A review on the “in vitro” culture of freshwater mussels (Unionoida)

Many Unionoida are considered to be extinct, endangered, or of special concern. These bivalves have complex life cycle stages that limit successful culture. In nature, the larvae (glochidia) of these bivalves must successfully parasitize a host (mainly fish) in order to metamorphose into juveniles. The two artificial methods used to obtain juvenile freshwater mussels in laboratory are either by induced attachment to host fish or by in vitro culture of glochidia. This article is focused on the in vitro method that represents a novel and alternative process to fish infestation, offering the ability to obtain larger numbers of juveniles without the need for host fishes and reducing the overall costs of propagation. In vitro culture requires a medium which fulfills the nutritional needs of each glochidia species and avoids microbial contamination. Recently, this methodology has presented excellent results with survival and transformation rates up to 94% using host fish plasma. High efficiencies on growth, and survival rates (84%) of juvenile freshwater bivalve Hyriopsis myersiana (Lea, 1856) up to 120 days were obtained when reared in adequate recirculating aquacultural systems using a very specific diet. More research is still needed to demonstrate successful propagation, mainly concerning the media nutritional composition to increase glochidia transformation and juvenile quality.     

The efficacy of antibiotics in reducing morbidity and mortality from heatstroke – A systematic review

Severe hyperthermia, for example, classical heatstroke or exertional heatstroke from heatwaves or exercise respectively, or from drug ingestion or other non-infective pyrogens, is associated with a high mortality and morbidity, which may be chronic or permanent. Abolition of lipopolysaccharide, from gram-negative intestinal bacteria translocating into the systemic circulation via an intestinal wall rendered permeable from the hyperthermia, reduces the adverse effects, suggesting that antibiotics against the intestinal bacteria may have a similar effect. A systematic review searching Embase, MEDLINE and PubMed from the earliest date available until 2019 was conducted, according to PRISMA guidelines. Two papers were found which fit the criteria. In one, non-absorbable oral antibiotics were administered prior to the onset of heat stress, which reduced the cardiovascular dysfunction and rise in endotoxaemia, but animals succumbed at a lower temperature. In the second, non-absorbable oral antibiotics, in combination with a laxative and enema, given prior to the onset of heat stress, improved mortality; antibiotics administered after the heat stress did not, but the antibiotics used may have limited action against intestinal bacteria. Only two papers were found; both suggest an improvement in organ dysfunction or mortality after an episode of heat stress. No papers were found that investigate the sole use of antibiotics effective against intestinal bacteria given after the onset of heat stress, although biological plausibility suggest they warrant further research.     

The shape and mobility of the thoracic spine in asymptomatic adults – A systematic review of in vivo studies

A comprehensive knowledge of the thoracic shape and kinematics is essential for effective risk prevention, diagnose and proper management of thoracic disorders and assessment of treatment or rehabilitation strategies as well as for in silico and in vitro models for realistic applications of boundary conditions.After an extensive search of the existing literature, this study summarizes 45 studies on in vivo thoracic kyphosis and kinematics and creates a systematic and detailed database. The thoracic kyphosis over T1–12 determined using non-radiological devices (34°) was relatively less than measured using radiological devices (40°) during standing. The majority of kinematical measurements are based on non-radiological devices. The thoracic range of motion (RoM) was greatest during axial rotation (40°), followed by lateral bending (26°), and flexion (21°) when determined using non-radiological devices during standing. The smallest RoM was identified during extension (13°). The lower thoracic level (T8–12) contributed more to the RoM than the upper (T1–4) and middle (T4–8) levels during flexion and lateral bending. During axial rotation and extension, the middle level (T4–8) contributed the most. Coupled motion was evident, mostly during lateral bending and axial rotation. With aging, the thoracic kyphosis increased by about 3° per decade, whereas the RoM decreased by about 5° per decade for all load directions. These changes with aging mainly occurred in the lower region (T6–12). The influence of sex on thoracic kyphosis and the RoM has been described as partly contradictory. Obesity was found to decrease the thoracic RoM. Studies comparing standing, sitting and lying reported the effect of posture as significant.     

The hydraulic architecture of Pinaceae – a review

We reviewed the literature to examine the vulnerability to water stress-induced embolism of Pinaceae relative to other conifers and to study the inter-relationships among the main traits involved in the hydraulic function within the Pinaceae. Results showed that Pinaceae (particularly the genus Pinus) are more vulnerable to xylem embolism, and show less variability in this character, than other conifers. Detailed data from 12 populations of Pinaceae (11 species) from three different areas (Piñol and Sala 2000; Martínez-Vilalta and Piñol 2002; Oliveras et al. 2003) was used to study the relationships among hydraulic properties of stems. These included: leaf-to-wood area ratio (A_L:A _W), wood- and leaf-specific hydraulic conductivity (K_W and K_L, respectively), vulnerability to xylem embolism (Ψ_50PLC), carbon isotope composition of needles (δ¹³C) and minimum needle water potential (minimum Ψ_L). Results showed that hydraulic properties tended to be more correlated among each other than with indicators of environmental (precipitation to potential evapotranspiration ratio, P/E) or physiological water stress (minimum Ψ_L). The only exception was an increase of δ¹³C with decreasing minimum Ψ_L and P/E. Overall, A_L:A _W ratio decreased with increasing vulnerability to xylem embolism, and with increasing K_W and K_L (P<0.05). We found a strong positive relationship between carbon isotope composition and the estimated maximum loss of conductivity due to xylem embolism under field conditions, suggesting stronger stomatal control in more vulnerable species with higher levels of native embolism. Overall, results are consistent with a range of drought-avoidance strategies to minimise the gradient of water potential through the xylem, and show that different relationships among traits are possible depending on the scale of study (individual vs. species or populations). The strong interdependence among hydraulic traits implies that no single trait is a sufficient predictor of drought-resistance in Pinaceae. Finally, it is hypothesised that the intrinsically vulnerable xylem of pines may limit their survival under extremely dry conditions.     

Perfusion mammalian cell culture for recombinant protein manufacturing – A critical review

The manufacturing of recombinant protein is traditionally divided in two main steps: upstream (cell culture and synthesis of the target protein) and downstream (purification and formulation of the protein into a drug substance or drug product). Today, cost pressure, market uncertainty and market growth, challenge the existing manufacturing technologies. Leaders in the field are active in designing the process of the future and continuous manufacturing is recurrently mentioned as a potential solution to address some of the current limitations. This review focuses on the application of continuous processing to the first step of the manufacturing process. Enabling technologies and operation modes are described in the first part. In the second part, recent advances in the field that have the potential to support its successful future development are critically discussed.     

The use of wood during prehispanic times in the Upper Paraná Delta revealed though analysis of ancient charcoal

Vegetation History and Archaeobotany - Woody plant resources are important to human societies today and were also in the past. Here we assess the woody plant resources available to peoples in...     

The impact of landfilling and composting on greenhouse gas emissions – A review

Municipal solid waste is a significant contributor to greenhouse gas emissions through decomposition and life-cycle activities processes. The majority of these emissions are a result of landfilling, which remains the primary waste disposal strategy internationally. As a result, countries have been incorporating alternative forms of waste management strategies such as energy recovery from landfill gas capture, aerobic landfilling (aerox landfills), pre-composting of waste prior to landfilling, landfill capping and composting of the organic fraction of municipal solid waste. As the changing global climate has been one of the major environmental challenges facing the world today, there is an increasing need to understand the impact of waste management on greenhouse gas emissions. This review paper serves to provide an overview on the impact of landfilling (and its various alternatives) and composting on greenhouse gas emissions taking into account streamlined life cycle activities and the decomposition process. The review suggests greenhouse gas emissions from waste decomposition are considerably higher for landfills than composting. However, mixed results were found for greenhouse gas emissions for landfill and composting operational activities. Nonetheless, in general, net greenhouse gas emissions for landfills tend to be higher than that for composting facilities.     

Beneficial endophytic microorganisms of Brassica – A review

Brassica species display enormous diversity and subsequently provide the widest assortment of products used by man from a single plant genus. Many species are important for agriculture, horticulture, in bioremediation, as medicines, soil conditioners, composting crops, and in the production of edible and industrial oils such as liquid fuels and lubricants. Many wild Brassica relatives possess a number of useful agronomic traits, including beneficial microbial endophytes that could be incorporated into breeding programs. Endophytes of Brassica, and/or their metabolites, have been demonstrated to improve and promote plant growth; increase yield; reduce disease symptoms caused by plant pathogens; reduce herbivory from insect pests; remove contaminants from soil; improve plant performance under extreme conditions of temperature and water availability; solubilise phosphate and contribute assimilable nitrogen to their hosts. Brassica napus (oilseed rape) and Brassica oleracea var. botrytis (broccoli and cauliflower) are the most economically important species of Brassica worldwide. These commercial crops are attacked by a wide range of pathogens and insect pests that are responsible for millions of dollars in lost revenue, with current control options offering little mitigation. No alternative control products are available for the Brassica industry, although it has been well documented in the literature that the use of endophytic microorganisms can offer beneficial traits to their host plants, including pest and disease resistance. The aim of this review is to describe the literature concerning beneficial microbial endophytes and their prospects to enhance or provide additional traits to their Brassica host species.     

The enzymology of sulfur metabolism in phototrophic bacteria — A review

Summary The two functions of sulfur metabolism in phototrophic bacteria are to supply electrons for photosynthesis and to supply sulfur for biosynthetic purposes. The pathways for both functions may be partly identical. For the electron-supplying pathway the following enzymes are needed: a sulfide-oxidizing enzyme, a sulfur-oxidizing enzyme system, APS reductase, ADP sulfurylase and — in the case of thiosulfate utilization — thiosulfate reductase. Assimilatory reactions are catalyzed by ATP sulfurylase, APS kinase, sulfotransferases, PAPS reductase, sulfite reductase and o-acetylserine sulfhydrylase. Paper read at the Symposium on the Sulphur Cycle, Wageningen, May 1974.     

Measurements of peripheral and deep body temperature in cattle – A review

Automation of the measurement of the physiological and behavioural parameters of livestock has become an important goal for both scientists and farmers. Accurate data and knowledge about farmed animals, especially in cattle breeding, are needed. Proper early diagnosis of a cow's health status in real time allows for preventing the development of infection, oestrus detection and leads to reduced environmental stress. Thus, it contributes to more effective herd management. Among the physiological parameters, body temperature and its fluctuations are key indicators of health and well-being in animals. Currently, along with the development of technical solutions and their implementation, increasingly more attention is being paid to the continuously measurement of body core and peripheral temperature in animals. Recently there has been an increased number of publications devoted to this subject. However, there is a need to systematise this knowledge as these studies have had different purposes, have been performed in various environmental conditions, and the measurements were taken using different methods and equipment. As such, the results obtained by the different authors often may not be comparable. For this reason, this paper has two main purposes: to present the most widely used continuous methods of peripheral and body core temperature measurement, and to show its references values which characterise the individual locations of the cattle body in thermoneutral ambient. An analysis of the professional publications regarding measurements of peripheral and deep body temperature led to the conclusion that these methods have high research and diagnostic potential. However, it is necessary to standardised research to enable better and more comparable results, including among others; different cattle groups, animal age, health and environmental conditions.     

The use of concept maps during knowledge elicitation in ontology development processes – the nutrigenomics use case

Background  

Incorporation of ontologies into annotations has enabled 'semantic integration' of complex data, making explicit the knowledge within a certain field. One of the major bottlenecks in developing bio-ontologies is the lack of a unified methodology. Different methodologies have been proposed for different scenarios, but there is no agreed-upon standard methodology for building ontologies. The involvement of geographically distributed domain experts, the need for domain experts to lead the design process, the application of the ontologies and the life cycles of bio-ontologies are amongst the features not considered by previously proposed methodologies.     

In vitro Hardening – The Role of Ventilation on Acclimation Stress in Kniphofia leucocephala

Culture-induced phenotypes, which are caused by conditions in vitro, may result in poor survival of plantlets during acclimatisation. In vitro hardening of these phenotypes, however, may reduce the stress incurred with transplantation by inducing morphological or anatomical differences. Despite morphological differences, however, ventilated plantlets of Kniphofia leucocephala incurred stress of a similar magnitude to the controls as indicated by similar reductions in PSII photochemical efficiency (F _v/F _m). Thus, in vitro hardening in this species does not improve its capacity to tolerate environmental stresses during acclimatisation.     

The potential of earthworms to restore ecosystem services after opencast mining – A review

Opencast coal mining has several environmental impacts, which require land rehabilitation when mining operations are finished. For that reason, restoration after such extractive industries’ work is common and has been well studied. However, many ecological restoration schemes do not examine to what extent complete and functioning ecosystems have been restored above and below ground. While the aim should be to restore functioning ecosystems, most restoration plans focus only on vegetation and above ground macro-fauna.Among the potential species that are likely to be important early in mine land restoration, earthworms are particularly good candidates. They provide several ecosystem services that are likely to accelerate soil restoration, improve primary production and facilitate the restoration of a functional ecosystem in mining areas. These services include the following: increase in topsoil fertility, food for a wide range of predators and recycling of waste organic materials on rehabilitated areas.Here, we outline some of the challenges specifically facing opencast mining restoration and describe how the ecosystem services provided by earthworms may address some of these challenges.     

Advances in the human genome project – A review

While celebrating its fifth official birthday last year it seems that the Human Genome Project (HGP) has and will continue to yield important biochemical information to mankind. It is exhilarating to think about the transition from studying genome structure to understanding genome function. The collective actions of information dessimination, technology development for efficient and faster sequencing, high-volume sequencing and developing model organisms has led to its success sofar. Various genome-wide STS-based human maps were completed in 1995, including a genetic map, a YAC map, a RH map with, and an integrated YAC-RH genetic map. These maps provide comprehensive frameworks for positioning additional loci, with the current genetic and RH maps spanning essentially 100% of the human genome and the YAC maps covering 95%. Few genes, however, have yet been localized on these framework maps. To date the Human Genome Project has experienced gratifying success. The technology and data produced by the genome project will provide a strong stimulus to broad areas of biological research and biotechnology. However, enormous challenges remain.     

Assessment of polyembryony in lemon: rescue and in vitro culture of immature embryos

The 27 lemon cultivars analysed could be considered slightly or moderately polyembryonic, with 25 to 43% of seeds being polyembryonic and from 1.3 to 1.6 embryos per seed. On this basis, it is necessary to rescue zygotic embryos at an immature stage. Rescue and in vitro embryo development have been studied in two Citrus limon polyembryonic cultivars. Sucrose (50 and 70 g/l) was combined with Murashige and Skoog and Gamborg’s B5 media and tested for optimal growth response. An important effect of genotype was observed: embryos from cultivar ‘Eureka’ had greater survival, germination percentage, and radical development. While the sucrose concentration in the medium did not have an effect on germination, the medium affected the embryo survival and root development of the seedlings, Gamborg’s B5 medium giving the best results. The ability to form plants in vitro was affected by an increase of embryo developmental stage. The germination and seedling height were greater with embryos of seeds collected 135–150 days after anthesis.     

Intergeneric pollen – megagametophyte relationships of conifers in vitro

 Germinating pollen from larch (Larix occidentalis), Sitka spruce (Picea sitchensis) and white pine (Pinus monticola) were co-cultured with megagametophytes dissected from cones of other genera (Pseudotsuga menziesii, Larix×eurolepis and Pinus monticola). Pollen was presented to megagametophytes possessing archegonia which were either alive, degenerating or dead. In addition, pollen was presented to fertilized megagametophytes and to megagametophytes that had been cut in half. Megagametophyte penetration by pollen tubes and male gamete release into archegonia were verified by serial sections of glycomethacrylate-embedded specimens. Pollen tubes penetrated through any part of the apex of the megagametophyte. Division of the body cell into the two gametes was regularly observed. Delivery of gametes was confirmed between spruce and larch. Pollen tubes also penetrated fertilized megagametophytes, dead or degenerating archegonia as well as wounded and/or cut surfaces. This demonstrates the inability of the male gametophyte to optimize its mating efforts, since it is unable to differentiate between healthy and unhealthy archegonia. The megagametophyte cells are unable to optimize male selection. They may produce secretions of a generally attractive nature, as pollen is attracted to the apex of the megagametophyte, but archegonia themselves do not produce pollen-specific signals of either a promotive or inhibitory nature. These results open new avenues for the development of novel breeding strategies where natural breeding barriers may be bypassed. Received: 19 March 1998 / Accepted: 29 April 1998     

Aspects on properties, use and ethical considerations of embryonic stem cells – A short review

Mammalian embryonic stem cells have the potential to differentiate into all cell types of an adult individual. The culturing of human embryonic stem cells renders possible studies that were previously only available in animal models. Embryonic stem cells constitute a particularly attractive tool for studies of self-renewal, commitment, differentiation, maturation and cell-cell interaction. There is currently considerable hope that studies of embryonic stem cells will lead to new therapies; either by themselves, through cell replacement strategies, or by generating results assisting other fields of research to reach clinical results. There are, however, considerable challenges to be met before embryonic stem cells can be used in large-scale clinical trials.Stem cell research is an area that has given rise to much debate internationally, within science, law and politics as well as within philosophy and ethics. The ethical attitudes expressed in the public debate over stem cell research notably divide over three important distinctions: (1) Reproductive versus therapeutic cloning; (2) Using already existing embryos versus producing new embryos for research purposes; (3) Production of embryos from eggs and sperm versus through somatic-cell nuclear transfer. The potential medical benefits that may result from embryonic stem cell research arguably support a continued development in this area. However, some opponents argue that this research offends the (relative or absolute) moral status of an unborn human. Furthermore, the research would probably prove to be a both time-consuming and very expensive method for treating disease. Thus, the questions arise whom the new technique wouldbenefit and at what cost, if ever developed. This revised version was published online in July 2006 with corrections to the Cover Date.     

The use of ultrasound to identify milk ejection in women – tips and pitfalls

Background

Rates of exclusive breastfeeding in China are relatively low and below national targets. The aim of this study was to document the factors that influence exclusive breastfeeding initiation in Zhejiang, PR China.

Methods

A cohort study of infant feeding practices was undertaken in Zhejiang Province, an eastern coastal region of China. A total of 1520 mothers who delivered in four hospitals located in city, suburb and rural areas during late 2004 to 2005 were enrolled in the study. Multivariate logistic regression analysis was used to explore factors related to exclusive breastfeeding initiation.

Results

On discharge from hospital, 50.3% of the mothers were exclusively breastfeeding their infants out of 96.9% of the mothers who had earlier initiated breastfeeding. Exclusive breastfeeding was positively related to vaginal birth, baby's first feed being breast milk, mother living in the suburbs or rural areas, younger age of mother, lower maternal education level and family income.

Conclusion

The exclusive breastfeeding rate in Zhejiang is only 50.3% on discharge and does not reach Chinese or international targets. A number of behaviours have been identified in the study that could be potentially incorporated into health promotion activities.     

Hand pollination of global crops – A systematic review

Global pollinator declines and land-use change can lead to pollination limitation with implications for agricultural productivity. Hand pollination is used in agricultural production as a technique to manually pollinate crops. But the prevalence of hand pollination, as well as benefits and costs, remain unknown. We systematically reviewed the literature for examples, methods, drivers, and economic motivations of hand pollination. Furthermore, we discuss the risks, constraints, and opportunities of hand pollination. We found evidence for 20 hand-pollinated crops, including minor but also economically important crops (e.g. apple, oil palm, cacao). The lack of pollinators was the most important reason for the application of hand pollination (50% of crops), while insufficient proportion or proximity of pollinizers (8% of crops) and skewed sex ratio or dichogamy (8% of crops) were second most important. The main economic motivations for practicing or recommending hand pollination were to increase fruit set, and/or fruit quality (78% of crops). Hand pollination is practiced in large- and small-scale farming, home gardens, and greenhouses. Opportunities of hand pollination are the control of pollen origin and quantity, pollination timing and frequency as well as independence from environmental fluctuations. Farmers can increase yields, improve fruit quality, avoid fruit abortion, increase employment, and secure subsistence food. The main constraints of hand pollination are high labor inputs, high material costs, and required skills. Major risks of hand pollination include management ignoring pollinator conservation, high food prices, over-pollination, labor accidents, and unfair labor. We conclude that in the face of global change, hand pollination allows improved control of pollination and is likely to increase in importance. The benefits of hand pollination need to outweigh the costs and fair labor is essential. Altogether, hand pollination can be a valuable tool for crop systems where pollinators are absent or are not reliable for sustaining high-quality crop production.     

Effects of shear stress on microalgae – A review

Cultivation of microalgae requires consideration of shear stress, which is generated by operations such as mixing, circulation, aeration and pumping that are designed to facilitate mass and heat transfer as well as light distribution in cultures. Excessive shear stress can cause increased cell mortality, decreased growth rate and cell viability, or even cell lysis. This review examines the sources of shear stress in different cultivation systems, shear stress tolerance of different microalgal species and the physiological factors and environmental conditions that may affect shear sensitivity, and potential approaches to mitigate the detrimental effects of shear stress. In general, green algae have the greatest tolerance to shear stress, followed by cyanobacteria, haptophytes, red algae, and diatoms, with dinoflagellates comprising the most shear-sensitive species. The shear-sensitivity of microalgae is determined primarily by cell wall strength, cell morphology and the presence of flagella. Turbulence, eddy size, and viscosity are the most prominent parameters affecting shear stress to microalgal cells during cultivation.