The Abdominal Circulatory Pump

Blood in the splanchnic vasculature can be transferred to the extremities. We quantified such blood shifts in normal subjects by measuring trunk volume by optoelectronic plethysmography, simultaneously with changes in body volume by whole body plethysmography during contractions of the diaphragm and abdominal muscles. Trunk volume changes with blood shifts, but body volume does not so that the blood volume shifted between trunk and extremities (Vbs) is the difference between changes in trunk and body volume. This is so because both trunk and body volume change identically with breathing and gas expansion or compression. During tidal breathing Vbs was 50–75 ml with an ejection fraction of 4–6% and an output of 750–1500 ml/min. Step increases in abdominal pressure resulted in rapid emptying presumably from the liver with a time constant of 0.61±0.1SE sec. followed by slower flow from non-hepatic viscera. The filling time constant was 0.57±0.09SE sec. Splanchnic emptying shifted up to 650 ml blood. With emptying, the increased hepatic vein flow increases the blood pressure at its entry into the inferior vena cava (IVC) and abolishes the pressure gradient producing flow between the femoral vein and the IVC inducing blood pooling in the legs. The findings are important for exercise because the larger the Vbs the greater the perfusion of locomotor muscles. During asystolic cardiac arrest we calculate that appropriate timing of abdominal compression could produce an output of 6 L/min. so that the abdominal circulatory pump might act as an auxiliary heart.     

Competitive interactions and partial displacement of Anastrepha obliqua by Ceratitis capitata in the occupation of host mangoes (Mangifera indica)

1. We examined the competitive interactions between a native fruit fly species (Anastrepha obliqua Macquart) and the invasive medfly (Ceratitis capitata Wiedemann) when these co-occur on a shared mango fruit host (Mangifera indica L.).
2. Using mango fruits of distinct levels of ripeness, we investigated both competition among larvae and among adult females for oviposition. We quantified competition by the numbers of eggs laid and the intensity of agonistic interactions between adult females.
3. Interactions between immature fruit flies led to reduced size and number of emerged adults of both species. These impacts were felt more acutely in the native species.
4. Interspecific competition between females led to fewer eggs laid on semi-ripe fruit by both species, which may be the result of niche overlap associated with oviposition.
5. Intraspecific interactions between A. obliqua individuals led to intense agonistic behaviour, with a concurrent decrease in number of landings on these host fruits.
6. These results suggest that the native species undergoes a partial niche displacement when facing the invasive species. A portion of the fundamental niche of A. obliqua remained unoccupied by the invading C. capitata, which may allow their coexistence under natural conditions.

     

TRACE ELEMENT ANALYSIS OF PROTEINS DIRECTLY FROM 2D-PAGE: AN EFFICIENT STRATEGY FOR METALLOPROTEOMICS

Inductively coupled plasma–mass spectrometry (ICP-MS) is a sensitive analytical method to detect the total concentrations of elements in biological samples, but it is unable to identify molecules that can bind to metals, and for this reason it is vital to combine this method's use with other biochemical techniques. Therefore, in order to identify elements complexed to specific proteins, a very relevant combination of bidimensional electrophoresis followed by ICP-MS was used. Protein spots from gels were excised and submitted directly to element detection, a method not reported before. This report focused on the use of plasma from people with laryngeal carcinoma. Most elements were below detection level, with only Cr and Pb being observed in all samples. Although the relationship between metals and laryngeal cancer was not conclusive, it is possible to affirm that the methodology utilized here is successful and has the advantage of determining to which proteins the elements bind.     

Diagnostic reliability of an immunochromatographic test for Chagas disease screening at a primary health care centre in a rural endemic area

Many patients with Chagas disease live in remote communities that lack both equipment and trained personnel to perform a diagnosis by conventional serology (CS). Thus, reliable tests suitable for use under difficult conditions are required. In this study, we evaluated the ability of personnel with and without laboratory skills to perform immunochromatographic (IC) tests to detect Chagas disease at a primary health care centre (PHCC). We examined whole blood samples from 241 patients and serum samples from 238 patients. Then, we calculated the percentage of overall agreement (POA) between the two groups of operators for the sensitivity (S), specificity (Sp) and positive (PPV) and negative (NPV) predictive values of IC tests compared to CS tests. We also evaluated the level of agreement between ELISAs and indirect haemagglutination (IHA) tests. The readings of the IC test results showed 100% agreement (POA = 1). The IC test on whole blood showed the following values: S = 87.3%; Sp = 98.8%; PPV = 96.9% and NPV = 95.9%. Additionally, the IC test on serum displayed the following results: S = 95.7%; Sp = 100%; PPV = 100% and NPV = 98.2%. Using whole blood, the agreement with ELISA was 96.3% and the agreement with IHA was 94.1%. Using serum, the agreement with ELISA was 97.8% and the agreement with IHA was 96.6%. The IC test performance with serum samples was excellent and demonstrated its usefulness in a PHCC with minimal equipment. If the IC test S value and NPV with whole blood are improved, then this test could also be used in areas lacking laboratories or specialised personnel.     

Relative influence of male and female genital morphology on paternity in the dung beetle Onthophagus taurus

Studies of fertilization success have demonstrated that maleeffects are often a strong and important source of variationin P₂ (the proportion of offspring that are fertilized by thesecond male to mate). More recently there has been emphasison female processes that occur during and after copulation thatmight bias the outcome of male-male interactions. Here we usedthe sterile male technique to evaluate whether female genitalmorphology influences the repeatability of P₂ when the samepair of male dung beetles, Onthophagus taurus, copulated witha series of full-sib females or unrelated females that wereall unrelated to the male pair. Repeatability estimates of measuresof female genital morphology showed that full-sib females variedless in their genital morphology than did unrelated females.Therefore, if female genital traits are an important sourceof variation in male fertilization success, P₂ should be morerepeatable across full-sib than unrelated females. Contraryto this prediction, we show that the repeatability of P₂ didnot differ between female groups. Moreover, specific dimensionsof the female genitalia (sclerotized vagina and bursa) did notcontribute significantly to variance in P₂. In contrast, maleeffects had consistent and repeatable influences on paternityacross females. These were partly explained by variation inthe morphology of male genital sclerites.     

Aspergillus niger inulinase immobilized in polyurethane foam and treated in pressurized LPG: A potential catalyst for enzymatic synthesis of fructooligosaccharides

Inulinase from Aspergillus niger was immobilized in polyurethane foam (PU). Immobilized catalyst was treated in pressurized liquefied petroleum gas (LPG) system. This biocatalyst was used in the fructooligosaccharide production using sucrose as substrate in aqueous system. The main objective of this study was to evaluate the reaction yield and productivity by using polyurethane foam as a low-cost support for enzyme immobilization in an alternative processes for fructooligosaccharide production in pressurized LPG system with potential for industrial application. The total FOS concentration obtained were 31% as a result of sucrose concentration reduction, and formation of FOS long chain (GF3 and GF4) from kestose (GF2). FOS concentrations of 5%, 22%, and 3% were obtained for GF2, GF3, and GF4, respectively. The methodology suggested in this research work, enzyme immobilization in a low-cost support, and treatment in LPG, showed potential technology for fructooligosaccharide synthesis.     

Application of molecular tools in detecting zoonotic pathogens in organic fertilizers and liquid supplements

The use of organic fertilizers and liquid supplements for crop production is rapidly growing as an alternative system to conventional agriculture. However, very little is known about the public health issues related to pathogens. This study endeavors to identify the important zoonotic pathogens with the current molecular diagnostic tools, Loop-mediated isothermal amplification (LAMP) and Recombinase polymerase amplification (RPA), against the conventional pathogen detection. These cost-effective molecular techniques have proven to be confirmatory tests of the target pathogens present in organic fertilizers and liquid supplements, which recommends an advancement for the comprehensive field surveillance-response approach in many developing countries with resource-limited settings quality assurance and safety implementation of organic biosolids for sustainable agricultural farming.     

A marine protected area network does not confer community structure resilience to a marine heatwave across coastal ecosystems

Marine protected areas (MPAs) have gained attention as a conservation tool for enhancing ecosystem resilience to climate change. However, empirical evidence explicitly linking MPAs to enhanced ecological resilience is limited and mixed. To better understand whether MPAs can buffer climate impacts, we tested the resistance and recovery of marine communities to the 2014–2016 Northeast Pacific heatwave in the largest scientifically designed MPA network in the world off the coast of California, United States. The network consists of 124 MPAs (48 no-take state marine reserves, and 76 partial-take or special regulation conservation areas) implemented at different times, with full implementation completed in 2012. We compared fish, benthic invertebrate, and macroalgal community structure inside and outside of 13 no-take MPAs across rocky intertidal, kelp forest, shallow reef, and deep reef nearshore habitats in California's Central Coast region from 2007 to 2020. We also explored whether MPA features, including age, size, depth, proportion rock, historic fishing pressure, habitat diversity and richness, connectivity, and fish biomass response ratios (proxy for ecological performance), conferred climate resilience for kelp forest and rocky intertidal habitats spanning 28 MPAs across the full network. Ecological communities dramatically shifted due to the marine heatwave across all four nearshore habitats, and MPAs did not facilitate habitat-wide resistance or recovery. Only in protected rocky intertidal habitats did community structure significantly resist marine heatwave impacts. Community shifts were associated with a pronounced decline in the relative proportion of cold water species and an increase in warm water species. MPA features did not explain resistance or recovery to the marine heatwave. Collectively, our findings suggest that MPAs have limited ability to mitigate the impacts of marine heatwaves on community structure. Given that mechanisms of resilience to climate perturbations are complex, there is a clear need to expand assessments of ecosystem-wide consequences resulting from acute climate-driven perturbations, and the potential role of regulatory protection in mitigating community structure changes.