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of fish fed Se2.06 were significantly higher than those of fish fed other diets (p<0.05). The survival rate of the groups of fish fed Se6.31 and Se14.7 diets were significantly lower than those of fish fed other diets (p<0.05). Selenium concentrations of liver, muscle and gill tissues were recorded to increase in the dose dependent manner. Whereas, lysozyme activity of fish fed Se0.30 diet was significantly lower than those of fish other diets. Observations for myeloperoxidase (MPO) and superoxide dismutase (SOD) activities showed an increasing pattern up to 6.31mgSe/kg (Se6.31) inclusion and afterwards decline. Broken-line regression analysis of WG indicated that the minimum Se requirement level could be 1.06mgSe/kg diet. Therefore, these results may suggest that, optimum dietary Se level could be >1.06 but <2.06mgSe/kg for in juvenile Nile tilapia. Whereas, the toxicity level for dietary Se level could be between 6.31–14.7mgSe/kg diet for juvenile Nile tilapia, Oreochromis niloticus characterized by reduced growth performance and nonspecific enzymatic activity using Se-Methionine as the source of Se. Statement of relevanceThe importance of trace mineral, selenium (Se) supplementation in fish feed formulation has been well accepted since Se from ambient water and feed itself cannot supply the optimal level required by the cultured aquatic species. Even though, Se is typically required in much lower quantity in fish diet but its supplementation at optimum level is a critical issue in fish feed formulation. Scientific reports gathered over last two decades indicate, Se is quite sensitive and proper care should be taken to ensure their inclusion at optimum level in fish feed formulation. The present experiment clearly demonstrated that, freshwater fish juvenile Nile tilapia has a specific requirement level for dietary Se which cannot be met by regular feed and ambient water. Inclusion of dietary Se at optimum level is imperative to promote the maximum growth, tissue saturation and to ensure an optimum enzyme activity in Nile tilapia. Supplementing Se in fish feed beyond the requirement level may have toxic effects in freshwater aquaculture.

Synaptophysin depletion and intraneuronal Aβ in organotypic hippocampal slice cultures from huAPP transgenic mice.

BackgroundTo date, there are no effective disease-modifying treatments for Alzheimer’s disease (AD). In order to develop new therapeutics for stages where they are most likely to be effective, it is important to identify the first pathological alterations in the disease cascade. Changes in Aβ concentration have long been reported as one of the first steps, but understanding the source, and earliest consequences, of pathology requires a model system that represents all major CNS cell types, is amenable to repeated observation and sampling, and can be readily manipulated. In this regard, long term organotypic hippocampal slice cultures (OHSCs) from neonatal amyloid mice offer an excellent compromise between in vivo and primary culture studies, largely retaining the cellular composition and neuronal architecture of the in vivo hippocampus, but with the in vitro advantages of accessibility to live imaging, sampling and intervention.ResultsHere, we report the development and characterisation of progressive pathological changes in an organotypic model from TgCRND8 mice. Aβ1-40 and Aβ1-42 rise progressively in transgenic slice culture medium and stabilise when regular feeding balances continued production. In contrast, intraneuronal Aβ continues to accumulate in close correlation with a specific decline in presynaptic proteins and puncta. Plaque pathology is not evident even when Aβ1-42 is increased by pharmacological manipulation (using calpain inhibitor 1), indicating that soluble Aβ species, or other APP processing products, are sufficient to cause the initial synaptic changes.ConclusionsOrganotypic brain slices from TgCRND8 mice represent an important new system for understanding mechanisms of Aβ generation, release and progressive toxicity. The pathology observed in these cultures will allow for rapid assessment of disease modifying compounds in a system amenable to manipulation and observation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13024-016-0110-7) contains supplementary material, which is available to authorized users.

Evidence that ghrelin may be associated with the food intake of gibel carp (Carassius auratus gibelio)

Ghrelin, a non-amidated peptide hormone, is a potent anorectic neuropeptide implicated in feeding regulation in mammals and non-mammalian vertebrates. However, the involvement of ghrelin in the feeding behavior of teleosts has not been well understood. To better understand the role of ghrelin in the regulation of appetite in fish, in this study, we cloned the cDNAs encoding ghrelin and investigated their mRNA distributions in gibel carp tissues. We also assessed the effects of different nutritional status on ghrelin mRNA abundance. Ghrelin mRNAs were ubiquitously expressed in ten tissues (intestine, liver, brain, mesonephron, head kidney, spleen, skin, heart, muscle, gill and pituitary gland), and relatively high expression levels were detected in the gut. Postprandial studies analysis revealed a significant postprandial decrease in ghrelin mRNA expression in the gut (1 and 3h after the regular feeding time). In addition, ghrelin mRNA expression in the gut significantly increased at day 7 after fasting and declined sharply after refeeding, which suggested that ghrelin might be involved in the regulation of appetite in gibel carp. Overall, our result provides basis for further investigation into the regulation of feeding in gibel carp.

Effect of Trigona Honey to mRNA Expression of Interleukin-6 on Salmonella Typhi Induced of BALB/c Mice

Weak inflammatory response after Salmonella infection can cause persistent infection and facilitate the long survival of pathogens. Honey can induce key immunomodulators such as TNF-α, interleukin-6 (IL-6) and IL-1, that it can be used in the treatment of bacterial infectious diseases caused by Salmonella typhi. The purpose of this study is to determine the effect of honey on the mRNA expression of IL-6 in Salmonella enterica Typhi induced of BABL/c mice. The study used experimental pretest-posttest control design. Honey treatment was given for 7 days commencing after the induction of Salmonella bacteria. 20 BABL/c males mice whose weight 25-29 grams, were divided into four groups where 5 mice per group within; the negative control group was given regular feed without bacteria induction, the positive control group was given regular feed with bacteria induction, 0.27 ml/kg-weight honey group and 0.27 ml/kg-weight of Propolis honey group. Blood samples for examination of mRNA expression was examined three times that prior to the induction, 24 hours after induction and 72 hours after induction of Salmonella. The results showed that 0.27 ml/kg-weight of Propolis honey group showed the highest mRNA expression (p = 0.000) for both after 24 hours after induction of Salmonella typhi (p = 0.000) and 72 hours after induction of Salmonella typhi (p = 0.000). We conclude that there was effect of honey on the mRNA IL-6 expression in Salmonella typhi induced of BALB/c mice.

Changes of lipid levels in mice with hypoxic pulmonary arterial hypertension

To observe the changes of lipid levels in mice with pulmonary hypertension induced by hypoxia. The animal model of hypoxic pulmonary hypertension was established by exposing the mice to isobaric hypoxic chamberfor 3 weeks (23 h/d, regular chow feed). Twenty male C57BL/6 mice were randomlydivided into normoxia group and hypoxia group (n=10). The concentrations of total cholesterol, low density lipoprotein (LDL) and high density lipoprotein (HDL) in plasma were detected by Elisa method.The mRNA levels of HMG-CoAreductase (HMGCR), low density lipoprotein receptor (LDLR), scavenger receptor class B1 (SR-B1), and sterol regulatory element-binding factor-2 (SREBF2) in liverwere measured by real-time PCR. ① The right ventricular systolic pressure (RVSP) and the weight ratio of right ventricle (RV) to left ventricle plus septum (LV+S) of hypoxia group were significantly higher than those of normoxia group (P<0.05).② The concentrations of HDL and HDL/LDL in plasma were significantly higher in hypoxia group, compared with normoxia group (P<0.05).③The mRNA levels of LDLR and SR-B1in liver were significantly down-regulated in hypoxia group(P<0.05).④RVSP were significantly negative correlated with HDL/LDL, the gene expression of LDLR and SR-B1 (P<0.05). Abnormal lipid metabolism participates in the pathological proceeding of pulmonary hypertension induced by hypoxia.

Timing and size of daily pollen meals eaten by adult females of a solitary bee (Nomia melanderi) (Apiformes: Halictidae)

Pollen feeding by solitary bees has been studied mainly with their larvae, overlooking pollen feeding by adults. To address this knowledge gap, we determined the amounts and temporal (daily and lifetime) schedules of pollen consumption by freely nesting, adult females of the alkali bee (Nomia melanderi, Halictidae). Nesting females of known ages were taken at different hours of the day from nesting aggregations managed for alfalfa pollination in southeastern Washington State (USA). Each dissected bee was visually scored for pollen fill of the crop, midgut, and hindgut; we also quantified the crop’s pollen capacity. Our dissections of 188 bees show that adult females ate pollen daily for at least the first 2 weeks following emergence. Most bees (85 %) had pollen boluses in one or more gut regions, indicating active pollen feeding. Pollen masses were most likely in the midgut; the daily volume consumed usually filled both the crop and midgut at least once. Full crops contained 34,000 alfalfa pollen grains, equivalent to <20 % of a full scopal load and 0.8 % of the pollen in a nest provision. Proportionately more females ate pollen as the day progressed, indicated by pollen masses in the crop. By early evening, crops of all bees were filled with pollen. Our study reveals the dietary importance of regular pollen feeding for nesting adult female solitary bees, and not just their larvae, with implications for bee foraging ecology, dietary physiology, reproduction, toxicology, and pollination ecology.

The effects of different cycles of starvation and re-feeding on growth and body composition in rainbow trout (Oncorhynchus mykiss , Walbaum, 1792)

Summary This study was designed to investigate the effects of starvation and re-feeding cycles on the growth performance and body chemical composition of Oncorhynchus mykiss juveniles. A total of 360 juveniles with initial mean weights (IW) of 8.46 ± 0.07 g (n = 360) were stocked into 400-L tanks in triplicate for each group, with 30 juveniles per tanks. The control group received regular feed, as is the common practice. The three other groups were periodically starved: 1 day starvation followed by 6 days re-feeding (S1), 2 days starvation followed by 5 days re-feeding (S2) and 3 days starvation followed by 4 days re-feeding (S3). The experiment lasted for 10 weeks, over the course of which the water flow rate was 4 L min−1 and the water quality parameters determined as: temperature 14.4 ± 1.1°C, oxygen 8.2 ± 0.4 mg L−1 and pH 7.5 ± 0.2. At the end of the study, S1 had the best growth performance (final weight, specific growth rate, average daily growth) of all test groups (P < 0.05). The lowest daily feed intake (DFI) and growth performance parameters were observed in S3 (P < 0.05), while protein efficiency ratio (PER), net protein utilization (NPU) and lipid efficiency ratio (LER) were higher in the S3 fish group than in the other groups (P < 0.05). Whole body protein and lipid contents were highest in S1 fish. The hepatosomatic index (HSI) and viscerosomatic index (VSI) were significantly different among groups (P < 0.05). Feed conversion ratio (FCR) was significantly lower in starvation groups S1, S2 and S3 than in the control (P < 0.05). Compensation coefficient (CC) values were higher than 1 in all starvation groups. The concluding indicate that rainbow trout exposed to 1 and 2 days of starvation in week cycles could achieve over compensation compared to the control. Additionally, partial growth compensation and improved feed utilization could be achieved in a starvation group within 3 days in a week, by beginning with the juvenile size over a 10-week experimental period.

Effect of Fee on Cervical Cancer Screening Attendance--ScreenFee, a Swedish Population-Based Randomised Trial.

BackgroundAttendance in the cervical cancer screening programme is one of the most important factors to lower the risk of contracting the disease. Attendance rates are often low in areas with low socioeconomic status. Charging a fee for screening might possibly decrease attendance in this population. Screening programme coverage is low in low socio-economic status areas in Gothenburg, Sweden, but has increased slightly after multiple interventions in recent years. For many years, women in the region have paid a fee for screening. We studied the effect of abolishing this fee in a trial emanating from the regular cervical cancer screening programme.MethodIndividually randomised controlled trial. All 3 124 women in three low-resource areas in Gothenburg, due for screening during the study period, were randomised to receive an offer of a free test or the standard invitation stating the regular fee of 100 SEK (≈11 €). The study was conducted during the first six months of 2013. Attendance was defined as a registered Pap smear within 90 days from the date the invitation was sent out.ResultsAttendance did not differ significantly between women who were charged and those offered free screening (RR 0.93; CI 0.85–1.02). No differences were found within the districts or as an effect of age, attendance after the most recent previous invitation or previous experience of smear taking.ConclusionAbolishment of a modest screening fee in socially disadvantaged urban districts with low coverage, after previous multiple systematic interventions, does not increase attendance in the short term. Other interventions might be more important for increasing attendance in low socio-economic status areas.Trial RegistrationClinicalTrials.gov NCT02378324

Effects of human-related disturbance on breeding success of urban and non-urban blue tits (Cyanistes caeruleus)

There is a need to study the effects of urbanization on wildlife in order to understand the ecological implications of increasing urbanization and find out how to reduce its threats to biodiversity. The blue tit evolved as a forest species and prefers deciduous and mixed forests, whereas its nesting in urban habitats is a more recent phenomenon. Our long-term study of blue tit populations has been conducted in two habitats: an urban parkland (frequently visited by people) and a deciduous forest outside of the city. Using linear mixed modeling, we revealed that a relationship of blue tit breeding success (and the number of fledglings) with thermal conditions in May differed between the urban parkland and the forest. While the relationship was positive in the forest, it was negative in the parkland. In addition, breeding success in the parkland increased with increasing number of rainy days in May. We argue that the main possible reason for such patterns is human activity in the parkland, which interferes with tit parental care, especially the regular feeding of nestlings, whereas it is evidently associated with weather conditions. Human disturbance in the forest is likely to be negligible.

Mycotoxin Contamination in the EU Feed Supply Chain: A Focus on Cereal Byproducts.

Mycotoxins represent a risk to the feed supply chain with an impact on economies and international trade. A high percentage of feed samples have been reported to be contaminated with more than one mycotoxin. In most cases, the concentrations were low enough to ensure compliance with the European Union (EU) guidance values or maximum admitted levels. However, mycotoxin co-contamination might still exert adverse effects on animals due to additive/synergistic interactions. Studies on the fate of mycotoxins during cereal processing, such as milling, production of ethanol fuels, and beer brewing, have shown that mycotoxins are concentrated into fractions that are commonly used as animal feed. Published data show a high variability in mycotoxin repartitioning, mainly due to the type of mycotoxins, the level and extent of fungal contamination, and a failure to understand the complexity of food processing technologies. Precise knowledge of mycotoxin repartitioning during technological processes is critical and may provide a sound technical basis for feed managers to conform to legislation requirements and reduce the risk of severe adverse market and trade repercussions. Regular, economical and straightforward feed testing is critical to reach a quick and accurate diagnosis of feed quality. The use of rapid methods represents a future challenge.

Waste to Energy: Management of Biodegradable Healthcare Waste through Anaerobic Digestion

This research was carried out in 21m3 Technology for Economic Development (TED) model biogas plant constructed and operated at Bir Hospital, Kathmandu. The digester was fed with 95 kg of mixed waste per day in average generated at Bir Hospital. Average biogas production recorded per day was 5.78 m3 which increased to 8.09m3 per day after the feeding reached 15 tons after five months of regular feeding. The recorded burning time for this volume of gas was 12-14 hours per day in a stove of 0.22m3. Methane content in the gas reached up to 54% of the total volume and pH in the biodigester was maintained in a range of 6-7. The retention time of the biodigester was 147 days and the average energy content of biogas has been found as 4.38 Kwhth/m3. The payback period of the biodigester installed is 4 years when compared with LPG, since most of the hospitals use LPG as their cooking fuel it was only analyzed with the LPG. The total reduction of the GHGs was found to be 75.8 tons of CO2 equivalents per annum and the total reduction in terms of monetary benefits was 531.18 USD per annum. Except in one case the presence of E.coli was identified, beside its presence none of other harmful pathogens were detected in the slurry obtained.Nepal Journal of Science and Technology Vol. 16, No.1 (2015) pp. 41-48

Performance of Broilers Supplemented with Natural Herb Extract

The objective of this research was to investigate the effects of a natural herb extract on the general performance, carcass parameters and mortality of broiler chicks. A total of 720 one-day old chicks (Cobb 500) were used in the experiment and randomly partitioned into nine pens (80 chicks per pen). Three experimental diets (C: regular starter feed; CC plus: regular starter feed supplemented with chicken plus herbal extract; AFC plus: antibiotic-free diet supplemented with chicken plus) were assigned each to three randomly selected pens. The herbal extract was supplemented in drinking water at rate of 300 ml/cubic meter. Results showed that weights, feed conversion ratios (FCR) and dressing percentages (DP) increased (P < 0.05) in birds supplemented with herb extract compared to control birds. Mortalities and sudden deaths were minimized via herbal supplementation. However, herbal supplementation had no significant effects on carcass cuts and some visceral organs. The relative economic efficiency (REE) was up to 13% improved by the herb supplementation. It can be concluded that feeding the herbal extract has significant positive effects on broilers general performance as feed efficiency is increased by 11% and on mortality and sudden death cases.

Oral Feeding of Probiotic Bifidobacterium infantis: Colonic Morphological Changes in Rat Model of TNBS-Induced Colitis.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology. It has been proposed that modifying the bacterial flora in intestine with probiotics may decrease the inflammatory process and prevent relapses in UC. We investigated the possible protective and therapeutic effects of a single strand of probiotic, Bifidobacterium infantis (BI), on colonic inflammation, in rats with regular feedings. Two groups of Lewis rats were prepared (n = 8). The first group was the control, sham-fed group (n = 4). The other group was the experimental BI-fed group (n = 4). Colitis was induced in both groups by intrarectal administration of TNBS under light anesthesia. The sham-fed colitis induced groups received a daily oral gavage feeding of 1.0 mL distilled water, whereas the B. infantis-fed group received 0.205 g of B. infantis dissolved in 1.0 mL distilled water daily. The change in body weight and food and water intake was recorded over the course of each study and analyzed. The rats were euthanized and tissues from the descending colon were harvested and analyzed microscopically and histologically. Results of our study indicated significant reduction in inflammation, mucosal damage, and preservation of goblet cells, as compared to the control animals. Modulation of gastrointestinal (GI) flora suggests a promising field in developing strategies for prevention and treatment of inflammatory bowel diseases by dietary modifications.

Effectiveness of Natural Herbal Oil Formulation against White Spot Syndrome Virus in Penaeus vannamei

The Natural Herbal Oil Formulation (NHOF) have been designed to work against White Spot Syndrome Virus (WSSV) in Shrimp. The essential oil blend extracted from the following plants, Lavandula latifolia, Pinus sylvestris, Jasminum officinale, Citrus limon, Prunus avium, Viola odorata, Gardenia jasminoides, Cocos nucifera, Rosa damascene and Eucalyptus globulus, mixed together to develop as anti-WSSV product. The product were added in the feed, as feed additive. Another product developed which was applied in tank water as water supplement named as “Pondguard” (Reg no. KKP RI no. D16060285-HBC). The Pondguard is composed of three essential oils i.e., Eucalyptus globulus, Pinus sylvestris and Lavandula latifolia. A bioassay trial was conducted to determine the efficacy of developed formulation as an anti-WSSV candidate. The experimental shrimp was fed on NHOF-mixed feed and “Pondguard” applied in the tank water whereas control shrimp were fed on the regular feed. The shrimp of both experimental and control were challenged by WSSV on 15th day of feeding. Two methods of WSSV challenge were applied, per-os challenge and immersion challenge. The cumulative mortality in positive control reached up to 100% on DPI 10 whereas no mortality appeared in the experimental group and in negative control. The trial results show that the developed natural herbal formulation has significant effect against WSSV in a controlled condition.

Age-Dependent Changes of the Temporal Order--Causes and Treatment.

This review summarizes current knowledge on deteriorations in temporal order with advanced age. Changes of the overt rhythms will be described but also their putative causes and possible treatments of the disturbances. In aging animals and humans, all rhythm characteristics change. The most prominent changes are a decrease of circadian amplitude, leading to an extra-circadian dissemination (ECD), and a diminished ability to synchronize with the periodic environment. ECD is a shift from circadian to ultradian and infradian frequencies, accompanied by the loss of day-to-day phase stability. Responsiveness to photic and non-photic cues is decreased. As a consequence, both internal and external temporal order are disturbed not only under steady-state conditions but and even more markedly after changes in the periodic environment or following stressful events. Many of the changes seem to occur within the suprachiasmatic nucleus (SCN), the central circadian pacemaker, itself. The number of functioning neurons decreases with advancing age as does the coupling between them. Accordingly, the SCN generates a weaker and less stable circadian signal, insufficient to entrain peripheral oscillators properly or to regulate body functions rhythmically. However, age-dependent disturbances in peripheral organs must also be considered. These changes may occur at different ages, thus causing further internal desynchronization. Several possibilities exist with regard to treating circadian disruptions or at least minimizing their consequences for health and fitness and preventing sleep disturbances. Benefits of bright light, melatonin and other chronobiotics, physical activity, social contacts and regular feeding schedules in preserving the temporal order of aged organisms are discussed.

Dynamics of Physicochemical Variables and Cultivable Bacteria in Vermicompost During Steady Food Waste Addition and Upon Feed Interruption

ABSTRACTVermicomposting is a bio-oxidation process mediated by epigeic earthworms, which act synergistically with microbes to stabilize organic matter. Vermicompost bins are popular in homes and classrooms, but we know little about how physicochemical and bacteriological characteristics of vermicompost evolve with regular feed addition or upon feed interruption. Temperature, moisture, pH, organic carbon, total nitrogen, and labile and total carbohydrates were measured in twenty-four small-scale bins amended with fruit, vegetable, and coffee wastes for 266 days. Monitoring was maintained for 240 days following the last waste input. A canonical correspondence analysis with forward selection of explanatory parameters revealed that pH (p = 0.0100), organic C (p = 0.0140), and labile carbohydrates (p = 0.0110) significantly affected the composition of cultured bacteria through time. Through culture on different media for isolation and amplification (polymerase chain reaction) and sequencing of the 16S rRNA gene, several Bacillaceae, Enterobacteriaceae, and Pseudomonadaceae were observed in both active and maturing vermicompost, but Actinobacteria, Xanthomonadaceae, and Aeromonadaceae were most abundant after feeding interruption. Three phases of vermicomposting were observed in this semi-batch experiment: initiation, active degradation, and, following final feed addition, a phase akin to maturation. Our culture-based approach yields a subset of all microbes present in vermicompost, but provides further knowledge on which media are most useful for isolating vermicompost bacteria. This data will be helpful for low budget tracking (e.g., domestic or university operations), and cultivated vermicompost bacteria can also be characterized for their ability to efficiently metabolize organic waste.

Association Between High-Flow Nasal Cannula and End-Expiratory Esophageal Pressures in Premature Infants.

High-flow nasal cannula (HFNC) is commonly being used to provide noninvasive respiratory support in newborn infants. Continuous distending pressure generated by these devices in preterm infants has not been elucidated. The aim of this work was to determine the association between HFNC flow in L/min and end-expiratory esophageal pressure in cm H2O in premature infants. In a prospective observational study, end-expiratory esophageal pressure measurements were conducted in clinically stable premature infants who required HFNC. The end-expiratory esophageal pressure generated by the HFNC was measured by a regular feeding tube overlying the lower esophagus and connected to a pressure transducer. Each infant had different end-expiratory esophageal pressure measurements at different high flows ranging from 2 to 8 L/min. Nineteen premature infants were studied. Their birthweight (mean ± SD) was 904 ± 574 g, and gestational age was 26.6 ± 3.1 weeks. Overall, 93 end-expiratory esophageal pressure measurements were conducted. At the time of the end-expiratory esophageal pressure measurements, infants were 1,458 ± 828 g and 7.2 ± 4.8 weeks old. At HFNC flows ranging from 2 to 8 L/min, the corresponding esophageal pressures ranged from 2 to 15 cm H2O. There was a statistically significant association between esophageal pressures and flows. In a linear regression model with the end-expiratory esophageal pressure as the dependent variable and HFNC flow as the independent variable, there was a significant correlation between the 2 variables: end-expiratory esophageal pressure (cm H2O) = 1.18 × HFNC (L/min) (r(2) = 0.95, P < .001). HFNC-associated end-expiratory esophageal pressure is measurable in premature infants. There is a significant association between flows and generated esophageal pressures. There is also variability in the amount of end-expiratory esophageal pressure generated. These observations should be kept in mind when using high HFNC flows in preterm infants.