155 research outputs found
Effect of vessel wettability on the foamability of "ideal" surfactants and "real-world" beer heads
The ability to tailor the foaming properties of a solution by controlling its chemical composition is highly desirable and has been the subject of extensive research driven by a range of applications. However, the control of foams by varying the wettability of the foaming vessel has been less widely reported. This work investigates the effect of the wettability of the side walls of vessels used for the in situ generation of foam by shaking aqueous solutions of three different types of model surfactant systems (non-ionic, anionic and cationic surfactants) along with four different beers (Guinness Original, Banksâs Bitter, Bass No 1 and Harvest Pale). We found that hydrophilic vials increased the foamability only for the three model systems but increased foam stability for all foams except the model cationic system. We then compared stability of beer foams produced by shaking and pouring and demonstrated weak qualitative agreement between both foam methods. We also showed how wettability of the glass controls bubble nucleation for beers and champagne and used this effect to control exactly where bubbles form using simple wettability patterns
Efeito da fisioterapia na amplitude de movimento articular e deposição de colågeno muscular no modelo golden retriever muscular dystrophy (GRMD)
OBJETIVO: Elucidar o efeito da fisioterapia na Amplitude de Movimento Articular (ADM) e na fibrose muscular em animais GRMD. MĂTODOS: Estudo nĂŁo randomizado, com grupo controle, cego, seis meses de intervenção, avaliação antes e depois da intervenção. Seis animais da raça Golden Retriever, distrĂłficos, machos, mĂŠdia de idade 10,16Âą3,46 meses e peso de 17,75Âą6,01 kg foram separados em grupo tratado (n=3) e nĂŁo tratado. Esses grupos de animais foram nomeados: G1=grupo tratado antes do tratamento; G2=grupo tratado apĂłs tratamento; G3=grupo nĂŁo tratado antes do tratamento; G4=grupo nĂŁo tratado apĂłs tratamento. O G1 participou do programa de fisioterapia que consistiu em um circuito de 300 metros com obstĂĄculos. As ADMs do joelho, tarso, cotovelo e carpo foram avaliadas com goniĂ´metro antes e apĂłs o tratamento. A ĂĄrea de colĂĄgeno do mĂşsculo vastus lateralis foi mensurada por histomorfometria, e a localização dos tipos de colĂĄgeno I, III e IV foi estudada por Imuno-histoquĂmica (IHC). RESULTADOS: Os valores da ADM do tarso do G2 apresentaram uma tendĂŞncia a aumentar. A ĂĄrea de colĂĄgeno muscular foi diferente entre os grupos apĂłs o tratamento, e uma tendĂŞncia ao aumento desses valores no G4 foi observada. Os colĂĄgenos dos tipos I e III foram os mais observados, constituindo feixes largos no perimĂsio nos dois grupos (G2 e G4). O colĂĄgeno do tipo I foi mais observado no endomĂsio do que o colĂĄgeno do tipo III. O colĂĄgeno do tipo IV foi observado apenas na lâmina basal. CONCLUSĂO: A Fisioterapia parece aumentar a ADM do tarso dos animais do grupo tratado sem aumentar a fibrose muscularOBJECTIVE: To elucidate the effect of physical therapy on joint range of motion (ROM) and muscle fibrosis in GRMD animals.METHODS: This was a nonrandomized blinded study with a control group, with six months of intervention evaluated beforehand and afterwards. Six dystrophic male Golden Retrievers of mean age 10.16Âą3.46 months and weight 17.75Âą6.01 kg were divided into a treated group (n=3) and an untreated group. These groups of dogs were named: G1=treated group before treatment; G2=treated group after treatment; G3=untreated group before treatment; and G4=untreated group after treatment. G1 underwent a physical therapy program that consisted of a 300-meter circuit with obstacles. Stifle, tarsal, elbow and carpal ROM were assessed using a goniometer before and after treatment. The area of collagen in the vastus lateralis muscle was measured using histomorphometry. The locations of collagen types I, III and IV were studied usingmmunohistochemistry. RESULTS: The tarsal ROM values in G2 presented an increasing trend. The area of muscle collagen differed between the groups after treatment and an increasing trend in these values was observed in G4. Collagen types I and III were the ones most frequently observed, forming broad bands in the perimysium of both G2 and G4. Type I collagen was observed in the endomysium more than type III collagen. Type IV collagen was observed only in the basal layer. CONCLUSION: Physical Therapy seemed to improve tarsal ROM in the treated group without increasing muscular fibrosi
Effect of Particle Size on Droplet Infiltration into Hydrophobic Porous Media As a Model of Water Repellent Soil
The wettability of soil is of great importance for plants and soil biota, and in determining the risk for preferential flow, surface runoff, flooding,and soil erosion. The molarity of ethanol droplet (MED) test is widely used for quantifying the severity of water repellency in soils that show reduced wettability and is assumed to be independent of soil particle size. The minimum ethanol concentration at which droplet penetration occurs within a short time (â¤10 s) provides an estimate of the initial advancing contact angle at which spontaneous wetting is expected. In this study, we test the assumption of particle size independence using a simple model of soil, represented by layers of small (0.2â2 mm) diameter beads that predict the effect of changing bead radius in the top layer on capillary driven imbibition. Experimental results using a three-layer bead system show broad agreement with the model and demonstrate a dependence of the MED test on particle size. The results show that the critical initial advancing contact angle for penetration can be considerably less than 90° and varies with particle size, demonstrating that a key assumption currently used in the MED testing of soil is not necessarily valid
Morphological analysis and description of the ovaries of female silky sharks, Carcharhinus falciformis (MĂźller & Henle, 1839)
This work aims to study the female reproductive tract of silky sharks, Carcharhinus falciformis, captured in the South and
Equatorial Atlantic Ocean. Samples were collected between January 2008 and March 2010 through oceanic commercial vessels
that targeted tuna and swordfish, with a total of 17 females collected. The methodologies followed for analyzing the ovaries
of those females included both macroscopic and histological analysis. Macroscopically, it was possible to determine that the
ovaries on these sharks is suspended by mesenteries in the anterior section of the body cavity, heavily irrigated by blood
vessels, and contains a wide range of oocytes. Ovaries were found in three distinct maturational stages: Stage I (Immature),
Stage II (Maturing) and Stage III (Mature). Immature ovaries were small, with widths ranging from 1.0 to 3.1 cm, and had a
gelatinous or granulose internal structure; maturing ovaries were slightly larger, ranging in width between 5.2 and 6.0 cm;
mature ovaries ranged in width between 6.5 and 7.8 cm, and had a more rounded shape and the presence of large and well
developed oocytes. Under microscopic examination, it was observed that the ovaries were covered with simple epithelial
tissue during the early development stages and a simple cubic epithelium in the final stages of maturation. During the initial
maturation stages the epigonal organ was not differentiated from the ovary. In mature specimens, the ovary showed a simple
cubic epithelium and just below this epithelium there was a layer of dense connective tissue and muscle with the presence of
vitellogenic oocytes and fat cells. A thin yolk membrane enclosing the oocytes was also evident. Finally, it was possible to
distinguish a zona pellucida, separating the oocytes from the follicle wall and a basal lamina between the granular layers and
the teak layer.info:eu-repo/semantics/publishedVersio
Passive water control at the surface of a superhydrophobic lichen
Some lichens have a super-hydrophobic upper surface, which repels water drops, keeping the surface dry but probably preventing water uptake. Spore ejection requires water and is most efficient just after rainfall. This study was carried out to investigate how super-hydrophobic lichens manage water uptake and repellence at their fruiting bodies, or podetia. Drops of water were placed onto separate podetia of Cladonia chlorophaea and observed using optical microscopy and cryo-scanning-electron microscopy (cryo-SEM) techniques to determine the structure of podetia and to visualise their interaction with water droplets. SEM and optical microscopy studies revealed that the surface of the podetia was constructed in a three-level structural hierarchy. By cryo-SEM of water-glycerol droplets placed on the upper part of the podetium, pinning of the droplet to specific, hydrophilic spots (pycnidia/apothecia) was observed. The results suggest a mechanism for water uptake, which is highly sophisticated, using surface wettability to generate a passive response to different types of precipitation in a manner similar to the Namib Desert beetle. This mechanism is likely to be found in other organisms as it offers passive but selective water control
Exercise is medicine in rural health centers and federally qualified health centers
The American College of Sports Medicine in collaboration with the American Medical Association developed the the Exercise is Medicine (EIM) initiative to promote physical activity as a vital sign among health care providers. The purpose of the study is to inform initiative advocacy efforts among Rural Health Centers and Federally Qualified Health Centers. An interview guide was developed through literature review and expert feedback. Provider responses will be recorded via field notes which are coded to extract common themes. The qualitative data collected from these interviews will be used to examine healthcare provider knowledge and awareness of the initiative current behaviors related to patient physical activity, assessment, counseling, prescription, referral and follow-up and the likelihood of these providers using existing Exercise is Medicine (EIM)materials and resources in the future. Our findings and recommendations will be communicated back to the American College of Sports Medicine through the Exercise is Medicine (EIM) Community Health Committee
Reproductive Strategy of the Giant Electric Ray in the Southern Gulf of California
The objective of the present study was to describe and characterize macroscopic and microscopic aspects of the reproductive biology of the Giant Electric Ray Narcine entemedor, a viviparous elasmobranch targeted by commercial fishers in Mexico. A total of 305 individual rays were captured (260 females, 45 males); all males were sexually mature. The median size at maturity for females was estimated to be 58.5 cm TL, the median size at pregnancy was 63.7 cm TL, and the median size at maternity was 66.2 cm TL. The range of ovarian follicles recorded per female was 1â69; the maximum ovarian fecundity of fully grown vitellogenic oocytes was 17, and uterine fecundity ranged from 1 to 24 embryos per female. The lengths of the oblong ovarian follicles varied significantly among months, and the largest ovarian follicles were found in July, August, and September. Median embryo size was largest in August, and the size at birth was between 12.4 and 14.5 cm TL. Histological evidence of secretions from the glandular tissue of the uterine villi indicate that this species probably has limited histotrophy as a reproductive mode. Vitellogenesis in the ovary occurred synchronously with gestation in the uterus. The Giant Electric Ray has a continuous annual reproductive cycle; a period of ovulation occurs between May and September and two peaks of parturition, one in January and one in August, occur, suggesting that embryonic diapause occurs in some individuals. These results provide useful information for the management of this important commercial species in BahĂa de La Paz, Mexico, and will allow possible modification of the current Mexican regulations to enable better protection of this species
Deep sequencing of subseafloor eukaryotic rRNA reveals active fungi across marine subsurface provinces
Š The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS ONE 8 (2013): e56335, doi:10.1371/journal.pone.0056335.The deep marine subsurface is a vast habitat for microbial life where cells may live on geologic timescales. Because DNA in sediments may be preserved on long timescales, ribosomal RNA (rRNA) is suggested to be a proxy for the active fraction of a microbial community in the subsurface. During an investigation of eukaryotic 18S rRNA by amplicon pyrosequencing, unique profiles of Fungi were found across a range of marine subsurface provinces including ridge flanks, continental margins, and abyssal plains. Subseafloor fungal populations exhibit statistically significant correlations with total organic carbon (TOC), nitrate, sulfide, and dissolved inorganic carbon (DIC). These correlations are supported by terminal restriction length polymorphism (TRFLP) analyses of fungal rRNA. Geochemical correlations with fungal pyrosequencing and TRFLP data from this geographically broad sample set suggests environmental selection of active Fungi in the marine subsurface. Within the same dataset, ancient rRNA signatures were recovered from plants and diatoms in marine sediments ranging from 0.03 to 2.7 million years old, suggesting that rRNA from some eukaryotic taxa may be much more stable than previously considered in the marine subsurface.This work was performed with funding from the Center for Dark Energy Biosphere Investigations (C-DEBI) to William Orsi (OCE-0939564) and The Ocean Life Institute (WHOI) to Virginia Edgcomb (OLI-27071359)
Acute effects of fine particulate air pollution on ST segment height: A longitudinal study
Background
The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms.
Methods
We investigate the acute effects and the time course of fine particulate pollution (PM2.5) on myocardium ischemic injury as assessed by ST-segment height in a community-based sample of 106 healthy non-smokers. Twenty-four hour beat-to-beat electrocardiogram (ECG) data were obtained using a high resolution 12-lead Holter ECG system. After visually identifying and removing all the artifacts and arrhythmic beats, we calculated beat-to-beat ST-height from ten leads (inferior leads II, III, and aVF; anterior leads V3 and V4; septal leads V1 and V2; lateral leads I, V5, and V6,). Individual-level 24-hour real-time PM2.5 concentration was obtained by a continuous personal PM2.5 monitor. We then calculated, on a 30-minute basis, the corresponding time-of-the-day specific average exposure to PM2.5 for each participant. Distributed lag models under a linear mixed-effects models framework were used to assess the regression coefficients between 30-minute PM2.5 and ST-height measures from each lead; i.e., one lag indicates a 30-minute separation between the exposure and outcome.
Results
The mean (SD) age was 56 (7.6) years, with 41% male and 74% white. The mean (SD) PM2.5 exposure was 14 (22) ĂÂźg/m3. All inferior leads (II, III, and aVF) and two out of three lateral leads (I and V6), showed a significant association between higher PM2.5 levels and higher ST-height. Most of the adverse effects occurred within two hours after PM2.5 exposure. The multivariable adjusted regression coefficients Ă² (95% CI) of the cumulative effect due to a 10 ĂÂźg/m3 increase in Lag 0-4 PM2.5 on ST-I, II, III, aVF and ST-V6 were 0.29 (0.01-0.56) ĂÂźV, 0.79 (0.20-1.39) ĂÂźV, 0.52 (0.01-1.05) ĂÂźV, 0.65 (0.11-1.19) ĂÂźV, and 0.58 (0.07-1.09) ĂÂźV, respectively, with all p < 0.05.
Conclusions
Increased PM2.5 concentration is associated with immediate increase in ST-segment height in inferior and lateral leads, generally within two hours. Such an acute effect of PM2.5 may contribute to increased potential for regional myocardial ischemic injury among healthy individuals
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